hormones Flashcards
coordination and homeostasis
what does glucagon do?
converts glycogen to glucose
what does insulin do?
converts glucose to glycagon
where are oestrogen and progesterone produced?
ovaries
where are FSH and LH produced?
pituitary gland
what are some secondary sexual characteristics in boys?
-voice breaks
-sperm production begins
-growth and development of genitalia
-pubic hair growth
what are some secondary sexual characteristics in girls?
–menstrual cycle begins
-pelvis broadens in preparation for pregnancy and labour
-armpit and pubic hair growth
what gland is progesterone secreted from?
ovary(corpus luteum)
what is the target organ/tissue for progesterone?
pituitary gland and uterus lining
what is the effect of progesterone?
-inhibits FSH and LH- stops further ovum being matured and released
-thickness of uterus lining maintained
what gland is LH secreted from?
pituitary gland
what is the target organ/tissue for LH?
the follicle in the ovary
what is the effect of LH?
ovulation
what gland is FSH secreted from?
pituitary gland
what is the target organ/tissue for FSH?
the ovary
what is the effect of FSH?
-follicle develops and ovum matures
-maturing follicle releases oestrogen
what is the endocrine system?
the bodys second coordination system
what do glands do?
make hormones (chemical messengers)
what are hormones?
chemical messengers used in the body created by the endocrine system
where are hormones carried?
in the bloodstream
do excrine glands have a duct?
yes
do endocrine glands have a duct?
no
what does the pituitary gland contain?
neurones linking it to the hypothalamus
where is the pituitary gland found?
at the base of the brain
where is ADH produced?
pituitary gland
where is the growth hormone produced?
pituitary gland
where is glucagon produced?
pancreas
where is adrenaline produced?
adrenal gland
where is thyroid stimulating hormone produced?
pituitary gland
where is thyroxine produced?
thyroid
where is insulin produced?
pancreas
how do messages move around the body (nervous system)?
nerve impulses- transmitted through nerve cells
how do messages move around the body? (endocrine system)
hormones transmitted in the bloodstream (plasma)
speed of travel and time for effect to happen (nervous system)?
travel fast and usually have an instant effect
speed of travel and time for effect to happen? (endocrine system)
travel more slowly and usually take longer to act
effect localised or widespread (nervous system)?
short lived
effect localised or widespread (endocrine system)?
usually longer-lasting
example of an act of the nervous system?
iris reacting to bright light
example of an act of the endocrine system?
controls the blood glucose levels
3 ways in which the 2 methods of coordination are similar?
-both begin with a stimulus
-both end in a response
-both go through an effector organ
3 ways in which the 2 methods of coordination are similar?
-nervous coordination goes through the CNS
-nervous coordination involves neurones
-nervous coordination goes to the receptor organ after the stimulus -hormonal goes to the gland
when is adrenaline secreted?
when you are scared/angry/excited
where are the adrenal glands?
on top of your kidneys
in order for the body to be prepared for action what do the muscles require?
a good supply of oxygen and glucose
effects of adrenaline on the heart?
-beats faster
-heart rate increases
how does the heart beat faster and increase its rate?
sends more blood to the muscles-they receive more glucose and oxygen for respiration
effect of adrenaline on the lungs?
-breathing rate increases
-breaths become deeper
how does breathing rate increase and our breaths become deeper?
taking more oxygen into the blood
effect of adrenaline on the arterioles in muscles?
increases blood flow
how do the arterioles in the muscles gain an increase in blood flow?
more oxygen and glucose supplied to respiring cells
effect of adrenaline on arterioles in the digestive system?
blood flow diverted away
why is the blood flow diverted away from the arterioles in the digestive system?
more blood for muscles
what is the effect of adrenaline on the liver?
glucose is released from it
why is glucose released from the liver?
glycogen is changed into glucose and released into the blood-muscle cells absorb more glucose and use it for respiration
effect of adrenaline on eyes?
pupils dilate
why do the pupils dilate when adrenaline acts on the eyes?
increased visual sensitivity
what happens to the skin hairs when adrenaline acts upon it?
they rise/stand up
why do animals skin hairs stand up?
to make the animal look bigger
what is the effect of adrenaline on the brain?
mental awareness increases
why does your mental awareness increase upon the act of adrenaline?
your reactions are faster
what is homeostasis?
the maintaining of a constant environment in the body predominantly in the blood and tissue fluid
examples of internal conditions that are controlled?
temperature, water, oxygen, carbon dioxide, blood sugar and pH
how is homeostatic control achieved?
using negative feedback
what do the control systems do?
they inhibit the original stimulus
what does negative feedback mean?
whenever a change occurs in a system, negative feedback causes a corrective mechanism to start which reverses the original change and brings the system back towards the set point (normal)
what happens in a positive feedback system?
the output enhances the original stimulus
what hormone is responsible for controlling water levels in the blood?
