PBL 1

Question 1

whats the cutaneous innervation to the upper medial leg?

Answer 1

obturator nerve

Question 2

whats the cutaneous innervation to lateral thigh?

Answer 2

lateral cutaneous nerve of the thigh

Question 3

whats the cutaneous innervation to anteromedial thigh?

Answer 3

anterior cutaneous nerve - branch of femoral nerve

Question 4

whats the cutaneous innervation to the posteromedial thigh?

Answer 4

posterior cutaneous nerve of thigh from sacral plexus

Question 5

whats the cutaneous innervation for the anteromedial half of the leg?

Answer 5

saphenous branch of femoral nerve

Question 6

whats the cutaneous innervation of between big toe and 2nd metatarsal?

Answer 6

deep branch of common fibular nerve

Question 7

whats the cutaneous innervation to medial half of plantar foot?

Answer 7

medial plantar nerve (branch of tibial)

Question 8

what innervates the skin of the lateral half of the plantar foot?

Answer 8

lateral plantar nerve (branch of tibial nerve)

Question 9

what innervates skin over ball of foot?

Answer 9

medial calcaneal branches (branch of tibial nerve)

Question 10

what innervates bottom half of lateral leg?

Answer 10

superficial branch of common fibular nerve

Question 11

what innervates top half of lateral leg?

Answer 11

lateral cutaneous nerve of the calf (branch of Common Fibular)

Question 12

what innervates the lateral posteriorlower half of the leg?

Answer 12

sural nerve

Question 13

outline the order of branches in the lumbar plexus?

Answer 13

iliohypogastric
ilioinguinal
genitofemoral
lateral cutaneous
femoral
obturator

Question 14

what is the root for iliohypogastric nerve?

Answer 14

T12 and L1

Question 15

what does the iliohypogastric nerve innervate?

Answer 15

motor - internal oblique and transversus abdominis

sensory - posterolateral gluteal skin on pubic region

Question 16

whats the nerve root for the ilioinguinal nerve?

Answer 16

L1

Question 17

what does the ilioinguinal nerve innervate?

Answer 17

motor - internal oblique and transversis abdominis

sensory - superoanteromedial thigh, penis, mons pubis, anterior scrotum, labia majora

Question 18

whats the nerve root for the genitofemoral nerve?

Answer 18

L1, L2

Question 19

what des the genitofemoral nerve split into?

Answer 19

genital and femoral branches

Question 20

what does the genital branch innervate?

Answer 20

motor - cremasteric muscle

sensory - anterior scrotum, mons pubis and labia majora

Question 21

what does the femoral branch of the genitofemoral nerve innervate?

Answer 21

sensory - upper anterior thigh

Question 22

whats the nerve roots for lateral cutaeous nerve?

Answer 22

L1, L2

Question 23

what does the lateral cutaneous nerve innervate?

Answer 23

sensory - anteror and lateral thigh down to knee

Question 24

whats the nerve roots for the femoral nerve?

Answer 24

L2, L3, L4

Question 25

wht does the femoral nerve innervate?

Answer 25

motor - muscles of anterior thigh

Question 26

what does the femoral nerve split into?

Answer 26

anterior cutaneous nerve and saphenous nerve

Question 27

what does the anterior cutaneous branch of the femoral nerve innervate?

Answer 27

skin of anteromedial thigh

Question 28

what does the saphenous branch of the femoral nerve innervate?

Answer 28

skin of medial leg and foot

Question 29

what are the nerve roots for the obturator nerve?

Answer 29

L2, L3, L4

Question 30

what does the obturator nerve innervate?

Answer 30

motor - muscles of medial thigh | sensory - skin over upper medial thigh

Question 31

what are the branches of the sacral plexus?

Answer 31

superior gluteal, inferior gluteal, sciatic, posterior femoral and pudendal

Question 32

what are the nerve roots of the superior gluteal nerve?

Answer 32

L4, L5, S1

Question 33

what are the nerve roots of thr inferior gluteal nerve?

Answer 33

L5, S1, S2

Question 34

what are the nerve roots of the sciatic nerve?

Answer 34

L4, L5, S1, S2, S3

Question 35

what are the nerve roots of the posterior femoral cutaneous nerve?

Answer 35

S1, S2, S3

Question 36

what are the nerve roots of the pudendal nerve?

Answer 36

S2, S3, S4

Question 37

what does the superior gluteal nerve innervate?

Answer 37

gluteus medius, gluteus minimus, tensor fascia lata

Question 38

what does the inferior gluteal nerve innervate?

Answer 38

gluteus maximus

Question 39

what does the tibial portion of the sciatic nerve innervate?

Answer 39

posterior compartment of thigh muscles and hamstring part of adductor magnus all muscles in posterior leg sole of foot skin on posterolateral leg (sural nerve), lateral foot (sural nerve), sole of foot (plantar nerves)

Question 40

what does the common fibular branch of the sciatic nerve innervate?

