Thyroxine Flashcards
What does homeostasis control?
Blood glucose concentration
Body temperature
Water levels
Why are optimal conditions important
Enzymes will only function properly under a small range of certain conditions, if conditions are outside the range the enzymes won’t function
What does negative feedback mean?
If the level of something rises control systems reduce it again
If the level of something falls, control systems will raise it again
What happens if body temperature rises?
Blood vessels dilate, resulting in heat loss to the environment. Sweat glands secrete fluid. As the fluid evaporates heat is lost from the body
What does positive feedback mean?
If the level of something rises control systems continue to raise it again If
What is metabolic rate?
The rate at which energy from food that is transferred by all chemical reactions that take place in your body to keep you alive
What happens when too much thyroxine is released from the thyroid
More thyroxine causes more respiration which breaks down more food molecules and releases more energy than normal
What is stimulation
Making something more active
What is inhibition
Making something less active
How does thyroxine self regulate itself to avoid and overactive metabolism?
If too much thyroxine is produced it has a greater inhibiting effect in the hypothalamus so that less TRH is released which leads to the pituitary being stimulated less so releasing less TSH which reduces the stimulus on the thyroid gland, so less thyroxine is released.
