Hypothalamopituitary axis & Adrenal

Question 1

What are the three classes of hormones?

Answer 1

• Amines
• Steroids
• Peptides

Question 2

What are the three layers of the adrenal cortex?

Answer 2

outside: zona glomerulosa
middle: zona fasciculata
inner: zona reticularis

Question 3

What hormone is secreted by the zona glomuerulosa?

Answer 3

aldosterone

Question 4

What hormones are secreted by the zona fasciculata?

Answer 4

cortisol and androgens

Question 5

What hormones are secreted by the adrenal medulla?

Answer 5

epinephrine, norepinephrine

Question 6

A steroid secreting cell would be dominated by:

A. Granular endoplasmic reticulum

B. Agranular endoplasmic reticulum

Answer 6

B. Agranular endoplasmic reticulum (granules are for making proteins; steroids are lipids)

Question 7

Steroid hormones are all derivatives of ______.

Answer 7

cholesterol

Question 8

What stimulates cholesterol desmolase?

Answer 8

ACTH

Question 9

Steroid hormones have a direct action on a cytosolic or nuclear receptor that controls gene transcription.

T/F

Answer 9

True

Question 10

Cortisol and growth hormone are both released in a pulsatile fashion throughout the day.

T/F

Answer 10

True

Question 11

The lowest secretory rate for cortisol occurs:

A. Late morning

B. Afternoon

C. Late evening/early morning

Answer 11

C. Late evening/early morning

Question 12

Which of the following is NOT an action of the glucocorticoids?

A. Stimulation of gluconeogenesis

B. Anti-inflammatory effects

C. Suppression of immune system

D. Stimulus for bone formation

E. Maintain vascular responsiveness to catecholamines

Answer 12

D. Stimulus for bone formation

Question 13

Biosynthesis of the mineralocorticoid, aldosterone depends, in part, on secretion of ACTH.

T/F

Answer 13

True

Question 14

What is the difference between Cushing syndrome and Cushing disease?

Answer 14

• Primary adrenal tumor -> excess cortisol = Cushing’s syndrome (↓ACTH)
• Secondary pituitary tumor -> excess ACTH = Cushing’s disease

Question 15

What is released from the SON?

Answer 15

ADH

Question 16

What is released from the PVN?

Answer 16

oxytocin

Question 17

Both the posterior and anterior pituitary have neuronal connection to the hypothalamus through the infundibulum.

T/F

Answer 17

FALSE. Hypothalamus only sends neurons down through to the posterior pituitary. Hormonal communication between hypothalamus and anterior pituitary is via an unusual blood vessel connection. The capillaries at the base of the hypothalamus (median eminence) join to form the hypothalamo-pituitary portal vessels.

•These vessels pass down the infundibulum to the anterior pituitary where they drain into a second capillary bed.

Question 18

Is there any cell that is NOT responsive to cortisol?

Answer 18

No.

Question 19

What stimulates the release of growth hormone?

Answer 19

GHRH from hypothalamus

Question 20

What effect does growth hormone have?

Answer 20

Liver: secrete IGF-1

Many cells: protein synthesis, carbohydrate and lipid metabolism

Question 21

What inhibits the release of growth hormone?

Answer 21

somatostatin

Question 22

Growth hormone directly stimulates growth.

T/F

Answer 22

False. Growth is mediated through mitogens (like somatomedin, IGF-1, secreted by liver)

Mitogen = chemical stimulating cell division

Question 23

Anti-insulin hormones (Glucose counter-regulatory hormones):

Answer 23

“Gang of Five”

1. Glucagon
2. Cortisol
3. Epinephrine
4. Thyroid hormones
5. Growth hormone

Question 24

Prediction: Obesity will retard growth.

T/F? Why or why not?

Answer 24

True. Decreases GH secretion

Question 25

What is the target of IGF-1 (somatomedin) in bone?

Answer 25

chondrocytes and osteocytes

Question 26

Prepubescent excess of GH hormone results in what condition?

Answer 26

gigantism

Question 27

Postpubescent excess of GH hormone results in what condition?

Answer 27

acromegaly

Question 28

Lack of GH results in what condition?

Answer 28

pituitary dwarfism