NPTE Neuro Mt hood: Innervation
Which of the following muscles is innervated by the anterior division of the obturator nerve? pectineus adductor magnus adductor longus gracilis
Correct Answer: adductor longus All of the options are innervated by the obturator nerve (L2-L4), but only the adductor longus is innervated by the anterior division. The pectineus is innervated by the obturator nerve in slightly less than 10% of individuals, while most often it is innervated by the femoral nerve.
sciatic nerve (tibial division)
Semitendinosus Semimembranosus Biceps femoris (long head)
The __________ is innervate by the upper subs cap and lower subscapular nerves
Subscapularis
T/F the obturator nerve innervates the adductor magnus
True
T/F: biceps brachii is innervated by the musculocutaneous nerve
True
T/F: the sacral plexus innervates the piriformis
True
T/F: the superior gluteal nerve innervates the TFL
True
T/F: the biceps femoris is innervated by the sciatic nerve
True: long: tibial division Short: common fib division
lateral plantar nerve
Abductor digiti minimi Flexor digiti minimi Opponens digiti minimi Dorsal interossei Quadratus plantae Adductor hallucis Lumbrical II, III, IV Plantar interossei
Which spinal nerve roots contribute to the brachial plexus? C1-T1 C3-C8 C5-C8 C5-T1
Correct Answer: C5-T1 The brachial plexus is made up of spinal nerve roots C5 through T1.
An inability to splay the fingers would indicate damage at which spinal segments? C5-C6 C6-C7 C7-C8 C8-T1
Correct Answer: C8-T1 The majority of the intrinsic muscles of the thumb and fingers are innervated at the C8-T1 spinal segments.
What artery is used as a point of reference when naming the cords of the brachial plexus? axillary artery carotid artery subclavian artery vertebral
Correct Answer: axillary artery The brachial plexus includes three cords (i.e., lateral, medial, posterior) that are named according to their position with respect to the axillary artery.
Deltoid atrophy may be associated with an injury to the: axillary nerve median nerve radial nerve subclavian nerve
Correct Answer: axillary nerve The axillary nerve arises from the C5-C6 nerve roots and innervates the deltoid muscle. Damage to the axillary nerve commonly occurs following a fracture to the head of the humerus.
Which muscle of the lower extremity is not innervated by the tibial nerve? flexor hallucis longus flexor digitorum longus flexor digiti minimi tibialis posterior
Correct Answer: flexor digiti minimi The flexor digiti minimi is innervated by the lateral plantar nerve.
Which nerve innervates the cremasteric muscle? ilioinguinal nerve obturator nerve genitofemoral nerve femoral nerve
Correct Answer: genitofemoral nerve The genital branch of the genitofemoral nerve arises from the roots of L1 and L2 and innervates the cremaster muscle. The cremaster muscle receives blood supply from the cremasteric artery.
Which of the following nerves does not have a connection from all three trunks of the brachial plexus? lower subscapular radial suprascapular thoracodorsal
Correct Answer: suprascapular The suprascapular nerve (C4, C5, C6) extends from the superior trunk of the brachial plexus. The nerve innervates the supraspinatus and infraspinatus muscles.
Suprascapular nerve Origin: Muscles:
From trunks of plexus: Superior
Nerve to subclavius Origin: Muscles:
From trunks of plexus: Superior Subclavius
Inferior gluteal nerve
Glute max
Musculocutaneous nerve Origin: Muscles:
Lateral cord Coracobrachialis, biceps brachii, brachialis
Lateral root of median nerve Origin: Muscles:
Lateral cord Forearm flexors except flexor carpi ulnaris and 5 muscles in hand
lateral pectoral nerve Origin: Muscles:
Lateral cord pec major - clavicular head
Which 2 nerves originate from the rami of the brachial plexus?
Long thoracic Dorsal scapular
ulnar nerve Origin: Muscles:
Medial cord Flexor carpi ulnaris, flexor digitorum profundus, most small muscles of hand
Medial pectoral Origin: Muscles:
Medial cord Pec major/minor
Medial root of median nerve Origin: Muscles:
Medial cord: Forearm flexors except flexor carpi ulnaris and 5 muscles in hand
Wasting of the thenar eminence musculature indicates damage to which nerve?
Median nerve
Which nerves innervate the hip adductor musculature?
Obturator
Obturator nerve
Obturator externus Adductor longus/brevis/magnus Gracilis
Tibial nerve
Popliteus Gastroc/soleus/plantars Tibialis posterior Flexor hallucis longus Flexor digitorum longus
Femoral nerve
Quads Iliacus Sartorius Pectineus
The medial half of flexor digitorum profundus is innervated by the _________ nerve
Ulnar nerve
Which nerves innervate the muscles that ulnar deviate the wrist?