ADH (anti-diuretic hormone)
what is the region in the brain that regulates the concentration of blood?
the hypothalamus
what does the loss of water mean for the conc of blood?
the conc starts to increase
how does the body know the body has lost water?
detected by special cells in the hypothalamus
what do the cells in the hypothalamus do? (water LOSS)
the pituitary gland releases more ADH
where does ADH travel to? (water LOSS)
in the blood to the kidney
does the collecting duct become more or less permeable to water? (water LOSS)
more permeable
what does the collecting duct being more permeable mean? (water LOSS)
more water is reabsorbed back into the blood
more water being reabsorbed into the blood means what for the urine? (water LOSS)
urine is more concentrated and has less volume and the blood is more dilute
what does the gain of water mean for the concentration of water in the blood?
starts to decrease
how is this change detected? ( water GAIN)
by special cells in the hypothalamus
what do these special cells in the hypothalamus do? (water GAIN)
cause the pituitary gland to release LESS ADH
does the collecting duct become more or less permeable to water? (water GAIN)
less permeable
what does the collecting duct being less permeable mean for water and urine concentration? ( water GAIN)
-less water reabsorbed into the blood-makes urine more dilute and increases the volume and blood becomes more concentrated
what does diuretic mean?
increasing volume of urine- adding water
what 5 things can the level of water in the blood plasma depend on?
-external temperature
-amount of exercise
-amount of water
-salt content intake
how does external temperature affect the level of water in the blood plasma?
when its hot we sweat more and lose more water making the blood plasma more concentrated
how does the amount of exercise we do affect the level of water in our blood plasma?
if we exercise we get hot and then increase our sweating so we lose more water and the blood plasma becomes more concentrated
how does the amount of water affect the level of water in our blood plasma?
the more we drink the more we dilute the blood plasma- the kidneys respond by producing more dilute urine to get rid of the excess water
how does your salt content affect the water level in your blood plasma?
salt makes the plasma more concentrated and so it makes us thirsty- we drink more water until the excess salt has been excreted by the kidneys
how do drugs affect the water level in your blood plasma?
drugs cause the kidneys to produce a smaller volume of less dilute urine- can result in the body having too much water
how does alcohol affect the bodys water level in your blood plasma?
causes the kidneys to produce a greater volume of more dilute urine- can lead to dehydration
what is glucose stored as in humans and where?
stored in the liver as glycogen which is a large insoluble polysaccharide
what happens when the body is short of glucose?
the glycogen can be broken down into glucose and passed into the bloodstream
the role of insulin and glucagon?
insulin-lowers blood glucose
glucagon-raises blood glucose
what can increase your blood glucose?
eating a meal
what can decrease your blood glucose?
exercise
what is type 1 diabetes?
bodys immune system attacks and destroys cells that produce the insulin
what is type 2 diabetes?
body doesnt produce enough insulin or the bodys cells dont react to insulin properly
1st step when you do vigorous exercise?
blood sugar level falls
2nd step of doing vigorous exercise?
cells in pancreas signal to make/release glucagon
3rd step of doing vigorous exercise?
glucagon tells the liver to convert glycogen to glucose
4th step of doing vigorous exercise?
glucose is released into the blood
5th step of doing vigorous exercise?
blood sugar levels back to normal again
6th step of doing vigorous exercise?
muscles use up glucose in respiration
what is the stimulus for thermoregulation?
change in environmental temperature
temperature receptors do what?
send electrical impulses to the hypothalamus
what do the temperature receptors stimulate our brains to do?
find shade, have a cool drink, take off a layer of clothing
what does the thermoregulatory centre in the hypothalamus do?
detects a change in the temperature of the blood flowing through it (core temperatures)
what does homeothermic mean?
warm-blooded
what happens when the thermoregulatory centre in the hypothalamus detects a change in the temperature of the blood flowing through it?
this sends a signal via nerves to other organs in the body which then regulate the temperature by physiological nerves
what does poikilothermic mean?
cold-blooded
does body temperature fluctuate in homeothermic organisms?
stays constant
does body temperature fluctuate in poikilothermic organisms?
yes
why is homeostasis important for organisms?
it ensures the maintenance of optimal conditions enzyme activity and cell function
what is the link between the stimulus and the receptor made by?
the nervous or endocrine system
what is homeostasis?
the control or regulation of the internal conditions of a cell or organism
what are 2 examples of homeostasis in humans?
- the control of body temperature
- the control of body water content
what is body temperature monitored and controlled by?
the thermoregulatory centre in the base of the brain
what does the thermoregulatory centre contain?
receptors that are sensitive to the temperature of the blood
what does the skin also contain?
temperature receptors
what does the skin send impulses to and what kind?
nervous impulses to the thermoregulatory centre
what is a coordination centre?
receives and processes information from receptors such as the brain, spinal cord & pancreas