Peripheral Nerve Anatomy Flashcards
What supplies the majority of the sensory information for the face?
Trigeminal Nerve (CN V)
What is the anesthetic interest for blocking CN V?
Trigeminal Neuralgia
Can be blocked to relieve pain, diagnostic prior to neurolysis
What are the 3 nerve branches from the trigeminal nerve (CN V)?
Opthalamic
Maxillary
Mandibular
Innervation of the glossopharyngeal nerve (CN IX)
oropharynx soft palate posterior 1/3 portion of the tongue pharyngeal (anterior) surface of epiglottis vallecula
What does a glossopharyngeal nerve block block?
Blocks gag reflex, and posterior pharynx (nasal intubation)
What is the landmark for the glossopharyngeal nerve block (APEX)
palatoglossal arch at the anterior tonsillar pillar
Innervation of the Superior Laryngeal Nerve
Base of tongue
Posterior surface of epiglottis
Aryepiglottic fold
Arytenoids
The SLN can be blocked by…
mucosal saturation
The SLN divides into internal and external branches.
What does the internal branch innervate?
What does the external branch innervate?
Internal: sensory ONLY to larynx and hypopharynx
External: cricothyroid muscle
What is the landmark for the SLN block? (APEX)
Greater cornu of hyoid bone
Innervation of Recurrent Laryngeal Nerve
Vocal cords (below) and trachea
What should you have the patient say after ENT surgery to ensure no damage to the RLN?
eeeee
Innervation of the cervical plexus
Muscles, joints, and skin in the anterior neck
Where is the cervical plexus located?
Ventral rami C1-C4
Where is the site for skin infiltration for the cervical plexus block?
posterior border of the sternocleidomastoid muscle
How many: Ventral Rami (Roots) Trunks Divisions Cords Branches
Ventral Rami (Roots): 5 Trunks: 3 Divisions: 6 Cords: 3 Branches: 5
Where are roots, trunks, divisions found?
Found in posterior triangle of the neck
Supraclavicular
Where are cords and branches found?
Found in the Axilla
Infraclavicular
What rami (roots) are involved?
C5-T1 (can include C4 and T2)
Roots are located from the ____ to the ____
from lateral foramina to lateral border of scalene muscles
Which nerve roots connect with the superior, middle and inferior trunks?
Superior: C5-C6
Middle: C7
Inferior: C8-T1
Trunks are enveloped in a _____
fascial sheath
Injection into the fascial sheath when blocking at the trunks level commonly produces what block?
Complete block of the upper ext.
The fascial sheath is in the interscalene space, where is this located?
Emerge between anterior and middle scalene muscle
When doing an interscalene block with ultrasound, what are we looking for?
“stoplight” that will be dark (hypoechoic)
Divisions divide into 3 Anterior (Ventral) & 3 Posterior (Dorsal), what do each supply?
3 Anterior (Ventral): Supply flexor portions
3 Posterior (Dorsal): Supply extensor portions
The posterior (dorsal) divisions form to make the ____ cord
The anterior (ventral) divisions form to make the ___ & ___ cords
posterior (dorsal) division –> posterior cord
anterior (ventral) division –> lateral & medial cord
The posterior cords makes up what branches?
Axillary and radial
and thoracodorsal nerve
The lateral cord makes up what branches?
Musculocutaneous & ½ of the Median Nerve
The medial cord makes up what branches?
Ulnar & ½ of the median nerve
and Median Cutaneous Nerve of arm and forearm
Axillary Nerve
Formed from ____
Passes from ____ to ____
Posterior to neck of ____
Innervation of the ____
C5-C6
axilla to shoulder
humerus
Shoulder
What is the cutaneous innervation of the axilla nerve?
