Lower Limb Fascia, Muscles & Neurovasculature

Vocabulary flashcards summarizing key fascia, muscles, vessels, nerves and structural landmarks of the lower limb as presented in the lecture notes.

Superficial fascia of thigh/leg

Subcutaneous tissue containing fat, cutaneous nerves, superficial veins (great & small saphenous) and lymphatics.

Deep fascia of lower limb

Strong fibrous layer that invests the limb like an elastic stocking and assists venous return by limiting outward muscle expansion.

Fascia lata

Deep fascia of the thigh that encloses thigh muscles and forms intermuscular septa dividing anterior, medial & posterior compartments.

Iliotibial tract (IT band)

Lateral thickening of fascia lata; common aponeurosis of tensor fasciae latae & gluteus maximus running from iliac tubercle to anterolateral tibia.

Saphenous opening

Gap in fascia lata inferior to medial inguinal ligament through which great saphenous vein enters femoral vein.

Crural fascia

Deep fascia of leg; thicker proximally, forms intermuscular septa & extensor retinacula around ankle.

Extensor retinacula

Superior and inferior thickened bands of crural fascia that prevent bow-stringing of anterior tendons during dorsiflexion.

Plantar aponeurosis

Thick central part of plantar fascia; supports longitudinal arch and gives fibrous digital sheaths & superficial transverse metatarsal ligament.

Fibrous digital sheath

Tubular extensions of plantar aponeurosis that enclose flexor tendons of toes.

Superficial transverse metatarsal ligament

Transverse fibers reinforcing plantar aponeurosis just inferior to metatarsal heads.

Pectineus

Flat muscle in anterior thigh that adducts & flexes hip; innervated by femoral nerve (L2-L3).

Iliopsoas

Combined iliacus & psoas major/minor; chief hip flexor; iliacus by femoral n., psoas by lumbar ventral rami (L1-L3).

Sartorius

Longest muscle; crosses hip & knee, produces hip flexion, abduction, lateral rotation and knee flexion; femoral n.; inserts into pes anserinus.

Pes anserinus

Common medial tibial insertion of sartorius, gracilis & semitendinosus.

Adductor longus

Medial-thigh muscle that adducts hip; obturator n. (L2-L4).

Adductor brevis

Short adductor of thigh; obturator n. (L2-L4).

Adductor magnus

Largest adductor; adductor part adducts thigh (obturator n.), hamstring part extends thigh (tibial division sciatic n.); forms adductor hiatus.

Adductor hiatus

Gap between adductor magnus & femur allowing femoral vessels to enter popliteal fossa.

Gracilis

Most medial thigh muscle; adducts hip & flexes/medially rotates knee; obturator n.; inserts into pes anserinus.

Obturator externus

Lateral rotator of thigh in medial compartment; obturator n.

Hamstring muscles

Semitendinosus, semimembranosus & biceps femoris long head; extend hip & flex knee; tibial division of sciatic n.

Semitendinosus

Hamstring inserting into pes anserinus; extends hip, flexes knee; tibial sciatic n.

Semimembranosus

Hamstring with distal slips to tibia, popliteal fascia & oblique popliteal ligament; extends hip, flexes knee; tibial sciatic n.

Biceps femoris

Long & short heads flex knee; long head also extends hip; long head tibial sciatic n., short head common fibular sciatic n.

Gluteus maximus

Largest gluteal; extensor & lateral rotator of hip; forms IT tract; inferior gluteal n.

Gluteus medius

Deep to maximus; abducts & medially rotates hip; superior gluteal n.

Gluteus minimus

Smallest gluteal; same function & innervation as medius (sup. gluteal n.).

Tensor fasciae latae

Anterior gluteal muscle that tenses fascia lata & assists hip abduction/medial rotation; superior gluteal n.

Piriformis

Exits pelvis via greater sciatic foramen; landmark dividing gluteal vessels; laterally rotates extended & abducts flexed thigh; n. to piriformis (L5-S1).

Triceps coxae

Collective term for obturator internus & superior/inferior gemelli acting together as one lateral rotator.

Obturator internus

Leaves pelvis via lesser sciatic foramen; lateral rotator & abductor of flexed thigh; n. to obturator internus (L5-S1).

Gemelli muscles

Small muscles above & below obturator internus tendon; superior gemellus by n. to obturator internus, inferior gemellus by n. to quadratus femoris.

Quadratus femoris

Quadrilateral muscle inferior to gemelli; strong lateral rotator; n. to quadratus femoris (L5-S1).

Femoral triangle

Subfascial space below inguinal ligament containing (lat → med) femoral nerve, artery, vein & deep inguinal nodes.

Retro-inguinal space

Compartment deep to inguinal ligament transmitting iliopsoas & femoral nerve (lateral) and femoral vessels (medial).

Femoral sheath

Funnel of transversalis & iliopsoas fascia surrounding femoral vessels (not nerve); its medial compartment forms femoral canal.

Femoral canal

Medial part of femoral sheath allowing expansion of femoral vein; common site of femoral hernia.

Adductor canal

Intermuscular passage deep to sartorius conveying femoral vessels & saphenous nerve through mid-thigh.

