The hormonal system and glands Flashcards
What is the main order of hormonal communication?
Stimulus-> Receptors-> Hormone-> Effectors-> Response
How do hormones trigger second messenger molecules (process)
1) hormone binds to the receptor, which activates an enzyme inside the cell membrane
2) This enzyme catalyses the production of a signalling molecule.
3) The signalling molecule ( 2nd messenger molecule) carries a chemical message, from receptors to other parts of the cell
4) second messenger then activates a cascade ( chain of reactions) inside the cell
How adrenaline triggers the release of the messenger molecule “cyclic AMP”
1) Hormone adrenaline is a first messenger molecule
2) It binds to specific receptors in the cell membrane, which activate an enzyme called ( adenylyl cyclase)
3) This enzyme catalyses the production of a second messenger molecule called Cyclic AMP ( which comes from ATP)
4) The signalling molecule cAMP activates a cascade.
where are the adrenal glands found
Just above the kidneys
What is the outer part of the adrenal gland called
Cortex
What is the inner part of the adrenal gland called
Medulla
What response are the cortex and medulla involved in
The response to stress
What type of hormones does the cortex secrete
and give 2 examples
- Cortex secrete steroid hormones
2 types of steroid hormones are:
1) Cortisol
2)Aldosterone - these provide both short and long term responses
what do steroid hormones released by the cortex do?
3 things
1) Stimulate the break down of protein and fats into glucose. This increases the amount of energy available so brain and muscles can respond to the situation
2) Increasing the uptake of Sodium and water ions by the kidney, which causes an increase in blood volume and blood pressure
3) Supress the immune system
What type of hormones does the medulla secrete?
and give 2 examples:
Catecholamine hormones ( modified amino acids)
1) Adrenaline
2) Noradrenaline
- these provide short term responses
What do catecholamine hormones do?
3 things
1) Increases heart rate and breathing rate
2) Causes cells to break down glycogen into glucose
3) Constricts blood vessels so blood is diverted to the brain and muscles.
where is the pancreas found
Below the stomach
What is the area of pancreas that contains endocrine tissue called?
Islets of Langerhans
^ they secrete hormones directly into the blood
What are the 2 types of cells islets of Langerhans are made up of
1) Alpha cells - secrete glucagon
2) Beta cells- secrete insulin
