Results for "bloodstream"

BIOC 503 - Lipoproteins

Chapter 7:6 Study Guide NERVOUS SYSTEM P179-187 Nervous System-complex, highly organized system that coordinates all the activities of the body. *The basic structural unit of the nervous system is the neuron, or nerve cell. It consists of a cell body containing:  Nucleus  Nerve fibers called dendrites (carry impulses toward the cell body)  Single nerve fiber called axon (carry impulses away from the cell body) Many axons have a lipid covering called a myelin sheath, which increases the rate of impulse transmission and insulates and maintains the axon. The axon of one neuron lies close to the dendrites of many other neurons. The spaces between them are known as synapses. Special chemicals, called neurotransmitters, located at the end of each axon allow the nerve impulses to pass from one neuron to another. Nerves are a combination of many nerve fibers located outside the brain and spinal cord. Meninges are membranes or protective lining that covers the brain and spinal cord. Afferent, or sensory, nerves carry messages from all parts of the body to the brain and spinal cord. Efferent, or motor, nerves carry messages from the brain and spinal cord to the muscles and glands. Associative, or internuncial, nerves carry both sensory and motor messages. There are two main divisions to the nervous system: 1. 2. Central nervous system: consists of the brain and spinal cord Peripheral nervous system: consists of the nerves. A separate division of the peripheral nervous system is the autonomic nervous system. This system controls involuntary body functions. *Brain-mass of nerve tissue well protected by membranes and the cranium, or skull. The main sections include:  Cerebrum-the largest and highest section of the brain. Responsible for: reasoning, thought, memory, speech, sensation, sight, smell, hearing, and voluntary body movement.  Cerebellum-section below the back of the cerebrum. Responsible for: muscle coordination, balance and posture, muscle tone.  Diencephalon-section between the cerebrum and midbrain. o Thalamus-acts as a relay center and directs sensory impulses to the cerebrum. o Hypothalamus-regulates and controls the autonomic nervous system, temperature, appetite, water balance sleep and blood vessel constriction and dilation. Also involved in emotions such as anger, fear, pleasure, pain and affection.  Midbrain-the section located below the cerebrum at the top of the brain stem. Responsible for conducting impulses between brain parts and for certain eye and auditory reflexes.  Pons-located below the midbrain and in the brain stem. Responsible for conducting messages to other parts of the brain; for certain reflex actions including chewing, tasting, and saliva production; and for assisting with respiration.  Medulla oblongata-the lowest part of the brain stem. Connects with the spinal cord and is responsible for regulating heartbeat, respiration, swallowing, coughing, and blood pressure. The spinal cord continues down from the medulla oblongata and ends at the first or second lumbar vertebrae. *The meninges are three membranes that cover and protect the brain and spinal cord. 1. 2. 3. Dura mater-thick, tough, outer layer Arachnoid membrane-delicate and web like Pia mater-closely attached to the brain and spinal cord and contains blood vessels that nourish the nerve tissue. The brain has four ventricles, hollow spaces that connect with each other and with the space under the arachnoid membrane. The ventricles are filled with a fluid called cerebrospinal fluid. This fluid circulates continually between the ventricles and through the subarachnoid space. It serves as a shock absorber to protect the brain and spinal cord. It also carries nutrients to some parts of the brain and spinal cord and helps remove metabolic products and wastes. After circulating, it is absorbed into the blood vessels of the dura mater and returned to the bloodstream through special structures called the arachnoid villi. The peripheral nervous system consists of the somatic and autonomic nervous systems. The somatic nervous system consists of 12 pairs of cranial nerves and their branches and 31 pairs of spinal nerves and their branches. Some of the cranial nerves are responsible for special senses such as sight, hearing, taste, and smell. The Autonomic nervous system is an important part of the peripheral nervous system. It helps maintain a balance in the involuntary functions of the body and allows the body to react in times of emergency. *There are two divisions to the autonomic nervous system: Sympathetic nervous system: prepares the body in times of emergencies. Prepares the body to act by increasing heart rate, respiration, and blood pressure and slowing activity in the digestive tract. This is known as the fight or flight response. Parasympathetic nervous system: After the emergency, this slows down the heart rate, decreases respirations, lowers blood pressure and increases activity in the digestive tract. Cerebral Palsy is a disturbance in voluntary muscle action and is caused by brain damage. Lack of oxygen to the brain, birth injuries, prenatal rubella, and infections can all cause cerebral palsy. Cerebrovascular Accident or CVA (stroke) occurs when the blood flow to the brain is impaired, resulting in a lack of oxygen and a destruction of brain tissue. CVA includes loss of consciousness; weakness or 1. 2. paralysis on one side of the body (hemiplegia); dizziness; dysphagia (difficulty swallowing); visual disturbances; mental confusion; aphasia (speech and language impairment); and incontinence. When a CVA occurs, immediate care within the first three hours can help prevent brain damage. Treatment with thrombolytic or “clot-busting” drugs such as TPA (tissue plasminogen activator) can dissolve the blood clot and restore blood flow to the brain. Aphasia is a speech or language impairment. There are different types. ALS is amyotrophic lateral sclerosis. Also called Lou Gehrig’s disease. This is a chronic degenerative neuromuscular disease. The cause is unknown. Carpal tunnel syndrome is a progressive, painful condition of the wrist and hand. It occurs when the median nurse is pinched or compressed. Concussions are traumatic brain injuries, usually from a blow to the head by an accident, injury or fall. The brain slides back/forward and forcefully hits against the skull. Think of it like a bruise on the brain. Encephalitis is an inflammation of the brain and is caused by a virus, bacterium, or chemical agent. Epilepsy or seizure syndrome is a brain disorder associated with abnormal electrical impulses in the neurons of the brain. Hydrocephalus is an excessive accumulation of cerebrospinal fluid in the ventricles and, in some cases, the subarachnoid space of the brain. It is usually cause by a congenital (at birth) defect, infection, or tumor that obstructs the flow of cerebrospinal fluid out of the brain. The condition is treated by the surgical implantation of a shunt (tube) between the ventricles and the veins, heart, or abdominal peritoneal cavity to provide for drainage of the excess fluid. Meningitis is an inflammation of the meninges of the brain and/or spinal cord and is caused by a bacterium, virus, fungus, or toxins such as lead and arsenic. Multiple Sclerosis (MS) is a chronic, progressive, disabling condition resulting from a degeneration of the myelin sheath in the central nervous system. Neuralgia is nerve pain. Inflammation, pressure, toxins, and other disease cause it. Paralysis usually results from a brain or spinal cord injury that destroys neurons and results in a loss of function and sensation below the level of injury. Hemiplegia is paralysis on side of the body and is caused by a tumor, injury, or CVA. Paraplegia is paralysis in the lower extremities or lower part of the body and is caused by a spinal cord injury. Quadriplegia is paralysis of t harems, legs, and body below the spinal cord injury. Parkinson’s disease is a chronic, progressive condition involving degeneration of brain cells, usually in persons over 50 years of age

Bone & Joint, Bloodstream & Line

24 - Leukocytes. Count and functions of the different leukocyte types. Control of leukopoiesis and leukocyte count in the bloodstream. Immunity.

