SB7b Hormonal Control Flashcards
Metabolic rate?
Rate at which food is transferred by all the reactions that take place in your body to keep you alive
When is resting metabolic rate measured?
~when the body is at rest
~in a warm room
~a long time aftert they have eaten
Why is it important to measure resting metabolic rate under its conditions?
So we are not using excess energy to keep warm, move around or digest food
Negative feedback?
A change in one factor leads to the opposite effect, restoring conditions to normal
What does thyroxine effect?
Metabolic rate
2 things that thyroxine does to the body?
~causes heart rate to increase
~increases the rate at which proteins and carbohydrates are broken down inside cells
steps with glands and hormones on metabolic rate as an example of negative feedback
~hypothalamus releases TRH which stimulates the pituitary gland
~pituitary gland releases TSH which stimulates the thyroid gland
~thyroid gland releases thyroxine which stimulates the target organ
what happens if thyroxine blood levels are too high in metabolic rate as an example of negative feedback?
thyroxine inhibits (makes less active) the pituitary and hypothalamus gland
what happens if thyroxine blood levels are too low in metabolic rate as an example of negative feedback?
thyroxine stimulates the hypothalamus to produce more TRH
where is adrenaline released from?
the adrenal gland
example of a target organ for adrenaline?
liver
how does adrenaline prepare our body for fight or flight? 4
~heart muscle cells contract more rapidly increasing heart rate
~heart muscle cells contract more strongly increasing blood pressure
~diameter of blood vessels widen which increases blood flow to muscles
~liver cells change glycogen to glucose and release into blood increasing blood sugar concentration
