Neurones Flashcards
What are neurones?
The cells making up the nervous system which conduct electrical impulses. There are various kinds of neurones which come in a variety of shapes and sizes but they all poses the same, basic underlying structure.
Why are sensory neurones different from other neurones (relay and motor)?
Sensory neurones are unipolar, relay and motor neurones and multipolar.
How do motor neurones differ from sensory and relay neurones?
Motor neurones are mylienated whereas the other two are not.
What do sensory neurones do?
They carry information from the body’s sensory receptors to the spinal cord and brain (CNS). They convert information from the body’s sensory receptors to neural impulses which travel to the brain and are translated into sensations (heat, pain etc) so we can respond accordingly.
Describe the structure of a sensory neurone.
Sensory neurones have a cell body, with two stems on either side.
What is the function of motor neurones?
The function of motor neurones is to carry motor commands from the CNS to skeletal muscles or glands, allowing control of movement and responses of internal systems.
How do motor neurones inhibit or encourage movement?
Motor neurones form synapses with muscles to control their contractions. When stimulated neurotransmitters are released which bind to receptors on the muscle, triggering a response resulting in muscle movement. Muscle relaxation results from the inhibition of the motor neurone.
Describe the structure of a motor neurone.
A single axon and many dendrites.
What are relay neurones?
Neurones within the CNS which interconnect different parts of the CNS. They pass messages to other neurones within the CNS and allow sensory and motor neurones to communicate with each other.
Describe the structure of a relay neurones.
Relay neurones have a cell body surrounded entirely by dendrites.
What do dendrites do?
Receive signals from other neurones or sensory receptors.
What is the cell body’s function?
Control centre of the neurone.
What is the function of an axon?
Conducts nerve impulses away from cell body and towards other neurones.
