Nervous System

Question 1

Two parts of the nervous system

Answer 1

CNS - Central Nervous System

PNS - Peripheral Nervous System

Question 2

Neuron

Answer 2

A nerve cell

Question 3

Types of Neurons

Answer 3

Sensory Neuron - to CNS
Motor Neuron - away to muscles and glands
Interneuron - within CNS

Question 4

Dendrites

Answer 4

Receive information

Carry electrical impulse towards cell body

Question 5

Axons

Answer 5

Carry electrical impulses AWAY from cell body

Question 6

Cell body

Answer 6

Contains a nucleus

Forms dendrites and axons

Question 7

Myelin sheath

Answer 7

Insulates electrical impulses

Question 8

Schwann cells

Answer 8

Secretes myelin sheath

Question 9

Neurotransmitter swellings

Answer 9

Produce neurotransmitter chemicals

Question 10

Movement of an Impulse

Answer 10

Receives a stimulus of sufficient strength
Ions move in and out of dendrites and axons
Electrical impulse travels along a neuron

Question 11

Threshold

Answer 11

Least possible stimulus needed to send an impulse

Question 12

Features of a nerve impulse

Answer 12

All or nothing rule (threshold is reached or not)
Impulses travel at same speed
Delay between impulses (to allow message to pass between neurons)
Only travel from sensory to motor neurons

Question 13

Synapse

Answer 13

A region where two neurons come in close contact

Question 14

Synaptic cleft

Answer 14

Tiny gap between two neurons

Question 15

Events at a Synapse

Answer 15

• Electrical impulse at synapse stimulates release of neurotransmitter chemicals
• Chemicals diffuse along synaptic cleft
• Chemicals Enter neuron and are broken down
• Electrical impulse is regenerated

Question 16

Function of Synapse

Answer 16

Control the direction of impulses in the nervous system

Question 17

What surrounds the brain and spinal cord

Answer 17

Meninges (3 membranes) and cerebro-spinal fluid

Question 18

Color of cell bodies

Answer 18

Grey

Question 19

Color of myelin sheath (near dendrites and axons)

Answer 19

White

Question 20

Cerebrum

Answer 20

Conscious movement

Senses, intelligence, personality

Question 21

Left hemisphere of brain

Answer 21

Language, maths, logic

Question 22

Right side of brain

Answer 22

Music, art, emotions, shapes

Question 23

Cerebellum

Answer 23

Balance

Muscular co-ordination

Question 24

Medulla

Answer 24

Involuntary muscles

Question 25

Thalamus

Answer 25

Sorting centre for the brain | Directs incoming impulses to correct part of brain

Question 26

Hypothalamus

Answer 26

Homeostasis

Question 27

Meninges

Answer 27

Surrounds and enclose entry of materials to brain and spinal cord

Question 28

Spinal nerves

Answer 28

31 pairs | Carry impulses to and from spinal cord

Question 29

Dorsal root

Answer 29

Carries impulses into spinal cord along sensory neurons

Question 30

Ganglion

Answer 30

Swelling that contains the cell bodies of sensory neurons

Question 31

White matter

Answer 31

Contains Axons

Question 32

Grey Matter

Answer 32

Contains cell bodies

Question 33

Central Canal

Answer 33

Contains cerebrospinal fluid

Question 34

Ventral Root

Answer 34

Carries impulse OUT OF the spinal cord along motor neurons

Question 35

Reflex Action

Answer 35

Automatic, involuntary or unconscious response to a stimulus • Knee jerk, blinking for protection • Protect the body from harm through faster responses

Question 36

Reflex Arc

Answer 36

Path taken by electrical impulse

Question 37

Events of a Reflex Action

Answer 37

* Receptors on finger detect reflex action * Impulse travels along sensory neuron to spinal cord into spine through dorsal root * Impulse splits: crosses Synapse onto an interneuron/crosses another Synapse to brain (brain becomes aware) * Impulse crosses another synapse from interneuron and travels out of ventral root * Motor neutron connects to a muscle that causes the response

Question 38

PARKINSON’S DISEASE

Answer 38

CAUSE: Failure to produce dopamine SYMPTOMS: Trembling of hands and legs, muscular stiffness, difficulty in waking PREVENTION: Protective clothes from pesticides TREATMENT: Levadopa (drugs)