B10-Reflex Acttions

Question 1

Why are reflexes important

Answer 1

Reflexes are important to a living organisms because some activities like breathing etc don’t need a signal by brain to breath.It is by the peripheral nervous system and do not involve CNS

Question 2

How do actions work

Answer 2

receptor
sensory neurone
CNS.
relay neurone
motor neurone.
effector organ.

Question 3

When you step on a pin, and just when the pin is about to pierce our PNS sends signal by reflex arc to the muscles of leg to lift off the leg as soon as possible. The mechanism involved is:

Answer 3

An electrical impulse from a receptor passes along a sensory neurone to the CNS – in this case, the spinal cord.
When an impulse from the sensory neurone arrives at the synapse with a relay neurone, a chemical is released.

The chemical diffuses across the synapse to the relay neurone where it sets off a new electrical impulse that travels along the relay neurone.

The chemical diffuses across the synapse and starts a new electrical impulse travelling down the motor neurone to the effector.