adrenal

Question 1

Which is false?
A The adrenal cortex is derived from mesodermal cells that arise near the genital ridges during development.
B This mesodermal cell is later invaded by endodermal cells.
C Arterial blood supply to the adrenals is 20-30 small branches
D The right adrenal gland empties directly into the vena cava, and the left empties into the left renal vein.

Answer 1

B mesodermal cell layer invaded by neural crest ectoderm

Question 2

Name the zones of the adrenal cortex and what they secrete?

Answer 2

Glomerulosa: Mineralocorticoids (outer)
Fasciculata: Glucocorticoids
reticularis: sex hormones (inner)

Question 3

What are adrenal corticoids made from? Describe the process.

Answer 3

cholesterol
Enzymatic cleavage of carbon side-chain within mitochondria —> steroid pregnenolone —> hydroxylated at C-17 —> glucocorticoid

Question 4

What is different about the process to make aldosterrone?

Answer 4

No 17a-hydroxylase in zona glomerulosa —> no hydroxyl group at C-17

Question 5

Which is true?
A Steroids travel freely in the blood stream
B The primary function of catecholamines is regulation of metabolism
C The rate limiting enzyme in catecholamine formation is tyrosine hydroxylase
D The ratio of catecholamines in the cat is 60% epinephrine and 40% norepinephrine.

Answer 5

A: hydrophobic= lipids; most protein bound (albumin, transcortin)
B: glucocorticoids –> reg. metabolism
C true
D dog 60E/40N and cats 70 epi/30norepi

Question 6

Describe the RAAS system

Answer 6

Renin (made in JGA in kidney) —> cleaves angiotensinogen (liver) —> ang I —> ang II (ACE in pulm capillary endothelium) —> stim peripheral vasoconstriction and aldosterone secretion.

Question 7

True/ false: Transcortin binds 75% of cortisol and 10% of aldosterone

Answer 7

True
Cortisol= 75% transcortin and 15% albumin, 10% unbound
aldosterone= 10% trancortin, 50% albumin, 40% free state

Question 8

What is the negative feedback of glucocorticoids?

Answer 8

–> inhibit hypothalmic corticotropini-releasing hormone, –> dec corticotropin sec. by pituitary gland

Question 9

What is the function of aldosterone?

Answer 9

promote sodium, chloride and water reabsorption and potassium excretion (renal tubules)

Question 10

Products of adrenal: 
Glomerulosa
Fasciulata
Reticularis
Medulla

Answer 10

Glomerulosa: mineralocorticoids
Fasciulata: glucocorticoids
Reticularis: sex hormones
Medulla = Norepi and epi

Question 11

What is different about aldosterone versus corticosteroids?

Answer 11

17 alpha-hydroxylase** = Step from c-21 steroid pregnenolone to a glucocorticoid
Not present in glomerulosa → aldosterone

Question 12

What are other names for vasopressin?

Answer 12

AVP;

also called antidiuretic hormone, or ADH

Question 13

____ is a hormone that is synthesized in the hypothalamus and released at the level of the posterior pituitary gland when stimulated by hypothalamic osmoreceptors and peripheral baroreceptors

Answer 13

vasopressin aka ADH