B11 hormonal coordination Flashcards
what is a hormone
a chemical messenger secreted by a gland
what is the endocrine system
made up of glands that secrete hormones directly into the bloodstream
what is the pituitary gland
found in the brain
secretes several hormones in response to the bodies conditions
These hormones in turn act on other glands to stimulate other
hormones to be released to bring about effects
what is thyroxine
its a hormone produced by the thyroid gland
increases metabolic rate
controls growth and development in young animals
controlled by negative feedback
what is adrenaline
produced by the adrenal glands in times of stress and fear
increases heart rate boosting delivery of oxygen to brain and muscles
prepares body for ‘flight or fight’
how is blood glucose concentration monitored and controlled
the pancreas
what happens if blood glucose concentration is too high
pancreas releases more insulin
insulin causes glucose to move from blood into cells
in liver and muscle cells excess glucose is converted into glycogen for storage
what happens if blood glucose concentration is too low
pancreas releases glucagon
glucagon stimulates glycogen to be converted to glucose and released into blood
what is type 1 diabetes
a disorder caused by the pancreas failing to produce sufficient insulin resulting in uncontrolled high blood glucose levels
how is type 1 diabetes treated
normally treated with insulin injections
what is type 2 diabetes
a disorder caused by the body cells no longer responding to insulin
name a type 2 diabetes risk factor
obesity
how is type 2 diabetes treated
a carbohydrate controlled diet
regular exercise
what do reproductive hormones do during puberty
cause secondary sex characteristics to develop
where is oestrogen found
the ovaries
what is oestrogen
the main female reproductive hormone
At puberty eggs begin to mature and one is released approximately every 28 days. This is called ovulation
where is testosterone produces
the testes
what is testosterone
the main male reproductive hormone produced by
the testes and it stimulates sperm production
how many hormones control the menstrual cycle
4
what is the follicle stimulating hormone secreted by
pituitary gland
what is the function follicle stimulating hormone
causes eggs to mature in the ovaries in the first part of the cycle
stimulates ovaries to produce oestrogen
what is the function of oestrogen
inhibits FSH release
stimulates LH release
makes lining of uterus grow again after menstruation
what is the luteinising hormone secreted by
pituitary gland
what is the function of LH
stimulates release of egg in the ovary
where is progesterone secreted
by an empty follicle in the ovaries
what is the function of progesterone
maintains lining of the uterus during second half of the cycle
inhibits both FSH and LH release
what are the 2 hormonal methods of contraception
oral contraceptive (the combined pill) contain oestrogen and progesterone inhibiting FSH production meaning no egg is released
name the non hormonal methods of contreception
barrier methods e.g condom preventing sperm reaching egg
intrauterine devices - prevent embryos implanting in the uterus
spermicidal creams- kill or disable sperm
not having intercourse when egg may be in oviduct
surgical methods of sterilization
how does the fertility drug increase fertility
doctors may give FSH and LH in a fertility drug to a woman if her own level of FSH is too low to stimulate eggs to mature
describe the process of IVF
IVF involves giving a mother FSH and LH to stimulate the
maturation of several eggs.
The eggs are collected from the mother and fertilised by
sperm from the father in the laboratory.
The fertilised eggs develop into embryos.
At the stage when they are tiny balls of cells, one or two
embryos are inserted into the mother’s uterus (womb).
what are the disadvantages to fertility treatment
emotionally and physically stressful
sucess rates are not high
can lead to multiple birth a risk for the baby and mother
