The Nervous System

Question 1

What is the purpouse of the nervous system?

Answer 1

it means humans can react to their surroudings and cooridinate their behaviour

Question 2

what are the different parts that make up the nervous system?

Answer 2

1)the central nervous system(CNS)
2)the sensory neurones
3)the motor neurones
4)the effectors

Question 3

what is the CNS made up of?

Answer 3

-in vertebrates (animals with backbones) this consits of the brain and spinal chord only
-in mammals it is connected to the body by sensoy neurones and motor neurones

Question 4

what are sensory neurones?

Answer 4

they are neurones that carry information as electrical impulses from the receptors to the CNS

Question 5

what are motor neurones?

Answer 5

these carry electrical impulses from the CNS to effectors

Question 6

what are effectors?

Answer 6

-all the muscles and glands which respond to nervous impulses and bring about change
-e.g. muscles contract in response to a nervous impulse wheras glands secrete hormones

Question 7

what are receptors?

Answer 7

• these are cells that detect stimuli e.g. taste receptors on the tongue and sound receptors in the ears
  -they can also form part of larger complex organs e.g. the retina of the eye is covered in light receptor cells

Question 8

what is the purpouse of the CNS?

Answer 8

it receives information from the receptors and then coordinates a response which is carried out by effectors

Question 9

How would the CNS carry out its function if a small bird saw a cat predator coming its way?

Answer 9

1)after spotting the cat coming towards it (the stimulus) the receptors in the bird’s eyes would be stimulated
2)sensory neurones would then carry information from the receptors to the CNS and the CNS would coordinate a response by sending information to the muscles in the bird’s wings (the effectors) along motor neurones
3)the muscles would then contract and the bird would be able to fly away to safety