Neuromuscular Physiology

Question 1

Brain tissue is divided into

Answer 1

Grey matter, white matter

Question 2

What is in grey matter

Answer 2

Dense with cell bodies

Question 3

What is in white matter

Answer 3

Mainly connecting axons

Question 4

Folds of cortex

Answer 4

Gyrus = ridge
Sulcus = groove

Question 5

Purpose of folds in cortex

Answer 5

Allows for more grey matter

Question 6

How many cerebral hemispheres

Answer 6

2

Question 7

What connects 2 hemispheres

Answer 7

Corpus callosum

Question 8

Name the 4 lobes

Answer 8

Frontal, temporal, parietal, occipital

Question 9

What is the cerebrum the origin of

Answer 9

Conscious thought and intellectual function

Question 10

What does cerebrum exert

Answer 10

Voluntary/involuntary control over some somatic motor neurones

Question 11

Primary motor cortex=

Answer 11

Pre-central gyrus

Question 12

Primary sensory cortex=

Answer 12

Post central gyrus

Question 13

What info does gyrus get from receptors

Answer 13

Touch,pain,pressure,tempereature

Question 14

Occipital lobe =

Answer 14

Visual cortex

Question 15

Frontal lobe =

Answer 15

Gustatory cortex

Question 16

Temporal lobe =

Answer 16

auditory and olfactory cortex

Question 17

Somatic sensory association areas

Answer 17

Monitors activity in primary sensory cortex, allows recognition of somatic senses, special senses have their own association areas

Question 18

Somatic motors association areas

Answer 18

Coordinates learned movement, instructions for primary motor cortex arise here

Question 19

Structure of spinal cord

Answer 19

White matter = ascending (afferent) and descending (efferent) tracts
Grey matter = motor and sensory spinal neurone cell bodies
Sensory N enter via dorsal horn
Motor N enter via ventral horn

Question 20

How many sets of spinal nerves

Answer 20

31

Question 21

What do the spinal N contain

Answer 21

Motor and sensory fibres from ventral and dorsal roots

Question 22

Where does cord end

Answer 22

Lower lumbar area, sacral and coccygeal vertebrae carry N roots (cauda equina ) from higher levels

Question 23

What is myasthenia gravis

Answer 23

Autoimmune destruction of ACH receptors, causes muscle weakness/fatigue

Question 24

How to treat myasthenia gravis

Answer 24

1. Increase ACH conc in synaptic cleft -inhibit acetylcholinesterase
2. Immunosuppression by drugs or removal of thymus

Question 25

3 brain stem motor areas

Answer 25

Rubrospinal tract, vestibulospinal tract, reticular formation

Question 26

Rubrospinal tract

Answer 26

Innervates mainly spinal motor neurones innervating distal limb muscles ie fine movement Crosses midline, descends contralaterally

Question 27

Vestibulospinal tract

Answer 27

Input from vestibulocochlear nerve Descends and innervate ipsilateral motor neurones Innervate proximal muscles, control balance, locomotion

Question 28

Reticular formation

Answer 28

Extensive network in brain stem Many connections with sensory and motor paths Descend and innervate ipsilateral motor neurones

Question 29

Inputs of cerebullum

Answer 29

Vestibular apparatus Peripheral sensory receptors, especially muscle spindles and joint receptors Visual and auditory systems Corticospinal paths

Question 30

Outputs of cerebellum

Answer 30

(Via thalamus) Motor cortex, brain stem motor areas

Question 31

Grey matter beneath lateral ventricles =

Answer 31

Basal (cerebral) nuclei

Question 32

Function of cerebral nuclei

Answer 32

Directs many activists outside conscious control

Question 33

What inhibits basal nuclei

Answer 33

Substantia nigra

Question 34

Damage to alpha motor neurone or anterior horn =

Answer 34

Paralysis & wasting of muscle Decreased muscle tone Stretch reflex absent

Question 35

Bilateral spinal cord injury (1st response)

Answer 35

Spinal shock, paralysis of all muscles below defect

Question 36

Bilateral Spinal cord injury (second response)

Answer 36

Gradual increased musc tone Exaggerated stretch reflex Mechanism not clear Increased sprouting of excitatory motor nerve endings and interneurones?

Question 37

Upper motor lesions

Answer 37

Interference with vascular supply to brain - stroke

Question 38

Cerebellar damage results in:

Answer 38

Loss of balance, unsteady gait, decreased muscle tone, reflects loss of facilitation of cortex and brain stem motor areas

Question 39

Function of somatosensory system

Answer 39

Touch, temperature, proprioception, pain

Question 40

Somatosensory 1st order neurones

Answer 40

Nerves with receptor endings Cell bodies with dorsal root ganglia Enter SC via dorsal roots

Question 41

2nd order somatosensory neurones

Answer 41

Travel to brain via 2 primary ascending tracts Connect to cerebral cortex - 3rd order

Question 42

Spinothalamic tract

Answer 42

Pain and tempo receptors cross to contra lateral side via synapse Ascend in spinothalamic tract Synapse in thalamus Travel to sensory cortex

Question 43

Dorsal column

Answer 43

Proprioceptor/touch/vibration info ascend by ipsilateral dorsal column No synapse in spine Ascend to dorsal column nuclei Cross midline in medulla to thalamus

Question 44

Peripheral somatosensory defects

Answer 44

Localised symptoms

Question 45

Damage to primary sensory axons

Answer 45

Nerve root damage, neuropathy - impaired conduction Leads to: numbness, pins and needles, all modalities affected

Question 46

Ascending tract damage

Answer 46

Bilateral; sensory loss in all modalities below level of lesion Unilateral(rare): joint position sense lost on same side of lesion. Temp and pain lost on opposite side

Question 47

Somatosensory damage within brain caused by and leads to

Answer 47

Stroke; damaging tracts from thalamus to cortex - sensory loss from opposite side of body. Motor deficits from nearby affected areas common