pancreas - insulin and glucagon

Question 1

pancreas location

Answer 1

in the abdominal cavity (head and neck in the c-shaped curve of the duodenum and the body extends behind the stomach.

Question 2

exocrine gland of the pancreas

Answer 2

secretes digestive enzymes

Question 3

endocrine gland of the pancreas

Answer 3

pancreatic islets - 2% of mass
made of beta cells that produce insulin and
alpha cells that produce glucagon

Question 4

blood glucose concentration

Answer 4

must be maintained high enough at all times for normal functioning. 3.5-6 mmolL
the brain must be suppled wiht glucose at all times, as glucose is the only fuel that the brain uses.
blood glucose concentration changes throughout the day as we use fuel continuously but we eat intermediately

Question 5

the fed state

Answer 5

we have just eaten, usually more glucose uptake than what we need at that time
cellular uptake of nutrients and anabolic metabolism. (synthesis of glycogen, protein and fat)

Question 6

the fasting state

Answer 6

haven’t eaten in a while mobilisation of nutrients and catabolic metabolism (breakdown of glycogen, protein and fat)

Question 7

how is blood glucose concentration regulated?

Answer 7

Hormonal regulation

insulin and glucagon maintain blood glucose concentration between 3.5-6 mmoL-1

Question 8

Insulin

Answer 8

regulates fuel storage
secreted by BETA cells and secreted into the blood stream.
beta cells are the sensor and the integrator
insulin is the only hormone that can decrease the blood glucose concentration
insulin is a peptide hormone
target cells have membrane receptors
liver is a big glycogen and fat storage
muscle is more for protein storage and glycogen and protein synthesis

Question 9

type I diabetes mellitus symptoms

Answer 9

high blood glucose (hyperglycaemia) 
glucose in urine (glycosuria) 
large urine volumes (polyuria)
thirst (polydipsia) 
hunger
typically in younger children and teenagers

Question 10

type I diabetes mellitus causes

Answer 10

insulin producing beta cells have been destroyed (autoimmune disease) and insulin levels are low/ zero.
so there is too much glucose in the blood. there is no back up system as beta cells are the only cells in the body that produce insulin.

Question 11

type I diabetes mellitus treatment

Answer 11

insulin injections with regular testing of blood glucose concentrations

Question 12

type II diabetes mellitus causes

Answer 12

cells are resistant to insulins signal to store fuel e.g. there are fewer receptors so insulin level is also lowered
symptoms are the same as type I.
reduced number or functioning of the cells
altered intracellular signalling in the target cells.

Question 13

type II diabetes mellitus treatment

Answer 13

insulin injections, drugs promoting insulin release much as incretins.
research shows that life style changes - dietary changes of reduced fat and increased protein and more exercise can reduce hyperglycaemia for type II diabetics already on a drug treatment.

Question 14

complications of diabetes

Answer 14

over time hyperglycaemia damages many parts of the body
- atherosclerosis - can lead to stroke or heart attack
- kidney disease
- nerve damage
- retinal changes (blindness)
glucose changes the chemistry of cells, proteins will become damaged, small capillaries will become damaged

Question 15

Glucagon

Answer 15

regulates fuel release
pancreatic islet alpha cells secrete glucagon
alpha cells are the integrator and the sensor
target cells are the liver cells which increase the breakdown of glycogen, increase glucose synthesis and increase ketone synthesis
liver is main target as glucose is stored ay glycogen and fats in the liver
a peptide hormone target cells have membrane receptors
not the only hormone that can increase blood glucose concentration

Question 16

glycogenolysis

Answer 16

new glucose being made

Question 17

gluconeogenesis

Answer 17

new glucagon being made

Question 18

glycogen

Answer 18

stored form of glucose