Endocrine Monday, Wk2

T/F: The same ligands may trigger different responses.

T

Hormone Z travels through the _______ while paracrine Z travels through the ______ even though the receptors on these different cells are exactly the same.

blood; interstitium

The hormone testosterone in the blood stimulate _________ in muscles.

protein synthesis

The paracrine testosterone in the testes are released by the ______ cells and stimulate _______ to begin the process of ________.

leydig; Type A Dark spermatogonia; spermatogenesis

Ligands targets its receptors known as the "_____________" called the induced fit model.

"lock and key"

T/F: Some ligands can bind more than one hormone.

T

Mineralcorticoids (MR receptors) are designed for ________ but also bind to _______ with equal affinity.

aldosterone; cortisol

_______ and _______ causes reabsorption of salt and water, and excretes _______ and _______.

vasopressin and aldosterone; K+ and H+

What is the function of the enzyme, 11 beta-hydroxysteroid dehydrogenase type 2 (11 B-HSD2)?

converts cortisol into cortisone in the kidney

Cortisone, unlike cortisol can't bind well to MR receptors, so that means no ________.

hypertension

Overproduction of cortisol is the main indicator for what condition?

Cushing's syndrome

T/F: Cushing syndrome poses a real problem for 11bHSD2.

T

Patients with hypercortisolism (Cushing' syndrome) can present with signs and symptoms of what?

hyperaldosteronism

Hypernatremia (salty blood) immediately causes the release of _______ to reabsorb free water and match the resorption of sodium.

ADH (vasopressin)

Over secretion of both aldosterone and cortisol allows for too much salt to enter the bloodstream, therefore the patient will become....

hypertensive

Angiotensin II binds to ________ cells in the zona glomerulosa to release _______.

glomerulosa; aldosterone

Adrenocorticotropic hormone (ACTH) binds to _______ cells to release _______.

fasciculata; cortisol

ACTH binds to ______ cells to stimulate the release of _________.

reticularis; dehydroepiandrosterone (DHEA)

Angiotensin II binds to _______ cells to stimulate the release of _________.

chromaffin; catecholamines

What is the job of corticotropin releasing hormone?

to stimulate corticotroph cells to release ACTH

T/F: High levels of cortisol negatively feedback upon (turn off) CRH production and ACTH production.

T

The placenta is made of two components. What are they?

maternal and fetal

What are three functions of the placenta?

1. protection of the baby

2. filters mom's blood from baby's blood

3. secretes all kinds of hormones

How does an increase in fetal cortisol affect parturition?

1. helps the lungs mature

2. helps the GI tract mature

3. stimulates myometrial contractions

4. blocks the effects of progesterone

Does cortisol drive a positive or negative feedback cycle the placenta?

positive

DHEA can be converted to _______ in week 36.

estrogen

What two types of prostaglandin initiate parturition?

PGE2 and PGF2-alpha