The Nervous System

Question 1

What does the nervous system do?

Answer 1

-Reacts to its surroundings.
-Co-ordinates its behaviour.

Question 2

What is a stimulus?

Answer 2

A change in the environment that triggers a response.

Question 3

What are receptors?

Answer 3

A cell that receives a stimulus and converts it into an electrical impulse to be sent to the brain and or spinal cord.

Question 4

What is a synapse?

Answer 4

A gap between 2 neurons.

Question 5

What are the 2 types of neurons?

Answer 5

Sensory & Motor.

Question 6

How does the body respond to change? (SHORT ANSWER)

Answer 6

RECEPTOR —> (SENSORY NEURON) —> CENTRAL NERVOUS SYSTEM —> (MOTOR NEURON) —> EFFECTOR

Question 7

How does the body respond to change? (LONG ANSWER)

Answer 7

The NERVOUS SYSTEM carries fast ELECTRICAL impulses. STIMULI are picked up by the NEURONS. Impulses initially travel along SENSORY neurones which transmit the impulses from the RECEPTOR organs to the CNS. Here, impulses then travel along the spinal cord to the brain which CO-ORDINATES a response. The impulse then travels along MOTOR neurones to MUSCLES or GLANDS. These act as the EFFECTORS which carry out the response.

Question 8

How does the Sensory Neurone work?

Answer 8

They transmit messages from sense receptors, such as the eye or nose, to the brain or spinal cord.

Question 9

How does the Motor Neurone work?

Answer 9

They transmit messages from the brain & spinal cord to the muscles and glands.

Question 10

What are reflexes for?

Answer 10

• Help humans and animals avoid danger.
• Some help basic body functions.

Question 11

What are the 5 steps of a reflex?

Answer 11

• Stimulus picked up by Receptor cells in finger (skin)
• Impulse passed on to sensory neuron
• Sensory neuron passes impulse to spinal cord
• Spinal cord sorts out response and send message to motor neuron
• Motor neuron tells the finger to pull away

Question 12

How do synapses work?

Answer 12

• The gaps between your nerves are called SYNAPSE.
  
  • The impulses travelling down your NEURONS have to cross these.
  • The ELECTRICAL impulse arriving at the end of one neurone causes a CHEMICAL to be released in the gap. In the next neurone, the chemical initiates an electrical impulse that continues onwards to the EFFECTOR organ which is stimulated to respond.

Question 13

If the EYE is the sense organ, what is the stimulus?

Answer 13

Light

Question 14

If the EYE is the sense organ, what are the receptors?

Answer 14

Rods & Cones

Question 15

If the EARS are the sense organs, what is the stimulus?

Answer 15

Sound/Gravity

Question 16

If the EARS are the sense organs, what are the receptors?

Answer 16

Hair cells in the cochlea & Semi-circular canals

Question 17

If the NOSE is the sense organ, what is the stimulus?

Answer 17

Smell & Taste

Question 18

If the NOSE is the sense organ, what are the receptors?

Answer 18

Chemical Receptors

Question 19

If the TONGUE is the sense organ, what is the stimulus?

Answer 19

Taste (Sour, Sweet, Bitter, Salty)

Question 20

If the TONGUE is the sense organ, what are the receptors?

Answer 20

Taste Buds

Question 21

If the SKIN is the sense organ, what is the stimulus?

Answer 21

-Touch
-Pressure
-Temperature (Hot/Cold)
-Pain

Question 22

If the SKIN is the sense organ, what are the receptors?

Answer 22

Receptive Nerve Endings