Module 1 Communication and Homeostasis

HideShow resource information
Stimulus
Any change in the environment that causes a response
1 of 26
Response
A change in behaviour or physiology as a result of a change in the environment
2 of 26
Negative feedback
A process that brings about the reversal of any change in conditions. It ensures that an optimum steady state can be maintained
3 of 26
Homeostasis
The maintenance of the internal enviroment in a constant state despite external changes
4 of 26
Positive feedback
A process that increases any change detected by receptors. It tends to be harmful and does not lead to homeostasis
5 of 26
Ectotherm
An organism that relies on external sources of heat to regulate its body temperature
6 of 26
Endotherm
An organism that can use internal sources of heat, such as heat generated from metabolism in the liver, to maintain its body temperature
7 of 26
Polarised membrane
Has a potential difference across it. This is the resting potential
8 of 26
Depolarisation
The loss of polarisation across the membrane. It refers to the period when sodium ions are entering the cell making the inside less negative with respect to the outside
9 of 26
Generator potential
A small depolarisation caused by sodium ions entering the cell
10 of 26
Action potential
Achieved when the membrane is depolarised to around +40mV. It is an all or nothing response
11 of 26
Resting potential
Is the potential difference or voltage across the neurone cell membrane while the neurone is at rest. It is around -60mV inside the cell compared to outside
12 of 26
Threshold potential
A potential difference across the membrane of around -50mV
13 of 26
Saltatory conduction
'Jumping conduction'. Refering the way that the action potential jumps from one node of ranvier to another
14 of 26
Cholinergic synapse
Uses acetylcholine as their transmitter substance
15 of 26
Neurotransmitter
A chemical that diffuses across the cleft of the synapse to transmit a signal to the postsynaptic neurone
16 of 26
Acetylcholinesterase
An enzyme in the synaptic cleft. It breaks down the transmitter substance acetylcholine
17 of 26
Endocrine gland
A gland that secretes hormones directly into the blood. Endocrine glands have no ducts
18 of 26
Exocrine gland
A gland that secretes molecules into a duct that carries the molecules to where they are used
19 of 26
Adenyl cyclase
An enzyme associated with the receptor for many hormones, including adrenaline. It is found on the inside of the cell surface membrane
20 of 26
First messenger
The hormone that transmits a signal around the body. The second messenger is cAMP, which transmits a signal inside the cell
21 of 26
Islets of Langerhans
Small patches of tissue in the pancreas that have an endocrine function
22 of 26
α cells and β cells
α cells secrete the hormone glucagon. β cells secrete the hormone insulin
23 of 26
Genetically engineered bacteria
Bacteria in which the DNA has been altered.
24 of 26
Medualla oblongata
Found at the base of the brain. It is the region of the brain that coordinates the unconscious functions of the body such as breathing rate and heart rate
25 of 26
Cardiovascular centre
A specific region of the medualla oblongata that recieves sensory imputs about levels of physical activity, blood CO2 concentration and blood pressure. It sends nerve impulses to the SAN in the heart to alter the frequency of excitation waves
26 of 26

Other cards in this set

Card 2

Front

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

Back

Response

Card 3

Front

A process that brings about the reversal of any change in conditions. It ensures that an optimum steady state can be maintained

Back

Preview of the back of card 3

Card 4

Front

The maintenance of the internal enviroment in a constant state despite external changes

Back

Preview of the back of card 4

Card 5

Front

A process that increases any change detected by receptors. It tends to be harmful and does not lead to 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, homeostasis and energy (F2144) resources »