Physiology Exam Study Guide #3 (ch 11, 13, 14, 16)

What is the main function of the endocrine system?

The endocrine system is a major physiological control system that regulates bodily functions by secreting hormones.

What distinguishes endocrine glands from exocrine glands?

Endocrine glands are ductless and secrete hormones directly into the bloodstream; exocrine glands have ducts.

Define hormone.

A hormone is a biologically active molecule that acts as a chemical messenger in the blood.

What is the role of receptor sites in hormone action?

Receptors in plasma membrane for polar hormones and receptors in cytoplasm for nonpolar hormones receive hormones and cause a response.

Name one example of an amine hormone.

Thyroid hormones, epinephrine, norepinephrine, dopamine, or melatonin.

What do polypeptide and protein hormones primarily do?

They make up most hormones and can have multiple active sites.

Give an example of a glycoprotein hormone.

Thyroid-stimulating hormone (TSH), luteinizing hormone (LH), or follicle-stimulating hormone (FSH).

What type of hormones are steroids derived from?

Steroids are lipids based on cholesterol.

What are the three types of inputs that regulate hormone secretion?

1. Concentration of ions or nutrients, 2. Nervous System inputs, 3. Hormonal inputs.

What happens to insulin when blood glucose levels rise?

Insulin secretion is stimulated to lower blood glucose concentration.

What hormones are synthesized in the hypothalamus?

Oxytocin and antidiuretic hormone (ADH).

How does the anterior pituitary gland function in hormone secretion?

It releases trophic hormones that stimulate other endocrine glands to secrete their hormones.

What are gonadotropins?

Hormones (FSH and LH) secreted by the anterior pituitary gland that affect gonads.

What is the relationship between the hypothalamus and the pituitary gland?

The hypothalamus secretes hormones that control the anterior pituitary, which then regulates various bodily functions.

What is the role of cortisol during stress?

Cortisol helps maintain blood pressure and regulate metabolic processes during stress.

What indicates a low blood pressure condition?

Hypotension, where blood flow to critical organs is reduced.

What is the normal range for blood pressure?

Under 120 mmHg systolic and under 80 mmHg diastolic.

What is congestive heart failure (CHF)?

A condition where cardiac output is insufficient to maintain adequate blood flow, leading to fluid retention and other complications.

What is ventilation?

The mechanical process of moving air into and out of the lungs.

What is the function of the alveoli?

They are the site of gas exchange in the lungs.

Define hypoventilation.

Inadequate ventilation, leading to increased levels of carbon dioxide in the blood.

What is the primary transporter of oxygen in the blood?

Hemoglobin binds to oxygen, transporting it to tissues.

How is carbon dioxide primarily transported in the blood?

About 70% is transported as bicarbonate (HCO3-).

What are the main components of blood?

The main components of blood include red blood cells (RBCs), white blood cells (WBCs), platelets, and plasma.

What is hemostasis?

Hemostasis is the process that prevents and stops bleeding, involving a clotting cascade.

What are the basic steps in the clotting cascade?

The basic steps in the clotting cascade include vascular spasm, platelet plug formation, coagulation cascade activation, and clot formation.

Describe the chambers of the heart.

The heart has four chambers: the right atrium, right ventricle, left atrium, and left ventricle.

What is the function of heart valves?

Heart valves prevent the backflow of blood and ensure unidirectional flow through the heart.

Describe the path of blood flow through the heart.

Blood flows from the body to the right atrium, into the right ventricle, then to the lungs, returns to the left atrium, flows into the left ventricle, and is pumped out to the body.

What are systole and diastole?

Systole is the phase of the cardiac cycle when the heart contracts and pumps blood, while diastole is when the heart relaxes and fills with blood.

What do the P, QRS, and T waves on an ECG represent?

The P wave represents atrial depolarization, the QRS complex represents ventricular depolarization, and the T wave represents ventricular repolarization.

What is the conduction system of the heart?

The conduction system includes the SA node, AV node, Bundle of His, and Purkinje fibers, coordinating heart contractions.

What are the different lung volumes and capacities?

Lung volumes include tidal volume (TV), inspiratory reserve volume (IRV), expiratory reserve volume (ERV), and vital capacity (VC).

What is gas exchange in the lungs?

Gas exchange occurs when oxygen and carbon dioxide are exchanged between the alveoli and blood due to differences in partial pressures.

What is the oxygen-hemoglobin dissociation curve?

The oxygen-hemoglobin dissociation curve illustrates how readily hemoglobin binds to oxygen at different partial pressures of oxygen, showing what shifts it left or right.

What mechanisms control breathing?

Breathing is controlled by the medulla oblongata and pons, which respond to chemoreceptor signals regarding carbon dioxide and oxygen levels.

What is asthma?

Asthma is a chronic respiratory condition characterized by airway inflammation and difficulty in breathing due to bronchoconstriction.

What is COPD?

Chronic Obstructive Pulmonary Disease (COPD) is a progressive lung disease characterized by increased breathlessness and airflow limitation.

What is emphysema?

Emphysema is a type of COPD that causes damage to the alveoli, leading to reduced gas exchange and difficulty breathing.

What is cardiac output (CO)?

Cardiac output is the volume of blood the heart pumps per minute, calculated as heart rate (HR) multiplied by stroke volume (SV).

How do you manipulate the equation CO = HR × SV?

