Central Nervous System

Question 1

intelligence is associated with what feature of the cerebral cortex?

Answer 1

area of infolds

Question 2

what does rostral mean?

Answer 2

towards the nose

Question 3

what does caudal mean?

Answer 3

towards the tip of the spinal cord

Question 4

layers of the brain from bottom to top

Answer 4

• medulla oblongata
• pons and cerebellum
• mid brain
• Diencephalon (hypothalamus and thalamus)
• cerebrum

Question 5

what are foramen?

Answer 5

holes in bones where nerves pass out:
• vertebral foramen where the spinal cord occupies
• intervertebral foramen where the mixed spinal nerves exit
• foramen magnum where the spinal cord exits the base of the skull

Question 6

describe the vertebral column

Answer 6

C1-7
T1-12
L1-5
S1-5 fused
Coccygeal 1-4 fused

Question 7

how many nerves and how many vertebral segments?

Answer 7

31 pairs of nerves- C8, T12, L5, S5, Cocc1

33 vertebral segments

Question 8

where does the spinal cord end?

Answer 8

around L1, nerves after T12 emerge lower than their spinal cord level.

Question 9

where is a lumbar puncture usually undertaken?

Answer 9

L3-4 or L4-5, the spinal cord in not present here, however there is a continuation of the dura mater forming the lumbar cistern wheres cerebrospinal fluid is present. this minimises damage.

Question 10

what are the ventral and dorsal horns?

Answer 10

where grey matter parts of the sensory (dorsal) and motor (ventral) synapse with the CNS. this leads to a dorsal root (afferent) and ventral root (efferent).

Question 11

what are ascending and descending tracts of the spinal column?

Answer 11

allow communication between periphery and brain in the white matter of spinal cord.

Question 12

spinal cord functions:

Answer 12

• Connects PNS and ANS with brain

* reflexes

Question 13

where do the cranial nerves emerge from?

Answer 13

brain stem

Question 14

how is the brain classified?

Answer 14

• embryologically eg rhombencephalon (hindbrain) mesencephalon (midbrain) prosencephalon (forebrain)
• functionally eg brainstem, cerebellum, cerebrum

Question 15

function of the diencephalon/

Answer 15

• Hypothalamus: integration hub, homeostatic function, autonomic function
• Thalamus: integrates sensory info and routes it to cortex, emotional status, consciousness.

Question 16

what are ganglia?

Answer 16

collection of cell bodies in the PNS

Question 17

what are nuclei?

Answer 17

collection of cell bodies in the CNS

Question 18

what is in the cerebral hemisphere

Answer 18

• cortex

* basal ganglia

Question 19

what are the components of the basal ganglia?

Answer 19

• globus pallidus
• nucleus accumbens
• caudate nucleus
• putamen
• amygdala

Question 20

what is the corpus striatum?

Answer 20

putamen + caudate

Question 21

what is the lentiform nucleus?

Answer 21

Putamen + globus pallidus

Question 22

function of the basal ganglia?

Answer 22

control movement, facilitating voluntary movement, inhibiting unwanted or inappropriate movement

FINE TUNING OF MOVEMENT

Question 23

which system is the amygdala part of?

Answer 23

limbic system

Question 24

what is the cerebral cortex?

Answer 24

2-4mm thick section of the cerebrum, lobes separated by fissures.

Question 25

what are the cerebral cortex lobes?

Answer 25

* frontal * occipital * temporal * parietal within these lobes there are certain areas

Question 26

which areas are present in the frontal lobe?

Answer 26

- prefrontal cortex (behaviour, mood, personality, think) - broca area (motor program for speech) - motor association area (where plan is generated) - primary motor cortex (contralateral impulses sent to effector muscles)

Question 27

which areas are present in the parietal lobe?

Answer 27

- primary somesthetic cortex (primary somatosensory cortex, pain temperature touch) - somesthetic association area (interprets information by comparing it with previous, cognition) - primary gustatory cortex (taste signals received)

Question 28

which areas are present in the occipital lobe?

Answer 28

- primary visual cortex (received visual signals) | - visual association area (recognise familiar things)

Question 29

which areas are present in the temporal lobe?

Answer 29

- primary auditory cortex (receives auditory signals) - auditory association area (recognises and interprets) - Wernicke's Area (recognition of spoken language)

Question 30

features of the cortex?

Answer 30

laminar, has 6 cell layers | somatotopic, each part of the brain maps on to a certain area of the brain

Question 31

function of the limbic system?

Answer 31

emotion, memory, motivation, instinctive behaviour

Question 32

what is the cerebellum?

Answer 32

attached to the brainstem by 3 peduncles two hemispheres with folium (folds) separated by vermis outer grey matter layer, with infolds inner white matter layer

Question 33

function of cerebellum?

Answer 33

- associated with vestibular system for balance - posture - learned movement - manual skills - fine movement - trajectory all in close association with spinal cord, thalamus, motor cortex.

Question 34

types of white matter in the brain

Answer 34

- commissural fibres, connecting two hemispheres of the brain (corpus callosum) - association fibres, connections within hemispheres - projection fibres, vertical eg connecting spinal cord to cortex via internal capsule between lentiform nucleus and then fan out to the curter in the corona radiata.

Question 35

bones of the cranium

Answer 35

- frontal - ethmoid - sphenoid - occipital - temporal - parietal contains many foramen for blood vessels and nerves.

Question 36

layers of the meninges which encase the whole CNS

Answer 36

- periosteal and meningeal dura mater - arachnoid mater which holes blood vessels in place (subarachnoid space)- filled with CSF - pia mater which follows gyri and sulci

Question 37

describe the ventricular system (filled with CSF)

Answer 37

lateral ventricles with anterior, posterior and inferior horns. This is connected to the third ventricle via the intraventricular foramina. the third ventricle is connected to the fourth ventricle via the aqueduct. the fourth ventricle is continuous with the central canal of spinal cord.

Question 38

what produces CSF?

Answer 38

ependymal cells in the choroid plexus in the ventricles produce 500ml per day to fill 150ml of ventricular space

Question 39

composition of CSF?

Answer 39

``` similar to plasma but lower: glucose protein calcium and potassium pH ``` but Higher: chloride magnesium

Question 40

function of CSF?

Answer 40

cushioning nutrition removing waste contains immune cells

Question 41

what is hydrocephalus and how is it caused?

Answer 41

blockage of CSF duct means CSF fluid builds up in ventricles which affects areas of the brain negatively. can be caused by meningitis, acquired or genetic

Question 42

epidural and subdural haematomas?

Answer 42

epidural is between dura and skull (lentiform) | subdural is between arachnoid and dura (crescent)