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