Reflex arc

1.

REFLEX ARC

2.

Lesson objectives
To investigate the reflex arc.

3.

What is a reflex?
A reflex is a sudden, involuntary
contraction of muscles in response to a
stimulus.
It is a some kind of automatic response
for protection.

4.

5.

6.

Reflex arc
Reflex arc is neural pathway of nerve signals,
which include:
1. Receptor. It receives signals from outside
2. Sensory neuron. It transmits signal from
receptor to CNS, mainly to spinal cord
3. Spinal cord interneurons. They interpret the
information and decides what to do. Then it
sends signal to motor neuron.
4. Motor neuron. It carry signal from spinal cord
to effector.
5. Effector. It is an organ that produce an reflex
action.

7.

8.

Let’s do a labwork on p.95

9.

Homework
Read p. 94-95
Answer to literacy questions on p 95.
Fill in the labwork sheet.
New words