Y11 animal coordination control and homeostasis Flashcards
where are hormones produced
endocrine glands
define hormones
chemical messengers in the body
thyroid gland produces
thyroxine
regulates energy use in body
how does adrenaline work in the heart
adrenaline binds to receptors in the heart, causing the heart to beat more intensely
blood pressure increases
muscles have more oxygen for respiration
how does adrenaline work in the liver
adrenaline binds to receptors in the liver
glycogen is broken down into glucose
glucose fuels muscle contractions
homeostasis definition
the maintenance of a constant internal environment
How is hypothalamus involved in homeostasis
It detects the temperature of blood in the brain via the thermoregulatory centre
How does sweat cool body temperature
It takes heat energy away from the body when it evaporates
Vasodilation
If body is too cold
blood vessels at skin surface widen
more heat radiates from body
Vasoconstriction
If body is too hot
Blood vessels near skin narrow
Less heat is radiated from skin
How does shivering warm us
Increases rate of respiration in muscles, producing more heat
How does body hair regulate temperature
Hairs stand when too cold
Traps an insulating layer of air by skin
Order of menstrual cycle
old Uterus lining exits
oestrogen builds up new lining
follicle matures in ovary due to FSH
LH causes follicle to burst
Mature ovum released
Burst follicle becomes corpus luteum
Corpus luteum maintains uterus lining
how can hormones improve fertility
ART increases LH and FSH in blood
How does In Vitro Fertilisation work
woman injects herself with FSH and LH to make more eggs
Eggs collected from woman and fertilised with man’s sperm
Fertilised eggs grow into embryos which are put back into woman’ uterus
