Communication and homeostasis

HideShow resource information
  • Created by: robert
  • Created on: 23-03-14 12:11
Stimulus
Any change in the environment that causes a response
1 of 33
Response
A change in the behaviour or physiology as a result of a change in the environment
2 of 33
Homeostasis
the maintenance of a constant internal environment despite changes to the external environment
3 of 33
Negative fedback
a process that brings about the reversal of a change in conditions, ensuring a constand state is maintained
4 of 33
Positive feedback
process that increases a change detected by receptors can be harmful and does not lea dto homeostasis
5 of 33
Ectotherm
Organism that relies on external source of heat to regulate body temperature
6 of 33
endotherm
organism that used internal heat from metabolism to maintain body temperature
7 of 33
polarised
membrane with a potential difference across it. this is the resting potential
8 of 33
depolarisation
loss of polarisation across membrane.
9 of 33
generator potential
small depolarisation caused by Na+ entering cell
10 of 33
Action potential
achieved when depolarisation reaches +40mV. all or nothing response.
11 of 33
Voltage-gated channel
Channels in membrane that allow passage of ions. can open and close depending on polarity.
12 of 33
threshold potential
potential difference about -50mV. if this is not reached, then action potential is not made
13 of 33
Local current
movement of ions along a neurone. increased conc leads to diffusion to next region.
14 of 33
Saltatory conduction
action potential jumps between nodes of Ranvier
15 of 33
Neurotransmitter
chemical used to pass impulse across synapse
16 of 33
Synaptic knob
Swelling at the end of a pre-synatic neurone
17 of 33
Summation
the way several potential changes can combine to produce one larger potential difference.
18 of 33
Hormone
molecules released by endocrine glands into the blood. They act as messengers
19 of 33
Endocrine gland
gland secreting hormones into blood
20 of 33
Exocrine gland
gland secreting into a duct
21 of 33
target cell
a cell with the specific receptor for a hormone
22 of 33
Adenyl Cyclase
Enzyme associated with many hormones.
23 of 33
First messenger
Hormone that transmits signal around body
24 of 33
Second messenger
cAMP, transmits the signal into the cell
25 of 33
Pancreatic duct
Dust collecting secretions from exocrine glands in pancreas
26 of 33
Islets of langahans
small patches on tissue tht have endocrine function. made up of alpha and beta cells.
27 of 33
Diabetes Mellitus
blood glucose can't be controlled
28 of 33
Hyperglycaemia
blood glucose is too high
29 of 33
Hypoglycaemia
blood glucose is too low
30 of 33
Myogenic
muscle that can contract on its own
31 of 33
Medulla Oblongata
Base of brain stem, responsible for unconsious functions such as heart rate.
32 of 33
cardiovascular centre
region in Medulla Oblongata that recieves sensory input about activity levels, CO2 conc and blood pressure. sends impulse to SAN to alter frequency of wave of exitation.
33 of 33

Other cards in this set

Card 2

Front

A change in the behaviour or physiology as a result of a change in the environment

Back

Response

Card 3

Front

the maintenance of a constant internal environment despite changes to the external environment

Back

Preview of the back of card 3

Card 4

Front

a process that brings about the reversal of a change in conditions, ensuring a constand state is maintained

Back

Preview of the back of card 4

Card 5

Front

process that increases a change detected by receptors can be harmful and does not lea dto homeostasis

Back

Preview of the back of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all communication and homeostasis resources »