lecture 19: endocrine sys

Question 1

thyroid gland

Answer 1

butterfly-shaped
- located inferior to the thyroid cartilage of the larynx

Question 2

thyroid hormones

Answer 2

Follicular/T thyrocyte (T3&T4)
- O2 use and basal metabolic rate
- cellular metabolism
- growth and development

Parafollicular/C thyrocyte (Calcitonin)
- regulates calcium homeostasis

Question 3

parathyroid glands

Answer 3

• 4 pea sized glands embedded in the posterior surface of the thyroid gland

Question 4

parathyroid hormone

Answer 4

PTH*

1. regulates calcium homeostasis
2. promote formation of the hormone calcitriol, the active form of vitamin D

Question 5

calcium homeostasis feedback loop

Answer 5

1. if calcium level rises above set point
2. thyroid gland releases calcitonin
3. blood calcium levels fall
4. if calcium is too low
5. parathyroid glands release parathyroid hormone (PTH)
6. blood calcium level rises

Question 6

calcitonin

Answer 6

depositing more calcium in bone

DECREASES the level of calcium in blood
opposite to PTH

Question 7

PTH

Answer 7

releasing more calcium from bone

Question 8

supra = (adrenal glands)

Answer 8

above

Question 9

renal = (adrenal glands)

Answer 9

kidney

Question 10

right = (adrenal glands)

Answer 10

pyramidal

Question 11

left = (adrenal glands)

Answer 11

semilunar

Question 12

adrenal cortex

Answer 12

3 zones:

zona glomerulosa
- produces mineralocorticoids
- ex. aldosterone

zona fasciculata
- produces glucocorticoids
- ex. cortisol

zona reticularis
- produces androgens
- involved in growth and puberty

*salt, sugar, sex

Question 13

adrenal medulla

Answer 13

chromaffin cells (type of cell makes neurohormones and releases them into the blood)
- under the control of the autonomic nervous system
- quick!

secrete catecholamines
- epinephrine
- norepinephrine

Question 14

pancreas

Answer 14

• endocrine and exocrine
• pancreatic exocrine cells: pancreatic acini
• pancreatic endocrine cells: pancreatic islets (islets of langerhans)
• “romance organ”

Question 15

islets of langerhans: alpha

Answer 15

secretes glucagon

Question 16

islets of langerhans: beta

Answer 16

secretes insulin

Question 17

islets of langerhans: delta

Answer 17

secretes somatostatin

somatostatin: inhibits the release of insulin and glucagon, and other thyroid-stim hormone