Bloodstream Infections Clinical Microbiology II

ASSESSMENT OF THE LIVER Anatomic and Physiologic Overview The liver, the largest gland of the body and a major organ, can be considered a chemical factory that manufactures, stores, alters, and excretes a large number of substances involved in metabolism (Hammer & McPhee, 2019; Sanyal, Boyer, Terrault, et al., 2018). The location of the liver is essential because it receives nutrient-rich blood directly from the gastrointestinal (GI) tract and then either stores or transforms these nutrients into chemicals that are used elsewhere in the body for metabolic needs. The liver is especially important in the regulation of glucose and protein metabolism. The liver manufactures and secretes bile, which has a major role in the digestion and absorption of fats in the GI tract. The liver removes waste products from the bloodstream and secretes them into the bile. The bile produced by the liver is stored temporarily in the gallbladder until it is needed for digestion, at which time the gallbladder empties and bile enters the intestine (see Fig. 43-1). Anatomy of the Liver The liver is a large, highly vascular organ located behind the ribs in the upper right portion of the abdominal cavity. It weighs between 1200 and 1500 g in the average adult and is divided into four lobes. A thin layer of connective tissue surrounds each lobe, extending into the lobe itself and dividing the liver mass into small, functional units called lobules (Barrett, Barman, Brooks, et al., 2019; Hammer & McPhee, 2019). The circulation of the blood into and out of the liver is of major importance to liver function. The blood that perfuses the liver comes from two sources. Approximately 80% of the blood supply comes from the portal vein, which drains the GI tract and is rich in nutrients but lacks oxygen. The remainder of the blood supply enters by way of the hepatic artery and is rich in oxygen. Terminal branches of these two blood vessels join to form common capillary beds, which constitute the sinusoids of the liver (see Fig. 43-2). Thus, a mixture of venous and arterial blood bathes the hepatocytes (liver cells). The sinusoids empty into venules that occupy the center of each liver lobule and are called the central veins. The central veins join to form the hepatic vein, which constitutes the venous drainage from the liver and empties into the inferior vena cava, close to the diaphragm (Barrett et al., 2019; Hammer & McPhee, 2019; Sanyal et al., 2018). In addition to hepatocytes, phagocytic cells belonging to the reticuloendothelial system are present in the liver. Other organs that contain reticuloendothelial cells are the spleen, bone marrow, lymph nodes, and lungs. In the liver, these cells are called Kupffer cells (Barrett et al., 2019; Hammer & McPhee, 2019). As the most common phagocyte in the human body, their main function is to engulf particulate matter (e.g., bacteria) that enters the liver through the portal blood. The smallest bile ducts, called canaliculi, are located between the lobules of the liver. The canaliculi receive secretions from the hepatocytes and carry them to larger bile ducts, which eventually form the hepatic duct. The hepatic duct from the liver and the cystic duct from the gallbladder join to form the common bile duct, which empties into the small intestine. The sphincter of Oddi, located at the junction where the common bile duct enters the duodenum, controls the flow of bile into the intestine. Figure 43-1 • The liver and biliary system, including the gallbladder and bile ducts. Reprinted with permission from Norris, T. L. (2019). Porth’s pathophysiology: Concepts of altered health states (10th ed., Fig. 38.1). Philadelphia, PA: Wolters Kluwer. Figure 43-2 • A section of liver lobule showing the location of hepatic veins, hepatic cells, liver sinusoids, and branches of the portal vein and hepatic artery. Functions of the Liver Glucose Metabolism The liver plays a major role in the metabolism of glucose and the regulation of blood glucose concentration. After a meal, glucose is taken up from the portal venous blood by the liver and converted into glycogen, which is stored in the hepatocytes. Subsequently, the glycogen is converted back to glucose through a process called glycogenolysis and is released as needed into the bloodstream to maintain normal levels of blood glucose. However, this process provides a limited amount of glucose. Additional glucose can be synthesized by the liver through a process called gluconeogenesis. For this process, the liver uses amino acids from protein breakdown or lactate produced by exercising muscles. This process occurs in response to hypoglycemia (Barrett et al., 2019; Hammer & McPhee, 2019). Ammonia Conversion The use of amino acids from protein for gluconeogenesis results in the formation of ammonia as a by-product. The liver converts this metabolically generated ammonia into urea. Ammonia produced by bacteria in the intestines is also removed from portal blood for urea synthesis. In this way, the liver converts ammonia, a potential toxin, into urea, a compound that is excreted in the urine (Barrett et al., 2019; Hammer & McPhee, 2019). Protein Metabolism The liver also plays an important role in protein metabolism. It synthesizes almost all of the plasma proteins (except gamma-globulin), including albumin, alpha-globulins and beta-globulins, blood clotting factors, specific transport proteins, and most of the plasma lipoproteins. Vitamin K is required by the liver for synthesis of prothrombin and some of the other clotting factors. Amino acids are used by the liver for protein synthesis (Barrett et al., 2019; Hammer & McPhee, 2019). Fat Metabolism The liver is also active in fat metabolism. Fatty acids can be broken down for the production of energy and ketone bodies (acetoacetic acid, beta-hydroxybutyric acid, and acetone). Ketone bodies are small compounds that can enter the bloodstream and provide a source of energy for muscles and other tissues. Breakdown of fatty acids into ketone bodies occurs primarily when the availability of glucose for metabolism is limited, as in starvation or in uncontrolled diabetes. Fatty acids and their metabolic products are also used for the synthesis of cholesterol, lecithin, lipoproteins, and other complex lipids (Hammer & McPhee, 2019; Sanyal et al., 2018). Vitamin and Iron Storage Vitamins A, B, and D and several of the B-complex vitamins are stored in large amounts in the liver. Certain substances, such as iron and copper, are also stored in the liver. Bile Formation Bile is continuously formed by the hepatocytes and collected in the canaliculi and bile ducts. It is composed mainly of water and electrolytes such as sodium, potassium, calcium, chloride, and bicarbonate, and it also contains significant amounts of lecithin, fatty acids, cholesterol, bilirubin, and bile salts. Bile is collected and stored in the gallbladder and is emptied into the intestine as needed for digestion. The functions of bile are excretory, as in the excretion of bilirubin; bile also serves as an aid to digestion through the emulsification of fats by bile salts. Bile salts are synthesized by the hepatocytes from cholesterol. After conjugation or binding with amino acids (taurine and glycine), bile salts are excreted into the bile. The bile salts, together with cholesterol and lecithin, are required for emulsification of fats in the intestine, which is necessary for efficient digestion and absorption. Bile salts are then reabsorbed, primarily in the distal ileum, into portal blood for return to the liver and are again excreted into the bile. This pathway from hepatocytes to bile to intestine and back to the hepatocytes is called the enterohepatic circulation. Because of the enterohepatic circulation, only a small fraction of the bile salts that enter the intestine are excreted in the feces. This decreases the need for active synthesis of bile salts by the liver cells (Hammer & McPhee, 2019). Bilirubin Excretion Bilirubin is a pigment derived from the breakdown of hemoglobin by cells of the reticuloendothelial system, including the Kupffer cells of the liver. Hepatocytes remove bilirubin from the blood and chemically modify it through conjugation to glucuronic acid, which makes the bilirubin more soluble in aqueous solutions. The conjugated bilirubin is secreted by the hepatocytes into the adjacent bile canaliculi and is eventually carried in the bile into the duodenum. p. 1366 p. 1367 In the small intestine, bilirubin is converted into urobilinogen, which is partially excreted in the feces and partially absorbed through the intestinal mucosa into the portal blood. Much of this reabsorbed urobilinogen is removed by the hepatocytes and secreted into the bile once again (enterohepatic circulation). Some of the urobilinogen enters the systemic circulation and is excreted by the kidneys in the urine. Elimination of bilirubin in the bile represents the major route of its excretion. Drug Metabolism The liver metabolizes many medications, such as barbiturates, opioids, sedatives, anesthetics, and amphetamines (Goldman & Schafer, 2019; Hammer & McPhee, 2019; Sanyal et al., 2018). Metabolism generally results in drug inactivation, although activation may also occur. One of the important pathways for medication metabolism involves conjugation (binding) of the medication with a variety of compounds, such as glucuronic acid or acetic acid, to form more soluble substances. These substances may be excreted in the feces or urine, similar to bilirubin excretion. Bioavailability is the fraction of the given medication that actually reaches the systemic circulation. The bioavailability of an oral medication (absorbed from the GI tract) can be decreased if the medication is metabolized to a great extent by the liver before it reaches the systemic circulation; this is known as first-pass effect. Some medications have such a large first-pass effect that their use is essentially limited to the parenteral route, or oral doses must be substantially larger than parenteral doses to achieve the same effect. Gerontologic Considerations Chart 43-1 summarizes age-related changes in the liver. In the older adult, the most common change in the liver is a decrease in size and weight, accompanied by a decrease in total hepatic blood flow. However, in general, these decreases are proportional to the decreases in body size and weight seen in normal aging. Results of liver function tests do not normally change with age; abnormal results in older patients indicate abnormal liver function and are not a result of the aging process itself. Chart 43-1 Age-Related Changes of the Hepatobiliary System •Atypical clinical presentation of biliary disease •Decreases in the following: •Clearance of hepatitis B surface antigen •Drug metabolism and clearance capabilities •Intestinal and portal vein blood flow •Gallbladder contraction after a meal •Rate of replacement and or repair of liver cells after injury •Size and weight of the liver, particularly in women •Increased prevalence of gallstones due to the increase in cholesterol secretion in bile •More rapid progression of hepatitis C infection and lower response rate to therapy •More severe complications of biliary tract disease Adapted from Townsend, C. M., Beauchamp, R. D., Evers, B. M., et al. (2016). Sabiston’s textbook of surgery: The biological basis of modern surgical practice. Philadelphia, PA: Elsevier. Metabolism of medications by the liver decreases in the older adult, but such changes are usually accompanied by changes in intestinal absorption, renal excretion, and altered body distribution of some medications secondary to changes in fat deposition. These alterations necessitate careful medication administration and monitoring; if appropriate, reduced dosages may be needed to prevent medication toxicity

