Sacral plexus Flashcards
L4 and L5 are able to contribute to the sacral plexus due to what
the lumbosacral trunk
what forms the sacral plexus
anterior primary rami of L4,L5 S1-S3 and part of S4
where does the sacral plexus form
on the piriformis muscle
where do the nerve roots that contribute to the sacral plexus divide into anterior and posterior divisions
shortly after exiting their IVF/sacral foramina
what roots contribute to quadratus femoris and gemllus inferior nerve
L4,L5, and S1
how does the nere to the quadratus femoris and gemellus inferior leave the pelvis
through the greater sciatic foramen
what is the action of the quadratus femoris and inferior gemellus
lateral rotation and adduction of the femur
what roots contribute to the nerve to the obturator internus and gemellus superior
L5, S1 and S2
how does the nerve to the obturator internus and gemellus superior leave the pelvis
through the greater sciatic foramen gibing off branches to the gemllus superior
how does the nerve to the obturator internus and gemllus superior supply the obturator internus
after exiting the pelvis it reenters the pelvis via the lesser sciatic foramen
what is the action of the obturator internus and gemllus superior
lateral rotation and abduction of the femur
what roots contribute to the pudendal nerve
S2,S3, and S4
what branches come off of the pudendal nerve within the pudendal cnal
the inferior rectal nerves, perineal nerve, and the dorsal nerve of the penis/clitoris
what sensory information does the inferior rectal nerves carry
the skin around the anus and the inferior 2/3 of the anal canal
what muscles are innervated by the inferior rectal nerves
the external anal sphincter
what does the perineal nerve divide into
deep and superficial branches
what muscles are supplied by the deep branches of the perineal nerve
the external anal sphincter, bulbocavernous , ishiocavernous, superficial transverse perineus
the deep branches of the perineal nerve carry primarily what type of information
motor
the superficial branches of the perineal nerve carry primarily what type of information
sensory
what does the superficial branches of the perineal nerve supply in males
posterior scrotum, urethral mucosa and bulb of the penis
what does the superficial branches of the perineal nerve supply in females
labium majus, external urethral orifice and vestibule
what is the terminal branch of the pudendal nerve
the dorsal nerve of the penis/clitoris
what muscles does the dorsal nerve of the penis/clitoris supply
deep transverse perineus, urethral sphincter muscles
what sensory information is carried in the dorsal nerve of the penis/clitoris
in males the corpus cavernosum, glans penis and skin covering the penis
in females the corpus cavernosum, and clitoris
what do individual muscular branches from the anterior division of the sacral plexus that contain S4 fibers supply
levator ani and cocygeus muscles
what type of information do pelvic splanchnic nerves carry
parasympathetic
what are the nerves that come off the posterior division of the sacral plexus
the nerve to the piriformis, superior gluteal nerve, inferior gluteal nerve, and the perforating cutaneous nerve
what fibers contribute to the nerve to the piriformis
S1, S2
what roots contribute to the superior gluteal nerve
L4,L5, and S1
what does the superior branch of the superior gluteal nerve supply
the gluteus medius and gluteus minimus
what does the inferior branch of the superior gluteal nerve supply
the gluteus medius, gluteus miniumus, and tensor fascia lata
what roots contribute to the inferior gluteal nerve
L5, S1, and S2
what does the inferior gluteal nerve supply
the gluteus maximus
what roots contribute to the perforating cutaneous nerve
S2 and S3
what two landmarks can the sacrotuberous ligament be found between
the sacrum and ischial tuberocity
what nerves are formed by both anterior and posterior divisions of the sacral plexus
the posterior cutaneous nerve of the thigh and the sciatic nerve
what forms the posterior cutaneous nerve of the thigh
fibers from the anterior divisions of S2 and S3 as well as posterior divisions S1 and S2
what does the posterior cutaneous nerve of the thigh supply
skin on the posterior and medial thigh
what is the largest nerve in the human body
Sciatic nerve
