Reflex Action

Question 1

What is reflex action?

Answer 1

An automatic involuntary, unthinking response to a stimulus

Question 2

What is the simplest form of activity in the nervous system?

Answer 2

Reflex action

Question 3

What are some examples of reflex actions?

7 points

Answer 3

The grasp reflex in children
The movement of the iris of the eye 
Blinking the eyes for protection
Breathing 
Control of blood pressure 
The protective actions we take when falling 
The knee jerk

Question 4

What are the advantages of the reflex action?

Answer 4

It is a fast response so it can protect the body from damage

Question 5

What is a reflex arc?

Answer 5

The pathway taken by a nerve impulse in a reflex action

Question 6

What is a reflex arc the unit of?

Answer 6

It is the unit of function of the nervous system

Question 7

Describe what happens when ones finger touches a hot flame.

6 points

Answer 7

Receptors in the finger are stimulated by the flame
Sensory neurons carry an impulse into the spinal cord through the dorsal root
An interneuron carries the impulse across the spinal cord to a motor neuron
Another neuron takes the impulse up to the brain
Motor neurons take the impulse straight out of the spine through a ventral root to the effector muscle or gland which causes the hand to be pulled back
At the same time the hand is withdrawn the impulse reaches the brain which makes us aware of what has happened and we feel pain but this is involuntary