Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FHB Endocrinology > L73: Adrenal Gland > Flashcards

L73: Adrenal Gland Flashcards

1
Q

What are mineralocorticoids?

A

Hormones secreted in the Zona Glomerulosa of the Adrenal Cortex that promotes sodium retention and water retention in the kidney
Aldosterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What enzyme is found in Zona Glomerulosa cells that allow them to produce Aldosterone?

A

Aldosterone Synthase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the target tissues of Aldosterone?

A 
MR highly expressed in:
Distal Tubule
Colon
Salivary Ducts
Sweat Ducts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does Aldosterone do?

A

Stimulate sodium and water reabsorption

Increases potassium secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does aldosterone cause its effects?

A

Increases transepithelial Na+ transport in distal tubule and collecting duct of nephron
Increases potassium excretion in collecting duct cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What stimulates Aldosterone release?

A

Increases in EC fluid K+ conc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does the Renin-Angiotensin-Aldosteron System work?

A

Decreased BP stimulates renin release from kidney from JGA -> Renin cleaves angiotensinogen from liver to angiotensin I -> ACE converts angiotensin II -> Vasocontrictor and stimulates Aldosterone release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the net result of Aldosterone secretion?

A

Increased EC fuid volume and increased BP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the net result of AVP/ADH?

A

STimulate distal nephron water permeability -> increased water retention -> decreases plasma osmolality and decreases sodium concentration in blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does Mineralocorticoid receptor (MR) bind?

A

Binds with high affinity to both glucocorticoids and mineralocorticoids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Does Aldosterone have a specific binding protein?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What inactivates glucocorticoids in the kidney?

A

11B-HSD Type II converts cortisol to cortisone and thus inactivates it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does Carbenoxolone do?

A

Inhibit 11B HSD2 -> excess MR activation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What produces similar results as Carbenoxolone?

A

Licorice: inhibit 11B HSD2 -> increased sodium and water retention with excessive consumption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What enzyme converts cortisone back to cortisol?

A

11B HSD1 : potential DM T2 drug target

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is produced in the Zona Reticularis of hte Adrenal Cortex?

A

Adrenal Androgens: DHEA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is DHEA?

A

Precursor for testosterone and estrogen
Declines with age
Weak androgen due to low binding affinity for androgen receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the first step in steroid hormone biosyntehsis?

A

Conversion of cholesterol to pregnenolone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How are adrenal steroid hormones synthesized?

A

Cholesterol imported into cell as LDL or HDL -> STAR transports cholesterol form outer mitochondria to inner mitochondria (rate limiting step) -> Converted to pregnenolone by CYP11A1(P450scc)

20
Q

What does cholesterol ester hydrolase do?

A

Esterifies cholesterol; Stimulated by ACTH

21
Q

What are the common causes of congenital adrenal hyperplasia (CAH)?

A

21a hydroxylase deficiency
11B hydroxylase deficiency

Both lead to excess ACTH stimulation of cortex due to lack of negative feedback

22
Q

What does 21ahydroxylase deficiency lead to?

A

Excess DHEA
No glucocorticoids or mineralocoritcoids

Sx: Virilization (masculinization), ambiguous genitalia, sodium loss

23
Q

What does 11B hydroxylase deficiency lead to?

A

Salt and water retention due to excess mineralocorticoid activity

24
Q

Where are 21a-hydroxylase found in the Adrenal Cortex? What is its gene code

A

CYP21A2

Z. Fasciculata and Z.Glomerulosa

25
Q

Where are 11 hydroxylase found in the Adrenal Cortex? What is its gene code

A

CYP11B1/CYP11B2

Z. Fasciculata and Z.Glomerulosa

26
Q

Where are 17a-hydroxylase found in the Adrenal Cortex? What is its gene code

A

CYP17

Z.Fasciculata and Z.Reticularis

27
Q

Where are Aldosterone Synthase found in the Adrenal Cortex? What is its gene code

A

CYP11B2

ZGlomerulosa

28
Q

Where are Desmolase/P450scc found in the Adrenal Cortex? What is its gene code

A

CYP11A1

All

29
Q

What is the major cell type found in the adrenal medulla?

A

Chromaffin cells (Pheochromocytes)

30
Q

What causes Epi/NE release from the adrenal medulla?

A

Sympathetic nerve stimulation (ACh)

31
Q

What innervates the adrenal medulla?

A

Splanchnic nerve

32
Q

Where is epinephrine synthesized?

A

Only in the adrenal medulla

33
Q

When is epinephrine release?

A

As response to acute stress

Rapid activation and rapid return

34
Q

How do peripheral nerves release NE

A

Convert dopamine to norepinephrine

35
Q

What does cortisol do in the adrenal medulla?

A

Stimulate conversion of NE to epinephrine (only in adrenal medulla)

36
Q

What are the physiological effects of Epi?

A

Act through adrenergic receptors (a and B)
Arousal: pupil dilation, sweating, GI and bronchial muscle relaxation
Metabolic: glucose release, inc metabolic rate
CV: vasoconstriction, tachycardia

37
Q

What are the 3 main targets for the metabolic effects of Epinephrine?

A

Muscle:Increase glycogenolysis, dec glucose uptake
Fat: inc lipolysis, dec glucose uptake
Liver: inc gycogenolysis, inc gluconeogenesis,inc glucose release, inc ketogenesis

38
Q

How does epinephrine affect pancreatic hormone secretio?

A

decrease insulin

increase glucagon

39
Q

How do cortisol and Epi work together to deal with a stress response?

A

Cortisol: CRH ->Pituitary->ACTH ->Adrenal Cortex -> Cortisol
Epi: Sympathetic neurons in hypothalamus -> spinal cord-> adrenal medulla -> epinephrine

Result: Increase energy mobilization and redistribution, cardiovascular response inc, arousal, behavioral activaiton, aggression

40
Q

How are catecholeamines metabolized?

A

Short half life

Degraded by COMT or MAO to produce VMA which is excreted in urine

41
Q

How can VMA levels be clnically useful?

A

Metabolic byproduct of catecholeamines

Detect tumors producing excess Epi/NE

42
Q

What are pheochromocytomas?

A

The 10% tumor

Tumors of chromaffin cells leading to catecholeamine overproduction

43
Q

What are the symptoms of pheochromocytomas? How is it treated?

A

HTN wihtout response to medication
Headaches
Tachycardia

Treatment: surgery and alpha/beta blockers pre surgery

44
Q

Where are the pheochromocytomas found?

A

Extra-adrenal sites (10%): Sympathetic nerve chain, distal aorta, ureter, urinary bladder

Adrenal Glands (90%)

45
Q

Why are pheochromocytomas called the 10% tumor?

A 
10% are:
Malignant
Bilateral
In children
Familial
Recur
MEN Syndrome
Stroke presented with
Extraadrenal

FHB Endocrinology (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions