Adrenal Gland

Question 1

Which is the steroid secreting portion of the Adrenal gland?

Answer 1

the cortex

Question 2

Which is the catecholamine secreting portion of the adrenal gland?

Answer 2

the medulla

Question 3

Where do the cells of the cortex originate from embryologically?

Answer 3

mesodermal mesenchyme

Question 4

Where do the cells of the medulla originate from embryologically?

Answer 4

neural crest

Question 5

What is the function of the parenchymal cells of the adrenal cortex?

Answer 5

regulate metabolism, maintaining normal electrolyte balance

Question 6

Where do the corticol and medullary sinusoids drain into?

Answer 6

adrenomedullary collecting veins—> central adrenomedullary veins –> left renal or IVC (right side)

Question 7

What is unique about the central adrenomedullary vein?

Answer 7

It has a tunica media with longitudinal smooth muscle bundles

Question 8

Chromaffin cells are considered postsynaptic neurons but why do they lack axonal processes?

Answer 8

axonal growth is inhibited by glucocorticoids, a hormone secreted by the adrenal cortex

Question 9

Mineralocorticoids are produced where? what is its functino?

Answer 9

Parenchymal cells of the zona glomerulosa in the adrenal cortex – control electrolyte homeostasis (@ distal tubule of kidney to increase sodium reabsorptionand decrease potassium reabsorption) maintain osmotic balance in urine and prevent serum acidosis (EX. ALDOSTERONE)

Question 10

Glucocorticoids are produced where? what is its function?

Answer 10

parenchymal cells of zona fasciculata in adrenal cortex– promote normal metabolism (increase rate of aa transport, promote removal of protein from skeletal muscles and its transport to liver, supress inflammatory response and some allergic reactions

Question 11

Gonadocorticoids are produced where? what is its function?

Answer 11

parenchymal cells of the zona reticularis in the adrenal cortex– induce weak masculinizing effect

Question 12

norepinephrine and epinephrine is produced where? what are their functions?

Answer 12

chromaffin cells of the andrenal medulla– similar to sympathetic effects

Question 13

What are the two different chromaffin cell populations? what do they secrete?

Answer 13

1. dense core vesicle: norepinephrine

2. contains vesicles (smaller): epinephrine

Question 14

What are chromogranins?

Answer 14

They are soluble proteins that help bind catecholamines and are exocytosed with the hormones

Question 15

What is the effect of the drug, reserpine?

Answer 15

causes depletion of catecholamines form vesicles by inhibiting its magnesium activated ATPase transport mechanisms

Question 16

What hormone induces methylation of norepinephrine to epinephrine?

Answer 16

glucocorticoids

Question 17

What are the three zones of the adrenal cortex?

Answer 17

zona glomerulosa (outermost), zona fasciculata, zona reticularis (innermost)

Question 18

What are pheochromocytomas?

Answer 18

Tumors derived from chromaffin cells –> cause excessive catecholamine secretion.

Question 19

What are effects of alpha-adrenergic receptor stimulation?

Answer 19

elevated blood pressure, increased cardiac contractility, glycogenesis, gluconeogensis, and intestinal relaxation

Question 20

Stimulation of beta- adrenergic receptors results in what?

Answer 20

increase in heart rate and contractility

Question 21

What is the function of aldosterone?

Answer 21

blood pressure, sodium levels and blood volume increase

Question 22

What is the system that provides feedback control of the zona glomerulosa?

Answer 22

renin-angiotensin-aldosterone system

Question 23

Describe the conversion of angiotension –> angiotensin II

Answer 23

Renin: Angiotensin –> angiotensin I
ACE: angiotensin I –> Angiotensin II
(angiotensin II stimulates aldosterone)

Question 24

Describe the function of glucocorticoids in:

liver, adipose tissue, other tissue, cells

Answer 24

liver: stimulate conversion of amino acids to glucose, polymerization of glucose to glycogen, promote uptake of AA and fatty acids
adipose tissue: breakdown of lipids to glycerol, and free fatty acids
other tissue: reduce rate of glucose use and promote oxidation of fatty acids
cells: inhibit protein synthesis to provide amino acids for conversion to glucose in liver

Question 25

CRH-ACTH system is the feedback system of which part of the adrenal gland?

Answer 25

Zona fasiculata and zona reticularis and also fetal adrenal gland

Question 26

What does ACTH do?

Answer 26

stimulates steroid synthesis and increases blood flow through adrenal gland

Question 27

What are the two parts of the fetal adrenal gland?

Answer 27

Outer narrow permanent cortex and inner thick fetal cortex (fetal zone)

Question 28

What cells contain P450 linked side chain clevage enzyme (Desmolase or P450ssc) found?

Answer 28

mitochondria of steroid producing cells

Question 29

Describe the cells of fetal adrenal gland.

Answer 29

The permanent cortex exhibits some basophilia while the fetal zone is eosinophilic. Cells in the fetal zone are considerable larger and arranged in irregular cords.

Question 30

What is the significance of the fetal-placental unit?

Answer 30

The placenta and fetal adernal gland each lack certain enzymes necessary for steroid synthesis (glucocorticoids, aldosterone, androgens, and estrogens)