Hormonal Communication Flashcards
What are steroid hormones?
Lipid soluble hormones. They diffuse into the cell through the phospholipid bilayer and bind with receptors in the cell. An example is oestrogen.
What are non steroid hormones?
They are non lipid soluble so instead bind to receptors on the cell surface membrane of target organs/cells. An example is insulin.
Where are adrenal glands located and what are they made of?
They are located on top of each kidney and are made up of the adrenal cortex, adrenal medulla and capsule (the outer layer).
What controls the adrenal cortex?
Hormones secreted by the pituitary gland.
What hormoes does the adrenal cortext secrete?
Cortisol (stress hormone that regulates metabolism of glucose, proteins and fats to release usable energy)
Aldosterone (regulating water balance in the blood. this has an impact on blood volume and pressure).
What is the adrenal medulla controlled by?
The Nervous SystemW
What is the effect of sympathetic nervous system stimulation on the adrenal medulla?
Release of adrenaline which increases heart rate and blood glucose concentration.
Release of Noradrenaline - increases heart rate, pupil dilation, widens airways in the lungs and narrows blood vessels to non-essential organs to create higher blood pressure.
What are the 3 actions of insulin?
1.attaches to receptors of target cells. Changes chape of channel proteins so more glucose is absorbed via facilitated diffusion.
2.more protein carriers are incorporated into cell membranes so more glucose absorbed from blood to cells.
3.Activating enzymes involved in the conversion of glucose to glycogen. This results in glycogenesis in the liver.
What hormone is secreted by alpha cells in the islets of langerhand?
Glucagon
What hormone is secreted by the beta cells in the islets of Langerhan?
Insulin
What are the 3 effects when glucagon is released?
- Attaching to receptors on target cells (liver cells). Binding causes a protein to be activated into adenylate cyclase and convert ATP in cAMP.
cAMP activates protein kinase that hydrolyses glycogen to glucose. This is the second messenger model.
2.Activating enzymes involved in conversion of glycerol and AA to glucose (gluconeogenesis).
What is the role of adrenaline as a secondary messanger model?
- Attaches to receptors on surfaces of target cells. G protein activated and converts ATP to cAMP.
2.cAMP activates an enzyme that can hydrolyse glycogen to glucose.
It’s called the secondary messenger model of adrenaline and glucagon action because the process results in cAMP, which acts as second messenger.
What are the 3 liver functions in relation to controlling blood glucose level?
1.Glycogenesis - converting glucose to glycogen. This in liver and due to enzymes present there.
2.Glycogenolysis - hydrolysis of glycogen to glucose. This occurs in the liver due to the secondary messenger model.
3.Gluconeogenesis - creating of glucose from other molecules like amino acids and glycerol in the liver.
What is type 1 diabetes?
Unable to produce insulin. Usually from childhood. Could be result of autoimmune disease where B cells attacked. Treatment involves insulin injections (via genetically modified bacteria).
What is type 2 diabetes?
Receptors to insulin on target cells lose responsiveness. Usually in adults due to obesity & poor diet. Controlled by regulating intake of carbs, increasing exercise and sometimes insulin injections (produced by genetically modified bacteria).