Adding substance to bloodstream

Gas Transport in the Bloodstream and Control of Breathing

Week 3 - Bloodstream Infections

Bloodstream Infections - Bacterial and Viral

Endocrine System 1. What are hormones and what is their function in the body? Hormones are chemical messengers transported in the bloodstream that stimulate physiological responses in target cells or organs. 2. Types of hormones Endocrine System 1. What are hormones and what is their function in the body? Hormones are chemical messengers transported in the bloodstream that stimulate physiological responses in target cells or organs. 2. Types of hormones based on chemical composition and how they enter target cells: • Steroid hormones: Lipid-soluble, diffuse through cell membrane (e.g., cortisol). • Protein/Peptide hormones: Water-soluble, bind to surface receptors (e.g., insulin). • Biogenic/Monoamines: Derived from amino acids (e.g., T3/T4), may need carriers or membrane receptors. 3. Know all 6 hormones secreted by the anterior pituitary gland and their functions: • TSH: Stimulates thyroid to release T3 and T4. • ACTH: Stimulates adrenal cortex to release cortisol. • GH: Stimulates tissue growth and protein synthesis. • PRL: Stimulates milk production. • FSH: Stimulates egg maturation/sperm production. • LH: Triggers ovulation and testosterone production. 4. What is thymosin? Which gland secretes it? What is its function? Thymosin is secreted by the thymus and helps in the development and maturation of T-cells. 5. Know thyroid gland hormones, the cells that secrete them, and their functions: • T3 & T4 (follicular cells): Increase metabolism and regulate appetite. • Calcitonin (C cells): Lowers blood calcium levels. 6. Know the hormones secreted by the adrenal gland and their specific functions: • Cortex: • Aldosterone: Retains Na⁺, excretes K⁺, raises blood pressure. • Cortisol: Increases glucose, metabolism of fat/protein. • Androgens: Precursor to sex hormones. • Medulla: • Epinephrine/Norepinephrine: Increase heart rate, blood flow, and alertness. 7. Function of glucagon and insulin in maintaining homeostasis: • Insulin (beta cells): Lowers blood glucose. • Glucagon (alpha cells): Raises blood glucose. • Antagonistic: They have opposing effects to balance blood sugar levels. 8. Which cells are involved in spermatogenesis? Where does sperm production occur? • Sertoli (Sustentacular) cells support spermatogenesis. • Leydig (Interstitial) cells produce testosterone. • Occurs in the seminiferous tubules of the testes. 9. Know the hormones secreted by the testes and their functions: • Testosterone: Stimulates male development and sperm production. • Inhibin: Inhibits FSH to regulate sperm production. 10. What causes diabetes insipidus? How is it different from diabetes mellitus? • Diabetes insipidus: ADH deficiency → excessive urination. • Diabetes mellitus: Insulin issues → high blood glucose. 11. Know the 3 “P’s” of diabetes: • Polyuria: Excessive urination. • Polydipsia: Excessive thirst. • Polyphagia: Excessive hunger. 12. How are oxytocin and prolactin different? • Oxytocin: Stimulates uterine contractions and milk letdown. • Prolactin: Stimulates milk production. 13. Name the ovarian hormones and their functions: • Estrogen/Progesterone: Regulate cycle, pregnancy, and secondary sex characteristics. • Inhibin: Inhibits FSH secretion. ⸻ Muscle Physiology 14. Know 3 muscle types, their locations, and function: • Skeletal: Attached to bones; movement; voluntary. • Cardiac: Heart; pumps blood; involuntary. • Smooth: Organs/vessels; propels substances; involuntary. 15. Know the layers surrounding muscle: • Epimysium: Surrounds entire muscle. • Perimysium: Surrounds fascicle (bundle). • Endomysium: Surrounds individual fiber. 16. What is a fascicle? A bundle of muscle fibers. 17. What is a sarcomere? Name its regions: Smallest contractile unit (Z-disc to Z-disc). • Z-band, A-band (dark), I-band (light), H-zone. 18. What are actin and myosin? • Actin: Thin filament. • Myosin: Thick filament that pulls actin during contraction. 19. What is troponin and tropomyosin? • Tropomyosin blocks binding sites on actin. • Troponin binds Ca²⁺ to move tropomyosin and expose sites. 20. What is a motor unit? A motor neuron and all muscle fibers it controls. 21. Role of T-Tubule, SR, Terminal Cisternae: • T-Tubule: Conducts AP into cell. • SR: Stores calcium. • Terminal cisternae: Release calcium. 22. Which neurotransmitter is released at the neuromuscular junction? Acetylcholine (ACh). 23. What role does Ca²⁺ play in muscle physiology? Binds troponin, moves tropomyosin, exposes actin sites. 24. What happens to Ca²⁺ after action potential ends? Reabsorbed into SR by Ca²⁺ ATPase pump. 25. What is the function of ATP in muscle physiology? Powers myosin movement, detachment, and Ca²⁺ reuptake. 26. What is sliding filament theory? Myosin pulls actin filaments → sarcomere shortens → contraction. 27. What are DHP and Ryanodine receptors and their roles? • DHP: Voltage sensor in T-tubule. • Ryanodine: Releases Ca²⁺ from SR. 28. What is the function of AChE? Breaks down ACh to stop stimulation and contraction. 29. Difference between isotonic and isometric contractions: • Isotonic: Muscle changes length (shortens/lengthens). • Isometric: Muscle length stays same; tension builds. ⸻ Respiratory Physiology 30. Difference between conductive and respiratory divisions: • Conductive: Air passageways (nose to bronchioles). • Respiratory: Gas exchange (alveoli). 31. Type I & II alveolar cells and functions: • Type I: Gas exchange. • Type II: Secretes surfactant, repairs alveoli. 32. Dust cells and their functions: Alveolar macrophages that clean up particles/debris. 33. Muscles in relaxed vs. forced respiration: • Relaxed inhale: Diaphragm, external intercostals. • Forced inhale: Accessory neck muscles. • Forced exhale: Internal intercostals, abdominals. 34. What happens to pressure and volume when inhaling/exhaling? • Inhale: Volume ↑, pressure ↓. • Exhale: Volume ↓, pressure ↑. 35. Difference between systemic and pulmonary exchange: • Systemic: Gas exchange at tissues. • Pulmonary: Gas exchange in lungs. 36. What cells are involved in carrying gases? Red blood cells (RBCs). 37. Which enzyme converts CO₂ + H₂O → H₂CO₃? Carbonic anhydrase. 38. What does carbonic acid break into? H⁺ + HCO₃⁻ (bicarbonate ion). 39. What happens in hypoxia (low oxygen)? • ↓O₂, ↑CO₂, ↓pH (acidosis). 40. What happens in hypercapnia (high CO₂)? • ↑CO₂, ↓O₂, ↓pH (acidosis). 41. Receptors for blood pH and their locations: • Central (CSF pH): Medulla oblongata. • Peripheral (O₂, CO₂, pH): Carotid & aortic bodies. 42. CO₂ loading & O₂ unloading at tissues: • CO₂ enters blood → forms HCO₃⁻. • O₂ released to tissues. 43. CO₂ unloading & O₂ loading at alveoli: • CO₂ released from blood to lungs. • O₂ binds to hemoglobin. 44. Brain part for unconscious breathing: Medulla oblongata. 45. Obstructive vs. restrictive disorders + example: • Obstructive: Narrowed airways (asthma). • Restrictive: Reduced lung expansion (fibrosis). 46. Know spirometry volumes (not numbers): • Tidal volume, • Inspiratory/Expiratory reserve volume, • Residual volume, • Vital capacity, • Total lung capacity, • Inspiratory capacity, • Functional residual capacity. 47. Define eupnea, dyspnea, tachypnea, apnea, Kussmaul respiration: • Eupnea: Normal breathing. • Dyspnea: Labored breathing. • Tachypnea: Rapid, shallow breathing. • Apnea: No breathing. • Kussmaul: Deep, rapid (from acidosis Endocrine System 1. What are hormones and what is their function in the body? Hormones are chemical messengers transported in the bloodstream that stimulate physiological responses in target cells or organs. 2. Types of hormones based on chemical composition and how they enter target cells: • Steroid hormones: Lipid-soluble, diffuse through cell membrane (e.g., cortisol). • Protein/Peptide hormones: Water-soluble, bind to surface receptors (e.g., insulin). • Biogenic/Monoamines: Derived from amino acids (e.g., T3/T4), may need carriers or membrane receptors. 3. Know all 6 hormones secreted by the anterior pituitary gland and their functions: • TSH: Stimulates thyroid to release T3 and T4. • ACTH: Stimulates adrenal cortex to release cortisol. • GH: Stimulates tissue growth and protein synthesis. • PRL: Stimulates milk production. • FSH: Stimulates egg maturation/sperm production. • LH: Triggers ovulation and testosterone production. 4. What is thymosin? Which gland secretes it? What is its function? Thymosin is secreted by the thymus and helps in the development and maturation of T-cells. 5. Know thyroid gland hormones, the cells that secrete them, and their functions: • T3 & T4 (follicular cells): Increase metabolism and regulate appetite. • Calcitonin (C cells): Lowers blood calcium levels. 6. Know the hormones secreted by the adrenal gland and their specific functions: • Cortex: • Aldosterone: Retains Na⁺, excretes K⁺, raises blood pressure. • Cortisol: Increases glucose, metabolism of fat/protein. • Androgens: Precursor to sex hormones. • Medulla: • Epinephrine/Norepinephrine: Increase heart rate, blood flow, and alertness. 7. Function of glucagon and insulin in maintaining homeostasis: • Insulin (beta cells): Lowers blood glucose. • Glucagon (alpha cells): Raises blood glucose. • Antagonistic: They have opposing effects to balance blood sugar levels. 8. Which cells are involved in spermatogenesis? Where does sperm production occur? • Sertoli (Sustentacular) cells support spermatogenesis. • Leydig (Interstitial) cells produce testosterone. • Occurs in the seminiferous tubules of the testes. 