Lecture 1

Question 1

4 functions/roles of the endocrine system

Answer 1

homeostasis internal environment
energy metabolism
growth (hormone)
Reproduction and development

Question 2

endocrine system consists of

Answer 2

ENDOCRINE GLAND CELLS that secrete
HORMONES chemical messengers, which are
carried in the bloodstream to
RECEPTOR and 
TARGET CELL upon which they act

Question 3

6 main endocrine glands

Answer 3

hypothalamus
pituitary gland
thyroid gland
parathyroid glands
adrenal glands
pancreas

Question 4

what are hormones

Answer 4

CHEMICAL MESSENGERS produced in
ONE LOCATION and transported to
SECOND LOCATION (TARGET CELLS) which causes a
RESPONSE in those cells

Question 5

chemical classification of water soluble hormones

Answer 5

peptides (75% of hormones)

Catacholamines (adrenaline, noradrenaline)

Question 6

chemical classification of fat soluble hormones

Answer 6

steroids

thyroid hormones

Question 7

storage water soluble

Answer 7

made and stored until required

Question 8

storage fat soluble

Answer 8

steroids- not stored - made from cholesterol as required

thyroid hormones- stored until required

Question 9

transport water soluble

Answer 9

diffused in the blood

Question 10

transport fat soluble

Answer 10

travel in the blood bound to carrier protein

Question 11

receptors water soluble

Answer 11

on the cell surface

Question 12

receptors fat soluble

Answer 12

intracellular receptors (cytoplasm or nucleus)

Question 13

mechanism of action water soluble

Answer 13

via 2nd messengers

Question 14

mechanism of action fat soluble

Answer 14

alter gene transcription

Question 15

speed of response water soluble

Answer 15

very fast milliseconds to minutes

Question 16

speed of response fat soluble

Answer 16

very slow hours days

Question 17

cellular response to water soluble hormones

Answer 17

1. hormone binds to cell surface receptor
2. allows activation of associated G protein
3. G protein activates adenylyl cyclase
4. 2nd messenger production cyclic AMP
5. cAMP activates protein kinase
6. protein kinase activates specific enzyme
7. enzyme converts specific substrate to product (cell’s specific response

Question 18

cellular response to fat soluble hormones

Answer 18

1. lipid soluble hormone dissociates from carrier protein
2. hormone diffuses across cell membrane
3. hormone binds to intracellular receptor
4. hormone receptor complexspecific transcription factor
5. new mRNA is generated
6. new protein is generated by translation of mRNA
7. new protein mediates cell’s specific response (SLOW)