The Nervous System + Nerve Cells Flashcards
Name the 2 types of nervous system.
Central
Peripheral
Name the components of the central nervous system.
Spinal cord
Brain
Where is the peripheral nervous system found?
Away from the centre of the body.
Name 2 components of the peripheral nervous system.
Somatic
Autonomic
What is the autonomic nervous system?
The nervous system that allows us to carry out reflexes and actions that don’t require any conscious thought (involuntary), such as heart rate.
What is the somatic nervous system?
The nervous system that governs voluntary movement.
What are the 2 components of the autonomic nervous system?
Sympathetic
Parasympathetic
What does the sympathetic nervous system do?
Speeds up involuntary bodily functions.
What does the parasympathetic nervous system do?
Slows down any involuntary bodily actions.
What do sensory neurones do?
Carry impulses triggered by a receptor to the coordinator.
What do relay neurones do?
Carry the impulse through the central nervous system as a response is coordinated.
What do motor neurones do?
Carry the impulse from the central nervous system to the effector
Where are the dendrites found on a neurone?
Found as long branches extending out from the cell body.
What is an axon?
A long fibre extending from the cell body that points towards the neighbouring cell’s dendrites.
What are the myelin sheath and nodes of ranvier and how does they assist with speeding up rate of transmission?
The myelin sheath is a fatty substance that surrounds the axon. There are small gaps in between parts of myelin called nodes of ranvier. They allow the impulse to jump across the myelin from node to node which is faster.
Myelin is made by what type of cell?
Schwann Cellss
What do Schwann cells do that lead to production of myelin?
They wrap themselves around the axon.
What is saltatory conduction?
Where the electrical impulse jumps from node to node, speeding it up.
Which part of the pre/post synaptic cell are involved in transmission from one cell to the next?
Axon of pre synaptic cell and dendrite of the post synaptic cell
Describe length of the axon and dendrites in a sensory neurone.
Short axon, long dendrites.
Describe the axon and dendrite length in relay neurones.
Short axon, short dendrites.
Describe the axon and dendrite length in motor neurones.
Long axon, short dendrites.
