B3.2 The Endocrine System

Question 1

what are hormones

Answer 1

chemical messengers produced in endocrine glands and travel in the bloodstream

Question 2

what do hormones do

Answer 2

causes a specific response in target organs
regulates and controls body functions that need adjustment (i.e sugar levels)
homeostasis - keeping body conditions constant

Question 3

what are target cells

Answer 3

hormones can only bind to their respective target cells.
target cells have receptors in their membrane or cytoplasm which allows them bind with the hormones so that the hormone can stimulate the cell

Question 4

what is the endocrine system

Answer 4

it is comprised of all the endocrine glands and hormones
it allows the body to coordinate processes with the CNS
sends info around the body about stimuli

Question 5

negative feedback loop

Answer 5

body condition unstable->gland releases hormone to fix it->hormone fixes it so glands stop hormone production->body condition unstable again

Question 6

what is thyroxine

Answer 6

produced in thyroid gland
it controls the body’s metabolic rate (transfer of chemical energy from food to ATP)
produced from the iodine found in food and tyrosine amino acid

Question 7

what is adrenaline

Answer 7

produced in adrenal gland

for ‘flight or fight’ or in intensive stress

Question 8

how is thyroxine levels controlled

Answer 8

hypothalamus detects cells need more energy
pituitary releases TSH (thyroid stimulating hormone)
thyroid gland produces thyroxine
hypothalamus detects cell have enough energy
pituitary stops producing TSH
thyroid stops producing thyroxine
[loops]

Question 9

how adrenaline is controlled and what it does

Answer 9

when scared, adrenal gland produces adrenaline
when back to normal, adrenal gland stops adrenaline production
causes: cells to respire more, breathing to increase, increase BPM, divert blood to muscles