Random Flashcards
Sacral plexus
- L4-S4
- Forms superior gluteal N, inferior gluteal N, sciatic N, posterior femoral N, pudendal N
Superior gluteal N
- posterior divisions of the anterior rami of L4, L5, and S1
- innervates TFL, glute med, and glute min
Inferior gluteal N
- Posterior divisions of the L5lS1, and S2 spinal nerves
- innervates the glute max
Nerve to piriformis
- Posterior divisions of anterior rami of the S1 and S2 spinal nerves
- Innervates piriformis
Perforating cutaneous N
- Posterior divisions of S2 and S3
- cutaneous supply to a small area of skin on the inferior medial part of the buttock
Pelvic splanchnic N
- originate from the anterior rami of spinal nerves S2, S3, and S4
- parasympathetic outflow joins inferior hypogastric plexus.
- motor component supples the bladder and the distal part of the large intestines
Sciatic N
- formed from anterior and posterior positions of the anterior rami of spinal nerves L4 and S3
- Divided into common peroneal and tibial component
- Supplies hamstrings and ischial fibers of adductor magnus
Common peroneal N
- L4-S2
- Innervates the short head of the bicep femoris as well as the muscles in the lateral and anterior compartments of the leg
- fibularis longus and brevis, tibialis anterior, extensor digitorum longus, and extensor hallucis longus
Tibial N
- L4-L3
- medial and lateral gastrocnemius, soleus, plantaris, and popliteus muscles, tibialis posterior, superior tibiofibular joint
- cutaneous branch is the medial sural nerve
Nerve to quadratus femoris
- anterior divisions of the anterior rami of the L4, L5, and S1
- supplies inferior gemellus
Nerve to obturator internus
- anterior divisions of the anterior rami of spinal nerves L5, S1, and S2
- innervates the superior gemellus and the obturator internus
Posterior cutaneous nerve of the thigh
- fibers from both anterior and posterior divisions of the anterior rami (anterior S2 and S3, posterior S1 and S2)
- anteroposterior and superoinferior range of cutaneous and fascial supply between the anterior and posterior axillary lines from the buttock to the middle of the calf muscles.
Pudendal N
- anterior divisions of the anterior rami of the spinal nerve S2, S3, and S4
- inferior rectal N innervates the external anal sphincter, anal canal, and perianal skin
- perineal N cutaneous supply to part of the posterior scrotum, mucus membrane of the urethra and vagina, motor innervation to the muscles of the perineum
- dorsal N of the clitoris/penis provides cutaneous innervation to this region
Nerve to levator ani and ischiococcygeus muscles
- the last two branches of the sacral plexus are the nerve to the levator ani and the ischiococcygeus muscle.
Perineal branch of S4
- the perineal branch of S4 courses via coccygeus and iliococcygeus muscles.
Major branches if sacral plexus
SIPPS S- superior gluteal N I - inferior gluteal N P- posterior cutaneous N of thigh P- pudendal N S - sciatic N
Brachial plexus
- C5-8 and anterior branch of T1
- forms thoracodorsal N, lower subscapular N, ulnar N, musculocutaneous N, axillary N, radial N, median N.
Thoracodorsal N
- supplies the latissimus dorsi
Lower subscapular N
- lower portion of the subscapularis muscle, supplies teres major
- branches from the posterior cord of the brachial plexus
Ulnar N
- sensory innervation to the fifth digit and medial half of the fourth digit and corresponding part of the palm
- flexor carpi ulnaris, flexor digitorum profundus, opponens digiti minimi, abductor digiti minimi, flexor digiti minimi brevis, 3rd and 4th lumbrical muscles. dorsal and palmar interossei, adductor pollicis, flexor pollicis brevis
Radial N
- innervates the medial and lateral heads of the triceps brachii, anconeus, brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, supinator, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris, abductor pollicis longus, extensor pollicis longus, extensor pollicis brevis, extensor indicis
Musculocutaneous N
- innervates the coracobrachialis, biceps brachii, greater portion of the brachialis.
- sensation of the lateral side of the forearm from the elbow to the wrist.
Axillary N
- deltoid, triceps, teres minor