Nervous System

Question 1

Divisions of the peripheral NS

Answer 1

somatic sensory
somatic motor
visceral sensory
visceral motor

Question 2

neurons characterisitics

Answer 2

• basic structural and functional unit
• cell body (soma) → contains: nucleus/golgi/ER/mit
• dendrites → relays info to cell body (telodendria - postsynaptic region releasing NT)
• axons → nerve fibres that transmit electrical impulses

Question 3

neuroganglia

Answer 3

supportive structure (physically and metabolically) - 10:1 ratio to neurons 
- able to divide

Question 4

astrocytes

Answer 4

CNS

• hold and guide neurons during fetal brain dev
• repair brain injury and neurotransmission
• forms BBB (prevent entry of substances from blood to brain)

Question 5

microglial cells

Answer 5

• immune cell, dormant until activated

- via phagocytosis

Question 6

ependymal cells

Answer 6

in ventricles → secretes CSF

• cilia facilitates movement
• acts as neuronal stem cells

Question 7

oligodendrocyte

Answer 7

myelinated

- has phospholipid bilayer

Question 8

relationship b/w mutiple sclerosis and myelin

Answer 8

eroded myelin → slows impulse conduction → slows motor functions

Question 9

cells in peripheral NS

Answer 9

satellite cells

schwann cells

Question 10

satellite cells

Answer 10

provide nutrients to cells

- surround neurons within ganglia → encompasses whole nerve fibres

Question 11

schwann cells

Answer 11

are the oligodendrocyte in CNS

- myelinated → creates node of ranvier

Question 12

saltatory conduction

Answer 12

myelinated conduction

Question 13

nerve structure

Answer 13

axon → myelin sheath → endoneurium → fasicle → perineurium → epineurium

Question 14

membrane potential

Answer 14

difference b/w charge inside (-70mV) and outside cell

- pump 3 Na out, 2 K in

Question 15

steps of AP

Answer 15

1) stimuli from sensory cell → depol twd threshold
2) theshold reach → Na channel opens → depol
3) peak (+40mV) → K channel opens → repol
4) hyperpol (K leaves cells) → refractory period
5) K channel close → Na/K restore resting potential

Question 16

what is impulse velocity dependent on

Answer 16

diameter of axon and myelination

Question 17

synaptic transmission

Answer 17

• functional connection b/w pre & post synaptic neuron

- AP travels to telodendria to release NT

Question 18

gap junction

Answer 18

electrical synpases

- chemicals move from 1 cell directly to another

Question 19

chemical synapse

Answer 19

NT moves to synaptic → release chemical → triggers next AP

- Ca influx required for NT exocytosis

Question 20

CN1

Answer 20

olfactory

Question 21

CN2

Answer 21

optic

Question 22

CN3

Answer 22

oculomotor - constricts pupils and elevates eyelids

Question 23

CN4

Answer 23

trochlear → controls SUP oblique → controls I-M eye movement

Question 24

CN6

Answer 24

abducent → LAT rectus → controls LAT eye movements

Question 25

CN5

Answer 25

trigeminal - V1 → opthalic - V2 → maxillary - V3 → mandibular

Question 26

CN7

Answer 26

facial - muscles - taste to ANT 2/3 tongue - lacrimal & sublingual glands

Question 27

CN8

Answer 27

vestibulocochlear | - hearing and balance

Question 28

CN9

Answer 28

glossopharyngeal | - sensory 1/3 POS taste

Question 29

CN10

Answer 29

vagus, THE autonomic nerve

Question 30

CN11

Answer 30

spinal accessory | - motor to SCM and upper trapezius

Question 31

CN12

Answer 31

hypoglossal - muscle to tongue - tongue points to direction of defective branch side

Question 32

structure of CNS

Answer 32

gray (cell bodies and dendrites in cortex) white (axons underlie the cortex)

Question 33

tracts of CNS

Answer 33

bundle of axons

Question 34

CSF

Answer 34

1o formed by choroid plexus | - absorbed into venous blood through arachnoid villi (500ml/day)

Question 35

function of CSF

Answer 35

- suspend and cushion brain - monitor changes in internal env - vehicle for distributing hormones throughout CNS

Question 36

BBB

Answer 36

regulate exchange of substances b/w blood and brain - continuous layer of endothelial cells joined by tight junctions - lipid soluble substances able to penetrate - is incomplete in newborn and premature infants (prone to brain infection

Question 37

brain stem

Answer 37

controls basic functions to maintain life (resp/cardiac/consciousness) - pons + medulla oblongata + midbrain

Question 38

cerebellum

Answer 38

control fine motor movements (affected in parkinsons) - maintains equilibrium and posture - planning and coordination

Question 39

diencephalon

Answer 39

thalamus → relay centre for all sensory pathway to cerebral cortex hypothalamus

Question 40

cerebrum

Answer 40

4 lobes of the brain

Question 41

frontal lobe

Answer 41

- 1o motor cortex → voluntary motor function - pre-motor cortex → coordinate of complex movement and eye movement - prefrontal cortex → personality, insight

Question 42

parietal lobe

Answer 42

somatosensory cortex → processing of sensations and proprioception

Question 43

temporal lobe

Answer 43

limbic association cortex and primary auditory cortex | - language comprehension

Question 44

wenicke's aphasia

Answer 44

compromised ability to understand speech → speak fluently but no sense

Question 45

broca's aphasia

Answer 45

loss of ability to produce language

Question 46

occipital lobe

Answer 46

- 1o visual cortex → vision and coordination | - integration of all sensory input

Question 47

basal nuclei (ganglia)

Answer 47

- contains limbic system → controls emotion | - relay point for nerve fibres

Question 48

limbic system

Answer 48

located above diencephalon | - emotion and memory

Question 49

hippocampus

Answer 49

part of cerebral cortex - create new memories - atrophy in alzheimers

Question 50

amygdala

Answer 50

cluster of nuclei | - controls emotions

Question 51

cingulate gyrus

Answer 51

loop of cerebral cortex over corpus callosum | - integrates sensory input and adds emotional content (i.e. rxn to pain)

Question 52

blood supply to brain

Answer 52

originates from aorta - anastomose to circle of willis - susceptible to rupture and vascular disease

Question 53

spinal cord

Answer 53

extension of brainstem | - L4/5 cauda epquina

Question 54

ageing

Answer 54

- decrease of neurons in 30s - decrease ability to maintain and synthesise new nerve cells - dementia → consequence of degeneration of nerve cells

Question 55

division of white matter

Answer 55

divided within each half of cord → into 3 white columns (funiculi) → further divided ANT/POS/LAT white columns → subdivided into spinal tracts