Q5: Hormones + blood glucose, insulin, gluconeogenesis Flashcards
The regulation of blood glucose
is an example of
how different hormones interact in achieving homeostasis
Where are hormones produced?
glands
Glands that secrete hormones directly into the blood
endocrine glands
How are hormones carried?
in the blood plasma
Target cells of hormones
cells on which they act which have specific receptors on their cell-surface membranes that are complementary to a specific hormone
Hormones length of effect
can be effective in very low concentrations
but often have long-lasting and widespread effects
Second messenger model
mechanism of hormone action in regulation of blood glucose involving adrenaline and glucagon
Pancreas
large, pale gland which is situated in the upper abdomen, behind the stomach.
Islets of Langerhans
Hormone producing cells
Pancreas is made up of
cells that produces its digestive enzymes
Islets of Langerhans cells
2
alpha cells
beta cells
Alpha islets of Langerhans cells
larger and produce glucagon
Beta islets of Langerhans cells
smaller and produce insulin
Liver made up of
cells called hepatocytes
Where are hormones such as insulin and glucagon produced?
and where do they have their effects?
produced in the pancreas
effects in the liver
Glycogenesis
conversion of glucose into glycogen
Glycogenolysis
breakdown of glycogen into glucose
Gluconeogenesis
MUST KNOW FOR EXAM!
production of glucose from sources other than carbohydrate
When the liver supply of glycogen is exhausted but blood glucose concentrations need to increase what happens?
gluconeogenesis
What can the liver produce glucose from other than carbohydrates during gluconeogenesis
non-carbohydrates sources such as glycerol and amino acids
Glucose is a substrate for…
respiration
What happens if glucose concentration falls too low?
cells will be deprived of energy and die
What happens if glucose concentration rises too high?
lowers the water potential of the blood and creates osmotic problems which can cause dehydration and be dangerous
Homeostatic control of blood glucose is…
essential
