Ner 5: Lower Motor Neurons And Cranial Nerves

Front 1

Which of the 4 types of vertebrae are most susceptible to racture

Back 1

Cervical are most fragile and most susceptible

Front 2

At what 3 vertebral articulations are dislocations most likely to occur.

Back 2

The articulations of greatest mobility:
CV5-6, TV12-L1, and CV1-2

Front 3

Reciprocal vs Recurrent inhibition in reflexes

Back 3

reciprocal - sensory fiber that stims LMN of agonist also stims an interneuron which inhibits the antaginist
Recurrent - Motor fiber which stims the muscle sends off a collateral which stims an interneuron which inhibits that same motor neuron.

Front 4

What force does the muscle spindle sense

Back 4

Rate of stretch and amount of stretch when a muscle fiber is stretched.

Front 5

What force does the golgi tendon organ sense

Back 5

Shortening of muscle due to contraction

Front 6

Occulomotor Nucleus and lesion

Back 6

Midbrain @ superior colliculus.
Lesion = Eye looks down and out, ptosis, dilated pupil

Front 7

Trochlear nucleus and lesion

Back 7

Midbrain @ inferior colliculus
Outward, up rotation of globe, head tilted to good side.

Front 8

Trigeminal nucleus and lesion

Back 8

Mid pons
Atrophy of masseter, open jaw deviates toward side of lesion

Front 9

Abducens nucleus and lesion

Back 9

Caudal pons
Lesion leads to esotropia

Front 10

Facial nucleus and lesion

Back 10

Caudal pons
Lesion leads to total ipsilateral facial paralysis including upper face and hyperacusis. (bells palsy)

Front 11

Nucleus ambiguous and lesion

Back 11

Medulla; supplies 9, 10, and 11.
Lesion leads to dysphagia because of CN9
Lesion leads to vocal paralysis, sagging palat, and uvula deviation to the opposite side.

Front 12

Hypoglossal nucleus and lesion

Back 12

Located in medulla.
Lesion leads to tongue atrophy and deviation towards the side of injury.