13.2 neurones

Question 1

what are the three main types?

Answer 1

• sensory
• motor
• relay

Question 2

sensory neurones transmit from … to …..

Answer 2

from receptors to the CNS

Question 3

motor neurones transmit from … to …..

Answer 3

CNS to effectors

Question 4

relay neurones transmit from … to …..

Answer 4

between sensory and motor neurones

Question 5

what are the four types

sensory receptor

and there examples

Answer 5

• mechano-pacinian corpuscles
• chemo-olfactory receptor
• thermo- end-bulbs of Krause
• photo- cone cell

Question 6

what stimulus do

mechanoreceptors pick up??

Answer 6

pressure and movement

Question 7

what are the two main features of

a sensory receptor?

Answer 7

1. they’re specific to a single type of stimulus
2. they act as transducers (they convert a stimulus to a nerve impulse/generator potential

Question 8

what is a

nerve impulse?

Answer 8

electrical impulses also called action potentials

Question 9

communication (CNS) and effectors can be either

Answer 9

• neuronal
• hormonal

Question 10

outline the four

differences between neuronal and hormonal

Answer 10

1. faster vs slower
2. more targeted vs less
3. short vs long lived
4. neurones vs glands and bloodstreem and receptors

Question 11

what are the three main

key features of mamilain neurones

Answer 11

• cell body - with a cytoplasm surounded body, large amounts of endoplasmic reticulum and mitochondria involved in the production of neurotransmitters
• dendrons- wich divide into smaller brances known as dendrites, responsible for transmitting electrical impulses towards the cell body
• axons - are the signilar, elongated nerve fibres that transmit impulses away from the cell body, with a very narrow region of cytoplasm

Question 12

draw the

structure of the three neurones

sensory,relay,motor

Question 13

How can you differentiate between a motor neuron and a sensory neuron.

Answer 13

• Sensory neurons have a cell body in the middle of the cell. Motor neurones have the cell body at the far end.
• Sensory neurons have both axon and dendron. Motor neurons only have an axon.
• Sensory neurons transmit impulses from receptor to coordinator. Motor neurons transmit impulses from coordinator to effector.

Question 14

Where is a relay neuron located?

Answer 14

Spinal cord

Question 15

Give 2 functions of the myelin sheath

Answer 15

Insulate the neuron. Speed up transmission of the impulse.

Question 16

Which type of ‘cell signalling’ is fastest acting and more targeted?

Answer 16

neuronal

Question 17

Which type of ‘cell signalling’ do plants employ?

Answer 17

Hormonal only