Adrenaline And Thyroxine Flashcards
What is negative feedback?
A homoestatic mechanism that occurs when the body detects a change and makes an udjustment to return itself to normal
What happens if thyroxine levels are too high?
The brain, (a coordination centre) designed to maintain ideal thyroxine levels, will detect this change and would send this signal via a motor neurone to a pitutary gland, which is an effector
The pituatary gland releases less thyroxine stimulating hormone (TSH)
This hormone acts directly on the thyroid gland, less of this hormone means less thyroxine is released.
Where is the thyroid gland located?
In the neck
What is thyroxine?
A chemical that is linked very directly to your metabolic rate
What does less thyroxine mean?
Lower metabolism
Lower levels of protein synthesis
What is needed ti make thyroxine?
Iodine, along with some amino acids
Where does iodine come from?
Sources such as oily fish
What happens if thyroxine levels are too low?
The opposite that would happen if thyroxine levels were too high
What do you get when iodine levels are too low so the pituatary gland constantly increases thyroxine stimulating hormone?
The thyroid gland swells up, getting a condition called goiter, a mineral deficiency condition
What is adrenaline?
A hormone that is released when there is stress or a scary situation occurs
How does an adrenal gland produce adrenaline?
The brains sends a signal to it
Where does adrenalin travel?
In the blood
What are effects of adrenalin and when do they make up together?
Pupils dilate (more light)
Increased heart rate (pump blood faster)
Increased breathing rate
Glycogen released in muscle cells break down to release glugose (for increased respiration)
Blood from digestive system redirects to skeletal muscle
Fight or flight response for survival
What does a blood thyroxine level and time graph look like?
Fluctuates in a regular pattern a around zero value in X
What does a blood adrenalin level and time graph look like?
Zero then spikes up and goes quickly all the way down after that