9. Know the hormones secreted by the testes and their functions: • Testosterone: Stimulates male development and sperm production. • Inhibin: Inhibits FSH to regulate sperm production. 10. What causes diabetes insipidus? How is it different from diabetes mellitus? • Diabetes insipidus: ADH deficiency → excessive urination. • Diabetes mellitus: Insulin issues → high blood glucose. 11. Know the 3 “P’s” of diabetes: • Polyuria: Excessive urination. • Polydipsia: Excessive thirst. • Polyphagia: Excessive hunger. 12. How are oxytocin and prolactin different? • Oxytocin: Stimulates uterine contractions and milk letdown. • Prolactin: Stimulates milk production. 13. Name the ovarian hormones and their functions: • Estrogen/Progesterone: Regulate cycle, pregnancy, and secondary sex characteristics. • Inhibin: Inhibits FSH secretion. ⸻ Muscle Physiology 14. Know 3 muscle types, their locations, and function: • Skeletal: Attached to bones; movement; voluntary. • Cardiac: Heart; pumps blood; involuntary. • Smooth: Organs/vessels; propels substances; involuntary. 15. Know the layers surrounding muscle: • Epimysium: Surrounds entire muscle. • Perimysium: Surrounds fascicle (bundle). • Endomysium: Surrounds individual fiber. 16. What is a fascicle? A bundle of muscle fibers. 17. What is a sarcomere? Name its regions: Smallest contractile unit (Z-disc to Z-disc). • Z-band, A-band (dark), I-band (light), H-zone. 18. What are actin and myosin? • Actin: Thin filament. • Myosin: Thick filament that pulls actin during contraction. 19. What is troponin and tropomyosin? • Tropomyosin blocks binding sites on actin. • Troponin binds Ca²⁺ to move tropomyosin and expose sites. 20. What is a motor unit? A motor neuron and all muscle fibers it controls. 21. Role of T-Tubule, SR, Terminal Cisternae: • T-Tubule: Conducts AP into cell. • SR: Stores calcium. • Terminal cisternae: Release calcium. 22. Which neurotransmitter is released at the neuromuscular junction? Acetylcholine (ACh). 23. What role does Ca²⁺ play in muscle physiology? Binds troponin, moves tropomyosin, exposes actin sites. 24. What happens to Ca²⁺ after action potential ends? Reabsorbed into SR by Ca²⁺ ATPase pump. 25. What is the function of ATP in muscle physiology? Powers myosin movement, detachment, and Ca²⁺ reuptake. 26. What is sliding filament theory? Myosin pulls actin filaments → sarcomere shortens → contraction. 27. What are DHP and Ryanodine receptors and their roles? • DHP: Voltage sensor in T-tubule. • Ryanodine: Releases Ca²⁺ from SR. 28. What is the function of AChE? Breaks down ACh to stop stimulation and contraction. 29. Difference between isotonic and isometric contractions: • Isotonic: Muscle changes length (shortens/lengthens). • Isometric: Muscle length stays same; tension builds. ⸻ Respiratory Physiology 30. Difference between conductive and respiratory divisions: • Conductive: Air passageways (nose to bronchioles). • Respiratory: Gas exchange (alveoli). 31. Type I & II alveolar cells and functions: • Type I: Gas exchange. • Type II: Secretes surfactant, repairs alveoli. 32. Dust cells and their functions: Alveolar macrophages that clean up particles/debris. 33. Muscles in relaxed vs. forced respiration: • Relaxed inhale: Diaphragm, external intercostals. • Forced inhale: Accessory neck muscles. • Forced exhale: Internal intercostals, abdominals. 34. What happens to pressure and volume when inhaling/exhaling? • Inhale: Volume ↑, pressure ↓. • Exhale: Volume ↓, pressure ↑. 35. Difference between systemic and pulmonary exchange: • Systemic: Gas exchange at tissues. • Pulmonary: Gas exchange in lungs. 36. What cells are involved in carrying gases? Red blood cells (RBCs). 37. Which enzyme converts CO₂ + H₂O → H₂CO₃? Carbonic anhydrase. 38. What does carbonic acid break into? H⁺ + HCO₃⁻ (bicarbonate ion). 39. What happens in hypoxia (low oxygen)? • ↓O₂, ↑CO₂, ↓pH (acidosis). 40. What happens in hypercapnia (high CO₂)? • ↑CO₂, ↓O₂, ↓pH (acidosis). 41. Receptors for blood pH and their locations: • Central (CSF pH): Medulla oblongata. • Peripheral (O₂, CO₂, pH): Carotid & aortic bodies. 42. CO₂ loading & O₂ unloading at tissues: • CO₂ enters blood → forms HCO₃⁻. • O₂ released to tissues. 43. CO₂ unloading & O₂ loading at alveoli: • CO₂ released from blood to lungs. • O₂ binds to hemoglobin. 44. Brain part for unconscious breathing: Medulla oblongata. 45. Obstructive vs. restrictive disorders + example: • Obstructive: Narrowed airways (asthma). • Restrictive: Reduced lung expansion (fibrosis). 46. Know spirometry volumes (not numbers): • Tidal volume, • Inspiratory/Expiratory reserve volume, • Residual volume, • Vital capacity, • Total lung capacity, • Inspiratory capacity, • Functional residual capacity. 47. Define eupnea, dyspnea, tachypnea, apnea, Kussmaul respiration: • Eupnea: Normal breathing. • Dyspnea: Labored breathing. • Tachypnea: Rapid, shallow breathing. • Apnea: No breathing. • Kussmaul: Deep, rapid (from acidosis Endocrine System 1. What are hormones and what is their function in the body? Hormones are chemical messengers transported in the bloodstream that stimulate physiological responses in target cells or organs. 2. Types of hormones based on chemical composition and how they enter target cells: • Steroid hormones: Lipid-soluble, diffuse through cell membrane (e.g., cortisol). • Protein/Peptide hormones: Water-soluble, bind to surface receptors (e.g., insulin). • Biogenic/Monoamines: Derived from amino acids (e.g., T3/T4), may need carriers or membrane receptors. 3. Know all 6 hormones secreted by the anterior pituitary gland and their functions: • TSH: Stimulates thyroid to release T3 and T4. • ACTH: Stimulates adrenal cortex to release cortisol. • GH: Stimulates tissue growth and protein synthesis. • PRL: Stimulates milk production. • FSH: Stimulates egg maturation/sperm production. • LH: Triggers ovulation and testosterone production. 4. What is thymosin? Which gland secretes it? What is its function? Thymosin is secreted by the thymus and helps in the development and maturation of T-cells. 5. Know thyroid gland hormones, the cells that secrete them, and their functions: • T3 & T4 (follicular cells): Increase metabolism and regulate appetite. • Calcitonin (C cells): Lowers blood calcium levels. 6. Know the hormones secreted by the adrenal gland and their specific functions: • Cortex: • Aldosterone: Retains Na⁺, excretes K⁺, raises blood pressure. • Cortisol: Increases glucose, metabolism of fat/protein. • Androgens: Precursor to sex hormones. • Medulla: • Epinephrine/Norepinephrine: Increase heart rate, blood flow, and alertness. 7. Function of glucagon and insulin in maintaining homeostasis: • Insulin (beta cells): Lowers blood glucose. • Glucagon (alpha cells): Raises blood glucose. • Antagonistic: They have opposing effects to balance blood sugar levels. 8. Which cells are involved in spermatogenesis? Where does sperm production occur? • Sertoli (Sustentacular) cells support spermatogenesis. • Leydig (Interstitial) cells produce testosterone. • Occurs in the seminiferous tubules of the testes. 9. Know the hormones secreted by the testes and their functions: • Testosterone: Stimulates male development and sperm production. • Inhibin: Inhibits FSH to regulate sperm production. 10. What causes diabetes insipidus? How is it different from diabetes mellitus? • Diabetes insipidus: ADH deficiency → excessive urination. • Diabetes mellitus: Insulin issues → high blood glucose. 11. Know the 3 “P’s” of diabetes: • Polyuria: Excessive urination. • Polydipsia: Excessive thirst. • Polyphagia: Excessive hunger. 12. How are oxytocin and prolactin different? • Oxytocin: Stimulates uterine contractions and milk letdown. • Prolactin: Stimulates milk production. 13. Name the ovarian hormones and their functions: • Estrogen/Progesterone: Regulate cycle, pregnancy, and secondary sex characteristics. • Inhibin: Inhibits FSH secretion. ⸻ Muscle Physiology 14. Know 3 muscle types, their locations, and function: • Skeletal: Attached to bones; movement; voluntary. • Cardiac: Heart; pumps blood; involuntary. • Smooth: Organs/vessels; propels substances; involuntary. 15. Know the layers surrounding muscle: • Epimysium: Surrounds entire muscle. • Perimysium: Surrounds fascicle (bundle). • Endomysium: Surrounds individual fiber. 16. What is a fascicle? A bundle of muscle fibers. 17. What is a sarcomere? Name its regions: Smallest contractile unit (Z-disc to Z-disc). • Z-band, A-band (dark), I-band (light), H-zone. 18. What are actin and myosin? • Actin: Thin filament. • Myosin: Thick filament that pulls actin during contraction. 19. What is troponin and tropomyosin? • Tropomyosin blocks binding sites on actin. • Troponin binds Ca²⁺ to move tropomyosin and expose sites. 20. What is a motor unit? A motor neuron and all muscle fibers it controls. 21. Role of T-Tubule, SR, Terminal Cisternae: • T-Tubule: Conducts AP into cell. • SR: Stores calcium. • Terminal cisternae: Release calcium. 22. Which neurotransmitter is released at the neuromuscular junction? Acetylcholine (ACh). 23. What role does Ca²⁺ play in muscle physiology? Binds troponin, moves tropomyosin, exposes actin sites. 24. What happens to Ca²⁺ after action potential ends? Reabsorbed into SR by Ca²⁺ ATPase pump. 25. What is the function of ATP in muscle physiology? Powers myosin movement, detachment, and Ca²⁺ reuptake. 