biology flashcards homeostasis & inheritance
give 3 things that thyroxine does
Any 3 from:
stimulates basal metabolic rate
helps with growth and developement
effects how quickly substances are broken down and built up
how much oxygen your tissues use
how the brain of a child developes
give 3 things that adrenaline does
Any 3 from:
increases heart rate and breathing
stimulates stored gkycogen in the liver to convert to glucose for respiration
stimulates dilation of pupils to let more light in
increases mental awareness
stimulates blood to be diverted away from digestive system and towards limb muscles
definition of homeostasis
the regulation of internal conditions of a cell or organism to maintain optimum conditions for function in response to internal or external changes
what is negative feedback
a mechanism which returns a particular condition to its normal levels if they change
why must temperature be maintained at a constant level? and what will happen if the temperature is too high/low?
so that enzymes perform at their optimum level.
if the temperature is too high they will denature
if the temperature is too low reaction rates will slow down
what will happen if blood glucose levels are too high/low
if the blood glucose is too high, water concentration in the blood would drop which would effect osmosis between cells
if blood glucose levels were too low, there wouldnt be enough glucose for respiration which would lead to low energy levels
fill in the blanks.
The ____ system is composed of ____ which secrete chemicals called ____directly into the ____. the blood carries the ____ to a target ____ where it produces an effect. compared to the ____ system, the effects are ____ but act for _____.
endocrine, glands, hormones, blood, hormone, organ, nervous, slower, longer
where is the pituitary gland found
in the brain
where is the thyroid gland found
in the neck (below the larynx)
where is the adrenal gland found
kidneys
why is the pituitary gland known as the master gland
it secretes hormones which stimulate other glands to secrete different hormones
what is a hormone
a protein produced by glands to give chemical messages that travel through the blood
fill in the blanks
The menstual cycle lasts 28 days. on day 14, an egg is released from the ___. This is called ___ and is controlled by _____. If this ____ is unfertilised then it, along with the thickened lining of the ____ will be shed. This is called ____ and it begins on day 1 of the cycle
ovaries, ovulation, oestrogen, egg, uterus, menstruation
what hormones are produced by the pituitary gland
FSH and LH
What hormones are produced by the ovaries
Oestrogen and Progesterone