B11: Hormonal Coordination Flashcards
what is the second coordination and control system in our body
endocrine system
what is the endocrine system made up of
glands that secrete hormones into the bloodstream
where does the blood carry hormones in the endocrine system
the target organs, where is produces an effect.
what do target organs have to pick up on the hormones?
receptors on cell membranes that trigger the response.
give 2 examples of hormones with rapid responses
-insulin
-adrenaline
give two examples of hormones that are slow acting
-growth hormones
-sex hormones
what are most endocrine glands controlled by
pituitary gland in the brain
what does ADH affect?
the amount of urine produced in the kidney
what does FSH do?
stimulate the ovaries to make the female sex hormone oestrogen.
What does TSH do?
stimulates the thyroid gland to make thyroxine, a hormone that helps control the rate of your metabolism
6 endocrine glands:
-pituitary
-thyroid
-pancreas
-adrenal
-ovaries
-testes
what do pituitary glands control
-children’s growth
-production of thyroxine
-FSH
-male production of sperm and testosterone.
what does the pancreas gland control
levels of glucose in the blood.
what is the hormone controlling blood sugar that the pancreas uses
insulin
what does insulin do
allows glucose to move from the blood into your cells, where it is used.
what can soluble glucose be converted into
insoluble glycogen
how does glycogen help the body
keeps a stable blood sugar, can be converted back into glucose when needed.
what is excess glucose stored as
lipids (fat)
what is produced when your blood sugar is low
glucagon
what does glucagon do
makes the liver break down glycogen and convert it into glucose
name for the switching between two hormones
negative feedback control
what is type one diabetes caused by
not enough insulin produced, blood glucose too high
why is type 2 diabetes developed
your body stops responding to the insulin you make, also less produced
how can we TREAT type ONE diabetes
-insulin injections before meals
how can we TREAT type ONE diabetes
long term
-transplanted pancreas (risky, not enough donors, need medicine)
-transplanted pancreatic cells (limited success)
what is the easier way of treating type 2 diabetes
-healthy diet
-losing weight
-regular exercise
what is the harder way of treating type 2 diabetes
using drugs that help the effectiveness of insulin and pancreas. also reduce glucose absorbed from gut.
what is the final resort for a type 2 diabetic
insulin injections
put simply, negative feedback systems work to maintain a _____ _______
steady state
if there are low levels of thyroxine in the blood, what happens
amount of TSH increases, which stimulates production of more thyroxine.
what is the one hormone that does not involve a negative feedback loop.
adrenaline
what are primary sex characteristics
the ones you are born with
main female reproductive hormone
oestrogen
how long is the menstrual cycle (average)
28 days
What is FSH’s role during the menstrual cycle
causes the eggs in the ovary to mature
what does LH (luteinising hormone) do?
stimulates the release of the egg at ovulation
which two hormones stimulate the build-up and maintenance of the uterus lining?
oestrogen and progesterone
main male reproductive hormone
testosterone
what does the uterus lining do at the beginning of the menstrual cycle
thickens
when is progesterone secreted
by the empty egg follicle in the ovary after ovulation
as oestrogen levels rise, what happens to levels of FSH? (and vice versa)
they fall
what is in the contraceptive pill?
low doses of oestrogen which prevents the release of FSH and therefore no egg is matured.
also stop lining building up
thick mucus to stop sperm getting through
side effects of the pill
-raised blood pressure
-thrombosis
-breast cancer
what is a contraceptive implant
a tiny tube inserted under your skin and slowly releases progesterone
how long can a contraceptive implant last
3 years
contraceptive patch
contains a mixture of oestrogen and progesterone. sticks to your skin for a week, hormones absorbed by bloodsteam.
what is a chemical way to prevent pregnancy
spermicides (not that effective)
barrier methods:
condom, diaphragm
what are intrauterine devices
small structures inserted into the uterus. last 3-5 years. some prevent early embryos. some have progesterone.
what is the downside to intrauterine devices
may cause period problems or infections
abstinence
don’t have sex = don’t get pregnant
some follow their cycle closely and don’t have sex near ovulation
surgical methods of contraception
surgically sterilised e.g. vasectomy in men.
women need general anaesthetic
common causes of infertility
eating disorders, age, obesity
treatment of infertility due to lack of FSH
artificial FSH stimulates oestrogen
treatment for infertility due to no LH
artificial LH can stimulate ovulation
IVF, when is it used
if the oviducts have been damaged or blocked by infection, donor egg must be used, no obvious cause.
IVF process
-give mother synthetic FSH to stimulate egg production.
-give synthetic LH to make the woman ovulate.
-collect eggs and fertilise them with sperm.
-eggs are kept in warm environment until they become embryos.
-one or two are inserted back into the uterus
bad things about IVF:
-expensive
-not always successful
-health risks, emotionally and physically stressful
-increase chance of multiple pregnancy, stillbirths ect.
-ethical issues with wasted embryos
the response of a plant to light
phototropoism
the response of a plant to gravity
gravitropism or geotropism
the plant hormones that controls response towards light and gravity
auxin
why do plants always grow the right way
uneven distribution of auxin causes unequal growth rate. plant bends in right direction.
auxins affect on roots and shoot cells
high levels mean shoots grow and roots dont
low levels mean roots grow and shoots dont
the plant hormones that initiates seed germination
gibberellins
plant hormone that controls cell division
ethene gas
how do people use plant hormones
grow plants more successfully
how do we use auxin
-dipping cuttings in rooting powder, which stimulates the plant growth.
-weed killers
-modern plant tissue cultures (plant cloning)
how do we use gibberellins
-brewing, speeds up germination of barley
-promote flowering
-increase fruit size
using ethene
control ripening of fruit