To find CO, multiply heart rate (beats per minute) by stroke volume (amount of blood pumped per heart beat). For example, if HR is 70 bpm and SV is 70 mL, CO = 70 × 70 = 4900 mL/min.

What affects preload?

Preload is affected by venous return to the heart, blood volume, and the compliance of the ventricles.

What affects afterload?

Afterload is influenced by systemic vascular resistance and the pressure in the aorta during ventricular ejection.

What affects contractility?

Contractility is influenced by the availability of calcium ions, sympathetic nervous system stimulation, and the condition of the cardiac muscle.

What are the types of blood vessels?

The three main types of blood vessels are arteries, veins, and capillaries.

What is the function of arteries?

Arteries carry oxygenated blood away from the heart to the tissues of the body.

What is the function of veins?

Veins carry deoxygenated blood back to the heart from the tissues.

What is the function of capillaries?

Capillaries are small blood vessels where the exchange of oxygen, nutrients, and waste occurs between blood and tissues.

How is blood pressure regulated?

Blood pressure is regulated by baroreceptors, the renin-angiotensin-aldosterone system (RAAS), and various neural and hormonal mechanisms.

What is Mean Arterial Pressure (MAP)?

Mean Arterial Pressure (MAP) is the average pressure in a person's arteries during one cardiac cycle.

What is the formula for calculating MAP?

MAP can be calculated using the formula: MAP = DBP + (SBP - DBP) / 3, where DBP is diastolic blood pressure and SBP is systolic blood pressure.

What hormones does the hypothalamus produce and regulate?

The hypothalamus produces and regulates hormones such as oxytocin and vasopressin (ADH), and controls the pituitary gland.

What hormones are secreted by the pituitary gland?

The pituitary gland secretes hormones like growth hormone, prolactin, and adrenocorticotropic hormone (ACTH) among others.

What hormones are produced by the thyroid gland?

The thyroid gland produces hormones such as thyroxine (T4) and triiodothyronine (T3), which regulate metabolism.

What hormones do adrenal glands produce?

Adrenal glands produce hormones such as cortisol, adrenaline, and aldosterone, affecting stress response and blood pressure.

What hormones are produced by the pancreas?

The pancreas produces insulin, glucagon, and somatostatin which regulate blood glucose levels.

What is the difference between steroid and peptide hormones?

Steroid hormones are lipid-soluble and can pass through cell membranes, while peptide hormones are water-soluble and bind to receptors on the cell surface.

What are amine hormones?

Amine hormones are derived from amino acids and include hormones like epinephrine and norepinephrine, which influence the fight-or-flight response.

What is a negative feedback loop?

A negative feedback loop is a regulatory mechanism where an increase in a substance leads to a decrease in its production, helping to maintain balance.

What is cortisol's role in the body?

Cortisol is a steroid hormone released during stress; it helps regulate metabolism and immune response.

What are the primary functions of red blood cells (RBCs)?

Red blood cells (RBCs) transport oxygen from the lungs to the body and return carbon dioxide from the body to the lungs.

What are the primary functions of white blood cells (WBCs)?

White blood cells (WBCs) are part of the immune system and help defend the body against infections and foreign substances.

What is the role of platelets in the body?

Platelets are cell fragments that play a crucial role in blood clotting and wound healing.

What is plasma?

Plasma is the liquid component of blood, consisting mainly of water, electrolytes, nutrients, hormones, and waste products.

What factors can affect gas exchange efficiency in the lungs?

Factors affecting gas exchange include surface area of alveoli, partial pressure gradients, and thickness of the alveolar-capillary membrane.

How does exercise affect cardiac output?

During exercise, cardiac output increases due to higher heart rate and stroke volume, supplying more oxygen to muscles.

What are some signs of decreased oxygenation in tissues?

Signs of decreased oxygenation can include cyanosis (bluish skin), confusion, and decreased exercise tolerance.

What effects do high altitude have on oxygen-hemoglobin dissociation?

At high altitude, lower partial pressure of oxygen can shift the oxygen-hemoglobin dissociation curve left, reducing oxygen delivery to tissues.

What is the function of chemoreceptors in breathing control?

Chemoreceptors monitor levels of carbon dioxide and oxygen in the blood and send signals to regulate breathing rate accordingly.

What is the significance of the cardiac cycle?

The cardiac cycle describes the sequence of events in a single heartbeat, including contraction (systole) and relaxation (diastole) of the heart.

What is Eupnea?

Eupnea refers to normal, unlabored breathing.

What is Apnea?

Apnea is a temporary cessation of breathing.

What is Hyperpnea?

Hyperpnea is an increase in the depth and rate of breathing.

What is Dyspnea?

Dyspnea is a term used to describe difficult or labored breathing.

What is Polypnea?

Polypnea is a rapid and shallow breathing pattern.

What is Tachypnea?

Tachypnea refers to an abnormally rapid breathing rate.

What is Anoxia?

Anoxia is a condition characterized by a deficiency of oxygen in the tissues.

What is Hypercapnia?

Hypercapnia is an increased level of carbon dioxide in the bloodstream.

What is Asphyxia?

Asphyxia is a condition that arises from a lack of oxygen, leading to suffocation.

What is Atelectasis?

Atelectasis is the partial or complete collapse of the lung.

What is Dead Space?

Dead space refers to areas of the lungs where gas exchange does not occur.