what is the diameter of the sciatic nerve
2cm
what two nerves combine to from the sciatic nerve
tibial nerve (anterior division L4-S3) and common fibular nerve ( posterior division L4-S2)
what roots contribute to the fibular nerve
anterior division of L4-S2
what muscles fibers are given off from the common fibular nerve before the tibal nerve fibers separate from it
biceps femoris (short head)
what does the lateral sural cutaneous nerve supply
skin on the lateral aspect of the leg
what does the fibular communicatin branch combine with to form the sural nerve
the medial sural cutaneous nerve
what two muscles are supplied by the superficial fibular nerve
fibularis longus and fibularis brevis
what compartment are the fibularis longus and brevis located in
lateral compartment
what does the medial dorsal cutaneous nerve and the intermediate dorsal cutaneous nerve supply
the skin ove the dorsum of the foot, except for the skin between the first two toes
what muscles does the deep fibular branch supply
tibialis anterior, extensor digitorum longus and brevis, extensor hallicus longus, extensor hallucis brevis, and fibularis tertius
what compartment are the following muscles located in and what is the main function as a group:
tibialis anterior, extensor digitorum longus and brevis, extensor hallicus longus, extensor hallucis brevis, and fibularis tertius
the anterior compartment functioning to dorsiflex the foot
what does the terminal branch of the deep fibular nerve supply
the skin between the first two toes
what is a clinical consideration with the common fibular nerve
steppage gait/foot drop
is the common fibular nerve more lateral or medial
lateral
is the tibial nerve more lateral or medial
medial
what is larger the common fibular nerve or the tibial nerve
tibial
what roots contribute to the tibial nerve
L4-S3
while still combined with the common fibular nerve what muscles does the tibial nerve innervate
biceps femoris ( long head), semitendinosus, semimembranosus, adductor magnus
what do the following muscles all have in common: biceps femoris ( long head), semitendinosus, semimembranosus,
they are part of the hamstring group and all originate on the ischial tuberocity
what is given off in the popliteal fossa by the tibial nerve
articular braches that supply the knee joint as well as muscular branches, and a popliteal branch
what muscles are supplied by the muscular branches given off in the popliteal fossa by the tibial nerve
popliteus, gastrocnemius (both heads), soleus, plantaris
what compartment are the following muscles in, and what joints do each of them cross:
popliteus, gastrocnemius (both heads), soleus, plantaris
all in the superfiscial-posterior compartment , the popliteus cross the knee joint, the gastrocnemius (both heads) crosses both the knee and ankle joint. soleus and plantaris do not cross a joint
what sensory information is carried by the interosseous nerve of the leg
from the tibial periosteum, ankle, and tibiofibular joints
while in the leg the tibial nerve give off muscular branches to what muscles
flexor digitorum longus, and flexor hallucis longus
while in the leg the tibial nerve gives off what sensory branch and what does it supply
the medial calcaneal branches that supply the skin over the medial heel
what are the terminal branches of the tibial nerve
the medial plantar nerve and the lateral plantar nerve
what muscles does the medial plantar nerve supply before it devides
abductor hallucis, flexor digitorum brevis, flexor hallucis brevis
what does the medial plantar nerve divide into
the common plantar digital nerves
what motor supply is from the common plantar digital nerves supply
motor supply to lumbercals 1 and 2
how is sensory innervation to between the toes accomplished by the common plantar digital nerves
by dividing into propler plantar digital nerves
what branches does the lateral plantar nerve divide into
superficial and deep branches
what does the superficial branch of the lateral plantar nerve supply
skin around the 5th digit
what does the deep branch of the lateral plantar nerve supply
adductor hallucis, flexor digiti minimi brevis, lateral lumricals, and interossei muscles
what are the clinical considerations associated with the tibial nerve
flexor paralysis, hammer toes, “claw foot”
