The Nervous System

Question 1

What are effectors?

Answer 1

1. Effectors respond to nervous impulses and bring about a change.
2. Muscles and glands are known as effectors, they respon in different ways.
3. Muscles contract in response to a nervous impulse, whereas glands secrete hormones.

Question 2

What are receptors?

Answer 2

1. Receptors are the cells that detect stimuli.
2. There are many different types of receptors, such as taste receptors on the tongue and sound receptors in the ears.
3. Receptors can form part of larger, complex organs. E.g. the retina in the eye is covered in light receptor cells.

Question 3

What is the Central Nervous System (CNS)?

Answer 3

1. In vertabrates, this consists of the brain and spinal cord only. In mammals, the CNS is connected to the body by sensory neurones and motor neurones.

Question 4

What are sensory neurones?

Answer 4

1. Sensory neurones are the neurones that carry information as electrical impulses from the receptors to the CNS.

Question 5

What are motor neurones?

Answer 5

1. Motor neurones are the neurones that carry electrical impulses from the the CNS to effectors.

Question 6

What is a synapse?

Answer 6

1. A synapse is a junction between two neurones.
2. It allows for the tranmission of electric nerve impulses in the nervous system.

Question 7

How does information pass a synapse?

Answer 7

1. Neurotransmitters are released into the synaptic cleft.
2. The neurotransmitters diffuse through the synapse where they bind to the receptors on the post-synaptic neurone.

Question 8

What are reflex actions?

Answer 8

1. Reflex actions are rapid responses to harmful stimuli, protecting the body from injury.
2. They don’t involve the coscious part of your brain.
3. There are more synapses in the brain and synapses slow down transmission.