Nervous System

Question 1

WRT Neuron:

1. Define
2. State location
3. State function

Answer 1

1. the neuron is the structural and functional units of the nervous system.
2. They are located in the brain and spinal cord
3. They transmit nerve impulses from sense organs to the CNS and from the CNS to the muscles and glands

Question 2

Characteristics of cyton/Perikaryon

Answer 2

• It contains a well defined nucleus
• Nucleus surrounded by granular cytoplasm
• Has all organelles like other cells, but centrosome is absent as they have lost the ability to divide

Question 3

Fill in the blanks

The cyton has all cell organelles except _ _ _ _ _

Answer 3

Centrosome

Question 4

Define and state the function of dendrites.

Answer 4

Dendrites are branched cytoplasmic projections of the cyton
They conduct nerve impulses to the cyton

Question 5

State the Location and function of myelin/medullary sheath

Answer 5

Location- around the axon of a neuron
Function- Its an insulating sheath which speeds up the rate of transmission of nerve impulses as it travels down the axon

Question 6

what is a synapse?

Answer 6

the point of contact between the axon bulb of a neuron and the dendrite of the next neuron.

Question 7

what are the three types of neurons and what do they do?

Answer 7

The 3 types of neurons are: Sensory, Motor and Association neurons
Sensory neurons: Convey impulse from receptor to spinal cord or brain
Motor neurons: Carry impulse from CNS to an effector (muscle / gland)

Question 8

what are nerves

Answer 8

A nerve is a bundle of nerve fibres of separate neurons enclosed in a tubular sheath

Question 9

types of nerves

Answer 9

Sensory nerves(contain sensory neurons only) Ex: Optic nerve arising from eye and ending in the brain

Motor nerves (contain motor neurons only) Ex: Nerve arising from the brain and supplying the muscles of the eyeball for rotating the eye

Mixed nerves(contain both sensory and motor neurons) Ex: Spinal nerve

Question 10

parts of nervous system

Answer 10

• Central nervous system
• peripheral nervous system
• autonomic nervous system

Question 11

What are meninges? Name them

Answer 11

The three membranous coverings that protect the brain are called meninges
1. Dura mater (outer)
2. Arachnoid (middle)
3. Pia mater (inner)

Question 12

The inflammation of the meninges is called:

Answer 12

Meningitis

Question 13

Expand CSF. State its location and function.

Answer 13

Cerebrospinal fluid. It is located in the space between the meninges, ventricles in the brain and central canal of the spinal cord. It acts like a cushion and protects the brain from shocks

Question 14

The outer cortex of the cerebrum is made of ___________ matter. The inner medulla is made of ________ matter.

Answer 14

Gray ( contains cytons)
White (contains axons)

Question 15

what is cranial nerves?

Answer 15

the nerves that arise from the brain are called cranial nerves. there are 12 pairs of cranial nerves. cranial nerves supply different parts of head.

Question 16

what is spinal nerves

Answer 16

the nerves that arise from the spinal cord is the spinal nerve. there are 31 pairs. the spinal nerves have mixed nerves.

Question 17

what is a reflex action? (2)

Answer 17

it is an automatic involuntary action in the body brought about by a stimulus

Question 18

what is a reflex arc

Answer 18

The shortest route taken by an impulse from a receptor to an effector.

Question 19

What is Corpus Callosum? What is its function?

Answer 19

The sheet of fibres connecting the two cerebral hemispheres. Its function is to transfer info from one hemisphere to the other

Question 20

What are the divisions of the spinal nerves?

Answer 20

8 pairs in neck, 12 pairs in thorax, 5 pairs in lumbar, 5 pairs in sacral and 1 pair in coccygeal region

Question 21

What are the functions of the spinal cord?

Answer 21

• controls reflexes below the neck
• conducts sensory impulses from the skin and muscles to the brain
• conducts motor responses from the brain to the muscles of the trunk and limbs

Question 22

What are the functions of the cerebrum?

Answer 22

• Controls all voluntary actions
• enables us to think, memorise, plan, reason etc.

Question 23

What is the location of the cerebellum? State its functions

Answer 23

• Base of the brain and under the large cerebrum

F: maintains body balance and coordinates muscular activities

Question 24

State the location and function of the medulla oblongata

Answer 24

L: Base of the skull
F: Controls involuntary actions of the internal organs, ex: breathing peristalsis, beating of heart etc

Question 25

What does the forebrain consist of?

Answer 25

Cerebrum and Diencephalon (Thalamus, Hypothalamus)

Question 26

What does the hindbrain consist of?

Answer 26

Cerebellum, Pons, Medulla Oblongata

Question 27

State the location and function of pons.

Answer 27

L: Centre of the brain below the cerebellum
F: Carries impulses from one hemisphere to cerebellum to the other and coordinates muscle movement on both sides of the body.

Question 28

State the location of the spinal cord.

Answer 28

L: extends from medulla of the brain down almost the whole length of the backbone to the end at the second lumbar vertebra.

Question 29

What is a stimulus?

Answer 29

Any changes in the external or internal environment that brings about a response in the body.

Question 30

What are inborn reflexes?

Answer 30

Reflexes in which no previous experience or learning in required