blood sugar

Question 1

what is the role of the liver in regulating blood sugar levels

Answer 1

converts Glucose to glycogen for storage in liver and muscle cells (when blood sugar level is high)

converts Glycogen to glucose for release into the blood (when blood sugar level is low)

Question 2

what things may occur to the glucose which is carried to the liver

Answer 2

1. Glucose can be removed from the blood by the liver to provide energy for the liver functioning
2. It may be removed by the liver or muscles and converted into glycogen for storage.
3. It may continue to circulate in the blood where it is available for body cells to absorb and use as a source of energy – protein synthesis
4. Glucose in excess of that required to maintain both normal blood sugar level and tissue glycogen level is converted to fat for long term storage

Question 3

what is glycogenesis

Answer 3

glucose molecules are combined in long chains to form glycogen

stimulated by insulin (pancreas)

Question 4

what is glycogenolysis

Answer 4

breakdown of glycogen to glucose to be used by cells

stimulated by glucagon (pancreas)

Question 5

what is gluconeogenesis

Answer 5

conversion of fats of proteins to glucose

stimulated by glucagon

Question 6

explain the role of the pancreas in regulating blood sugar levels

Answer 6

within the pancreas are clusters of hormone secreting glands cells islets of Langerhans

each is made up of 2 types of cells:

1. alpha cells – secretes glucagon
2. beta cells – secretes insulin

Question 7

explain the role of insulin in regulating blood sugar levels

Answer 7

insulin: cause decrease in blood sugar by

increasing uptake of glucose from blood into body cells

increases conversion of glucose into glycogen through glycogenesis

stimulates conversion of glucose into fat in adipose tissue

cause an increase in protein synthesis in some cells

Question 8

explain the role of glucagon in regulating blood sugar levels

Answer 8

glucagon: cause increase in blood sugar by

stimulating glycogenolysis – converting glycogen back to glucose

stimulating liver to produce new sugar molecules from fats and amino acids – gluconeogenesis

Question 9

what 2 components are the adrenal glands composed of

Answer 9

adrenal cortex

adrenal medulla

Question 10

explain the role of the adrenal cortex in regulating blood sugar levels

Answer 10

secretes glucocorticoids e.g. cortisol

stimulated by adrenocorticotrophic hormone (ACTH) from anterior pituitary

stimulates conversion of glycogen to glucose

increase rate of amino acids being removed from cells and taken to liver

promote utilisation of fatty acids from adipose tissue, allowing muscles to use fatty acids first over glucose

Question 11

explain the role of the adrenal medulla in regulating blood sugar levels

Answer 11

secretes adrenaline and noradrenaline

increase in blood sugar levels by stimulating production of lactic acid from glycogen in muscle cells, which can be manufactured by liver for production of glucose

this counteracts effects of insulin