Ulnar: flexor carpi ulnaris Radial: extensor carpi ulnaris
What nerve innervates the deltoid?
axillary nerve
Tibialis anterior innervation
deep fibular nerve
What nerve innervates sartorius?
femoral nerve
Superficial fibular nerve
fibularis longus fibularis brevis
Superior gluteal nerve
gluteus medius, gluteus minimus, tensor fasciae latae
What nerve innervates glute max?
inferior gluteal nerve
Serratus anterior innervation
long thoracic nerve
Fibularis longus innervation
superficial fibular nerve
Supraspinatus is innervated by the ___________ Nerve
suprascapular nerve
Lats innervation
thoracodorsal nerve
Which nerve innervates the lats?
thoracodorsal nerve
Which nerves innervate the great toe flexors?
Tibial nerve Medial plantar nerve
medial plantar nerve
Abductor hallucis Lumbrical I Flexor digitorum brevis Flexor hallucis brevis
Which muscle is innervated by the ulnar nerve? anconeus extensor carpi radialis flexor digitorum profundus supinator
Correct Answer: flexor digitorum profundus The ulnar nerve arises from the medial cord of the plexus and innervates the flexor carpi ulnaris, flexor digitorum profundus, and most of the small muscles of the hand.
Paralysis of which nerve gives rise to scapular winging? suprascapular nerve long thoracic nerve subscapular nerve thoracodorsal nerve
Correct Answer: long thoracic nerve The serratus anterior maintains the scapula against the rib cage. Weakness in this muscle results in a characteristic winging of the scapula. The serratus anterior is innervated by the long thoracic nerve.
Injury to the posterior cord of the brachial plexus could involve all of the following except: thoracodorsal nerve radial nerve axillary nerve musculocutaneous nerve
Correct Answer: musculocutaneous nerve The musculocutaneous nerve arises from the lateral cord of the brachial plexus. The nerve innervates the coracobrachialis, biceps brachii, and brachialis.
At which of the following sites might the median nerve be compressed? passing through the two heads of the pronator teres passing beneath the pisohamate ligament passing between the two heads of the supinator passing through the canal of Frohse
Correct Answer: passing through the two heads of the pronator teres Pronator syndrome occurs when the median nerve is compressed as it passes through the two heads of the pronator teres. This will affect sensory and motor function of the median nerve.
Which nerve innervates the diaphragm? phrenic nerve ventral rami of lumbar nerves L2-L4 cranial nerve V cranial nerve XI
Correct Answer: phrenic nerve The diaphragm is the primary muscle of inspiration. It is a dome-shaped muscle that separates the thoracic cavity from the abdominal cavity. The muscle is innervated by the phrenic nerve.
Which muscle is innervated by the femoral nerve? adductor longus iliopsoas quadriceps femoris hamstrings
Correct Answer: quadriceps femoris The quadriceps femoris muscle is located on the anterior portion of the upper leg and serves as the primary extensor of the knee.
What nerve innervates the hamstrings? obturator nerve posterior femoral nerve sciatic nerve common peroneal nerve
Correct Answer: sciatic nerve The sciatic nerve runs along the posterior thigh before it splits into the tibial nerve and common peroneal nerve at the level of the knee. The sciatic nerve supplies the hamstrings muscle group. The hamstrings muscle group consists of the semitendinosus, semimembranosus, and biceps femoris.
The supraspinatus and infraspinatus muscles are both innervated by which nerve? axillary suprascapular lower subscapular upper subscapular
Correct Answer: suprascapular The supraspinatus and infraspinatus are innervated by the suprascapular nerve. The muscles are two of the four muscles that make up the rotator cuff in addition to the subscapularis and teres minor.
An inability to extend the elbow could result from pathology affecting the: dorsal nerve root of C7 ventral nerve root of C7 dorsal nerve root of C8 ventral nerve root of C6
Correct Answer: ventral nerve root of C7 Efferent fibers that control motor function are located in the ventral nerve root as they exit the spinal cord. The triceps receive their primary innervation from the C7 spinal segment.
T/F: triceps is innervated by the musculocutaneous nerve
False: radial nerve
T/F: the lumbar plexus innervates the glute med
False: superior gluteal nerve
T/F gastroc is innervated by the femoral nerve
False: tibial nerve
Which nerve innervates the knee extensor musculature?
Femoral nerve
Radial nerve Origin: Muscles:
Posterior cord Brachioradialis, triceps, supinator, wrist extensors, anconeus
Thoracodosral nerve Origin: Muscles:
Posterior cord Lats
upper subscapular nerve Origin: Muscles:
Posterior cord Subscap
Lower subscap nerve Origin: Muscles:
Posterior cord Subscap, teres major
Axillary nerve Origin: Muscles:
Posterior cord deltoid, teres minor
Lumbar plexus nerves
Psoas major/minor, quadratus lumborum (muscles)
Sacral plexus
Quad fem, piriformis, superior/inferior gemelli, obturator internus
What nerve innervates anconeous?
Radial nerve
Dorsal scapular nerve Origin: Muscles:
Rami of plexus: C5 Rhomboids, levator scap
Long thoracic Origin: Muscles:
Rami of plexus: C5-C7 Serratus anterior
Deep fibular nerve
Tibialis anterior Extensor digitorum longus/brevis Extensor hallucis longus Fibularis tertius
What nerve innervates popliteus?
Tibial nerve
Sciatic Nerve: common fibular division
biceps femoris short head
