171b - Intro to the Endocrine System: Physio, Pathophys

Question 1

Which hormone is secreted by the adrenal cortex in response to a decline in blood volume or blood pressure?

Answer 1

Aldosterone

-> Distal and collecting tubules reabsorb more Na+, H2O follows passively

Question 2

Which hormone ensures that our blood glucose levels are high enough to support brain activity?

Answer 2

Cortisol

(Technically, glucagon mobilizes energy stores to increase blood glucose, but cortisol send the alarm signal if the brain isn’t getting enough glucose?)

Question 3

Which hormone functions to increase blood calcium levels?

How?

Answer 3

Parathyroid hormone (PTH)

• Stimulates osteoclasts
• Decreases calcium excretion by the kidney
• Activates vitamin D -> Calcium absorption from GI

Question 4

Which hormone functions to lower serum Calcium?

How?

Answer 4

Calcitonin

• Slows the calcium-releasing activity of osteoclasts
• Increases calcium excretion by the kidney

Most active during childhood; excess in medullary cancer for adults (rare)

Question 5

Where in the cell are the receptors for steroid hormones?

Answer 5

Cytoplasm

Steroid hormones are lipid soluble and can cross the cell membrane

Question 6

In a patient with Graves’ disease (due to an antibody stimulating the TSH receptor), do you expect the following to be high, low, or normal?

• TSH:
• Free T4:
• T3:

Answer 6

• TSH: Low
• Free T4: High
• T3: High

High T3 and T4 feed back to inhibit TRH, resulting in low TSH

Question 7

Which two hormones are produced by the thyroid gland?

Answer 7

Thyroid hormone

Calcitonin

Question 8

Which of the following hormones is closest in structure to oxytocin?

a. Insulin
b. Prolactin
c. Vasopressin
d. Thyroxine
e. Estradiol

Answer 8

c. Vasopressin

Question 9

Which hormone acts most directly to increase blood glucose?

Which cells secrete it?

Answer 9

Glucagon

Alpha cells (in the Islets of Langerhans)

(Cortisol -> increased glucagon -> increased blood glucose)

Question 10

List 6 hormones produced by the anterior pituitary

What kind of hormones are these?

Answer 10

• Prolactin (PRL)
• Growth hormone (GH)
• Thyroid stimulating hormone (TSH)
• Adrenocorticotripic hormone (ACTH)
• Folicle stimulating hormone (FSH)
• Luteinizing hormone (LH)

All are peptide hormones

Question 11

What is the most common cause of hormone excess syndromes?

Answer 11

Benign adenoma that makes excess hormones

(Carcinomas are very rare)

Question 12

Which of the following conditions is most common in the U.S.?

a. Hyperparathyroidism
b. Type 2 diabetes mellitus
c. Obesity
d. Osteoporosis
f. Graves’ disease

Answer 12

c. Obesity

Question 13

What disease is caused by decreased vasopressin (ADH) secretion?

Answer 13

Central diabetes insipidus

Question 14

List 3 things secreted by the adrenal cortex

Answer 14

• Mineralocorticoids (aldosterone)
• Glucocorticoids (cortisol)
• Androgens

Question 15

Which hormone acts to lower blood glucose?

Which cells secrete it?

Answer 15

Insulin

Beta cells (in the Islets of Langerhans)

Question 16

Which of the following hormones is secreted in excess in a patient with Cushing’s disease?

a. ACTH
b. GH
c. TSH
d. Prolactin
e. Calcitonin

Answer 16

a. ACTH

Results in hypercortisolism

Question 17

List 2 hormones secreted by the adrenal medulla

Answer 17

• Epinephrine
• Norepinephrine

Question 18

Which amine hormones are derived from tyrosine?

Answer 18

Thyroid hormones

Catecholamines

Question 19

What is the major difference in the pathyphysiology of metabolic syndrome and type II diabetes?

Answer 19

Insulin resistance in both

• Metabolic syndrome
  
  • Beta cells produce enough insulin to compensate
  • -> Normoglycemia
• Type II Diabetes
  
  • Beta cells do not produce enough insulin to compensate
  • -> Hyperglycemia due to relative insulin deficiency

Question 20

Which hormone inhibits both glucagon and insulin?

Answer 20

Somatostatin

(Delta cells from the Islets of Langerhans)

Question 21

Which hormone increases the basal metabolic rate?

Answer 21

Thyroid hormone

Question 22

List 2 hormones secreted by the posterior pituitary gland

Answer 22

• Arginine-vasopressin aka Anti-Diuretic Hormone (ADH)
• Oxytocin