BSC2086 Final Exam Review: Human Body Systems

What are the layers and chambers of the heart and their functions?

The heart has three layers: the epicardium (outer layer), myocardium (muscle layer), and endocardium (inner layer). It has four chambers: the right atrium (receives deoxygenated blood), right ventricle (pumps deoxygenated blood to lungs), left atrium (receives oxygenated blood), and left ventricle (pumps oxygenated blood to the body).

Trace the pathway of blood through the pulmonary and systemic circulations.

Deoxygenated blood flows from the body into the right atrium, then to the right ventricle, which pumps it to the lungs via the pulmonary arteries for gas exchange. Oxygenated blood returns to the left atrium, moves to the left ventricle, and is pumped out to the body through the aorta.

What are the major branches of the coronary circulation and their supply areas?

The major branches include the left coronary artery (supplying the left atrium and ventricle) and the right coronary artery (supplying the right atrium and ventricle).

Compare the structure and function of A-V valves and semilunar valves.

A-V valves (tricuspid and mitral) are located between atria and ventricles, preventing backflow during ventricular contraction. Semilunar valves (pulmonary and aortic) are located at the exits of the ventricles, preventing backflow into the heart after contraction.

How do cardiac muscle cells differ from skeletal muscle cells?

Cardiac muscle cells are striated, branched, and interconnected by intercalated discs, allowing synchronized contraction. Skeletal muscle cells are long, cylindrical, and multinucleated, under voluntary control.

What are chemoreceptors and baroreceptors, and what do they sense?

Chemoreceptors sense changes in blood chemistry (like CO2 and O2 levels) and are located in the carotid arteries and aorta. Baroreceptors sense changes in blood pressure and are located in the carotid sinus and aortic arch.

What is the role of neurotransmitters and hormones in cardiovascular functions?

Neurotransmitters (like norepinephrine) and hormones (like adrenaline) regulate heart rate, contractility, and vascular tone, affecting blood pressure and flow.

What are the effects of parasympathetic and sympathetic stimulation on the heart and blood vessels?

Parasympathetic stimulation decreases heart rate and promotes vasodilation, while sympathetic stimulation increases heart rate and causes vasoconstriction.

What causes heart sounds?

Heart sounds are caused by the closure of heart valves during the cardiac cycle, specifically the 'lub' from A-V valve closure and 'dub' from semilunar valve closure.

What do the various waveforms on an EKG represent?

P wave (atrial depolarization), QRS complex (ventricular depolarization), T wave (ventricular repolarization). Abnormalities can indicate conditions like arrhythmias or myocardial infarction.

Describe the conducting system of the heart.

The wave of depolarization starts at the SA node, travels to the AV node, then through the bundle of His, and finally to the Purkinje fibers, causing coordinated heart contractions.

Define stroke volume, cardiac output, heart rate, ESV, EDV, and blood pressure.

Stroke volume is the amount of blood ejected by the heart per beat; cardiac output is stroke volume times heart rate; ESV is end-systolic volume; EDV is end-diastolic volume; blood pressure is the force of blood against vessel walls.

What is preload, contractility, and afterload?

Preload is the initial stretching of the cardiac muscle fibers; contractility is the strength of contraction; afterload is the resistance the heart must overcome to eject blood.

What are the structural and functional differences between arteries, veins, and capillaries?

Arteries have thick, elastic walls for high pressure; veins have thinner walls and valves to prevent backflow; capillaries are thin-walled for efficient gas and nutrient exchange.

What factors affect vascular pressure, resistance, and flow?

Factors include blood volume, vessel diameter, blood viscosity, and overall vessel length.

Describe capillary dynamics of filtration and reabsorption.

Filtration occurs when hydrostatic pressure exceeds osmotic pressure, pushing fluid out of capillaries. Reabsorption occurs when osmotic pressure exceeds hydrostatic pressure, pulling fluid back into capillaries.

