T3 Adrenal Hormones

Question 1

What does the medulla secrete?

Answer 1

epinephrine and norepinephrine

Question 2

The medulla is functionally related to the _______ nervous system.

Answer 2

sympathetic

Question 3

What does the cortex secrete?

Answer 3

corticosteroids

Question 4

What are corticosteroids synthesized from?

Answer 4

cholesterol

Question 5

The synthesis of corticosteroids synthesized from cholesterol is provided mainly by _______ in the plasma, mostly attached to coated pits

Answer 5

LDLs

Question 6

_______ increases the number of LDL receptors.

Answer 6

ACTH

Question 7

Where is cholesterol converted to pregnenolone?

Answer 7

mitochondria

Question 8

Conversion of cholesterol to pregnenolone is catalyzed by what? What is significant about this step?

Answer 8

cholesterol desmolase; rate limiting step

Question 9

Both ACTH and _______ increase the conversion of cholesterol to pregnenolone.

Answer 9

angiotensin II

Question 10

Progesterone can be converted to what?

Answer 10

deoxycorticosterone, which is then converted to aldosterone. Also can be converted to cortisol

Question 11

What is the major mineralocorticoid? What’s its half-life?

Answer 11

aldosterone; 20 minutes

Question 12

Hyperkalemia has what effects?

Answer 12

aldosterone secretion

Question 13

What substance increases sodium reabsorption by kidney tubules?

Answer 13

mineralocorticoids

Question 14

Aldosterone increase ___________ secretion by kidneys, by acting on __________ in _________.

Answer 14

potassium; principle cells; late distal tubules

Question 15

Aldosterone increase ___________ secretion by kidneys, by acting on __________ in _________.

Answer 15

hydrogen ion; intercalated cells; late distal tubules

Question 16

What is secretion of mineralocorticoids controlled by?

Answer 16

angiotensin II and K+

Question 17

What are mineralocorticoids secreted by?

Answer 17

zona glomerulosa

Question 18

What is the major glucocorticoid?

Answer 18

cortisol

Question 19

What is essential in the stress response?

Answer 19

cortisol

Question 20

What is cortisol secretion controlled by?

Answer 20

ACTH from anterior pituitary

Question 21

What are glucocorticoids secreted from?

Answer 21

zona fasciclutata

Question 22

Cortisol has a ______ feedback response to both CRH and ACTH.

Answer 22

negative

Question 23

Cortisol oscillates with circadian rhythm. When is it highest? when is it lowest?

Answer 23

highest = before wakeing
lowest = in evening

Question 24

What are the precursors to estrogens?

Answer 24

DHEA and androstenedione

Question 25

Where is DHEA converted to testosterone?

Answer 25

in the testes

Question 26

What is the outcome of a lack of aldosterone?

Answer 26

- total loss causes death in days - total ECF and blood volume reduced - diminished CO and progresses to shock-like state - hyperkalemia and serious cardiac toxicity follow

Question 27

What is the outcome of a excess of aldosterone?

Answer 27

- increase ECF and arterial pressure - hypokalemia and muscle weakness - causes alkalosis - Small effect on plasma sodium concentration because sodium reabsorption in renal tubules is accompanied by equivalent amount of water reabsorption

Question 28

What is the overall effect of aldosterone?

Answer 28

increases renal tubular reabsorption of sodium and increases potassium in the urine

Question 29

What are the functions of glucocorticoids

Answer 29

``` Stimulate gluconeogenesis by: -increase protein catabolism -mobilizes aa -enhances transport of aa into hepatic cells -increase enz req to convert aa to glucose -decrease glucose utilization by cells -increase lipolysis May lead to adrenal diabetes Resists stress Resists inflammation Causes resolution of inflammation Inhibits immune response Maintains vascular response to catecholamines ```

Question 30

What are catecholamines?

Answer 30

norepi and epi

Question 31

What is primary Addison's disease caused by?

Answer 31

injury to adrenal cortex

Question 32

What is secondary Addison's disease caused by?

Answer 32

impaired function of pituitary gland

Question 33

What are some disturbances of hypoadrenalism/addisons?

Answer 33

Due to mineralocorticoid deficiency, due to glucocorticoid deficiency, and melanin pigmentation

Question 34

What are symptoms of mineralocorticoid deficiency?

Answer 34

- decreased EC volume - hyponatremia - hyperkalemia - mild acidosis - rise in RBC concentration - decrease in CO and BP - metabolic acidosis - death from shock

Question 35

What are symptoms of glucocorticoid deficiency?

Answer 35

- hypoglycemia - weight loss, nausea, vomiting - muscle weakness - highly susceptible to stress - reduction in both proteins and fats leading to depression of other bodily functions

Question 36

What are symptoms of melanin pigmentation?

Answer 36

- may be caused by loss of negative feedback to pituitary, allowing increased amounts of MSH - results in uneven distribution of pigmentation, esp in thin skin areas

Question 37

What are the causes of Cushings/hyperadrenalism

Answer 37

- administration of glucocorticoids - adenomas of ant pituitary - abnormal function of hypothalamus - ectopoc secretion of ACTH by tumor - adenomas of adrenal cortex - excess ACTH secretion is cause of Cushing's

Question 38

What are the characteristics of Cushing's?

Answer 38

- increase in cortisol and androgen levels - "buffalo torso" - moon face - acne and hirsutism - hypertension - increased blood glucose - increase in protein catabolism and muscle wasting