Hormone Regulation

Question 1

glucagon

Answer 1

response to low blood sugar levels

Question 2

Glycogenolysis

Answer 2

increases blood sugar levels by breaking down glycogen

Question 3

Insulin

Answer 3

response to high blood sugar levels, will clear the elevated blood sugar levels

low in fasting

Question 4

prolactin

Answer 4

secreted by the pituitary gland

Question 5

growth hormone

Answer 5

secreted by the pituitary gland

Question 6

aldosterone

Answer 6

water-preserving hormones, increased levels increases sodium reabsorption in the kidneys (good for low sodium levels, so it is salt-preserving)

low salt, high aldosterone

Question 7

ADH

Answer 7

water-preserving hormone. does not act on sodium reabsorption.

decreased ADH -> decreased fluid retention, pee more

increased ADH, increase fluid retention

Question 8

TRH and TSH

Answer 8

TRH from the hypothalamus, TSH released by the pituitary

Question 9

negative feedback

Answer 9

for thyroid hormone: more disrupted when the hypothalamus is knocked out, rather than the pituitary (see practice question)

Question 10

during starvation

Answer 10

insulin levels are decreased, glucagon is increased, and gluconeogenesis is increased

Question 11

ghrelin

Answer 11

increases with hunger (fasting) – this is the sensation of hunger

“ghrrrr - I’m hungry!”

Question 12

leptin

Answer 12

decreases with hunger – this is the feeling of fullness

“I’m full-lep.”

leptin levels rarely change because they’re based on the amount of adipose in the body

Question 13

adipose tissue

Answer 13

stores triglycerides

Question 14

absorptive state

Answer 14

storing energy

Question 15

post-absorptive state

Answer 15

liver - glycogen broken down to glucose, exported all over the body
amino acids - taken by the liver, converted to keto-acids and give off ammonia as urea, to make glucose, exported all over the body
fatty acids - broken down to ketones (can be used by the brain)

Question 16

insulin

Answer 16

decreases blood sugar levels by storing glucose

insulin causes storage

• produces glycogen (glycogenesis - reversible)
• fat storage (lipogenesis - irreversible)
• glycolysis (breakdown of glucose into pyruvate - irreversible)

“in”storage”ulin - the In”

inhibits the release of glucagon

Question 17

glucagon

Answer 17

“glucagon releases”

release sugar from storage when blood sugar is low

[glc] increases

by glycogenolysis (glycogen), gluconeogenesis (amino acid), ketogenesis (fatty acids)

Question 18

how are amino acids converted to glucose?

Answer 18

gluconeogenesis

Question 19

how are fatty acids converted to glucose?

Answer 19

ketogenesis to form ketone bodies (last resort, used only by the heart and brain!)

irreversible

Question 20

type 1 diabetes

Answer 20

no insulin is released

Question 21

type 2 diabetes

Answer 21

cells are resistant to insulin

Question 22

how does the pancreas receive nutrients from the small intenstines?

Answer 22

portal venous system, triggers a hormonal release

Question 23

beta and alpha cells in the pancreas

Answer 23

beta releases insulin
alpha releases glucagon
pancreas is important for glucose metabolism

Question 24

channels in the pancreas (or…how the pancreas works)

Answer 24

potassium channel (allows the potassium to leave the cell via facilitated diffusion). there is more potassium outside the cell, which prevents the beta cell from becoming depolarized

calcium channel

glut 2 - allows glucose to enter the beta cell, where it is broken down and produces ATP, which blocks the potassium channel, creating a positive charge inside the cell, causing depolarization of the membrane of the cell, then increasing the calcium in the cell. the calcium binds to insulin which is released from the cell via exo cytosis to the portal venous, which leads to the liver