16.3: Hormones and the regulation of blood glucose conc.

Question 1

Hormones differ from each other chemically but have certain characteristics in common
3

Answer 1

• produced in glands, which secrete them directly into the blood
• carried in the blood plasma to target cells which have specific receptors
• effective in very low concs. but often have widespread and long-lasting effects

Question 2

Second messenger model

Answer 2

mechanism of hormone action

Question 3

Pancreas

Answer 3

large, pale-coloured gland which is situated in the upper abdomen behind the stomach, produces enzymes and hormones

Question 4

Pancreas is made up of

Answer 4

mainly cells that produces its digestive enzyme

and islets of Langerhans

Question 5

Islets of Langerhans

Answer 5

hormone producing cells

Question 6

Islets of Langerhans types

2

Answer 6

beta cells: smaller and produce insulin

alpha cells: larger and produce glucagon

Question 7

Liver

Answer 7

Located below the pancreas, made up of cells called hepatocytes and has a mass of 1.5kg

Question 8

Where do the effects of insulin and glucagon produced by the pancreas happen?

Answer 8

the liver

Question 9

Processes that occur in the liver in regulating blood glucose
3

Answer 9

glycogenesis
glycogenolysis
gluconeogenesis

Question 10

Glycogenesis

Answer 10

Conversion of glucose into glycogen. When blood glucose conc. is higher than normal this occurs.

Question 11

Glycogenolysis

Answer 11

Breakdown of glycogen to glucose. When blood glucose conc. is lower than normal this occurs.

Question 12

Gluconeogenesis

Answer 12

Production of glucose from sources other than carbohydrate

Question 13

What can the liver produce glucose from

Answer 13

non-carbohydrate sources:

glycerol, amino acids when its glycogen supply is exhausted

Question 14

Sources blood glucose comes from

3

Answer 14

1. directly from the diet, glucose from hydrolysis of carbohydrates
2. from glycogenolysis, hydrolysis of glycogen in the SI which is stored in liver and muscle cells
3. from gluconeogenesis, which is the production of glucose from sources other than carbohydrate

Question 15

Main hormones in regulating blood glucose concs.

3

Answer 15

insulin, glucagon and adrenaline