What are the components of blood and plasma?

Blood components include red blood cells, white blood cells, platelets, and plasma. Plasma contains water, electrolytes, proteins, hormones, and nutrients.

What are the functions of hemoglobin?

Hemoglobin carries oxygen from the lungs to tissues and transports carbon dioxide from tissues back to the lungs.

What are the various blood types and how are they determined?

Blood types (A, B, AB, O) are determined by the presence or absence of antigens on red blood cells.

What is agglutination and how does it occur?

Agglutination is the clumping of blood cells due to antigen-antibody reactions, often occurring during incompatible blood transfusions.

What are the characteristics of the nonspecific and specific immune response?

Nonspecific immunity includes barriers and innate responses (like inflammation). Specific immunity involves B and T cells targeting specific pathogens.

What are the functions of lymph nodes?

Lymph nodes filter lymph fluid, trap pathogens, and house immune cells that respond to infections.

What roles do B cells, antibodies, and T cells play in the immune response?

B cells produce antibodies that neutralize pathogens; helper T cells activate B cells and cytotoxic T cells destroy infected cells.

What are the functions of the spleen in the immune system?

The spleen filters blood, removes old red blood cells, and helps mount immune responses.

Which structures constitute the conducting zone and respiratory zone of the respiratory system?

The conducting zone includes the trachea, bronchi, and bronchioles; the respiratory zone includes alveoli where gas exchange occurs.

What factors can affect gas exchange between blood and alveoli?

Factors include surface area, membrane thickness, and partial pressure gradients of gases.

What tissue covers the lungs and lines the pleural cavities?

Pleura, a serous membrane, covers the lungs and lines the pleural cavities, reducing friction during breathing.

What factors affect pulmonary ventilation?

Factors include lung compliance, airway resistance, and the pressure gradient between the atmosphere and lungs.

What factors can increase resistance to airflow?

Factors include bronchoconstriction, inflammation, and excess mucus.

What factors can influence respiratory rate?

Factors include carbon dioxide levels, oxygen levels, pH, and neural input.

How is carbon dioxide transported in the blood?

Carbon dioxide is transported as bicarbonate ions (70%), bound to hemoglobin (23%), and dissolved in plasma (7%). Carbonic anhydrase facilitates the conversion to bicarbonate.

What are Dalton's and Boyle's laws?

Dalton's law states that the total pressure of a gas mixture is the sum of the partial pressures. Boyle's law states that pressure and volume are inversely related in a closed system.

What is the relationship between carbon dioxide and pH?

Increased carbon dioxide levels lower pH (more acidic), while decreased levels raise pH (more alkaline).

How is oxygen transported in the blood?

Oxygen is primarily transported bound to hemoglobin in red blood cells. Factors promoting delivery include high temperature and low pH.

What major dietary processes occur in the stomach and small intestine?

In the stomach, protein digestion begins; in the small intestine, carbohydrates, proteins, and fats are digested and absorbed.

What digestive enzymes and hormones are secreted by the stomach and small intestine?

The stomach secretes pepsin and gastric acid; the small intestine secretes enzymes like amylase, lipase, and hormones like secretin and cholecystokinin.

Define metabolism, catabolism, anabolism, oxidation, and reduction.

Metabolism is the sum of all chemical reactions; catabolism breaks down molecules for energy; anabolism builds complex molecules; oxidation involves loss of electrons; reduction involves gain of electrons.

What is the relationship between glucose, glycogen, glycogenesis, glycogenolysis, and gluconeogenesis?

Glucose is a simple sugar; glycogen is its stored form. Glycogenesis is the formation of glycogen from glucose; glycogenolysis is the breakdown of glycogen into glucose; gluconeogenesis is the production of glucose from non-carbohydrate sources.

What are the functions of the kidneys?

The kidneys filter blood, remove waste, regulate electrolyte balance, control blood pressure, and maintain acid-base balance.

