Homeostasis P3 Flashcards
When does a negative feedback control system set off
When conditions change from the ideal or set point and return conditions to this set point
Negative feedback flowchart
Conditions in the body change from set point-> change detected-> corrective mechanisms activate-> conditions return to set point-> corrective mechanisms switched off -> repeat
What does thyroxine do?
Stimulates the basal metabolic rate. Controls the speed at which oxygen and food products react to release energy for the body to use. plays an important role in growth and development.
What are thyroxine level controlled by?
Negative feedback
What structures detect and control thyroxine level levels?
The hypothalamus and pituitary gland
What happens when there are low thyroxine levels in the bloodstream?
This stimulates the hypothalamus to release TRH causing the pituitary to release TSH so the thyroid releases more thyroxine
What happens with normal thyroxine levels?
Inhibits TRH release from hypothalamus and this inhibits release of TSH from pituitary so normal blood levels are maintained
Is adrenaline controlled by negative feedback?
No
What are the effects of adrenaline in the bloodstream
Increase breathing and heart rate and conversion of glycogen to glucose. Divert blood away from areas to the muscle muscles.
Why is glucose needed by cells
Respiration
What is insulin and what is its function?
It is a hormone produced by the pancreas that regulates glucose concentrations in the blood
What happens if blood glucose concentration is too high?
The pancreas produces insulin that causes glucose to move from blood into cells
What is access glucose converted into in the liver and muscle cells?
Glycogen
What happens if blood levels are low?
Glucagon is produced by the pancreas. This causes the glycogen stored in the liver and muscles to be converted back into glucose.
Diabetes
A condition where blood glucose levels remain too high
