Hormones Flashcards
what are hormones?
chemical messengers sent in the blood to controls things in organs and cells
How are hormones produced?
produced and secreted by various glands called endocrine glands
Pituitary gland
produces hormones that regulate body conditions
direct glands to release hormones that bring about change
Ovaries
produce oestrogen
Testes
produce testosterone
what does testosterone do?
controls puberty and sperm production
thyroid gland
produced thyroxine
what does thyroxine do?
regulates things like rate of metabolism, heart rate and temperature
adrenal glands
produce adrenaline
pancreas
produced insulin which regulates blood sugar levels
Neurones features
very fast action
act for short period of time
act on precise area
Hormones features
slower action
act for long period of time
act in a more general way
what does adrenaline do?
prepares body to either face the threat or run away
How does adrenaline do its job?
activating processes that increase the supply of oxygen and glucose to cells
How does the body prepare for action?
the brain sends nervous impulses of the adrenal glands which respond by secreting adrenaline
what is negative feedback?
when the body detects that a substance has gone above or below the normal level it triggers a response to get it back to normal
Menstrual cycle stage one
the lining of the uterus breaks down
Menstrual cycle stage two
from day 4 to 14 the uterus lining is repaired so the egg can implant there
Menstrual cycle stage three
On day 14 an egg is developed and released from ovary
Menstrual cycle stage four
The lining is maintained til around day 28 and if no egg is on the uterus wall it breaks down again
where is FSH realised from?
pituitary gland
FSH function
causes a follicle to mature in ovaries
stimulates oestrogen production
Oestrogen function
causes lining of uterus to thicken and grow
stimulates an LH increase
where is LH released from?
pituitary gland
LH function
stimulates ovulation at day 14
stimulates follicle to develop into corpus luteum
what does corpus luteum secret?
progesterone
Progesterone function
maintains lining of uterus
inhibits release of FSH and LH
what happens if there is a low level of progesterone?
lining of uterus breaks down as low level of oestrogen
allows FSH to increase so cycle begins again
Clonifene Therapy
causes more FSH and LH to be released to stimulate egg maturation
What does clomifene therapy allow?
to know when a women will be ovulating so a couple can have intercourse at that time
IVF
collecting a women’s egg and fertilising them in a lab then placing them back in a women’s uterus as an embryo
why is FSH and LH given in IVF?
to stimulate egg production
how does oestrogen prevent pregnancy?
by taking it every day it inhibits the production of FSH and stops every development and production
how does progesterone prevent pregnancy?
reduces fertility by stimulating production of thick cervical mucus to prevent any sperm reaching the egg
which contraception methods contain oestrogen and progesterone?
combined pull
contraceptive patch
which contraceptives contain progesterone?
mini pill
contraceptive injection
disadvantages of hormonal methods
unpleasant side effects
don’t protect against sexually transmitted diseases
advantages of hormonal methods
prevent pregnancy
don’t have to think every time you have sex
what is homeostasis?
maintaining a constant internal environment
Examples of homeostasis
Blood glucose regulation
osmoregulation
thermoregulation
type one diabetes
where the pancreas produces little or no insulin
treatments for type 1 diabetes
injecting insulin
regular exercise
limiting intake of food of simple carbohydrates
type two diabetes
where the pancreas doesn’t produce enough insulin or when the body becomes resistant
treatments for type 2 diabetes
healthy diet
exercise regularly
insulin injections
