Cells and Tissues of the Nervous System

Question 1

what is the CNS and PNS made up of?

Answer 1

central nervous system-brain and spinal cord

peripheral nervous system-cranial and spinal nerves

Question 2

what does the PNS divide into?

Answer 2

sensory(afferent) division

motor(efferent) divison

Question 3

what are the two divisions of motor nerves?

Answer 3

somatic

autonomic

Question 4

what are the two divisions of autonomic system?

Answer 4

sympathetic

parasympathetic

Question 5

what are neurons?

Answer 5

Structural and functional unit
Excitable cells
Impulses carried as action potentials

Question 6

what are glial cells?

Answer 6

Non-excitable supporting cells

Much smaller than neurons

Question 7

Impulse transmission is by action potential which can travel in what direction?

Answer 7

in only one direction from cell body to synaptic terminal

Question 8

which part of the neuron cant grow back when damaged?

Answer 8

Axon can grow back but if cell body is damaged – loss is irreversible!

Question 9

what is the myelin sheath?

Answer 9

Increase conduction speed in axons by ‘saltatory conduction’

Question 10

what forms the myelin sheath?

Answer 10

Schwann cells in PNS

Oligodendrocytes in CNS

Question 11

what is the cause of multiple sclerosis?

Answer 11

Patchy loss/scarring of myelin sheath (demyelination)- nerve conduction across affected axons abnormal

Question 12

describe the type of neurone for interneurones & motor neurons

Answer 12

multipolar

Question 13

describe the type of neurone for olfactory neurons & retinal nerve fibres

Answer 13

bipolar

Question 14

describe the type of neurone for sensory neurons

Answer 14

pseudounipolar

Question 15

what does the collection of cell bodies & non-myelinated axons form if diffuse/localised?

Answer 15

grey matter (if diffuse) or nucleii (if localised)

Question 16

what does the collection of myelinated axons form?

Answer 16

white matter (diffuse) or tracts (bundles of axons carrying specific information within the white matter)

Question 17

in the periphery what do myelinated axons and cell bodies form?

Answer 17

Myelinated axons form nerves

Cell bodies form ganglia

Question 18

what type of glial cells in the CNS are important to know?

Answer 18

astrocytes-have efferent surround synapses&capillaries

help in K+ buffering

Question 19

what early embryology forms the nervous system?

Answer 19

ectoderm- neural tube

Question 20

which primary vesicle of the neural tube forms the forebrain?

Answer 20

telencephalon

Question 21

which vesicle of the neural tube forms the eyes?

Answer 21

diencephalon

Question 22

what are 4 ventricles of the brain

Answer 22

lateral ventricle
III ventricle
cerebral aqueduct
IV ventricle

Question 23

where do the lateral ventricles lie?

Answer 23

cerebral hemispheres

Question 24

where does the 3rd ventricle lie?

Answer 24

cavity within the diencephalon

Question 25

where does the cerebral aqueduct lie?

Answer 25

midbrain

Question 26

where does the 4th ventricle lie?

Answer 26

hindbrain

Question 27

what are the 3 coverings of the CNS?

Answer 27

Dura mater
Arachnoid mater
Pia mater

Question 28

where is the Cerebrospinal fluid (CSF) present?

Answer 28

Inside ventricles

Between pia & arachnoid

Question 29

what does the CSF do?

Answer 29

maintenance of the “intracranial pressure”

Question 30

where is the CSF formed?

Answer 30

By choroid plexus in each ventricle

Question 31

where s the CSF absorbed?

Answer 31

By Arachnoid villi into saggital sinus (venous channel in brain)

Question 32

what is the blood brain barrier?

Answer 32

protective mechanism

-maintains stable environment for the brain and prevents harmful amino acids & ions entering

Question 33

where is the BBB absent within the brain?

Answer 33

parts of hypothalamus, posterior pituitary