Answer 40

anterior leg muscles (deep) lateral leg muscles (superficial) cutaneous - between 1 and 2 metatarsl (deep), lateral upper half of anterior leg (lateral cutaneous branch), lateral lower half of anterior leg (superficial)

Question 41

what does the posterior femoral nerve innervate?

Answer 41

the skin of the posterior surface of the thigh, leg, buttock, and also the perineum.

Question 42

what does the pudendal nerve innervate?

Answer 42

motor - various pelvic muscles, the external urethral sphincter and the external anal sphincter sensory - external genitalia of both sexes and the skin around the anus, anal canal and perineum

Question 43

what is the myotome for hip flexion?

Answer 43

L2

Question 44

what is the myotome for hip extension?

Answer 44

S1

Question 45

whats the myotome for knee extension?

Answer 45

L3

Question 46

what is the myotome for knee flexion?

Answer 46

S2

Question 47

whats the myotome for ankle dorsiflexion?

Answer 47

L4

Question 48

whats the mytome for ankle plantar flexion?

Answer 48

S1

Question 49

whats the myotome for big toe extension?

Answer 49

L5

Question 50

whats the myotome for ankle eversion?

Answer 50

S1

Question 51

what is the cauda equina?

Answer 51

where the spinal cord ends at L2 but the nerves of lumbar, sacral and coccygeal regions have to travel further down, forming a nerve bundle

Question 52

what is cauda equina syndrome?

Answer 52

damage to the cauda equina

Question 53

what can cause damage to the cauda equine?

Answer 53

compression e.g. ruptured disc, stenosis, spinal lesion, tumour trauma e.g. spinal infection or fracture degenerative conditions e.g. ankylosing spondylitis

Question 54

what are symptoms of cauda equina syndrome?

