Lower Extremities Anatomy Final Flashcards
supplies pyramidalis m. & skin over the anterior iliac crest and greater trochanter
subcostal nerve (T12)
runs across transversus abdominalis & internal oblique, supplies them, supplies the skin suprapubic region
iliohypogastric nerve (L1)
Innervates internal oblique, passes through inguinal canal innervates the proximomedial thigh, root of penis, upper scrotum or mons pubis and labia majora
Ilioinguinal (L1)
runs through and across psoas major & divides into 2
Branches: Genital & Femoral
genitofemoral nerve (L1-2)
enters inguinal canal, supplies cremaster & scrotal skin
genital branch of genitofemoral nerve
passes under inguinal lig., innervates skin over the femoral triangle
femoral branch of the genitofemoral nerve
runs over iliacus to pass under inguinal lig. & supply the skin over lateral thigh
lateral femoral cutaneous (L2-3)
Innervates adductors of the thigh & innervates a patch of skin medial (adductor area) above the knee.
obturator nerve (L2-4) = anterior division
lateral border of psoas major & separates into several anterior femoral cutaneous branches and the saphenous n., passes under the inguinal ligament. Supplies knee extensors & thigh flexors. Provides sensation to anteromedial thigh
femoral nerve (L2-4) = posterior division
Emerges superior to obturator externus & adductor brevis.
Supplies adductor compartment, mixes fibers with communicating branches from femoral n. to form Subsartorial plexus supplies small patch of skin medial thigh
anterior branch of obturator nerve
Emerges through middle of obturator externus & lies deep to adductor brevis. *Supplies adductor magnus (1/2) & obturator externus, terminates at joint capsule of the knee
posterior branch of obturator nerve
exits greater sciatic foramen emerges from the inferior border of piriformis and runs to the popliteal fossa and branches into the tibial & common fibular (common peroneal) nn.
sciatic nerve (L4-S3)
*exits greater sciatic foramen runs deep to gluteus maximus and emerges from its inferior border
posterior femoral cutaneous nerve (S1-S3)
N. to quadratus femoris (L4-S1) innervation
- hip joint
- inferior gemellus m.
- quadratus femoris m.
N. to obturator internus (L5-S2) innervation
- superior gemellus
- obturator internus
Pudendal n. (S2-S4) innervation
innervates most of the perineum
Superior Gluteal Nerve Innervation
gluteus medius, minimus, TFL
Inferior Gluteal Nerve Innervation
Gluteus Maximus
Nerve to Piriformis Innervation
piriformis muscle
Perforating cutaneous nerve innervation
skin over lower medial gluteal region
Clinical Correlation of fractures of hip
Usually intraarticular
Often require surgical repair
Leads to lateral rotation of lower limb
May lead to “aseptic vascular necrosis”
Sural Nerve innervates what
skin along distal 2/3rds of posterolateral calf & lateral aspect of foot, over 5th digit
Gluneal nerves supply skin of
gluteal region
Nerve injured for trendelenburg sign
superior gluteal nerve (L4-S1)
Sacroiliac Joint is richly innervated by
unmyelinated nerve endings & posterior primary rami of L2-S3
Os Coxae Bones
ilium
ischium
pubis
Borders of Femoral Triangle
Superior: inguinal ligament
Medial: adductor longus
Lateral: sartorius
Contents of Femoral Triangle
Femoral n., a., v., & lymph
Floor of Femoral Triangle
pectineus & iliopsoas
Roof of Femoral Triangle
Fascia lata, cribiform fascia, subcutaneous tissue, skin
Adductor, Subsartorial, or Hunter’s Canal
Passage way for the femoral a. & v. as they transverse the anterior thigh to enter the posterior thigh. Approx. 15cm in length
Contents of Adductor, Subsartorial, or Hunter’s Canal
Femoral a., v., & N. to vastus medialis & saphenous n.
Psoas Major Muscle
Origin: T12-L5 vertebrae and intervertebral disks; and transverse processes of L1-L5
Insertion: With iliacus as iliopsoas into the lesser trochanter
Innervation: L1-L3 ventral primary rami
Action: Flex the thigh at the hip
Psoas Minor Muscle
Origin: T12, L1 vertebrae & intervertebral disk.
Insertion: pectineal line; iliopectineal eminence
Innervation: branch of L1.
Action: Assists iliopsoas
Iliacus Muscle
Origin: iliac fossa - as the tendon of psoas major passes over iliacus, their tendons fuse forming the iliopsoas.
Insertion: lesser trochanter.
