Nerves Flashcards
efferent
motor
afferent
sensory
are motor nerves susceptible to local anesthetics
no, block pain but not movement
cervical plexus location
located in the posterior triangle of the neck, halfway up the sternocleidomastoid muscle, and within the prevertebral layer of cervical fascia
what is the cervical plexus formed by
anterior rami divisions of cervical spine nerves C1-C4
a block in the innerscalene grove could potential block which nerve
phrenic nerve leading to hemi-diapraghmatic paralysis
what is the stellate ganglion a collection of
sympathetic nerves found anterior to the neck of the first rib
where do the somatic branches from the stellate ganglion provide sympathetic fibers to
anterior rami of C7, C8, T1
visceral branches of the stellate ganglion include what
The visceral branches include the inferior cardiac nerve; this is the contribution of this ganglion to the cardiac plexus in the thorax.
why block the stellate ganglion?
The brachial plexus is a nerve network that supplies the _______. _______ forms it.
upper extremity; C5-T1
the palpable space behind the lateral head of the sternocleidomastoid muscle and adjacent to the C6 lateral tubercle is also known as
Chaissaignac’s tubercle
horner’s syndrome is the result of what
blocking the stellate ganglion while placing a innerscalene block
signs of horner’s syndrome
partial ptsosis (drooping or falling of eye lid, miosis (constricted pupil), facial anhidrosis (absence of sweating)
is Horner syndrome result of paralysis of the ipsilateral sympathetic cervical chain
yes
The brachial plexus is a network of nerve fibers that supply skin and musculature of the __________. It begins in the root of the neck, passes through the ________, and runs through the entire ________
upper limb; axilla; upper extremity
what is the brachial plexus formed by the
anterior rami of C5, C6, C7, and C8 and T1
what is the brachial plexus divided into (5 parts)
roots, trunks, division, cords, and branches
(Read That Damn Cadaver Book)
spinal roots, sensory and motor functions for the axillary nerve
Spinal Roots = C5 and C6
Sensory Functions = rises to the upper lateral cutaneous nerve of the arm, which innervates the skin over the lower deltoid.
Motor Functions = innervates the teres minor and deltoid muscles
spinal roots, sensory and motor functions for the musculocutaneous nerve
Nerve Roots: C5-C7
Motor Functions: muscles in the anterior compartment of the arm (coracobrachialis, biceps brachii, and the brachialis).
Sensory Functions: lateral cutaneous nerve of the forearm, which innervates the lateral aspect of the forearm
spinal roots, sensory and motor functions for the median nerve
Nerve Roots: C6-T1
Motor Functions: innervates the flexor and pronator muscles in the anterior compartment of the forearm (except the flexor carpi ulnaris and part of the flexor digitorum profundus, innervated by theulnar nerve). It also supplies innervation to the thenar muscles and lateral two lumbrical in hand.
Sensory Functions: Gives rise to the palmar cutaneous branch, which innervates the lateral aspect of the palm, and the digital cutaneous branch, which innervates the lateral three and a half fingers on the anterior (palmar) surface of the hand.
spinal roots, sensory and motor functions of the radial nerve
spinal roots– C5-T1.
Sensory– Innervates most of the skin of the posterior forearm, the lateral aspect of the dorsum of the hand, and the dorsal surface of the lateral three and a half digits.
Motor–Innervates the triceps brachii and the extensor muscles in the forearm.
spinal roots, sensory and motor functions of the ulnar nerve
Spinal roots:C8-T1.
Motor functions:
Two muscles of the anterior forearm – flexor carpi ulnaris and medial half of flexor digitorum profundus
Intrinsic muscles of thehand(apart from the thenar muscles and two lateral lumbricals)
Sensory functions:Medial one and half fingers and the associated palm area.
Innervation of the hand
Lumbar plexus
The anterior rami of the L1-L4 spinal roots divides into several cords. These cords then combine to form the six major peripheral nerves of the lumbar plexus.
These nerves then descend down the posterior abdominal wall to reach the lower limb, where they innervate their target structures.
I,IGetLeftoversOnFridays. Iliohypogastric,Ilioinguinal,Genitofemoral,Lateral cutaneousnerve of the thigh,ObturatorandFemoral.
Iliohypogastric nerve
The iliohypogastric nerve is the first major branch of the lumbar plexus.
It runs to the iliac crest, across the quadratus lumborum muscle of the posterior abdominal wall.
It then perforates the transversus abdominis, and divides into its terminal branches.
spinal roots, sensory and motor function of iliohypogastric
Roots: L1 (with contributions from T12).
MotorFunctions: Innervates the internal oblique and transversus abdominis.
SensoryFunctions: Innervates the posterolateral gluteal skin in the pubic region.
(Tip: an easy way to remember that the IlioHypogastric comes before the IlioInguinal is thatH comes beforeIin the alphabet!)
ilioinguinal nerve
The ilioinguinal nerve follows the same anatomical course as the larger iliohypogastric nerve. After innervating the muscles of the anterior abdominal wall, it passes through the superficial inguinal ring to innervate the skin of the genitalia and middle thigh.
Roots: L1.
MotorFunctions:Innervates the internal oblique and transversus abdominis.
SensoryFunctions: Innervates the skin on the superior anteromedial thigh. In males, it also supplies the skin over the root of the penis and anterior scrotum. In females, it supplies the skin over mons pubis and labia majora.
Lateral Femoral Cutaneous nerve
This nerve has a purely sensory function. It enters the thigh at the lateral aspect of the inguinal ligament, providing cutaneous innervation to the skin.
Roots: L2, L3
Motor Functions:None.
Sensory Functions: Innervates the anterior and lateral thigh down to the level of the knee.
Obturator Nerve
Roots: L2, L3, L4.
Motor Functions: Innervates the muscles of the medial thigh – the obturator externus, adductor longus, adductor brevis, adductor magnus and gracilis.
Sensory Functions: Innervates the skin over the medial thigh.
Femoral nerve
Roots: L2, L3, L4.
Motor Functions: Innervates the muscles of the anterior thigh – the illiacus, pectineus, sartorius and quadriceps femoris.
Sensory Functions: Innervates the skin on the anterior thigh and the medial leg.
Sacral Plexus
Thesacral plexusis a network of nerve fibers that supplies the skin and muscles of the pelvis and lower limb. It is located on the surface of the posterior pelvic wall, anterior to the piriformis muscle.
The plexus is formed by theanterior rami(divisions) of the sacral spinal nervesS1, S2, S3 and S4. It also receives contributions from the lumbar spinal nerves L4 and L5.
Sciatic Nerve
Thesciatic nerveis a major nerve of the lower limb. It is a thick flat band, approximately 2cm wide – the largest nerve in the body.
Nerveroots:L4-S3.
Motor functions:
Innervates the muscles of the posterior thigh (biceps femoris, semimembranosus and semitendinosus) and the hamstring portion of the adductor magnus (remaining portion of which is supplied by the obturator nerve).
Indirectly innervates(via its terminal branches) all the muscles of the leg and foot.
Sensory functions: No direct sensory functions. Indirectly innervates (via its terminal branches) the skin of the lateral leg, heel, and both the dorsal and plantar surfaces of the foot.