Skin covering deltoid
Radial Nerve Formed from \_\_\_ Passes from \_\_\_ to \_\_\_ Innervation of \_\_\_\_ - Posterior branch of cutaneous muscle - Innervates skin covering muscle
C5 -T1
axilla to arm
long head of triceps
Radial Nerve
Descends along shaft of ____
- Inferior lateral cutaneous branch
–> Innervates _____
- Posterior antebrachial cutaneous branch
- -> innervates
humerous
posterior arm
posterior surface of arm
Continuing down the arm, the radial nerve crosses the elbow anterior to the _____
Lateral epicondyle
Radial nerve divides into deep and superficial
Superficial innervate:
Deep innervates:
Superficial: Dorsum of the hand onto the thumb, index, middle, and ring fingers
Deep: Many of the muscles of wrist and hand
Motor response to radial nerve stimulation
Wrist extension
Metacarpo-phalangeal extension
Thumb abduction
Musculocutaneous Nerve
Formed from ____
Pierces through _____
Descends between ____ & ____
C5-C7
coracobrachialis muscle
between brachialis muscle and the biceps brachii muscle (innervates all these muscles)
Musculocutansous Nerve
At the elbow, becomes the _____
Runs along the _____ muscle
Innervates _____
Lateral antebrachial cutaneous nerve
brachoradialis
innervates skin above muscle
Motor response to musculocutaneous stimulation
biceps flexion
Median Nerve Formed from \_\_\_\_ Descends arm with \_\_\_\_ Crosses cubital fossa \_\_\_\_ to the artery Passes into the forearm through \_\_\_ Innervation to \_\_\_
C5-T1 Brachial artery Medial Carpal Tunnel Palmer side of 1/2 thumb, index finger, middle finger and 1/2 ring finer & dorsal side finger tips of pointer finger, middle finger and 1/2 ring finger
Motor response to median nerve stimulation
Wrist flexion
Finger flexion
Thumb opposition
Medial Cutaneous Branch
Branches of medial cord (T1)
- Skin innervation of
Medial Antebrachial Cutaneous Branch
- Crosses the cubital fossa
Innervates skin on the medial aspect of the forearm
skin covering medial surface of arm
Ulnar Nerve
Formed from ____
Descends with ____ artery
Crosses the elbow posterior to __ epicondyle
C8-T1
Brachial
Medial (and then continuous down forearm)
Innervation for ulnar nerve
Motor
Skin
Motor: Many muscles in wrist, fingers and thumb
Skin: Dorsal and Medial surface of hand
Dorsam surface of the ring and little fingers
Motor response to ulnar nerve stimulation
Ulnar deviation of wrist
Finger flexion
Thumb adduction
The LumboSacral Plexus is formed from
L1-S5
may include T12
What is the Iliohypogastric nerve formed from
L1 (may include T12)
The Iliohypogastric nerve travels in the abd wall to the level of the
Symphasis pubis
What does is iliohypogastric nerve innervate?
Muscle, skin, and parietal peritoneum
Skin over inferior abdomen and buttocks
What is the Ilioinguinal nerve formed by?
L1 (may include T12)
Ilioinguinal nerve Travels in \_\_\_\_\_ Pierces posterior wall of the \_\_\_\_\_ Passes through superficial \_\_\_\_\_ Terminates on the anterior \_\_\_\_ or \_\_\_\_
abdominal wall
inguinal canal
inguinal ring
scrotum or labia majora
What does the Ilioinguinal nerve innervate?
Muscle, skin, parietal peritoneum along course
Skin
- Superior, medial thigh
- Portions of external genitalia
What is the Genitofemoral nerve formed by?
L1-L2
Genitofemoral Nerve Travels in \_\_\_\_\_ Passes through deep \_\_\_\_\_ Passes through superficial \_\_\_\_\_ Terminates on anterior \_\_\_\_ or \_\_\_\_\_
abdominal wall
inguinal canal
inguinal ring
scrotum or labia majora
What does the Genitofemoral nerve innervate?
Skin covering femoral hiatus
Skin on the scrotum or labia majora
What is the Pudendal Nerve formed from?
Anterior division of S2-S4
Passes from pelvis through greater sciatic foramen into gluteal region.
Passes posterior to ischial spine and into perineum.
What does the Pundendal Nerve innervate?
Muscle and skin of perineum
What is the Lateral Femoral Cutaneous Nerve formed from?
L2-L3
How does the Lateral Femoral Cutaneous Nerve travel?
