Topic 8 ~ Grey Matter Flashcards
What is a neurone
Single cell that transports impulses from one part of the body to another
What is a nerve
Bundle of axons of many neurones surrounded by a protective covering
What are the function of dentrites on a neurone
Conduct impulses towards the cell body of the neurone
What are the functions of axons on neurones
Transmit impulses away from the cell body of the neurone
What are the 3 main types of neurone
- motor neurone
- sensory neurone
- relay neurone
Role of motor neurones
Conduct impulses from central nervous system to effectors (muscles)
Cell body is in CNS
Axon extends out to muscles
Role of sensory neurones
Carry impulses from sensory cells to central nervous system
Role of relay neurones
They have large number of connections with other nerve cells
Also known as connector neurones
Structure of a neurone
- cell body consisting of nucleus and cell organelles within the cytoplasm
- dendrites
- axon
- myelin sheath made of schwann cells
What is the myelin sheath
Fatty insulating layer around the axon
What is a reflex
Rapid involuntary response to stimuli
Describe a reflex arc
- receptors detect a stimulus
- sensory neurones carry impulse to CNS
- sensory neurones enter spinal cord through dorsal route
- synapse forms between sensory and relay neurones
- synapse forms between relay and motor neurones
- motor neurone leaves spinal cord through ventral route, carrying impulse to an effector
- response is produced
