Chapter 13- Nervous System

Question 1

Role of nervous system

Answer 1

Controls the Activities of the body and how it reacts to the surrounding

Question 2

Stimulus

Answer 2

Any change in the environment that causes an organism to react is called a stimulus.

Question 3

Response

Answer 3

An organisms reaction to a stimulus

Question 4

Nervous system consists

Answer 4

• brain
• spinal cord
• spinal nerves
• hughly soecialosrd sense organs

Question 5

What do sense organs d⁷o

Answer 5

. Help body to adjust to stimulus

. Enable various parts of body to coordinate with one another quickly

Question 6

Involuntary actions

Answer 6

Automatic and not controlled
. Heart beat
. Breathung
. Peristalisis

Question 7

Voluntary actions

Answer 7

Controlled consciously

Question 8

Components of nervous system

Answer 8

CNS: brain nd spinal cord

PNS peripheral cranial :(nerves from brain) spinal nerves( from spinal cord) and sense organs

Question 9

How nervous system works

Answer 9

1. Sense organs receive stimulus: receptors
2. Through electrical impulses: nerve impulses, receptors inform CNS of any change in surroundings
3. Nerve impulses are transmitted to CNS by nerves
4. Muslces: Effectors rsspond to the processed stimulus

Question 10

Things by
•brain
•spinal cord

Answer 10

°voluntary action by geneeating nerve inpulses
°controls cranialreflexes e.g. salivation

° transmits nerve impulses to nd from the brain
°controls spinal reflexes e.g. knee jerk reflex

Question 11

Cranial nerves

Answer 11

Sensory nerves transmit impulses ftom receptors to brain

Motor nerves transmit impulses from brain to effectors

Question 12

Spinal nerves

Answer 12

• Sensory nerves transmit impulses from receptor to spinal cord
• Motor nerves transmit impulses from spinal cord to effectors

Question 13

Nervous tissue

Answer 13

It makes the nervous system. Consists of nerve cells called NEURONES.

Question 14

Sensory neurone

Answer 14

Receptor neurone

Transmits nerve impulses from the sense organs or receptors to the cns

Question 15

Motor neurones

Answer 15

Effectors neurones

Transmits nerve impulses from CNS to the effectors

Question 16

Relay neurone

Answer 16

Intermediate neurone

Transmits nerve impusles from sesnsory neurone to motor neurone. Found with in CNS

Question 17

Nerve fibre

Answer 17

Strand of cytoplasm extending from cell body

Question 18

Dendron

Answer 18

A nerve fibre that transmits impulses towars the cell bodyof a neurone

Question 19

Axon

Answer 19

Nerve fibre that transmits nerve impulse away from cell body

Question 20

Dendrites

Answer 20

Terminal branches: receive nerve impulses from other neurons

Question 21

Axon terminal

Answer 21

Terminal branches: transmit nerve impulses to another neuron

Question 22

Cell body

Answer 22

Nucleus adn cytoplasm

Question 23

Mylein Sheath

Answer 23

Fatty substancs->enclose many nerve fibres -> insulation for fast transmission of nerve impulses

Question 24

Neurilemma

Answer 24

Thun membrane arojnd myelin sheath

Question 25

Nodes of ranveir

Answer 25

Gaps in myelin sheThspeeds up rate of transmission of nerve inoulses along the fibres

Question 26

Motor end plate

Answer 26

Small gap between dendrite and nuscle fibres

Question 27

Synapse

Answer 27

Gap between rn and mn

Question 28

SN structure

Answer 28

Long dendron Short a on Cell body is round Transmit Nerve imoulse to rscepto to RN

Question 29

Mptor neuron structure

Answer 29

Short dendron Long axon Cell body is irregular Transmit nerve imoulses to releay neurone ro effector

Question 30

Dorsal root

Answer 30

SN only

Question 31

Dorsal root hanglion

Answer 31

A swellkng in dorsal root where cell bodirs of SN are locatdd

Question 32

Spinal nerves

Answer 32

Nerve fibres fron both axon and dendron

Question 33

Ventral root

Answer 33

Motor neurones only

Question 34

Cental canal

Answer 34

Carebrispinal fluid -> bribg nutients to spinal cords

Question 35

Grey matter

Answer 35

Comsistes of cell bodies of neurones | Forms outer layefd of brain dn centrak oarts of spinal cord

Question 36

Whiye matter

Answer 36

Consits of nerve fibres mainly | Forms central parts of brajn and outer layers of spinal cords

Question 37

Spinal cords transmits impulses from

Answer 37

Sensory neurone ip to brain | Brain down to motor neurone.

Question 38

Pthways of imoulses during senssation

Answer 38

Receptor to SN to RN in spinal cord to forebrain

Question 39

Pathway of impilses dyring voluntary actions

Answer 39

Forebrain to RN in spinal cord to motor neurone to effector

Question 40

Reflex action

Answer 40

An immmediate response to a specific stimulus without concious control

Question 41

Two classifciayions of reflex actions

Answer 41

■ cranial reflex -- contoled by brain but not concious will and usually occur in the head region e.g. pupil reflex,blinking and salivation ■ spinal reflex-- controlled by the spinal cords e.g. knee herk reflexand sudden withdrawal of hands on touching hot objects

Question 42

Reflex arc

Answer 42

Shortest pathwat by which N.I. trvel from receptor to effector in reflex action

Question 43

Parts of reflex arc

Answer 43

``` Receptor SN RN jn reflex cenyre MN Effector ```

Question 44

Hand withdrawal reflex

Answer 44

1. Receptors in skkn 2. SN 3. Spinal cord 4. MN 5. effecyor muscles contract

Question 45

Knee jerk reflex

Answer 45

1. Tap allied stretched upper thugh muscles 2. stretch recepto which is sensitive to stetchjng of thugh muscles 3. Recptor neurone leading to CNS 4. effector neurone leading back to CNS 5. Upper thigh muscles which is effdctor

Question 46

Cerebrum

Answer 46

Forebrain,cerebrum .interlligwnce,memory,learning,sensations and overall control of all voluntary actions jn humans .concerned with refulwayion og body temp a d water potential of blood,apperite,sleep and emotions Produces and releases i.t. hormones including ADH

Question 47

Mid brain

Answer 47

.concerned witi sight and visual reflexes e.g. movement of the eyeballd

Question 48

Hind brajn

Answer 48

.control mascular coordinatikn especially in maintaing balance .contols involuntary actions e.g heartbeat, peristalisis,rate of respiratory movemnets and contraction and dilation of blood vessels

Question 49

Parts of brain names

Answer 49

Forebeain cerbrum Mid brajn medulla oblongata Hind brain cerebellum