26. What is sliding filament theory? Myosin pulls actin filaments → sarcomere shortens → contraction. 27. What are DHP and Ryanodine receptors and their roles? • DHP: Voltage sensor in T-tubule. • Ryanodine: Releases Ca²⁺ from SR. 28. What is the function of AChE? Breaks down ACh to stop stimulation and contraction. 29. Difference between isotonic and isometric contractions: • Isotonic: Muscle changes length (shortens/lengthens). • Isometric: Muscle length stays same; tension builds. ⸻ Respiratory Physiology 30. Difference between conductive and respiratory divisions: • Conductive: Air passageways (nose to bronchioles). • Respiratory: Gas exchange (alveoli). 31. Type I & II alveolar cells and functions: • Type I: Gas exchange. • Type II: Secretes surfactant, repairs alveoli. 32. Dust cells and their functions: Alveolar macrophages that clean up particles/debris. 33. Muscles in relaxed vs. forced respiration: • Relaxed inhale: Diaphragm, external intercostals. • Forced inhale: Accessory neck muscles. • Forced exhale: Internal intercostals, abdominals. 34. What happens to pressure and volume when inhaling/exhaling? • Inhale: Volume ↑, pressure ↓. • Exhale: Volume ↓, pressure ↑. 35. Difference between systemic and pulmonary exchange: • Systemic: Gas exchange at tissues. • Pulmonary: Gas exchange in lungs. 36. What cells are involved in carrying gases? Red blood cells (RBCs). 37. Which enzyme converts CO₂ + H₂O → H₂CO₃? Carbonic anhydrase. 38. What does carbonic acid break into? H⁺ + HCO₃⁻ (bicarbonate ion). 39. What happens in hypoxia (low oxygen)? • ↓O₂, ↑CO₂, ↓pH (acidosis). 40. What happens in hypercapnia (high CO₂)? • ↑CO₂, ↓O₂, ↓pH (acidosis). 41. Receptors for blood pH and their locations: • Central (CSF pH): Medulla oblongata. • Peripheral (O₂, CO₂, pH): Carotid & aortic bodies. 42. CO₂ loading & O₂ unloading at tissues: • CO₂ enters blood → forms HCO₃⁻. • O₂ released to tissues. 43. CO₂ unloading & O₂ loading at alveoli: • CO₂ released from blood to lungs. • O₂ binds to hemoglobin. 44. Brain part for unconscious breathing: Medulla oblongata. 45. Obstructive vs. restrictive disorders + example: • Obstructive: Narrowed airways (asthma). • Restrictive: Reduced lung expansion (fibrosis). 46. Know spirometry volumes (not numbers): • Tidal volume, • Inspiratory/Expiratory reserve volume, • Residual volume, • Vital capacity, • Total lung capacity, • Inspiratory capacity, • Functional residual capacity. 47. Define eupnea, dyspnea, tachypnea, apnea, Kussmaul respiration: • Eupnea: Normal breathing. • Dyspnea: Labored breathing. • Tachypnea: Rapid, shallow breathing. • Apnea: No breathing. • Kussmaul: Deep, rapid (from acidosis based on chemical composition and how they enter target cells: • Steroid hormones: Lipid-soluble, diffuse through cell membrane (e.g., cortisol). • Protein/Peptide hormones: Water-soluble, bind to surface receptors (e.g., insulin). • Biogenic/Monoamines: Derived from amino acids (e.g., T3/T4), may need carriers or membrane receptors. 3. Know all 6 hormones secreted by the anterior pituitary gland and their functions: • TSH: Stimulates thyroid to release T3 and T4. • ACTH: Stimulates adrenal cortex to release cortisol. • GH: Stimulates tissue growth and protein synthesis. • PRL: Stimulates milk production. • FSH: Stimulates egg maturation/sperm production. • LH: Triggers ovulation and testosterone production. 4. What is thymosin? Which gland secretes it? What is its function? Thymosin is secreted by the thymus and helps in the development and maturation of T-cells. 5. Know thyroid gland hormones, the cells that secrete them, and their functions: • T3 & T4 (follicular cells): Increase metabolism and regulate appetite. • Calcitonin (C cells): Lowers blood calcium levels. 6. Know the hormones secreted by the adrenal gland and their specific functions: • Cortex: • Aldosterone: Retains Na⁺, excretes K⁺, raises blood pressure. • Cortisol: Increases glucose, metabolism of fat/protein. • Androgens: Precursor to sex hormones. • Medulla: • Epinephrine/Norepinephrine: Increase heart rate, blood flow, and alertness. 7. Function of glucagon and insulin in maintaining homeostasis: • Insulin (beta cells): Lowers blood glucose. • Glucagon (alpha cells): Raises blood glucose. • Antagonistic: They have opposing effects to balance blood sugar levels. 8. Which cells are involved in spermatogenesis? Where does sperm production occur? • Sertoli (Sustentacular) cells support spermatogenesis. • Leydig (Interstitial) cells produce testosterone. • Occurs in the seminiferous tubules of the testes. 9. Know the hormones secreted by the testes and their functions: • Testosterone: Stimulates male development and sperm production. • Inhibin: Inhibits FSH to regulate sperm production. 10. What causes diabetes insipidus? How is it different from diabetes mellitus? • Diabetes insipidus: ADH deficiency → excessive urination. • Diabetes mellitus: Insulin issues → high blood glucose. 11. Know the 3 “P’s” of diabetes: • Polyuria: Excessive urination. • Polydipsia: Excessive thirst. • Polyphagia: Excessive hunger. 12. How are oxytocin and prolactin different? • Oxytocin: Stimulates uterine contractions and milk letdown. • Prolactin: Stimulates milk production. 13. Name the ovarian hormones and their functions: • Estrogen/Progesterone: Regulate cycle, pregnancy, and secondary sex characteristics. • Inhibin: Inhibits FSH secretion. ⸻ Muscle Physiology 14. Know 3 muscle types, their locations, and function: • Skeletal: Attached to bones; movement; voluntary. • Cardiac: Heart; pumps blood; involuntary. • Smooth: Organs/vessels; propels substances; involuntary. 15. Know the layers surrounding muscle: • Epimysium: Surrounds entire muscle. • Perimysium: Surrounds fascicle (bundle). • Endomysium: Surrounds individual fiber. 16. What is a fascicle? A bundle of muscle fibers. 17. What is a sarcomere? Name its regions: Smallest contractile unit (Z-disc to Z-disc). • Z-band, A-band (dark), I-band (light), H-zone. 18. What are actin and myosin? • Actin: Thin filament. • Myosin: Thick filament that pulls actin during contraction. 19. What is troponin and tropomyosin? • Tropomyosin blocks binding sites on actin. • Troponin binds Ca²⁺ to move tropomyosin and expose sites. 20. What is a motor unit? A motor neuron and all muscle fibers it controls. 21. Role of T-Tubule, SR, Terminal Cisternae: • T-Tubule: Conducts AP into cell. • SR: Stores calcium. • Terminal cisternae: Release calcium. 22. Which neurotransmitter is released at the neuromuscular junction? Acetylcholine (ACh). 23. What role does Ca²⁺ play in muscle physiology? Binds troponin, moves tropomyosin, exposes actin sites. 24. What happens to Ca²⁺ after action potential ends? Reabsorbed into SR by Ca²⁺ ATPase pump. 25. What is the function of ATP in muscle physiology? Powers myosin movement, detachment, and Ca²⁺ reuptake. 26. What is sliding filament theory? Myosin pulls actin filaments → sarcomere shortens → contraction. 27. What are DHP and Ryanodine receptors and their roles? • DHP: Voltage sensor in T-tubule. • Ryanodine: Releases Ca²⁺ from SR. 28. What is the function of AChE? Breaks down ACh to stop stimulation and contraction. 29. Difference between isotonic and isometric contractions: • Isotonic: Muscle changes length (shortens/lengthens). • Isometric: Muscle length stays same; tension builds. ⸻ Respiratory Physiology 30. Difference between conductive and respiratory divisions: • Conductive: Air passageways (nose to bronchioles). • Respiratory: Gas exchange (alveoli). 31. Type I & II alveolar cells and functions: • Type I: Gas exchange. • Type II: Secretes surfactant, repairs alveoli. 32. Dust cells and their functions: Alveolar macrophages that clean up particles/debris. 33. Muscles in relaxed vs. forced respiration: • Relaxed inhale: Diaphragm, external intercostals. • Forced inhale: Accessory neck muscles. • Forced exhale: Internal intercostals, abdominals. 34. What happens to pressure and volume when inhaling/exhaling? • Inhale: Volume ↑, pressure ↓. • Exhale: Volume ↓, pressure ↑. 35. Difference between systemic and pulmonary exchange: • Systemic: Gas exchange at tissues. • Pulmonary: Gas exchange in lungs. 36. What cells are involved in carrying gases? Red blood cells (RBCs). 37. Which enzyme converts CO₂ + H₂O → H₂CO₃? Carbonic anhydrase. 38. What does carbonic acid break into? H⁺ + HCO₃⁻ (bicarbonate ion). 39. What happens in hypoxia (low oxygen)? • ↓O₂, ↑CO₂, ↓pH (acidosis). 40. What happens in hypercapnia (high CO₂)? • ↑CO₂, ↓O₂, ↓pH (acidosis). 41. Receptors for blood pH and their locations: • Central (CSF pH): Medulla oblongata. • Peripheral (O₂, CO₂, pH): Carotid & aortic bodies. 42. CO₂ loading & O₂ unloading at tissues: • CO₂ enters blood → forms HCO₃⁻. • O₂ released to tissues. 43. CO₂ unloading & O₂ loading at alveoli: • CO₂ released from blood to lungs. • O₂ binds to hemoglobin. 44. Brain part for unconscious breathing: Medulla oblongata. 45. Obstructive vs. restrictive disorders + example: • Obstructive: Narrowed airways (asthma). • Restrictive: Reduced lung expansion (fibrosis). 46. Know spirometry volumes (not numbers): • Tidal volume, • Inspiratory/Expiratory reserve volume, • Residual volume, • Vital capacity, • Total lung capacity, • Inspiratory capacity, • Functional residual capacity. 47. Define eupnea, dyspnea, tachypnea, apnea, Kussmaul respiration: • Eupnea: Normal breathing. • Dyspnea: Labored breathing. • Tachypnea: Rapid, shallow breathing. • Apnea: No breathing

