PHYSIOLOGY

1: What is the embryonic origin of the adrenal medulla?

Neural crest ectoderm.

2: Which embryonic tissue gives rise to the adrenal cortex?

Mesoderm.

3: What stimulates the adrenal cortex to secrete hormones?

ACTH from the anterior pituitary.

4: Name the three zones of the adrenal cortex.

Zona glomerulosa

5: Which hormone is produced by the zona glomerulosa?

Aldosterone.

6: What is the primary function of aldosterone?

To promote Na+ retention and K+ excretion.

7: Which hormone is secreted by the zona fasciculata?

Cortisol.

8: List two metabolic effects of cortisol.

Stimulates protein degradation and gluconeogenesis.

9: Why are glucocorticoids used medically?

To suppress immune responses and inflammation.

10: What are the main hormones secreted by the adrenal medulla?

Epinephrine and norepinephrine.

11: What is the approximate ratio of epinephrine to norepinephrine secretion?

4:1.

12: How do adrenal medulla hormones differ from sympathetic nervous system effects?

Hormonal effects last ~10 times longer.

13: What triggers adrenal medulla hormone secretion?

Sympathetic activation ("fight or flight").

14: Define the General Adaptation Syndrome.

Body's stress response: alarm

15: Which brain regions coordinate stress responses?

Prefrontal cortex

16: How does cortisol affect memory during stress?

Enhances consolidation but hinders retrieval.

17: What is the primary endocrine cell cluster in the pancreas?

Pancreatic islets (islets of Langerhans).

18: Which pancreatic hormone lowers blood glucose?

Insulin.

19: Which pancreatic hormone raises blood glucose?

Glucagon.

20: What is gluconeogenesis?

Production of glucose from non-carbohydrates (e.g.

21: What is a cardiac syncytium?

Network of interconnected cardiac muscle cells.

22: How many syncytia are in the heart?

Two (atrial and ventricular).

23: What is the function of heart valves?

Prevent backflow of blood during systole.

24: Where is the heart's primary pacemaker located?

Sinoatrial (SA) node.

25: What delays impulse conduction between atria and ventricles?

Atrioventricular (AV) node.

26: What is the role of T tubules in cardiac muscle?

Store and release calcium ions for contraction.

27: Define diastole.

Heart relaxation phase when chambers fill with blood.

28: Define systole.

Heart contraction phase when blood is pumped out.

29: What is inotropy?

Cardiac muscle contractility.

30: What is chronotropy?

Heart rate regulation.

31: How does sympathetic stimulation affect the heart?

Increases heart rate

32: How does parasympathetic stimulation affect the heart?

Decreases heart rate

33: Which neurotransmitter does the sympathetic system use?

Norepinephrine.

34: Which neurotransmitter does the parasympathetic system use?

Acetylcholine.

35: How do endocrine glands differ from exocrine glands?

Endocrine glands secrete into blood; exocrine use ducts.

36: What is a prohormone?

Inactive precursor converted to active hormone.

37: Give an example of a prehormone.

Thyroxine (T4).

38: What is synergistic hormone interaction?

Two hormones working together to amplify an effect.

39: What is a permissive hormone effect?

One hormone enhancing another's action.

40: Give an example of antagonistic hormones.

Insulin and glucagon.

41: What is upregulation?

Increased receptor synthesis due to low hormone levels.

42: What causes downregulation?

Prolonged exposure to high hormone concentrations.

43: Why is pulsatile hormone secretion important?

Prevents receptor desensitization.

44: What connects the pituitary to hypothalamus?

Infundibulum.

45: Which pituitary lobe stores hypothalamic hormones?

Posterior pituitary.

46: Name two posterior pituitary hormones.

Oxytocin and ADH.

47: What is ADH's primary function?

Promote water retention in kidneys.

48: What triggers oxytocin release in females?

Labor contractions and nipple stimulation.

49: What are trophic hormones?

Hormones that stimulate other endocrine glands.

50: How does negative feedback regulate anterior pituitary?

High target gland hormones inhibit pituitary secretion.

51: What is the effect of cortisol on glucose utilization?