Answer 54

``` decreased bowel and bladder control decreased sexual function saddle anaesthesia muscle weakness loss of knee and ankle reflexes paraplegia sciatic like pain back pain gait disturbance ```

Question 55

how do you treat cauda equina syndrome?

Answer 55

if sudden onset e.g. disc herniation then you must have surgical decompression within 48 hours if caused by degenerative diseases then treat with anti-inflammatory meds and corticosteroids

Question 56

what is a complication of untreated cauda equina syndrome?

Answer 56

permenant paralysis, impaired bladder/bowel control, loss of sexual sensation

Question 57

what do we call the symptoms of nerve root lesions?

Answer 57

radiculopathy

Question 58

what are some common causes of nerve root lesions?

Answer 58

herniated disc, degenerative disc, spinal stenosis

Question 59

what are some symptoms of radiculopathy?

Answer 59

pain weakness tingling loss of reflexes

Question 60

what are ascending spinal tracts

Answer 60

sensory pathways that start at the spinal cord and stretch up to the cerebral cortex?

Question 61

what are the 3 main ascending spinal tracts?

Answer 61

dorsal column medial lemniscus pathway spinothalamic system spinocerebellar system

Question 62

what are the 3 other ascending spinal tracts?

Answer 62

spinotectal spinoreticular spino-olivary

Question 63

whats the function of the spinotectal tract?

Answer 63

turning towards the source of sensory stimulation

Question 64

what is the function of the spinoreticular tract?

Answer 64

inducing or maintaining wakefulness

Question 65

what is the function of the spino-olivary tract?

Answer 65

modified cerebellar activity in response to environmental change

Question 66

whats the function of the dorsal column medial lemniscus system?

Answer 66

vibration, proprioception, 2 point discimination, touch

Question 67

outline the structure of the dorsal column medial lemniscus pathway?

Answer 67

mechanoreceptors and proprioceptirs are stimulated and send sensory information through 1st order neurons to dorsal root ganglion these enter the dorsal column and ascend in the gracilis fascicle (T6) up to the gracile/cuneate nuclei in the medulla. Here they synapse with a 2nd order neurone which deccassates and then ascend via the medial lemniscus to the nuclei in the thalamus here they synapse with the 3rd order neurons and ascend through the internal capsule up to the primary somatosensory cortex

Question 68

whats the function of the spinothalamic system?

Answer 68

crude touch, pain, pressure, temperature

Question 69

outline the structure of the spinothalamic system?

Answer 69

1st order neurons travel from from receptors to dorsal root ganglion, ascend 1-2 segments and synapse with 2nd order neuron in dorsal horn they decussate to anterior and lateral spinothalamic tract and ascend to the thalamus where they synapse with 3rd order neurons these neurones ascend through the internal capsule to the primary somatosensory cortex

Question 70

whats the difference between anterior and lateral spinothalamuc systems?

Answer 70

anterior - crude touch and pressure | lateral - pain and temperature

Question 71

whats the function of the spinocerebellar system?

Answer 71

to help coordinate muscles in trunks and limbs

Question 72

outline the structure of the spinocerebellar system?

Answer 72

proprioceptie info travels via 1st order neyrons to dorsal root ganglion, enter spinal cord and synapse with 2nd order nerons. Here they either decussate to ventral tract or remain ipsilateral as the dorsal tract. the dorsal tract ascends to inferior cerebellar peduncle, passes through and arrives at ipsilateral cerebellar cortex. the ventral tract ascends to the cerebella peduncle, decussates again and arrives at the ipsilateral cerebellar cortex too

Question 73

what are descending spinal tracts?

Answer 73

motor pathways that control the muscles of the trunk and extremetieis - made up of upper and lower motor neurones

Question 74

what are the 2 categories of descending tracts?

Answer 74

pyramidal and extrapyramidal tracts

Question 75

what are the 3 pyramidal tracts?

Answer 75

anteror and lateral corticospinal tract | corticobulbar tract

Question 76

whats the function of the corticospinal tract?

Answer 76

primary motor activity for the somatic motor system from the neck to the feet. lateral - limbs anterior - trunk

Question 77

outline the structure of the anterior corticospinal tract?

Answer 77

descends from pyramidal cells in primary motor cortex to spinal cord, reaches desired spinal segment, decussates and synapses with LMN in ventral horn. Leave as peripheral nerves to reach muscles of the trunk

Question 78

outline the structure of the lateral corticospinal tract?

Answer 78

descends from pyramidal cells and decussates at decussation of pyramids in medulla, descends down contralateral spinal cord until it reaches the ventral horn where it synapses with a LMN. These leave as peripheral nerves to reach muscles of extremities

Question 79

whats the function of the corticobulbar tract?

Answer 79

upper motor neuron input to cranial nerves

Question 80

outline the structure of the corticobulbar tract?

Answer 80

UMN descends from motor cortex to brainstem where it synapses with LMN for cranial nerves and either remains contralteral or ipsilateral

Question 81

whats the function of the vestibulospinal tract?

Answer 81

maintain equilibratory reflexes from the input of the vestibular apparatus = balance

Question 82

whats the function of the reticulospinal tract?

Answer 82

locomotion and postural control

Question 83

whats the function of the tectospinal tract?

Answer 83

controlling the movement of the head in response to auditory and visual stimuli.

Question 84

whats the function of the rubrospinal tract?

Answer 84

regulation of flexion and extension tone of large group muscles, as well as fine motor control.

Question 85

x

Answer 85

x

Question 86

why are they called extrapyramidal tracts?

Answer 86

they use interneurones between upper and lower motor neurones

Question 87

outline the structure of the vestibulospinal tract?

Answer 87

UMN descend from lateral vestibular nuclei in medulla to spinal cord where it synapses with interneurones which activates LMN in ventral horn medial tract stops in cervical region lateral tract travels through all spinal segments

Question 88

outline the structure of the reticulospinal tract?

Answer 88

UMN descend from reticular formation medial tract descends to ipsilateral spinal tract lateral tract descends to give off ipsilateral and contralateral branches

Question 89

outline the tectospinal tract?

Answer 89

UMN descend from superior colliculi and decends to contralateral cervical spinal cord where it synapses with a LMN in the ventral horn

Question 90

outline the rubrospinal tract?

Answer 90

UMN descend from red nucleus, decussate and enter contralateral spinal cord in cervical region where it synapses with internerons which activate LMN in ventral horn

Question 91

what would happen if we had a unilateral lesion in a ventromedial pathway?

Answer 91

no obvious defects as other side of body can control both sides

Question 92

what would happen if we had a bilateral lesion in a ventromedial pathway?

Answer 92

loss of posture correction, navigational control, trunk immobility, affecting proximal muscles of trunk and shoulder

Question 93

what would a lesion above the point of decusation in dorsolateral pathways cause?

Answer 93

contralateral spastic paresis, positive babinski | symptoms on contralateral side

Question 94

what would a lesion below the point of decusation in dorsolateral pathways cause?

Answer 94

ipsilateral spastic paresis and psoitive babibnski | symptoms on ipsilateral side

Question 95

what would a lesion in a dorsolateral pathway do?

Answer 95

normal walking and posture correction but arms hang limply and to reach out you would have to use shoulder circumduction as you have no fine movement control

Question 96

what are the symptoms of upper motor neuron lesions?

Answer 96

minimal muscle atrophy muscle weakness hyper-reflexic deep tendon reflexes but diminished/absent superficial reflexes positive babinski sign

Question 97

what ar the symptoms of a lower motor neuron lesion?

Answer 97

``` muscle atrophy flacid paresis normal or no plantar response absent tendon reflexes fasciculations of affected muscle ```

Question 98

outline the mechanism for locking and unlocking the knee?

Answer 98

to lock the knee, the Quadriceps muscle medially rotates the femur to pull the ligaments taught To unlock the knee, the popliteus muscle laterally rotates the femur.