Intro to lower extremity Flashcards
The lower limbs are extensions from the trunk designed for?
stability and weight bearing and to aid in locomotion
which ligament is anterior and provides a clear line of demarcation between trunk and lower extremity ?
the inguinal ligament
what is notable about the gluteal region?
it is posterior and a transitional zone
why is the gluteal region considered a transitional zone?
because it physically is part of the trunk but functionally part of the lower extremity
what is the gluteal region a necessity for with humans?
bipedalism. allowing for the abductors of the thigh to be placed superiorly
during embryonic development both limbs develop in which order?
cranial to caudal
torsion around the long axis is in what directions?
opposite (the upper limb rotating laterally and the lower limb rotating medially)
what is the time difference during embryonic development of the lower limb budding from the trunk compared to the upper limbs?
lower limbs bud one week later than upper (around week 6)
for bipedalism what is accompanied with the elongation of the lower extremity?
internal rotation
is the elongation of upper extremity and lower extremity accompanied with the same rotation?
no its internal for lower
how does internal rotation effect the lower extremities?
the knee and all distal joints flex posteriorly
what are the major contributors to the lower extremity?
segments L2-S2
what comprises the pelvic girdle?
the sacrum, part of the vertebral column, and the os coxae
what is the os coxae composed of?
3 fused pelvic bones (ilium, ischium, and pubis)
what articulates with the head of the femur?
acetabulum
how is the acetabulum formed?
by contributions from all 3 pelvic bones
what is the longest and heaviest bone in the body?
the femur
where does the femur transmit weight?
from the hip bone to the tibial plateau
List the prominent features of the femur?
head, neck, greater tubercle, lesser tubercle, and large condyles
what is the angle of inclination?
obtuse angle between the axis of the head/neck of the femur and the shaft (approx 126º) important for bipedalism
what is the torsion angle?
the difference between the axes of the femoral neck and femoral condyles when viewed along the longitudinal axis. important for bipedalism
list how body weight transferred?
from the vertebral column through the sacroiliac joints to the pelvic girdle and from the pelvic girdle to the hip joints, and onto the femurs
why do the femurs descend obliquely?
so their distal ends are medially placed
what do the intercondylar fossa align with?
the middle of the femoral head on the line of gravity
what is the only thing the femoral condyle articulates with?
tibia
T/F: the fibula does not play a role in weight bearing
true only an attachment point for muscles
at the ankle what articulates with the leg bones?
only the talus
where in the ankle is the body weight distributed to?
the calcaneus and the spring ligament
what are the two layers of the gluteal region?
superficial and deep
where do the superficial muscles of the gluteal region attach and their main actions?
proximally attach to the ala of the ilium and mainly extend, abduct, and medially rotate the thigh
where do the deep muscles of the gluteal region attach and their main actions?
these are much smaller. they attach distally on or near the intertrochanteric crest of the femur and mainly laterally rotate the thigh but also stabilize the hip joint by steadying the femoral head in the acetabulum along with ligaments
what is the role of the anterior thigh?
flexors of hip and extensors of knee
what is the role of the posterior thigh?
extend the thigh and flex the knee
what is the role of the medial thigh?
adduct the thigh
what is the role of the anterior leg?
dorsiflexors of ankle, extension of toes
what is the role of the posterior leg?
plantarflexion of ankle, inversion of foot and flexion of toes
what is the role of the lateral leg?
evert the foot
what is the largest branch of the lumbar plexus?
the femoral nerve
where does the femoral nerve originate and descend to?
originates within the psoas major m and descends to the thigh through the pelvis and enters the thigh deep to the inguinal ligament
what does the femoral nerve supply?
the anterior thigh muscles, skin on the anterior thigh, and a branch continues to the anteromedial skin of the knee, leg, and foot
what nerve runs medial to the psoas m. and along the lateral wall of the pelvis?
the obturator nerve
where does the obturator nerve exit?
through the obturator foramen
what does the obturator nerve supply?
muscles of the medial thigh
what is the largest nerve in the body?
sciatic nerve
where does the sciatic nerve exit the pelvis?
through the greater sciatic foramen, inferior to the piriformis m
where does the sciatic nerve appear but does not innervate muscles in that area?
in the gluteal region
what does the sciatic nerve innervate?
all posterior muscles of the lower extremity, all muscles of the leg and foot, most of the skin of the leg and foot and joints of the lower extremities by branches
when does the external iliac artery change name and to what does its name change to?
after it enters the femoral triangle it changes to the femoral artery
where does the external iliac artery travel?
inferiorly, deep to the inguinal ligament
what do anastamoses play an important role in?
blood flow around joints especially the knee
what is a continuation of the femoral artery?
the popliteal artery
where is the popliteal artery?
on the posterior aspect of the distal thigh
when does the femoral artery change its name?
as the femoral artery crosses the adductor hiatus and emerges posterior to the distal femur
what does the popliteal artery run deep in?
the popliteal fossa
how many genicular a. are given off of the popliteal artery?
5
what is the artery of the anterior compartment?
the anterior tibial artery
where does the anterior tibial artery become the the dorsal artery of the foot?
distal to the inferior extensor retinaculum
what is the more direct continuation of the popliteal a and is the artery of the posterior compartment?
the posterior tibial artery
what does the posterior tibial artery supply?
all muscles in the posterior compartment
where does the fibular artery run?
lateral and parallel to the posterior tibial artery
what does the fibular artery supply?
muscles of the posterior compartment and also lateral compartment via perforating branches
where is the deep group of veins?
deep to the deep fascia traveling with major arteries
which veins contain more valves the deep or superficial?
deep
what are the two major superficial veins?
the great and small saphenous veins
what gives rise to the great saphenous vein?
the union of the dorsal vein of the great toe and the dorsal venous arch
what arises from the lateral side of the foot where the dorsal vein of the small toe meets the dorsal venous arch?
the small saphenous vein
what does the small saphenous vein empty into
the popliteal vein after coursing along the posterior aspect of the leg
what is the great saphenous vein commonly used for?
coronary arterial bypasses