Inhibits glucose utilization.

52: What is the effect of cortisol on lipolysis?

Stimulates lipolysis.

53: What is the effect of aldosterone on blood volume?

Increases blood volume.

54: What is the effect of epinephrine on coronary blood vessels?

Dilates coronary blood vessels.

55: What is the effect of epinephrine on metabolic rate?

Increases metabolic rate.

56: What is the effect of glucagon on glycogenolysis?

Stimulates glycogenolysis.

57: What is the effect of insulin on fat formation?

Promotes fat formation.

58: What is the effect of glucagon on ketogenesis?

Stimulates ketogenesis.

59: What is the effect of sympathetic stimulation on cardiac output?

Increases cardiac output.

60: What is the effect of parasympathetic stimulation on heart rate?

Decreases heart rate.

61: What is the effect of calcium ions in cardiac muscle contraction?

Trigger contraction by binding to troponin.

62: What is the effect of the AV node delay?

Allows atria to contract before ventricles.

63: What is the effect of the sinoatrial node on heart rhythm?

Sets the heart's pace.

64: What is the effect of the bundle of His?

Conducts impulses to the ventricles.

65: What is the effect of Purkinje fibers?

Rapidly distribute impulses through ventricles.

66: What is the effect of the sympathetic system on bronchioles?

Dilates bronchioles.

67: What is the effect of the parasympathetic system on digestion?

Stimulates digestion.

68: What is the effect of the sympathetic system on pupil diameter?

Dilates pupils.

69: What is the effect of the parasympathetic system on salivary glands?

Stimulates saliva production.

70: What is the effect of the sympathetic system on skin blood vessels?

Constricts them.

71: What is the effect of the parasympathetic system on bladder contraction?

Stimulates bladder contraction.

72: What is the effect of the sympathetic system on liver glycogenolysis?

Stimulates glycogenolysis.

73: What is the effect of the parasympathetic system on heart conduction velocity?

Decreases conduction velocity.

74: What is the effect of the sympathetic system on sweat glands?

Stimulates sweating.

75: What is the effect of the parasympathetic system on pancreatic enzyme secretion?

Stimulates enzyme secretion.

76: What is the effect of the sympathetic system on adrenal medulla secretion?

Stimulates epinephrine and norepinephrine release.

77: What is the effect of the parasympathetic system on gastric motility?

Increases gastric motility.

78: What is the effect of the sympathetic system on blood glucose levels?

Increases blood glucose levels.

79: What is the effect of the parasympathetic system on insulin secretion?

Stimulates insulin secretion.

80: What is the effect of the sympathetic system on renin secretion?

Stimulates renin secretion.

81: What is the functional unit of the kidney?

Nephron.

82: Where does filtration occur in the nephron?

Glomerulus.

83: Which arteriole brings blood to the glomerulus?

Afferent arteriole.

84: What arteriole drains blood from the glomerulus?

Efferent arteriole.

85: Where is the loop of Henle located?

Renal medulla.

86: What is the main function of the kidney?

Regulate plasma volume

87: How much glomerular filtrate is produced daily?

180 L/day.

88: What is the normal GFR in men?

125 ml/min.

89: What is the normal GFR in women?

115 ml/min.

90: What is the minimal urine volume required to excrete waste daily?

400 ml/day.

91: What percentage of cardiac output do the kidneys receive?

25%.

92: Which hormone is secreted by the kidney to stimulate red blood cell production?

Erythropoietin.

93: Which structure detects changes in filtrate in the nephron for feedback control?

Macula densa.

94: Where is the macula densa located?

Thick ascending limb of the nephron loop.

95: What is the function of the juxtaglomerular apparatus?

Regulation of blood pressure and GFR.

96: What is nephrolithiasis?

Kidney stones.

97: What are most kidney stones composed of?

Calcium oxalate or calcium phosphate.

98: What condition can lead to uric acid stones?

Gout.

99: What is lithotripsy?

Procedure using shock waves to break kidney stones.

100: Which condition leads to stone formation in dehydrated people?

Increased solute concentration exceeding solubility.