13.2 Neurones

Question 1

Stimulus

Answer 1

Changes in the internal or external environment

Question 2

Function of cell body

Answer 2

Contains nucleus surrounded by cytoplasm
Lots of ER and mitochondria - produce neurotransmitters

Question 3

Function of dendrons

Answer 3

Short extensions coming from cell body
Extensions divide into smaller and smaller branches (dendrites)
Transmit electrical impulses towards the cell body

Question 4

Function of axons

Answer 4

Singular elongated nerve fibres that transmit impulses away from the cell body
Cylindrical in shape and contain narrow region of cytoplasm surrounded by a plasma membrane

Question 5

Types of neurones

Answer 5

Sensory
Motor
Relay

Question 6

Sensory neurone

Answer 6

Transmit impulses from sensory receptor to relay neurone, motor neurone or the brain
Contain one dendron and one axon

Question 7

Relay neurone

Answer 7

Neurones transmit impulses between neurones
Many short axons and dendrons

Question 8

Motor neurone

Answer 8

Neurones transmit impulses from a relay neurone or sensory neurone to an effector
One long axon and many short dendrites

Question 9

Pathway for electrical impulses

Answer 9

Receptor
Sensory neurone
Relay neurone
Motor neurone
Effector cell

Question 10

How is myelin sheath formed?

Answer 10

Schwann cells grow around the axon many times, by laying down a double layer of phospholipid bilayer each time

Question 11

Effect of myelin sheath

Answer 11

Acts as an insulating layer
Conduct electrical impulse at a much faster speed

Question 12

What are gaps between Schwann cells known as?

Answer 12

Node of Ranvier