Endocrine System

Question 1

Amino acid based hormones are known as what ?

Answer 1

Peptide hormones

• charged & cannot pass through membrane
• Effects quick but short lived
• Water soluble = travel through bloodstream freely
• in or -ine

Question 2

What are some common secondary messengers ?

Answer 2

cAMP, IP3 (inositol triphosphate), & Ca2+

Question 3

What type of hormones are derived from cholesterol and are produced mainly by the adrenal cortex & gonads ?

Answer 3

Steroid hormones

• Easily cross cell membrane
• Slower but longer lived effects (gene regulation)
• one, -ol, -oid

Question 4

Pairing of 2 receptor-hormone complexes is known as ?

Answer 4

Dimerization

Question 5

Amino acid hormones w/ some modifications are known as ?

Answer 5

Amino acid-derivative hormones

Question 6

The blood vessel system that connects the hypothalamus to the anterior pituitary is known as ?

Answer 6

Hypophyseal portal system

Question 7

What tropic hormones are released from the hypothalamus to the anterior pituitary, & which hormones are released from the AP as a result ?

Answer 7

GnRH---->FSH & LH
GHRH----->GH
TRH----->TSH
CRF----->ACTH
*PIF----->decreased prolactin secretion

Question 8

How does the hypothalamus interact with the posterior pituitary ?

Answer 8

Neurons in HT send axons down PP stalk directly into the PP

Question 9

What 2 hormones does the posterior pituitary store from the HT ?

Answer 9

Oxytocin: stimulates contractions of the uterine lining during labor, aids in milk production of mammary glands (lactation)
Antidiuretic hormone (vasopressin): reabsorption of H2O in collecting ducts of the kidneys

Question 10

The hormone that is released by the AP & is responsible for milk production in the mammary glands is known as ?

Answer 10

Prolactin

*release of dopamine (PIF) causes decreased secretion

Question 11

Hormones that decrease pain perception are known as ?

Answer 11

Endorphins (naturally occuring painkillers)

Question 12

Hormone that promotes the growth of bone & muscle is known as ?

Answer 12

GH

Question 13

What is ADH secreted in response to ?

Answer 13

Low blood volume or high blood osmolarity

*results in increased blood volume & pressure

Question 14

What are the 2 major functions of the thyroid ?

Answer 14

1. setting basal metabolic rate: mediated by T3 & T4 (iodination of amino acid tyrosine)
2. promoting Ca2+ homeostasis: calcitonin (decreases Ca2+ levels in plasma)

Question 15

A deficiency in iodine or inflammation of the thyroid may lead to what ?

Answer 15

Hypothyroidism

Question 16

What is the hormone produced by the parathyroid glands & what is its function ?

Answer 16

PTH functions as antagonist to calcitonin

• raises Ca2+ levels in plasma
• promotes phosphorous homeostasis
• activates vitamin D: required for absorption of Ca2+ & P in the gut

Question 17

What type of hormones does the adrenal cortex secrete ?

Answer 17

Corticosteroids

Question 18

What are the different type of corticosteroids ?

Answer 18

Glucocorticoids: regulate glucose levels (cortisol & cortisone)–>raise blood glucose by increasing gluconeogenesis & decreasing protein synthesis

Mineralocorticoids: regulate salt & H20 homeostasis (kidneys)
-aldosterone: increases Na+ reabsorption in distal convoluted tubule & collecting duct of nephron

Cortical sex hormones: androgens & estrogens

Question 19

Aldosterone is primarily under the control of which system ?

Answer 19

Renin-angiotensin-aldosterone:

1. Decreased BP—>juxtaglomerular cells secrete renin
2. Renin cleaves inactive angiotensinogen to active form—> angiotensin I
3. Ang I converted to ang II via enzyme (ACE) in lungs
4. Ang II—->adrenal cortex—-> aldosterone

Question 20

Which hormones are the adrenal medulla responsible for secreting ?

Answer 20

Epinephrine & norepinephrine

*Catecholamines

Question 21

Small clusters of hormone-producing cells in the pancreas are known as ?

Answer 21

islets of Langerhans:

alpha: glucagon: secreted when glucose levels are low
beta: insulin: secreted when glucose levels are high
delta: somatostatin: inhibits both glucagon & insulin secretion