Descends posterior abdominal wall
Crosses iliac crest into pelvis and down to inguinal ligament and anterior iliac spine
What does the Lateral Femoral Cutaneous Nerve innervate?
Sensory: Lateral Thigh
Motor: NONE
What is the Posterior Femoral Cutaneous Nerve formed from?
Anterior and Posterior Division of S1-S3
APEX says L4-S3
How does the Posterior Femoral Cutaneous Nerve travel?
Passes from pelvis into gluteal region
To posterior thigh
What does the Posterior Femoral Cutaneous Nerve innervate?
Skin Posterior thigh (Hip to mid calf)
What is the Obturator Nerve formed from?
L2-L4
How does the Obturator Nerve travel?
Travels to medial compartment of thigh
What does the Obturator Nerve innervate?
Sensory: medial thigh (cutaneous branches)
Motor: Controls adduction, flexion and extension of hip (articular branches)
What is the Femoral Nerve formed by?
Posterior division L2-L4
How does the Femoral Nerve travel?
Through pelvis
Deep into inguinal ligament
Enters anterior compartment of thigh
Divides into multiple branches
Where does the anterior/posterior division of the femoral nerve split?
Below inguinal ligament
Does the anterior or posterior division of the femoral nerve contain the saphenous nerve?
Posterior
What is the position of the vein/artery/nerve from
Medial to lateral
&
Lateral to medial
Medial to Lateral
VAN (Vein, Artery, Nerve)
remember: venous penis
Lateral to Medial
NAVEL (Nerve, Artery, Vein, Empty space, Ligament)
What does the Femoral Nerve innervate?
Sensory: Anterior thigh Motor: Rectus femoris Vastus lateralis Vastus Intermedius Vastus medialis Sartorious
The Saphenous Nerve is from the posterior femoral nerve, how does it travel?
Follows deep surface of Sartorius muscle to attachment on tibia
Accompanied by saphenous vein
Passes to skin
What does the Saphenous Nerve innervate?
Sensory: Medial leg from knee to the arch of the foot
Motor: NONE
What does stimulation of the Saphenous nerve cause?
Sartorious muscle contraction (bandlike across thigh) Patellar twitch (snap)
Sciatic Nerve forms which 2 nerves
Tibial Nerve (anterior) L4-S3 (largest)
Common Peroneal Nerve (posterior) L4-S2
T/F: In the Sciatic Nerve, the common peroneal and tibial nerves are distinct nerves from the beginning in the same sheath
True
How does the Sciatic Nerve travel?
Passes from pelvis through greater sciatic foramen into gluteal region Descends between: - gluteus maximus (posteriorly) - obturator internus (anteriorly) - lateral to ischial tuberosity Enters Posterior thigh
When the Sciatic Nerve innervates the muscles, what happens?
Hip Extension
Flexion of knee
The Sciatic Nerve descends _____ where it splits into Tibial & Common Peroneal
popliteal fossa
How does the tibial nerve travel
Exits popliteal fossa and into superficial posterior compartment of leg
Passes between tibial and fibular heads and enters deep posterior compartment
Passes posterior to medial malleolus into foot and branches
- Medial plantar nerve
- Lateral plantar nerve
- Two branches innervate plantar surface of foot
The Common Peroneal Nerve divides into superficial and deep, where does the superficial terminate?
Enters lateral compartment of leg and terminates in lateral and dorsal surface of foot
The Common Peroneal Nerve divides into superficial and deep, where does the deep terminate?
Enters anterior compartment
Crosses anterior surface of ankle into foot
Terminates as cutaneous fibers
- Skin between hallux and second toe
What 2 nerves is the Sural Nerve formed from?
branches from tibial and common peroneal
The Sural Nerve travels with which other nerve?
Saphenous Nerve
What does the Sural Nerve innervate?
Posterior sole of foot
Posterior heel
Achilles tendon above ankle
Motor innervation of tibial nerve
Inversion and plantar flexion
Motor innervation of superficial peroneal nerve
Eversion and abduction of foot
Motor innervation of deep peroneal nerve
Dorsiflexion
