Spinal segments and nerves Flashcards
C4
motor- upper trap
movement- shoulder shrug
sensory- upper trap, lower neck
C5
motor- deltoid, biceps
movement- shoulder abduction, elbow flexion
reflex- biceps tendon
sensory- deltoid area
C6
motor- wrist extension, biceps
movement- wrist extension, elbow flexion
reflex- brachioradialis tendon
sensory- radial border of hand
C7
motor- wrist flexors, triceps
movement- wrist flexion, elbow extension
reflex- triceps tendon
sensory- index, middle and ring fingers
C8
motor- thenar muscles
movement- thumb extension
sensory- ulnar border of hand
T1
motor- interossei
movement- abduction and adduction of fingers
sensory- medial arm
L2
motor- iliopsoas
movement- hip flexion
sensory- anterolateral thigh
L3
motor- iliopsoas, quadriceps
movement- hip flexion, knee extension
reflex- patellar tendon
sensory- anteromedial and distal thigh
L4
motor- tibialis anterior
movement- ankle DF
reflex- patellar tendon
sensory- medial calf and ankle
L5
motor- extensor hallucis longus
movement- toe extension
sensory-lateral leg, anterior shin and foot
S1
motor- fibularis longus/brevis
movement- PF and eversion
reflex- achilles tendon
sensory- lateral ankle and foot
S2
motor- hamstrings
movement- knee flexion
sensory- medial posterior thigh
Musculocutaneous nerve
SC segment: C5-6
Muscle innervation: coracobrachialis, biceps brachii, brachialis
Sensory distribution (via lateral antebrachial cutaneous nerve): anterolateral surface of forearm
Motor features of paralysis: loss of forearm flexion when supinated, weakened supination
Axillary nerve
SC segment: C5-6
Muscle innervation: deltoid, teres minor
Sensory distribution (via upper lateral brachial cutaneous nerve): lateral arm over lower portion of deltoid
Motor features of paralysis: loss of shoulder abduction, weakened ER
Radial nerve
SC segment: C5-T1
Muscle innervation: Triceps, anconeus, brachioradialis, supinator, and wrist, finger and thumb extensors
Sensory distribution:
- posterior arm via posterior brachial cutaneous nerve and inferior lateral brachial cutaneous
- posterior forearm via posterior antebrachial cutaneous nerve
- radial side of posterior hand via superficial branch of radial nerve and dorsal digital branches
Motor features of paralysis: loss of elbow, wrist, finger and thumb extension
Median nerve
SC segment: C6-T1
Muscle innervation: pronators, wrist and finger flexors on radial side, most thumb muscles
Sensory distribution: palmar aspects of thumb, 2nd, 3rd and 4th (radial half) fingers
Motor features of paralysis: loss of forearm pronation, thumb opposition, flexion and abduction
Ulnar nerve
SC segment: C7-T1
Muscle innervations: FCU, FDP (ulnar half), interossei, 4th and 5th lumbricals
Sensory distribution: 4th finger (ulnar half) and 5th finger
Motor features of paralysis: loss of wrist ulnar deviation, weakened wrist and finger flexion, weakened 4th and 5th flexion, loss of thumb adduction, loss of most intrinsics (claw hand)
Sciatic nerve
SC segment: L4-S3
Muscle innervations: hamstrings and adductor magnus
Sensory distributions: through its terminal branches of the tibial, superficial fibular, and deep fibular nerves
Motor features of paralysis: loss of knee flexion, weak hip adduction and loss of all muscle function below the knee
Femoral nerve
SC segment: L2-4
Muscle innervations: sartorius, quads, iliaus and pectineus
Sensory distributions: middle anterior thigh and medial thigh proximal to the knee
Motor features of paralysis: loss of hip flexion and knee extension
Tibial nerve
SC segment: L4-S3
Muscle innervations: gastrocnemius, soleus, plantaris, popliteus and tibalis posterior, foot flexors
Sensory distributions: posterior/lateral calf, ankle and heal
Motor features of paralysis: loss of PF and supination
Superficial fibular (peroneal) nerve
SC segment: L5-S2
Muscle innervations: peroneus longus and brevis
Sensory distribution: anterior/lateral distal lower leg and ankle and most of the dorsum of the foot
Motor features of paralysis: loss of eversion
Deep fibular (peroneal) nerve
SC segment: L4-S2
Muscle innervations: tibialis anterior, extensor hallucis longus, extensor digitorum longus, fibularis tertius, 1st&2nd dorsal interossei, extensor digitorum brevis, extensor hallucis brevis
Sensory distribution: web space between 1st and 2nd toes on the dorsum of the foot
Motor features of paralysis: loss of DF (drop foot) and weakness in the foot intrinsics
CN I
Olfactory
function: smell
Anosmia= loss of sense of smell
CN II
Optic
Function: sight, pupillary reflexes
damage: monocular blindness, loss of pupillary constriction, absence of blink reflex
CN III
Oculomotor
Function: moves the eye and elevates the upper eyelid
damage:
- ptosis: drooped eyelid
- dilation of pupil
- loss of accommodation of the light reflex
CN IV
Trochlear
function: motor nerve for the superior oblique muscle
damage: diplopia, failure to rotate eye up and out
CN V
Trigeminal
function: mastication and sensory nerve for the head
damage:
- loss of facial sensation
- weakness of muscles of mastication
- deviation of opened jaw to ipsilateral side
CN VI
Abducens
function: abducts the eye via nerve supply to the lateral rectus muscle
damage:
- diplopia
- convergent squint (medial strabismus)
- abductor paralysis of ipsilateral eye
CN VII
Facial
function: facial expression, speech articulation, winking, ingestion of food and drink, taste, salivary and nasal secretions
damage
- ipsilateral facial paralysis
- dry mouth
- loss of taste anterior 1/3 of tongue (bell’s palsy)
CN VIII
Vestibulocochlear
function: maintenance of equilibrium, hearing
damage: vertigo, nystagmus, dysequilibrium, tinnitus, loss of hearing
CN IX
Glossopharyngeal
function: elevates pharynx, salivary secretion, taste
damage: slight dysphagia, partial dry mouth, loss of taste posterior 1/3 of tongue
CN X
Vagus
function: phonation, visceral sensations and reflexes, cardiac depressor, bronchoconstrictor, GI tract peristalsis and secretion
damage:
- palpitation (forcible pulsation of the heart)
- tachycardia
- vomiting
- slowing of respiration
- ipsilateral paralysis of soft palate and larynx
- hoarseness
- anesthesia of the larynx
CN XI
Accessory
Function: deglutition and phonation (carotid part), movements of head and shoulders (spinal part)
Damage: weakness in shrugging ipsilateral shoulder, turning head to opposite side
CN XII
Hypoglossal
Function: movements of the tongue
Damage: unilateral paralysis of the tongue, deviation to the ipsilateral side with protrusion
