Endocrine

Question 1

endocrine signalling

Answer 1

secreted molecules diffuse into the bloodstream and trigger a response anywhere in the body

Question 2

paracrine signalling

Answer 2

secreted molecules diffuse locally and trigger a response in neighbouring cells

Question 3

autocrine signalling

Answer 3

secreted molecules diffuse locally and trigger a response in the same cell

Question 4

synaptic signalling

Answer 4

neurotransmitters diffuse across synapses and trigger responses in cells of neurons, muscles or glands

Question 5

neuroendocrine signalling

Answer 5

neurohormones diffuse into bloodstream and trigger a response anywhere in the body

Question 6

local regulator

Answer 6

molecule influencing nearby cells, involved in physiological processes (blood pressure, nervous system function + reproduction)

Question 7

prostaglandin

Answer 7

fatty acids that are secreted by all tissues, promote inflammation and pain, regulate platelets for clotting

Question 8

pheromones

Answer 8

molecule to communicate between members of the species, influencing physiology and behaviour

Question 9

NO

Answer 9

is a local regulator and neurotransmitter

endothelial cells in blood vessel walls synthesis and release NO in response to falling O2 levels, which then activates an enzyme leading to vasodilation

Viagra (increases blood flow to penis)

Question 10

Hormone classes

Answer 10

polypeptides (water soluble)

steroids (hydrophobic, lipid soluble)

amines (mostly water soluble)

Question 11

water soluble hormones

Answer 11

secreted by exocytosis and travel in bloodstream

cannot diffuse through plasma membranes, (lipid insoluble) so they bind to cell-surface receptors

Question 12

lipid soluble hormones

Answer 12

exit endocrine cells via diffusion, bind to transport proteins and enter targets via diffusion, binding to intracellular receptors or the nucleus

Question 13

adrenaline

Answer 13

secreted by glands in kidneys

amine hormone

1. binds to G protein-coupled receptor in membrane of target cells
2. triggers cascade synthesising cAMP
3. cAMP activates protein kinase A
4. enzyme that breaks down glycogen is triggered and enzyme that synthesis glycogen is inactivated
5. liver releases glucose in bloodstream

Question 14

steroid hormone receptors

Answer 14

1. binds to cytosolic receptor
2. forms a complex that moves into nucleus
3. interacts with DNA-binding protein and alters transcription

Question 15

negative feedback

Answer 15

dampens a stimulus

helps restore a pre-existing state (homeostasis)

Question 16

positive feedback

Answer 16

accelerates a stimulus

Question 17

hypothalamus

Answer 17

maintains homeostasis, coordinates endocrine and nervous systems, secretes hormones of posterior pituitary and regulates anterior pituitary

Question 18

parathyroid hormone

Answer 18

released when Ca2+ levels fall below 10 mg/100 mL

Question 19

hormone cascade

Answer 19

negative feedback

1. stimulus
2. hypothalamus
3. TRH (thryotropin - releasing hormone)
4. anterior pituitary
5. TSH (induces thyroid gland to secrete hormone)
6. Thyroid gland
7. Thyroid hormone