topic 7 - animal coordination, control and homeostasis Flashcards
how does thyroxine control metabolic rate as an example of negative feedback?
- low levels of thyroxine stimulates the production of TRH in the hypothalamus
- causes a release of TSH from the pituitary gland
- TSH acts on the thyroid to produce thyroxine
- when they thyroxine levels are normal, thyroxine releases TRH and produces TSH
what happens when they body goes into fight or flight?
- increased heart rate
- increased blood pressure
- increased blood flow to the muscles
- raised blood sugar levels by stimulating the liver to change glycogen into glucose
what are the general roles of hormones in the body?
- chemical messages sent around the body via blood
- they all travel to a specific target organ
- produced in glands around the body
what is the importance of hormones around the body?
they only affect specific cells called target organs
what are the names of the endocrine glands?
pituitary glands, thyroid gland, adrenal gland, ovaries/testes
what is the function of the endocrine glands?
where hormones are produced and secreted
what does the pituitary gland produce and release?
produces: hormones that affect/regulate heart rate
releases: hormones that bring about change
what does the thyroxine gland produce and release?
produces: thyroxine (regulates heart rate, temp, metabolic rate)
releases: none
what does the pancreas produce and release?
produces: insulin (regulated blood glucose levels)
releases: none
what does the adrenal gland produce and release?
produces: adrenaline (prepares for fight or flight)
releases: none
what do the ovaries produce and release?
produces: oestrogen
releases: unfertilised eggs
what do the testes produce and release?
produces: testosterone (controls puberty and sperm production
releases: sperm
how is type 2 diabetes caused?
when a person becomes resistant to insulin, blood glucose levels rise
increased risk of obesity
how is type 2 diabetes treated?
eating healthy diet, getting regular exercise and losing weight if needed
also medication or insulin injected
how is urea produced?
from the break down of amino acids in the liver
how do you calculate BMI?
weight / (height) squared
what is your BMI supposed to be to be considered obese?
over 30
how is type 1 diabetes caused?
pancreas producing little or no insulin
blood glucose levels rise to a level that can kill them
how can type 1 diabetes be treated?
insulin therapy - injecting insulin directly into the bloodstream
doing regular exercise removes excess glucose
limiting intake of food rich in simple carbohydrates
how is the hormone insulin used to control blood glucose concentration?
if blood glucose is too high, insulin is added
insulin is secreted by the pancreas
insulin makes the liver turn glucose into glycogen
how is blood glucose concentrated by glucagon?
if blood concentration is too low, glucagon is added
the glucagon is secreted by the pancreas
glucagon makes the liver glucagon into glucose
how does thermoregulation take place when you’re cold?
- erector muscles contract, hairs stand on end to trap an insulating layer of air near the skins surface
- very little/ no sweat is produced
- blood vessels near the skin vasoconstrict so the blood is further from the surface so less blood is transferred to the surroundings
how does themoregulation take place when you shiver?
muscles contract automatically (shiver)
- increases rate of transpiration which transfers more energy to the body
how does thermoregulation take place when you’re too hot?
- erector muscles relax to hairs lie flat
- lost of sweat is produced in the sweat glands in the dermis
- when the sweat evaporates, it transfers energy from your skin which cools you down
- blood vessels vasodilate to allow more blood flow nearer to the surface of the skin so more energy can be transferred to the surroundings
