Chapter 5 - Nerve Cells and Nerve Impulses

Question 1

What are the two parts of the nervous system?

Answer 1

Central Nervous System and the Peripheral nervous system

Question 2

What is the central nervous system and what does it consist of?

Answer 2

Its the control centre of the whole nervous system and contains the brain and spinal cord

Question 3

What is the peripheral nervous system made up of?

Answer 3

Nerves that connect the central nervous system with receptors, muscles and glands

Question 4

What do axons do?

Answer 4

Carry nerve impulses away from the cell body

Question 5

What do myelinated fibres have?

Answer 5

They have a myelin sheath

Question 6

What are neurotransmitters?

Answer 6

A molecule that carries a nerve impulse across the small gap between branches of adjacent nerve cells

Question 7

What is a synapse?

Answer 7

The junction between the branches of adjacent neurons

Question 8

What are nerve impulses?

Answer 8

Messages that travel along nerve fibres

Question 9

What do nerve impulses do?

Answer 9

Transmitted quickly making the body respond rapidly to any change

Question 10

What is an electrochemical change?

Answer 10

Change in the electrical voltage brought about by changes in the concentration of ions

Question 11

Unmyelinated fibres..:

Answer 11

Travel steadily along the fibre

Question 12

Why do myelinated nerves travel faster

Answer 12

Due to saltatory conduction

Question 13

What does extracellular fluid contain?

Answer 13

High concentration of sodium chloride

Question 14

What does intracellular fluid contain?

Answer 14

Low concentration potassium

Question 15

What is resting membrane potential?

Answer 15

The membrane potential of unstimulated nerve cells

Question 16

What is the nervous system?

Answer 16

Is the commnication network and control centre - maintains homeostasis

Question 17

What does the term polarised mean?

Answer 17

When the inside of the membrane of nerve cells is negatively charged

Question 18

What does the term depolarised mean?

Answer 18

When there is no difference in electrical charge between the inside and outside of the membrane

Question 19

What is the all or none response

Answer 19

A response of constant size regardless of the strength of the stimulus

Question 20

What is action potential?

Answer 20

When sodium ions move into a nerve cell at a particular place on the membrane

Question 21

What is a refractory period?

Answer 21

A short period following a stimulus during which a nerve cell cannot be stimulated

Question 22

What are interneurons?

Answer 22

Have branches/ send and receive messages from the neuron

Question 23

What is grey matter

Answer 23

Consists of nerve cell bodies

Unmyelinated fibres

Question 24

What is white matter?

Answer 24

Consists of myelinated fibres

Question 25

What do Schwann cells form?

Answer 25

Myelin sheath

Question 26

Sheath has 3 important functions

Answer 26

1. Insulator
2. Protects axons
3. Speed up movement of nerve impulses

Question 27

Types of neurons

Answer 27

1. Sensory: carry messages from receptors to cns
2. Motor: carry messages from CNS to muscles and glands
3. Interneurons: link between sensory and motor

Question 28

Structural types of neurons

Answer 28

1. Multipolar
2. Bipolar
3. Unipolar
4. Neuron
5. Nerve fibre
6. Nerve