What is the path of filtrate through a nephron?

Filtrate flows from the glomerular (Bowman's) capsule to the proximal tubule, loop of Henle, distal tubule, and collecting duct.

What are the components of the juxtaglomerular apparatus (JGA) and their functions?

The JGA includes macula densa (senses sodium concentration), juxtaglomerular cells (secrete renin), and extraglomerular mesangial cells (support function).

Describe glomerular filtration, tubular reabsorption, and tubular secretion.

Glomerular filtration is the process of filtering blood to form urine; tubular reabsorption reclaims water and solutes from filtrate; tubular secretion removes additional wastes from blood into filtrate.

What substances are normally absorbed and excreted by the kidneys?

Normal substances absorbed include water, glucose, and electrolytes; excreted substances include urea, creatinine, and excess ions.

What is the loop of Henle?

The loop of Henle is a U-shaped section of the nephron that concentrates urine and conserves water through countercurrent multiplication.

What are the major electrolytes in fluid compartments?

Major electrolytes include sodium (extracellular), potassium (intracellular), and chloride (extracellular). Excesses or deficiencies can lead to serious health issues.

Define metabolic acidosis, respiratory acidosis, metabolic alkalosis, and respiratory alkalosis.

Metabolic acidosis is a decrease in pH due to excess acid or loss of bicarbonate; respiratory acidosis is due to carbon dioxide retention. Metabolic alkalosis is an increase in pH due to loss of acid or gain of bicarbonate; respiratory alkalosis is due to excessive carbon dioxide loss.

Describe the anatomy of the epididymis, seminiferous tubules, vas deferens, and ejaculatory duct.

The epididymis stores and matures sperm; seminiferous tubules produce sperm; the vas deferens transports sperm; the ejaculatory duct carries sperm to the urethra.

Compare and contrast human egg and sperm.

Eggs are larger, non-motile, and contain nutrients for the embryo; sperm are smaller, motile, and designed for fertilization.

What are the sources and targets of LH, FSH, estrogen, progesterone, and hCG?

LH and FSH are produced by the anterior pituitary, targeting ovaries/testes; estrogen and progesterone are produced by ovaries; hCG is produced by the placenta.

What is the structure and function of the uterus?

The uterus has three layers: endometrium (inner lining), myometrium (muscle layer), and perimetrium (outer layer), functioning in menstruation and fetal development.

Describe the various parts of the sperm cell and their functions.

The head contains genetic material and acrosome for penetrating the egg; the midpiece has mitochondria for energy; the tail propels the sperm.

What is the correct sequence of early embryonic development?

The sequence begins with fertilization, followed by cleavage, blastocyst formation, implantation, and gastrulation.

What is the function of endocrine glands?

Endocrine glands secrete hormones that regulate various bodily functions, including metabolism, growth, and mood.

What hormones are released by the anterior pituitary gland?

The anterior pituitary releases LH, FSH, ACTH, TSH, prolactin, and growth hormone.

What are the three factors that control hormone release?

Hormone release is controlled by hormonal signals (e.g., tropic hormones), neural signals (e.g., nerve impulses), and humoral signals (e.g., blood levels of ions/nutrients).

What hormones are released by the adrenal cortex, medulla, and thyroid gland?

The adrenal cortex releases cortisol and aldosterone; the medulla releases epinephrine and norepinephrine; the thyroid gland releases thyroxine (T4) and triiodothyronine (T3).

What hormones regulate blood glucose levels?

Insulin lowers blood glucose; glucagon raises blood glucose; cortisol and epinephrine also influence glucose metabolism.

Compare amino acid-based hormones to steroid hormones.

Amino acid-based hormones are water-soluble and act on cell surface receptors; steroid hormones are lipid-soluble and act on intracellular receptors.

Describe the two lobes of the pituitary gland.

The anterior lobe produces and secretes hormones; the posterior lobe stores and releases hormones produced by the hypothalamus.