Innervation: femoral n. (L2 and L3)
Action: Flex the thigh at the hip
Sartorius Muscle
Origin: Anterior superior iliac spine (ASIS)
Insertion: Superior medial surface of the tibia
Action: Flexes, abducts and laterally rotates the thigh at the hip; flexes & medially rotates the leg at knee joint.
Spinal Levels: Femoral nerve L2, L3
Pes Anserinus
muscular tripod: - sartorius - gracilis - semitendinosus Insert at the superomedial tibia
Innervation of Quadriceps Muscles
femoral nerve (L2-4)
Actions of Quadriceps Muscles
all extend knee
- rectus femoris also initiates thigh flexion
Insertions of Quadriceps Muscles
tibial tuberosity as the patellar ligament
Rectus Femoris Origin
Straight head – AIIS
Reflected head - rim of the acetabulum
Vastus Medialis Origin
Medial lip of the linea aspera & intertrochanteric line of the femur
Clinical Finding of Vastus Medialis
Weakness of this m. allows patella to track laterally during knee extension causing bony contact with the lateral femoral condyle.
Vastus Intermedius Origin
Anterior & lateral surfaces of shaft of femur
Vastus Lateralis Origin
Greater trochanter & lateral lip of linea aspera
Articularis Genu Muscle
Deep to vastus intermedius, sometimes blended with it.
Origin: distal femoral shaft
Insertion: Synovial joint capsule of the knee.
Innervation: Femoral n. (L2-L4)
Action: Retracts synovial capsule to prevent pinching during leg extension.
Pectineus Muscle
Origin: Pectineal line of pubic bone Insertion: Pectineal line of the femur Action: Hip adduction & flexion Innervation: Femoral nerve Spinal levels: L2, L3
Muscles that originate from ramus and body of pubis bone
Adductor longus
Adductor brevis
Gracilis
Muscles that adduct and medially rotate thigh
Adductor longus
Adductor brevis
Gracilis
Insertion of Adductor Longus
middle third of linea aspera
Insertion of Adductor Brevis
pectineal line of femur and proximal linea aspera
Insertion of Gracilis
superomedial surface of tibia
Adductor Magnus Muscle
Origin:
- Lateral (Adductor) part: ischiopubic ramus pubis
- Medial (Hamstring) part: ischial tuberosity
Adductor part: insertion at gluteal tuberosity, linea aspera of femur, medial supracondylar line
Innervation: post. branch of obturator n. (L2, L3, L4)
Hamstring part: insertion at adductor tubercle and medial supracondylar line.
Innervation: Tibial division of sciatic n. (L4 )
Obturator Externus Muscle
Origin: Exterior margin of the obturator foramen & membrane Insertion: Trochanteric fossa Innervation: posterior division of the obturator n. (L3,L4) Action: lateral rotation
Anterior branch of obturator nerve lies between
adductors longus & brevis
Posterior branch of obturator nerve lies
- superficial to obturator externus and passes deep to adductor brevis
- superficial to adductor magnus
- lies between adductor brevis and magnus
Biceps Femoris Muscle
Origin:
- Long head – ischial tuberosity
- Short head – lateral lip of linea aspera & lateral supracondylar ridge femur.
Insertion: Head of fibula & lateral condyle of tibia
Innervation (L5-S2):
- Long head: tibial division of sciatic nerve
- Short head: common fibular
division of sciatic nerve
Action:
- Short head flexes & laterally rotates the leg at knee
- Long head extends thigh at hip.
Semitendinosus Muscle
Origin: Ischial tuberosity
Insertion: Medial surface proximal tibia
Innervation: Tibial division sciatic nerve (L5-S2)
Action:
- Flexes leg & medially rotates tibia
- Extends the thigh at hip
Semitendinosus tendon with sartorius & gracilis form Pes anserinus
Semimembranosus Muscle
Origin: Ischial tuberosity
Insertion: Posterior aspect of the medial condyle of the tibia
Innervation: Tibial division, sciatic n. (L5-S2)
Action: flexes the leg & medially rotates tibia; extends thigh at hip
Part tendon is reflected, forming oblique popliteal lig.
Contents of Popliteal Fossa
Popliteal a., v.,
Common Fibular n.
Tibial n.
Sural nerve will supply
skin along distal 2/3rds of posterolateral calf & lateral aspect of foot, over 5th digit
Muscles that arise from ischial tuberosity
semimembranosus
semitendinosus
biceps femoris long head
Muscle arising from linea aspera and lateral supracondylar ridge
biceps femoris short head
