Organisms Respond to Changes in their Internal and External Environments: Stimuli, Both Internal and External, are Detected and Lead to a Response - Survival and Response, Reflexes Flashcards
1
Q
What are receptors?
A
- Receptors detect stimuli
- Can be cells or proteins on cell surface membranes
2
Q
What are effectors?
A
- Cells that bring about a response to a stimulus
3
Q
What are neurones?
A
- Nerve cells
4
Q
What are the three types of neurones?
A
- Sensory neurones
- Motor neurones
- Relay neurones
5
Q
What is the central nervous system (CNS)?
A
- The brain and spinal cord
- Coordinator
6
Q
What is a coordinator?
A
- Coordinates information from receptors and sends instructions to effectors
7
Q
What are sensory neurones?
A
- Transmit electrical impulses from receptors to the central nervous system
8
Q
What are motor neurones?
A
- Transmit electrical impulses from the central nervous system (CNS) to effectors
9
Q
What are relay neurones?
A
- AKA intermediate neurones, interneurones or association neurones
- Transmit electrical impulses between sensory neurones and motor neurones
10
Q
Nervous communication
A
- Stimulus detected by receptor cells
- Electrical impulse sent along sensory neurone
- Electrical impulses reach end of neurone and neurotransmitters diffuse across synapse to postsynaptic neurone
- Another electrical impulse generated at postsynaptic neurone
- CNS processes information and sends impulses along motor neurones to effector
11
Q
Nervous response
A
- Electrical impulse reaches end of neurone
- Neurotransmitters secreted directly into cells so nervous response is localised
- Neurotransmitters removed once job done
- Electrical impulses fast, so response fast
12
Q
Simple reflexes
A
- Rapid, involuntary response to stimulus
- Nervous impulse goes through spinal cord but not through conscious part of brain
- Automatic response