05 Bloodstream infections

Chapter 3 - Tissues 1. Introduction Main tissue types: Epithelial, Connective, Muscle, Nervous Functions: Protection, secretion, absorption, connection, movement, information processing Tissue membranes: Epithelial membranes: Mucous, Serous, Cutaneous Connective tissue membranes: Synovial membranes (joints) 2. Types of Tissues Four categories: Epithelial: Covers surfaces, lines cavities Connective: Supports, connects, transports Muscle: Enables movement Nervous: Sends and receives signals Embryonic origin: Derived from ectoderm, mesoderm, endoderm 3. Epithelial Tissue Characteristics: Closely packed cells, avascular, polarity (apical/basal surfaces), rapid regeneration Cell Junctions: Tight junctions: Barrier function (e.g., intestines) Anchoring junctions: Stability (e.g., skin) Gap junctions: Communication (e.g., heart) Types: Simple (one layer) vs Stratified (multiple layers) Shapes: Squamous (flat), Cuboidal (cube-shaped), Columnar (tall) Specialized types: Pseudostratified: Appears layered but isn’t Transitional: Stretchable (e.g., bladder) Glands: Endocrine (ductless, secretes hormones into bloodstream) Exocrine (ducts, secretes onto surfaces) Modes of secretion: Merocrine: Exocytosis (e.g., sweat glands) Apocrine: Pinched off portion of cell (e.g., mammary glands) Holocrine: Entire cell disintegrates (e.g., sebaceous glands) 4. Connective Tissue Structure: Cells dispersed in extracellular matrix (ground substance + protein fibers) Fiber types: Collagen (strong, flexible) Elastic (stretchy) Reticular (supportive framework) Categories: Proper: Loose (Areolar, Adipose, Reticular) Dense (Regular, Irregular, Elastic) Supportive: Cartilage (hyaline, elastic, fibrocartilage) Bone (osteocytes in lacunae, vascularized) Fluid: Blood (RBCs, WBCs, plasma) Lymph (immune function) Functions: Structural support, transport, immune defense, energy storage 5. Muscle Tissue Properties: Excitable, contractile Types: Skeletal: Striated, voluntary, attached to bones Cardiac: Striated, involuntary, heart muscle (intercalated discs) Smooth: Non-striated, involuntary (digestive, respiratory, reproductive systems) 6. Nervous Tissue Function: Conducts electrical impulses, processes information Cell types: Neurons: Transmit signals (axon, dendrites) Neuroglia: Support, protect, nourish neurons 7

Ch 35 Endocrine Key Points • The principal endocrine glands include the pituitary, thyroid, parathyroid, adrenal, pineal, thymus. • The endocrine system alters chemical reactions and controls the rate at which chemical activities take place within cells. • Any type of dysfunction of the pituitary gland will affect one or more of the hormones and their target organs. • The thyroid gland secretes the hormones thyroxine (T4), triiodothyronine (T3), and thyrocalcitonin. • Parathormone is a hormone produced and secreted by the parathyroid glands that acts on the renal tubules to increase the excretion of phosphorus in the urine and to stimulate the reabsorption of calcium; it also stimulates the production of the active form of vitamin D, which enhances calcium absorption in the small intestine and acts on bone, causing the release of calcium from the bone into the bloodstream. • The adrenal medulla (middle portion) secretes two hormones—epinephrine and norepinephrine (called catecholamines)—in response to stimulation from the sympathetic nervous system. • T he two major types of hormones secreted by the adrenal cortex are the mineralocorticoids (aldosterone) and the glucocorticoids (cortisol). • The beta cells are responsible for producing and secreting insulin, while the alpha cells release glucagon. • Age-related changes in the endocrine system include the pituitary gland becoming smaller, the thyroid becoming more lumpy or nodular, increases and decreases in different hormones, and increases in blood glucose levels. • The endocrine system regulates metabolism, growth and development, sexual function, reproductive processes. • The secretion of a particular hormone normally depends on the need. • Endocrine disorders are caused by an imbalance in the production of hormone or by an alteration in the body’s ability to use the hormones produced. • Goiter, an overgrowth of the thyroid, may be prevented by sufficient intake of iodine. • Tests of the endocrine system are performed on blood samples; on urine samples; or by scans, ultrasounds, radiographs, or magnetic resonance imaging (MRI). • According to the 2020 American Diabetes Association guidelines, diagnosis of diabetes mellitus is based on one of four abnormalities: (1) Symptoms of diabetes mellitus plus a random glucose level greater than or equal to 200 mg/dL; (2) a fasting glucose level greater than or equal to 126 mg/dL; (3) a hemoglobin A1c level greater than 6.5%; and (4) a glucose tolerance test revealing a postprandial glucose greater than or equal to 200 mg/dL, 2 hours after 75 g of glucose is administered. • A full physical assessment and history are needed to evaluate a patient who is possibly experiencing an endocrine disorder. • An example of a problem statement for someone with an endocrine disorder is as follows: Altered fluid volume caused by increased urine output (DI, Hyperthyroidism, AD). An example of an expected outcome would be as follows: Patient will display a balance between intake and output. • Planning care for a patient with an endocrine disorder will depend on the type of disorder the patient has. Stress has a direct effect on endocrine function. Therefore, measures to help the patient decrease stress should be planned. • Evaluation is accomplished by determining whether symptoms are resolving and by laboratory testing to determine whether treatment of the endocrine problem is effective

