M34: Endocrine System - Pancreas and Stress

Question 1

What cell produces hormones in the pancreas?

Answer 1

Pancreatic islets

Question 2

4 types of cells in a pancreatic islet and their functions

Answer 2

1. ALPHA CELLS (17%)
   - secrete GLUCAGON
2. BETA CELL (70%)
   - secrete INSULIN
3. DELTA CELLS (7%)
   - secrete SOMATOSTATIN
4. F CELL (6%)
   - secrete PANCREATIC POLYPEPTIDE

very vascular to provide blood supply to all these cells

Question 3

glucagon function

Answer 3

raise blood glucose levels
- targets liver: glycogen breakdown
- GLUCONEOGENESIS (liver waste byproducts turned into glucose)

Question 4

insulin function

Answer 4

lowers blood glucose levels
- increasing glucose uptake
- increased synthesis of glycogen
- increases triglyceride and pr- uptake

Question 5

somatostatin function

Answer 5

• inhibits secretion of insulin and glucagon (keeps glucose levels at status-quo)
• slows GI absorption of some nutrients
• inhibits pancreatic polypeptide

Question 6

pancreatic polypeptide function

Answer 6

• inhibits somatostatin
• inhibits gallbladder contraction
• inhibits secretion of pancreatic digestive enxymes
• released after fasting, exercise, when blood-glucose low
• inhibited by high blood-glucose levels and somatostatin

Question 7

regulation of low blood-glucose levels

Answer 7

hypoglycaemia
- GLUCAGON released from alpha cells
- acts on liver hepatocytes to convert glycogen to glucose (glycogenolysis) and form glucose from certain AAs
- glucose released
- hyperglycaemia will inhibit glucagon release

Question 8

regulation of high blood-glucose levels

Answer 8

hyperglycaemia
- INSULIN released by beta cells
- accelerates glucose uptake to cells, conversion of glucose to glycogen, synthesis of fatty acids and uptake of AA for pr- synthesis
- glucose levels lowered
- hypoglycaemia inhibits insulin

Question 9

7 effects of direct nerve pathways in acute stress response

Answer 9

1. increased HR and force of beat
2. vasoconstriction
3. vasodilation in heart, lungs, brain and skeletal muscles
4. glycogen -> glucose
5. sweating
6. decreased digestive activities
7. water retention and elevated blood pressure (helps deal with increased CO)

Question 10

When direct nerve pathways can’t trigger stress response, which structure is backup?

Answer 10

adrenal medulla releasing epinephrine and norepinephrine

Question 11

resistance reactions

Answer 11

keep stress response going for a longer period of time (not acute)
- work via hormones from hypothalamus and AP (CRH, GHRH, TRH)

Question 12

role of ACTH in stress response

Answer 12

• effects adrenal cortex, releases CORTISOL
• liberating fuels to make ATP
• reduce inflammation caused by stress

Question 13

role of hGH in stress response

Answer 13

• targets liver to increase lipolysis and glycogenolysis

Question 14

role of TSH in stress response

Answer 14

• targets thyroid, increases T3 and T4
• increased use of glucose to produce ATP

Question 15

gluconeogenesis

Answer 15

liver metabolic byproducts turned into glucose

Question 16

anabolic hormone

Answer 16

stimulates processes in body that help to “build things”
e.g. insulin - glycogen synthesis

Question 17

glycogenolysis

Answer 17

hepatocytes in liver converting glycogen into glucose

Question 18

What pathway is used to respond to acute stress?

Answer 18

Nervous
because it’s fastest

Question 19

What pancreatic islet cell produces somatostatin

Answer 19

delta cells

Question 20

What pancreatic islet cell produces insulin

Answer 20

beta cells

Question 21

What pancreatic islet cell produces glucagon

Answer 21

alpha cells

Question 22

What pancreatic islet cell produces pancreatic polypeptide

Answer 22

F cells