Endocrine

Question 1

Up-regulation

Answer 1

increase in the number of receptors on/within a cell, allows more hormone molecules to bind receptors on target tissues. Usually occurs when hormone levels are low

Question 2

Downregulation

Answer 2

decrease in number of receptors on/within a cell. Usually occurs when hormone levels are high.

Question 3

Negative Feedback Mechanims

Answer 3

some glands respond to hormonal stimuli. thus, a negative feedback mechanism serves to turn up or turn down secretion.
Homeostasis is maintained by the negative feedback mechanism.
- Endocrine tissue (A) increases secretion of a hormone in response to stimulus
- Hormone circulates in the blood to produce effects on target tissue; hormone also binds to receptors on A which decrease secretion of hormone

Question 4

Cascade effect of hormone release from the hypothalamus to the pituitary gland to other endocrine gland to tissues.

Answer 4

• hypothalamus secretes hormone A into pituitary portal vessel
• hormone A stimulates cells in pituitary gland to secrete hormone B into circulation
• hormone B stimulates target tissue to secrete hormone C into the blood
• Hormone C stimulates target tissues and has inhibitory effects on hypothalamus and pituitary gland, decreasing A and B

Question 5

Hormonal Stimuli - Thyroid Hormone

Answer 5

• hypothalamus secretes thyroid releasing hormone (TRH)
• TRH stimulates pituitary glad to secrete thyroid stimulating hormone (TSH)
• TSH stimulates thyroid gland to secrete thyroid hormones
• Thyroid hormones affect many tissues in the body and inhibit the release of TRH and TSH

Question 6

Growth hormone: over-or under-production

Answer 6

hyposecretion: dwarfism, reduced muscle mass. (treated with GH replacement therapy)
hypersecretion: gigantism. Acromegaly (enlargement of facial bones). treated with GH receptor antagonists.

Question 7

Antidiuretic Hormone (ADH) over-or under-production:

Answer 7

Hyposecretion: Diabetes insipidus. large volumes of dilute urine.
hypersecretion: SIADH

Question 8

Thyroid hormone over-or under-production

Answer 8

• hypersecretion: graves disease

- Hyposecretion: myxedema

Question 9

Corticosteroids over-or under-production

Answer 9

• hyper: cushings syndrome

- hypo: addisons (aldosterone)

Question 10

Estrogen over-or under-production

Answer 10

• hypo: menstrual and metabolic dysfunction

Question 11

Progesterone over-or under-production

Answer 11

hypo: dysfunctional uterine bleeding

Question 12

Testosterone over-or under-production

Answer 12

• Hyposecretion: hypogonadism

Question 13

Parathyroid hormone over-or under-production

Answer 13

hyposecretion: hypoparathyroidism. Hypersecretion: hyperparathyroidism.

Question 14

Side effects of high doses of vasopressin.

Answer 14

• vasopressin is identical to ADH
• replacement therapy for patients with diabetes insipidus
• side effects: hypertension
• monitor I&O, VS, labs tests, signs of FVE, urine osmolality