Page 34 - Biology_Form_3

Biology for Secondary Schools

Nerve impulse produced when the nerve cells are activated.
Since the nerve fibre of one neurone is
Task 2.4
not in direct contact with that of another
Search from the library and internet neurone, there is a gap at the point where
sources for the animations illustrating the axon terminals of one neurone are in
FOR ONLINE READING ONLY
the transmission of nerve impulses across association with the dendrite or cell body
the neurones. Watch the animations of another neurone, or an effector organ.
and prepare a short summary about the This is called a synapse and its gap is called
animation. synaptic gap or synaptic cleft as shown in
Figure 2.7.

A nerve impulse is the electrical signal that
travels along the axon. These signals are

Synapse

Axon

Synaptic cleft

Dendrites

Axon terminals
Figure 2.7: synaptic gap between neurones

Exercise 2.1 5. In which ways is coordination
important to organism?
1. Explain how the neurone is adapted
to its function.
2. With the aid of a diagram describe the Central nervous system
components of coordination pathway Task 2.5
in mammals. Search from the library and internet
3. Explain the structural differences sources for the animations about
between motor and sensory neurones. components of the central nervous system

4. Describe the differences between including its structure and functions.
sensory neurone and interneurones. Watch the videos and write short notes
How are the two related? about the watched video.

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