primary functional unit

Question 1

neurons

Answer 1

a neuron is an individual nerve cell. referred to as building block of the nervous system.

Question 2

function of neurons

Answer 2

• carry messages in from of an action potential to the appropriate part of the nervous system, , or interpret the message and enable a response.
  They are specialised:
  Some only carry sensory information
  Some only carry motor information
  Some carry information between different neurons
• nerve impluse of tiny electro chemical energy

Question 3

structure of neuron

Answer 3

most neurons have the following features in common:
Dendrites
Soma
Axon
Myelin
Axon terminals

Question 4

Dendrites

Answer 4

A thin, branch-like extension of a neuron

Receives information from other neurons and transmits it to the soma

form connections with thousands of other neurons

Question 5

soma

Answer 5

Also called the cell body

Combines neural information received from many dendrites and send it to the axon

Within the soma is the nucleus, where all biochemical information that maintains the neurons functioning is contained

Question 6

axon

Answer 6

Transmits neural information from the
Soma to other neurons or cells

Question 7

Myelin Sheath

Answer 7

Many axons are myelinated- but not all

A white, fatty substance that coats and
Insulates the axon

It enables fast and efficient transmission of neural information

Gaps called the Nodes of Ranvier which enable a fast electrical impulse to be sent along the axon

Question 8

Axon Terminals

Answer 8

The axon branches off into smaller extensions

These extensions are known as axon terminals

The neural impulse travels down these terminals
until they reach the sac at the end of the axon
terminal where the impulse is converted to a
chemical message

Question 9

movement of connection

Answer 9

Dendrite (Don’t)
Soma (Swim)
Nucleus (Nude)
Axon (Around)
Myelin Sheath (My)
Axon Terminals (Aunt)

Question 10

motor and sensory neuron

Answer 10

There are two types of neurons in the nervous system
Sensory –Afferent
A nerve cell that detects and sends messages from the sense organs (eyes, ears etc) and sense receptor sites (skin) to higher brain centres via the ascending tract of the spinal cord.
Different types of sensory neurons each of which is specialised to respond only to a type of stimulation (sense)
Motor - Efferent
A specialised neuron that carries messages away from the central nervous system (via the descending tract), towards the muscles, organs and glands; thereby enabling bodily movements and activating internal organs and glandular secretions
- Located in the lower brain stem and spinal cord

Question 11

interneurons

Answer 11

Nerve cells found only in the CNS that act as a link between sensory and motor neurons.
Most of the neurons in the brain and spinal cord are interneurons.

Carry information from other interneurons

Question 12

glial cells

Answer 12

Provide insulation, nutrients and support for neuronal function, as well as aiding repair of neurons and eliminating waste materials.