The Nervous System Flashcards
1
Q
What are relay neurones?
A
- the nerve cells that carry signals from sensory neurones to motor neurones
2
Q
What are control systems?
A
- help to keep the conditions constant by responding to changes (stimuli)
- formed of receptors to coordination centre to effectors
3
Q
What is the order of how behaviours are performed?
A
- stimulus to
- receptor (passing through sensory neurone)
- coordinator (passing through motor neurone)
- effector to
- response
4
Q
What is the medulla responsible for?
A
- unconscious activities
- e.g. breathing and heart rate
- near stem of brain
5
Q
What is the central nervous system (CNS) and what does it do?
A
- consists of only the brain and spinal cord
- these coordination centres are where the information from receptors in the sense organs is sent to and where responses are coordinated
- neurons transmit the information (as electrical impulses) very quickly to and from the CNS
- instructions are the sent from CNS to effectors (muscles and glands)
6
Q
What are the sensory neurones?
A
- nerve cells that carry signals as electrical impulses from the receptors in the sense organs to the central nervous system
7
Q
What is the spinal cord responsible for?
A
- part of the central nervous system
8
Q
What is the passage of information in a reflex (from receptor to effector) called?
A
- the reflex arc
9
Q
Explain the reflex arc
A
- when a stimulus is detected by receptors, impulses are sent along a sensory neurone to the central nervous system (CNS)
- when the impulses reach a synapse between the sensory neurone and a relay neurone in the CNS, chemicals are released which diffuse across the gap, then send a new electrical signal along the relay neurone
- when the impulses reach another synapse between the relay neurone and the motor neurone, the same things happen. chemicals are related and cause impulses to be sent along the motor neurone
- impulses then travel along the motor neurone to the effector
- muscle contracts (or gland releases hormones)
10
Q
What is the cerebellum responsible for?
A
- muscle coordination
- lower back area
11
Q
What is the cerebral cortex responsible for?
A
- consciousness
- intelligence
- memory
- language
- outer wrinkly bit
12
Q
What are motor neurones?
A
- the nerve cells that carry signals from the central nervous system to the effector muscle or glands
13
Q
What are synapses and how do they work?
A
- the connection between two neurones is a synapse
- the nerve signal is transferred by chemicals which diffuse across the gap
- these chemicals then set off a new electrical signal in the next neutron
- the transmission of a nervous impulse is very fast, but it is slowed down a bit at the synapse because the diffusion of chemicals across the gap takes time
14
Q
What is a stimulus?
A
- a change in your environment that you may need to react to
- it can be light, sound, touch, pressure, pain, chemical or a change in position or temperature
15
Q
How can scientists study the brain?
A
- studying patients with brain damage: if a small part of the brain had been damaged, you can tell what part the damaged part does
- electrically stimulating the brain: pushing a tiny electrode into the tissue. e.g. when the motor area is stimulated, the muscles contract and move
- MRI scans: produces a detailed picture of the brain’s structures. Can find out which areas of the brain are active during different activities.