Digestion Notes (Biology 12) I. Introduction/Overview • Digestion: Breakdown of food into small, soluble molecules • Occurs physically and chemically • Absorption: The process of taking specific compounds into the body • Elimination: Expulsion of materials not absorbed into the body • Excretion: Removal of waste from metabolic processes II. Location of Parts and Function A. Teeth • Type of teeth depends on diet: • Carnivores: Sharp teeth for grasping prey and severing meat • Herbivores: Flat teeth for crushing plant fibers • Omnivores: A combination of tooth types for eating both meat and plants • Structure: • Enamel: Hard outer layer • Dentin: Bony layer under enamel • Pulp: Living part of the tooth (contains nerves and blood vessels) • Teeth are embedded in sockets in the jaw B. Tongue • Functions: • Taste: Detects salt, sour, sweet, and bitter flavors • Positioning food for chewing C. Salivary Glands • Three pairs: • Parotid (side of face; swells with mumps) • Sublingual (under tongue) • Submandibular (lower jaw) • Produce saliva, which contains enzymes for digestion D. Palates • Located at the top of the mouth • Hard palate: Front, separates the mouth from the nasal cavity • Soft palate: Back, ends in the uvula E. Pharynx • Area between mouth and esophagus • Used for both breathing and eating • Epiglottis: Closes over the glottis when swallowing to prevent choking F. Esophagus • Muscular tube that pushes food into the stomach using peristalsis • Composed of five tissue layers: 1. Mucosa (epithelial lining) 2. Submucosa (connective tissue) 3. Muscularis (two muscle layers: circular and longitudinal) 4. Serosa (outer epithelial layer; secretes fluid for lubrication) G. Cardiac Sphincter • Muscle at the junction of the esophagus and stomach • Opens to allow food into the stomach H. Stomach • J-shaped organ, located left of the body’s center • Capacity: About 1 liter • Inner lining contains gastric glands: • Parietal cells → Produce HCl • Chief cells → Produce pepsinogen, activated by HCl into pepsin • Epithelial cells → Produce mucus (protects stomach lining) • Functions: • Storage of food (empties in 2-6 hours) • Digestion using pepsin and salivary amylase • Absorption of water, ethanol • Regulation of pepsin production by the hormone gastrin I. Pyloric Sphincter • Muscle at the junction of the stomach and small intestine • Opens to allow chyme (partially digested food) into the small intestine J. Small Intestine • Length: ~ 3 meters (10 feet) • Highly convoluted to increase surface area for absorption • Interior folds covered with villi (tiny projections that increase surface area) • Divided into three parts: 1. Duodenum (first 25 cm): Produces lactase, peptidase, maltase, nuclease 2. Jejunum 3. Ileum • Functions: • Completes digestion • Absorbs nutrients into the bloodstream K. Liver • Largest organ in the body • Monitors blood composition via the hepatic portal vein L. Pancreas • Produces pancreatic juice (digestive enzymes and sodium bicarbonate to neutralize stomach acid) • Produces insulin (regulates blood glucose) M. Ileo-Caecal Opening • Joins the small intestine to the large intestine N. Caecum • Blind pouch at the end of the small intestine • No function in humans (vestigial), but in herbivores, it helps digest cellulose O. Large Intestine • Parts: 1. Ascending colon 2. Transverse colon 3. Descending colon 4. Rectum (stores feces) 5. Anus (controls feces release) • Functions: • Reabsorbs water (~95% of 10L daily intake) • Forms feces • Produces vitamins B and K using E. coli bacteria III. Digestive Enzymes Enzyme Source pH Digested Food Product Salivary Amylase Salivary Glands 7 Starch Maltose Pepsin Stomach 2 Protein Peptides Pancreatic Amylase Pancreas Basic Starch Maltose Trypsin Pancreas Basic Protein Peptides Lipase Pancreas Basic Fat Glycerol & Fatty Acids Peptidases Small Intestine Basic Peptides Amino Acids Maltase Small Intestine Basic Maltose Glucose Nuclease Pancreas Basic DNA/RNA Nucleotides IV. Swallowing and Peristalsis • Swallowing: Food forms a bolus (food ball) and is moved down the esophagus • Peristalsis: Rhythmic contractions of smooth muscle that push food through the digestive tract V. The 7 Functions of the Liver 1. Detoxifies harmful substances (e.g., alcohol) 2. Stores glucose as glycogen 3. Destroys old red blood cells (recycling heme into bile) 4. Produces urea from amino acid breakdown 5. Makes blood proteins 6. Stores iron and vitamins A, D, E, K 7. Converts amino acids to glucose if needed (gluconeogenesis) VI. Digestive Juices & Hormones Gastric Juice (Stomach) • Contains HCl, pepsinogen (activated into pepsin), and mucus • Helps digest proteins into peptides Pancreatic Juice • Contains sodium bicarbonate (neutralizes acid) • Enzymes: Pancreatic amylase, trypsin, lipase, nuclease Bile (Liver & Gallbladder) • Breaks down fats into small droplets for lipase to act on VII. Control of Digestive Gland Secretions • Nervous Reflex: Presence of food triggers digestion • Conditioned Reflex: External stimuli (e.g

