L20: Central Nervous System (CNS)

Question 1

what does the CNS consist of?

Answer 1

• brain

- spinal cord

Question 2

what does PNS consist of?

Answer 2

• 12 pairs of cranial nerves

- 31 pairs of spinal nerves

Question 3

what is gray matter

Answer 3

• largely cell bodies and unmyelinated axons

Question 4

what is white matter

Answer 4

largely myelinated axons of neurones

Question 5

how much of the bodies neural tissues does the brain hold?

Answer 5

98%

Question 6

how much does the brain weigh

Answer 6

typically 1.4kg

Question 7

volume of the brain?

Answer 7

between 750-2100cc

Question 8

what is considered typical brain volume

Answer 8

1200cc

Question 9

what is pia mater

Answer 9

• closest layer to brain

- follows irregularities of brain surface

Question 10

what is arachnoid mater?

Answer 10

• subdural layer with projections to pia

- forms subarachnoid space for CSF (cerebrospinal fluid)

Question 11

what is dura mater?

Answer 11

• external dense connective tissue (protection)

Question 12

what does meninges consist of

Answer 12

• pia mater
• arachnoid mater
• dura mater

Question 13

what is cerebrospinal fluid?

how much is produced per day?

Answer 13

• clear fluid

- 150,500ml produced per day

Question 14

role of cerebrospinal fluid?

Answer 14

• supplies nutrients
• removes waste products
• protection

Question 15

where is cerebrospinal fluid found?

Answer 15

• subarachnoid space in arachnoid mater

Question 16

what is prosencephalon?

Answer 16

forebrain

cerebrum: telencephalon), thalamus, (hypothalamus: diencephalon

Question 17

what is mesencephalon?

Answer 17

midbrain

- narrow connection of forebrain to hindbrain

Question 18

what does the midbrain contain?

Answer 18

cerebral aqueduct

Question 19

what is rhombencephalon?

Answer 19

hindbrain

• medulla oblongata (myelencephalon)
• pons (metencephalon)
• cerebellum

Question 20

what does the brainstem consist of ?

Answer 20

• midbrain
• pons
• medulla oblongata

Question 21

what are the folds of the cerebral surface?

Answer 21

• gyri (gyrus)

- sulci (sulcus)

Question 22

in the midbrain, what is the tectum?

Answer 22

-visual and auditory processing

Question 23

in the tectum, what is the superior colliculus?

Answer 23

• reflex to visual stimulation e.g light

Question 24

in the tectum, what is the inferior colliculus?

Answer 24

• reflex to auditory stimulation e.g loud noise

Question 25

what is the corpora quadrigemina?

Answer 25

the four colliculi

Question 26

in the midbrain, what is the tegmentum?

Answer 26

• subconscious control of upper limb position and muscle tone

Question 27

what does the tegmentum consist of?

Answer 27

• red nucleus

- substansia nigra

Question 28

what is the pons?

Answer 28

‘bridge’ linking the cerebellum with the mesencephalon, diencephalon, cerebrum and spinal cord

Question 29

what does the pons consist of?

Answer 29

• nuclei of cranial nerves ( V, VI, VII, VIII)

Question 30

role of the nuclei in the pons?

Answer 30

• respiration control
• relay info to and from cerebellum
• interconnect ascending and descending tracts of the CNS

Question 31

what is cerebellum?

Answer 31

• monitors all proprioceptive, visual, tactile, balance and auditory sensations

Question 32

primary functions of cerebellum?

Answer 32

• automatic control of postural muscles of body

- programming/fine tuning conscious and subconscious movements

Question 33

what does the medulla oblongata connect

Answer 33

brain to spinal cord

Question 34

what is the medulla oblongata responsible for

Answer 34

• complex autonomic reflexes

- control of visceral functions

Question 35

what does the medulla oblongata consist of

Answer 35

• cardiovascular centres
• respiratory centres
• cranial nerve nuclei
• relay stations for sensory and motor pathways