Anatomy USMLE RX Flashcards
Muscles of mastication
innervation
4 muscles total
3 close your jaw: Masseter, teMporalis, Medial pterygoid
1 opens your jaw: Lateral pterygoid
Innervated by trigeminal V3 - only brnch of CN V with a motor component [this muscle also has a sensory component carrying info from the lower lip]
M’s Munch and Lateral Lowers
carotid sheath:
common carotid is medial, internal jugular vein is lateral and the vagus nerve is posterior
what arteries are housed within teh cardinal ligament/transverse cervical ligament?
Uterine vessels (artery and vein)
connects cervix to pelvin wall
what nerve is commonly injured in a posterior hip dislocation?
what are the presenting symptoms?
Inferior gluteal nerve innervates the gluteus maximus, which is commonly injured with a posterior hip dislocation
gluetus maximus extends and laterally rotates teh thigh and aids in standing from a sitting position –>
sx: difficulty standing up from a sitting position, ascending stairs or jumping
pelvic fractures commonly injures what nerve?
the femoral nerve
responsible for flexing the thigh and extending the leg
what innervates teh quadratus femoris muscle?
L5-S1 nerves of the lumbosacral plexus
functions to laterally rotate the thigh
what nerve innervates the piriformis muscle?
S1-S2 branches of the sacral plexus innervates the piriformis m.
functions to laterally rotate when leg is extended
abduct when the the leg is flexed
Psoas test
the psoas test can be performed either by passive extension or active felxion of the right hip against resistance –> iliospoas muscle group pushes against the appedix and causes significant pain and irritation
psoas muscle is innervated by the lumbar plexus
iliacus muscle is innervated by the femoral nerve
what is ortner syndrome?
a growing left atrium can compress the left recurrent laryngeal nerve as it hooks around the aorta at the ligamentum arteriosum –> hoarseness