Introduction to Tissues A. Histology=the study of tissues. B. Although studying tissues can be accomplished using a light microscope, studying cell parts often requires an electron microscope and the study of atoms and molecules can only be examined through special imaging techniques and experimental procedures. Types of Tissues A. Despite the fact the body is composed of trillions of cells, there are only about 200 different cell types. These cells in turn produce only four principle tissue types: 1. Epithelial tissues=covers exposed surfaces; lines internal passageways; and produces glandular secretions. 2. Connective tissues=fills internal spaces; provides structural support, and stores energy 3. Muscle tissues=contracts to produce active movements 4. Nervous tissue=conducts electrical impulses; detects, interprets, and responds to stimuli B. Relative contribution of the four tissue types to the overall weight of the adult body. C. Embryonic origins: There are three types of embryonic tissues from which all adult tissues are derived. a. Endoderm=gives rise to the functional linings of the digestive and respiratory tracts as well as to the associated accessory glands and organs (i.e. liver, stomach, pancreas, etc.) b. Mesoderm= gives rise to the components of the skeletal, muscular, and circulatory systems c. Ectoderm= gives rise to the epidermis of skin and all of the components of the nervous system D. Tissue Membranes 1. Mucous Membranes=composed of epithelial tissues. These membranes line body cavities that open to the exterior environment such as those of the digestive tract, respiratory tract, or urogenital tract. In all cases, these are "wet" or moist membranes because of the secretion of mucous. The moisture helps reduce friction and in many cases, facilitates absorption or secretion activities. 2. Serous Membranes=consists of a mesothelium supported by areolar tissue. These are never exposed or connected to the exterior. Serous membranes secrete transudate, or serous fluid. There are three serous membranes that line the ventral body cavity: a. Pleura=lines the chest cavity and surrounds the lungs. b. Pericardium=lines the pericardial cavity and surrounds the heart c. Peritoneum=lines the peritoneal cavity and lines the surfaces of the visceral organs 3. Cutaneous Membranes=made of stratified squamous and areolar tissue reinforced by dense irregular connective tissue. In contrast to mucous and serous membranes, cutaneous membranes are dry, relatively thick, and waterproof. 4. Synovial Membranes=line mobile joint cavities but do not cover the opposing joint surfaces. Secretes synovial fluid. Although the covering of the synovial membrane is often called an epithelium, it differs from true epithelia in four respects: it develops within a connective tissue, no basal lamina is present, gaps of up to 1 mm may separate adjacent cells, and the synovial fluid and capillaries in the underlying connective tissue are continuously exchanging fluid and solutes. Epithelial Tissues A. Functions of Epithelial Tissues 1. Epithelia provide physical protection. Epithelial tissues protect exposed and internal surfaces from abrasion, dehydration, and destruction by chemical or biological agents. 2. Epithelia control permeability. Any substance that enters or leaves the body has to cross an epithelial tissue. Some epithelia are relatively impermeable, whereas others are permeable to compounds as large as proteins. Most are capable of selective absorption or secretion. The epithelial barrier can be regulated and modified in response to various stimuli. For example, a callus forms on your hands when you do rough work for an extended period of time. 3. Epithelia provide sensation. Sensory nerves extensively innervate most epithelia. Specialize epithelial cells can detect changes in the environment and convey information about such changes to the nervous system. 4. Epithelial cells that produce secretions are called glands. Individual gland cells are often scattered among other cell types in an epithelium that may have many other functions. B. Location of Epithelial Tissues 1. Epithelia=forms sheets or layers of cells that line the body tubes, cavities, or coverings of the body surfaces. 2. Glands=formed of epithelial cells with secretory functions. Two types of glands are found in the human body: a. Endocrine glands=secrete hormones (or hormonal precursors) into the interstitial fluid or bloodstream. These glands are ductless. b. Exocrine glands=secretes non-hormonal substances (milk, wax, enzymes, oil, acids, etc.) onto external surfaces or internal passageways (ducts) that connect to the exterior. C. Characteristics of Epithelial Tissues 1. Polarity=epithelial cells possess two structurally and functionally different surfaces: a. Apical surface=free edge which faces the exterior of the body or the lumen of an internal space. b. Basal surface=attached surface which anchors the cells to adjacent tissues. 2. Supported by a basal lamina=also known as the basement membrane, is a complex structure produced by the basal surface of the epithelial cells and the underlying connective tissue. The underlying connective tissue is composed of two things: 3. Cellularity=epithelial cells are extensively interconnected so that they create an effective barrier that behaves as if it were a single cell. a. Occluding junctions=form a barrier that isolates the basolateral surfaces and deeper tissues from the contents of the lumen. At an occluding junction, the attachment is so tight that it prevents the passage of water and solutes between the cells. b. Adhesion belt=locks together the terminal webs of neighboring cells, strengthening the apical region and preventing distortion and leakage at the occluding junctions. It forms a continuous band that encircles cells and binds them together. c. Gap junctions=permits chemical communication that coordinates the activities of adjacent cells. At a gap junction, two cells are held together by interlocking junctional proteins called connexons which serve as channels that form a narrow passageway to let small molecules and ions to pass from cell to cell. d. Desmosomes=provides firm attachment between neighboring cells by interlocking their cytoskeletons. At a desmosome, the opposing plasma membranes are very strong and resist stretching and twisting. Hemidesmosomes attach the basal surface to the basement membrane. e. CAM=cell adhesion molecules; present in the adhesion belt and desmosomes; transmembrane proteins that bind to each other and to extracellular materials. 4. Avascular=epithelial tissues lack blood vessels; all nutrient and waste exchange occurs as a result of diffusion and osmosis from underlying tissues. 5. Highly innervated=epithelial tissues are supplied with many nerve endings 6. Regenerate rapidly=although the exact rate varies from one type of epithelia to another, most epithelial tissues regenerate within days (rather than weeks or years). D. Naming Epithelial Tissues 1. Almost all epithelial tissues possess a two part name where the first part of their name indicates their arrangement (number of layers) while the second part of their name indicates the shape of the cells. 2. Arrangement of epithelial tissues a. Simple=only one layer thick b. Stratified=more than one layer thick c. Pseudostratified= “false layers”; it looks like more than one layer but in fact its only one layer thick 3. Shape of epithelial cells a. Squamous=thin, flat, and somewhat irregular in shape. From the surface, they look like fried eggs lay side by side. In a sectional view, they look like a pancake with a pat of butter (indicating the nucleus). b. Cuboidal=are about as wide as they are tall; resemble hexagonal boxes with the spherical nucleus located in the center of each cell. c. Columnar=are taller than they are wide; resemble rectangles with the elongated nuclei tend to crowd into a narrow band close to the basal lamina. E. Diversity of Epithelial Tissues 1. Simple squamous epithelium a. Description: single layer of flattened cells with a disc-shaped central nuclei and sparse cytoplasm. b. Function: allows passage of materials by diffusion and filtration in sites where protection is not important. Also secretes lubricant. c. Locations: Kidney glomeruli, air sacs of lungs, capillaries, linings of heart and lymphatic system. 2. Stratified squamous epithelium a. Description: thick layers of flattened cells; often keratinized layer and a mitotic layer. b. Function: protects underlying tissues in areas subject to abrasion c. Location: non-keratinized type lines the mouth and vagina; keratinized type forms the epidermis of skin. 3. Simple cuboidal epithelium a. Description: single layer of cube-like cells with large spherical centrally located nuclei. b. Function: secretion and absorption c. Locations: Kidney tubules, ducts and secretory portions of glands, ovary surface 4. Stratified cuboidal epithelium a. Relatively rare in the human body. b. Most common along the ducts of sweat glands, mammary glands, and other exocrine glands. c. DO NOT NEED TO KNOW FOR THE LAB PRACTICAL!! 5. Simple columnar epithelium a. Description: single layer of tall cells with round to oval nuclei; some cells bear cilia; may contain goblet cells that produce mucus; may contain microvilli. b. Function: absorption; secretion of mucus and enzymes; cilia propel substances. c. Location: non-ciliated type lines digestive tract, gallbladder, and ducts from glands; ciliated type lines small bronchi, uterine tubes, and uterus. 6. Stratified columnar epithelium a. Relatively rare in the human body. b. Most often found lining large ducts such as those of the salivary glands and pancreas. c. DO NOT NEED TO KNOW FOR THE LAB PRACTICAL!! 7. Pseudostratified columnar epithelium a. Description: single layer of cells of differing heights so that nuclei are a differing levels; may contain goblet cells and bear cilia. b. Function: secretion, propulsion by ciliary action. c. Location: non-ciliated type lines male reproductive ducts; ciliated type lines much of respiratory tract. 8. Transitional epithelium a. Description: resembles both stratified squamous and stratified cuboidal. Basal cells are cuboidal or columnar; surface cells are dome shaped. b. Function: stretches readily and permits distension. c. Location: Lines uterus, bladder, and urethra F. Glandular Epithelia are Specialized for Secretion 1. Endocrine glands= “ductless” glands that produce hormones. Secrete directly into interstitial fluids or bloodstream. Examples: pituitary gland, adrenal gland, thyroid gland, etc. 2. Exocrine glands=glands possessing ducts. Exocrine glands secret their substance either on the body surfaces or within ducts. They general demonstrates one of two different modes secretion: a. Merocrine=secrete products from secretory vesicles by exocytosis. Most common type. Example: salivary glands of the oral cavity b. Holocrine=accumulate products until the cell ruptures. Destroys the cell and must be replaced by cell division. Example: sebaceous glands of the skin c. Apocrine=products accumulate within the cells then the apex of the cell pinches off packets that contain the secretion. Example: mammary gland of the breast 3. Exocrine glands are unicellular or multicellular. a. Unicellular=goblet cells that produce mucin which mixes with water to form mucus. b. Multicellular=two structural classes: i. Simple=a single duct that does not branch on its way to the secretory cells (examples: gastric glands, sebaceous glands) ii. Compound= duct divides one or more times on its way to the secretory cells (examples: duodenal glands, mammary glands and salivary glands) Connective Tissues: Supports and Protects A. Location of Connective Tissues 1. Most abundant tissue in the body. 2. Never exposed to the outside environment. B. Characteristics of Connective Tissues 1. All types of connective tissue originate from mesenchyme. 2. Connective tissues vary widely in appearance and function but all forms share three basic components: a. Specialized cells=the cells present in each type of connective tissue helps to distinguish the various types from one another. A few of the cells are listed here: i. Fibroblast cells=produce connective tissue proper ii. Chondrocytes=produce cartilage iii. Osteocytes=produce bone iv. Hemocytoblast cells=produce blood b. Extracellular proteins fibers=three primary fibers are produced in connective tissues i. Elastic fibers=slender, straight, and very stretchy. They recoil to their original length after stretching or distortion. ii. Collagen fibers=thick, straight or wavy, and often forms bundles. They are very strong and resist stretching. iii. Reticular fibers=strong fibers that form a branching network or scaffolding c. Ground substance=material that fills the space between cells and surrounds the extracellular fibers. In some connective tissues the ground substance is gel-like while in others it is liquid based and in others it is rigid or calcified. Ground substance and extracellular fibers make up the matrix of connective tissues. 3. Many types of connective tissue are highly vascular and contain sensory receptors that detect pain, pressure, temperature, and other stimuli. C. Functions of Connective Tissues 1. Establish a structural framework for the body. 2. Transport fluids and dissolved materials. 3. Protect delicate organs. 4. Support, surround, and interconnect other types of tissue. 5. Store energy reserves, especially in the form of triglycerides. 6. Defend the body from invading microorganisms. D. Diversity of Connective Tissues 1. Connective Tissue Proper=includes connective tissues with many types of cells and extracellular fibers in a gel-like ground substance. a. Loose Connective Tissues – fibers created a loose, open framework i. Areolar tissue=most common form of connective tissue proper in adults. It is the general packing material in the body. Attaches skin to underlying body parts and is sometimes called the superficial fascia. All of the cell types found in other forms of connective tissue proper can be found in areolar. ii. Adipose tissue=found deep to the skin, especially at the flanks, buttocks, and breasts. It also forms a layer that provides padding within the orbit of the eyes, in the abdominopelvic cavity, and around the kidneys. The distinction between areolar tissue and adipose is the larger number of adipocytes (fat cells). iii. Reticular tissue=found in the liver, kidney, spleen, lymph nodes, and bone marrow, where it forms a tough, flexible network that provides support and resists distortion. In reticular tissue, reticular fibers create a complex supporting network known as a stroma. Fixed macrophages and fibroblasts are present but these cells are seldom visible. DO NOT NEED TO KNOW FOR THE LAB PRACTICAL!! b. Dense Connective Tissues – fibers are densely packed together i. Dense regular=all collagen fibers are oriented parallel to each other providing strength along the axis of the collagen fibers. Found in cords (such as tendons) or sheets (ligaments). Tendons connect muscle to bones. Ligaments connect bones to bones. ii. Dense irregular=collagen fibers are non-parallel forming an interwoven network. These tissues provide strength in many directions and are particularly important in areas subjected to stress from many directions such as the dermis of the skin. iii. Elastic=when elastic fibers outnumber collagen fibers, the tissue has a springy, resilient nature that allows it to tolerate cycles of extension and recoil. This elastic tissue is bound between the vertebrae of the spinal column and the erectile tissues of the penis. DO NOT NEED TO KNOW FOR THE LAB PRACTICAL!! 2. Fluid Connective Tissues=have distinctive populations of cells suspended in a watery matrix that contains dissolved proteins. NOT ON LAB PRACTICAL! a. Blood – flows within the cardiovascular system 3. Supporting Connective Tissues=differ from connective tissue proper in have a less diverse cell population and a matrix containing much more densely packed fibers. Supporting connective tissues protect soft tissues and support the weight of part or all of the body. a. Cartilage – solid, rubbery matrix containing chondrocytes. All cartilage is surrounded by a membrane of connective tissue called the perichondrium. i. Hyaline cartilage=found connecting the ribs to the sternum, covering the articular surfaces of long bones, supporting the respiratory passageways such as the trachea, and forming the tip of the nose and part of the nasal septum. Has an amorphous matrix with few visible fibers. It provides stiff but somewhat flexible support and reduces friction between bony surfaces. ii. Elastic cartilage=found in the ear and epiglottis. Has many more elastic fibers within the matrix and is therefore more flexible. iii. Fibrous cartilage=found within the intervertebral discs, the meniscus of the knee, and pubic symphysis. Has many more collagen fibers within its matrix and is therefore very strong. b. Bone – solid, crystalline matrix containing osteocytes. All bone is surrounded by a membrane of connective tissue called the periosteum. NOT ON LAB PRACTICAL! c. Comparison of cartilage and bone. Muscle Tissue in Motion (discussed in detail in Chapter 10-11) NOT ON LAB PRACTICAL! A. Highly vascularized muscular tissue is comprised of elongated cells (called fibers) containing myofilaments (actin and myosin proteins). 
 B

152 Virus Involved in the Bloodstream, CNS and other Sterile Sites I:

152 Virus Involved in the Bloodstream, CNS and other Sterile Sites I:

MICROORGANISMS INVOLVED IN THE BLOODSTREAM, CNS, AND OTHER STERILE SITES (BACTERIA I)

body sites 5.6 bloodstream