animal coordination, control and homeostatis Flashcards
what are hormones
chemical messengers sent in the blood
what are hormones secreted by
various glands called endocrine glands
what is the group of various glands called
endocrine system
where is the pituitary gland
base of the brain
where is the thyroid gland
windpipe
where is the adrenal gland
top of the kidney
where is the pancreas gland
pancreas
where is the ovaries gland
ovary
where is the testes gland
testicles
what is the pituitary gland
produces many hormones which regulate body conditions
sometimes known as a ‘master gland’
as the hormones act on other glands directing them to release hormones which brings about change
what is the thyroid gland
produces thyroxine, involves regulating things like the rate of metabolism, heart rate and temperature
what is the adrenal gland
these produce adrenaline, used to prepare the body for fight or flight response
what is the pancreas gland
produces insulin which is used to regulate blood glucose level
what is the testes gland
produces testosterone which controls puberty and sperm production in males
what is the ovaries gland
produces oestrogen which is involved in the menstrual cycle
what are the differences between neurones and hormones
neurones:
very fast, act for a short time, act on a very precise area
hormones:
slower action, act for a long time, act in a more general way
what does adrenaline do
prepares your ‘fight or flight’ - wether you stand your ground in a threat or run away
how does adrenaline have its effect
by activating a process which increases the supply of oxygen and glucose to cells,
adrenaline binds to receptors in the heart, causes muscles to contract more frequently, heart pumps more blood, muscle cells receive more oxygen and glucose this way
what does your brain do in a stressful situation
sends nervous impulses to the adrenal glands,secreting adrenaline, gets the body ready
what can affect hormone release
negative feedback
negative feedback
action taken by the body to return something to a normal / optimum level following a change from that level e.g. above or below
what does thyroxine do
regulates metabolism
what is metabolic rate
the speed at which chemical reactions in the body occur
how is the amount of thyroxine in the blood kept at the right level (2)
if it goes lower - the hypothalamus stimulates to release thyrotropin releasing hormone (TRH)
this then stimulates the pituitary to release thyroid stimulating hormone (TSH)
this then releases thyroxine from the gland, levels rise again towards normal
if they go higher - the release of TRH is inhibited, so then levels fall
what is the menstrual cycle
monthly sequence of events in which the female body releases an egg and prepares the uterus in case the egg is fertilised
what is the first stage of the menstrual cycle
DAY ONE
menstruation starts, lining of the uterus is broken down and released
what is the second stage of the menstrual cycle
DAY 4 - 14
uterus lining is repaired
it becomes a thick spongy layer ready for fertilise eggs to implant there
what is the third stage of the menstrual cycle
DAY 14
egg is developed and released from the ovary
what is the fourth stage of the menstrual cycle
DAY 14 - 28
the lining is then maintained, if there is no fertilised egg, the spongy lining breaks down, creates the cycle once again starting over again
what are the 4 hormones called in the menstrual cycle which controls it
FSH - follicle stimulating hormone
Oestrogen
LH - luteinising hormone
Progesterone
where is FSH released
pituitary gland
where is oestrogen released
Ovaries
where is LH released
pituitary gland
where is progesterone released
corpus luteum
what does FSH do
causes a follicle to mature in a ovary
stimulates oestrogen production
what does oestrogen do
causes the lining of the uterus to thicken and grow
causes a high surge of LH
what does LH do
stimulates ovulation
stimulates the remains of the follicle to develop a structure called a corpus luteum
what does progesterone do
maintains the lining of the uterus
inhibits the release of FSH and LH
low levels cause the cycle to restart as they allow FSH to increase and uterus lining breaks down
what happens with progesterone during pregnancy
levels stay high
what is clomifene therapy and how does it work
a drug which can be taken in order to ovulate or regulate ovulation
works by causing more FSH and LH to be released in the body, stimulates egg maturation and ovulation, improves chances of pregnancy
what is IVF and how does it work
IN VITRO FERTILISATION
involves collecting eggs from the woman’s ovaries and fertilising them in a lab using the man’s sperm
they then grow into embryos
once they are embryos they can be placed back into the women to improve chance of pregnancy, FSH and LH are also given to simulate egg production
what is ART and what does it do
assisted reproductive technology
involves eggs being handled and fertilised outside the body
what are some examples of contraceptives
hormones
combined pills
progesterone
barrier methods, condoms
how are hormones contraceptives
oestrogen can be used to prevent the release of an egg
how are progesterone contraceptives
reduces infertility, stops sperm from getting into the uterus and reaching the egg
how are the combined pill contraceptives
both oestrogen and progesterone
how are barriers contraceptives
stop the sperm from ever meeting the egg
what is the positives of hormones and barrier contraceptives
very effective
with hormones they don’t have to stop and think each time they have sex
what is the negatives of hormones and barrier contraceptives
can have unpleasant side effects
what is homeostasis
maintaining the right conditions inside your body, so everything works properly, maintaining a constant internal environment
why is homeostasis important
your cells need the right conditions for enzyme reactions, can be dangerous for health if conditions vary to much from normal levels.
osmoregulation
regulating water content, balance between water you take in and excrete out
thermoregulation
regulate body temp, reduce or increase depending on envrionemnt
blood glucose regulation
make sure your glucose levels don’t go to high or to low
what controls blood glucose levels (2)
insulin
glucagon
what is added when blood glucose levels go too high
insulin
what is added when blood glucose levels go too low
glucagon
where is insulin secreted from
pancreas
what happens to blood glucose when insulin is added
glucose moved from blood into liver and muscle cells
where is glucagon secreted from
pancreas
what happens to blood glucose when glucagon is added
glucose released into blood by liver
what does glucagon do to the liver
forces it to turn glycogen into glucose
what does insulin do to the liver
makes it turn glucose into glycogen
what is type one diabetes caused by
lack of insulin
what is type one
a condition where the pancreas produces little or no insulin, causes blood glucose to right to a level which can kill them
what can a type one be treated by
insulin therapy - involves injecting insulin into the blood, often done round mealtimes so the glucose is quickly removed after eating
what does a person with type one need to think about
limiting the intake of simple carbs (sugars)
taking regular exercise - removes excess glucose from blood
what is type 2 diabetes due to
resistance to insulin
what is type 2 diabetes
Andes the pancreas doesn’t produce enough insulin / body become resistant to insulin, causes blood glucose levels to rise
what is the correlation between obesity and type 2
obese people have a higher risk of developing type 2 diabetes
BMI equ
weight / height (m) (squared)
waist to hip ratio equ
waist circumference / hip circumference
what is thermoregulation
process your body uses to keeps its internal temperature steady
what is body temp controlled by
hypothalamus
what happens when your too hot
erector muscles relax
lots of sweat, is released through pores, so when it evaporates it transfers energy from your skin to environment, cooling you down
blood vessels close the surface of your skin
what happens when your cold
erector muscles contract, hairs stand up
very little sweat is produced
blood vessels near skin constrict
you also shiver (your muscles contract automatically)
increase rate of respiration to warm up