Femoral artery

Continuation of external iliac artery beyond inguinal ligament; traverses femoral triangle & adductor canal to become popliteal artery.

Deep artery of thigh (profunda femoris)

Largest branch of femoral artery; supplies medial, posterior & lateral anterior thigh compartments.

Medial circumflex femoral artery

Branch of profunda femoris supplying hip joint & femoral head.

Lateral circumflex femoral artery

Branch of profunda femoris dividing into ascending, transverse & descending branches; supplies hip & participates in genicular anastomosis.

Obturator artery

Branch of internal iliac entering medial thigh via obturator foramen; supplies adductors & femoral head.

Femoral vein

Continuation of popliteal vein; receives deep vein of thigh & great saphenous vein before becoming external iliac vein.

Superior gluteal artery

Internal iliac branch passing superior to piriformis; supplies gluteus medius/minimus & tensor fasciae latae.

Inferior gluteal artery

Internal iliac branch passing inferior to piriformis; supplies gluteus maximus, obturator internus, quadratus femoris & upper hamstrings.

Popliteal fossa

Fat-filled posterior knee depression containing popliteal vessels, tibial & common fibular nerves, small saphenous termination & lymph nodes.

Popliteal artery

Continuation of femoral artery after adductor hiatus; gives five genicular branches then divides into anterior & posterior tibial arteries.

Periarticular genicular anastomosis

Network around knee formed by five popliteal genicular branches plus descending genicular, lateral circumflex femoral & anterior tibial recurrent arteries.

Anterior tibial artery

Smaller terminal branch of popliteal artery supplying anterior leg; becomes dorsalis pedis at ankle joint.

Dorsalis pedis artery

Direct continuation of anterior tibial artery on dorsum of foot; gives deep plantar, arcuate & lateral tarsal branches.

Tibialis anterior

Most medial anterior-leg muscle; dorsiflexes ankle & inverts foot; deep fibular n. (L4-L5).

Extensor digitorum longus

Lateral anterior-leg muscle; dorsiflexes ankle & extends toes 2-5; deep fibular n.

Extensor hallucis longus

Deep anterior-leg muscle; dorsiflexes ankle & extends great toe; deep fibular n.

Fibularis tertius

Small anterior-leg muscle aiding dorsiflexion & eversion; deep fibular n.

Fibularis longus

Lateral-leg muscle; everts foot & weakly plantarflexes; superficial fibular n.

Fibularis brevis

Deep to fibularis longus; everts foot & weakly plantarflexes; superficial fibular n.

Gastrocnemius

Superficial posterior-leg muscle crossing knee & ankle; plantarflexes ankle & flexes knee; tibial n. (S1-S2).

Soleus

Deep to gastrocnemius; powerful plantarflexor; tibial n. (S1-S2).

Plantaris

Small posterior-leg muscle with long tendon; assists plantarflexion; absent in ~10-15%; tibial n.

Calcaneal (Achilles) tendon

Common tendon of gastrocnemius & soleus inserting into calcaneus; strongest tendon in body.

Popliteus (muscle)

Deep posterior-leg muscle that unlocks knee by medial rotation of tibia; tibial n. (L4-S1).

Flexor hallucis longus

Deep posterior-leg muscle flexing great toe & supporting medial longitudinal arch; tibial n. (S2-S3).

Flexor digitorum longus

Deep posterior-leg muscle flexing toes 2-5 & supporting arches; tibial n. (S2-S3).

Tibialis posterior

Deep posterior-leg muscle plantarflexing ankle & inverting foot; tibial n. (S2-S3).

Posterior tibial artery

Larger terminal branch of popliteal artery supplying posterior leg; gives fibular, medial & lateral malleolar and calcaneal branches before dividing into plantar arteries.

Fibular (peroneal) artery

Largest branch of posterior tibial artery descending along fibula; supplies posterior & lateral leg; gives lateral malleolar & calcaneal branches.

Medial plantar artery

Smaller terminal branch of posterior tibial artery supplying great-toe muscles & medial sole; helps form superficial plantar arch.

Lateral plantar artery

Larger terminal branch of posterior tibial artery supplying most of sole; joins deep plantar artery to form deep plantar arch.

Deep plantar arch

Arterial loop in deep sole formed by lateral plantar artery and deep plantar branch of dorsalis pedis.

Superficial plantar arch

Superficial arterial loop formed chiefly by medial plantar artery anastomosing with lateral plantar artery.

Abductor hallucis

1st-layer plantar muscle abducting & flexing great toe; medial plantar n.

Flexor digitorum brevis

1st-layer plantar muscle flexing toes 2-5; medial plantar n.

Abductor digiti minimi (foot)

1st-layer plantar muscle abducting & flexing 5th toe; lateral plantar n.

Quadratus plantae

2nd-layer plantar muscle assisting flexor digitorum longus; lateral plantar n.

Lumbricals (foot)

2nd-layer muscles flexing proximal phalanges; 1st by medial plantar n., others by lateral plantar n.

Flexor hallucis brevis

3rd-layer plantar muscle flexing proximal phalanx of great toe; medial plantar n.

Adductor hallucis

3rd-layer plantar muscle adducting great toe; lateral plantar n.

Plantar interossei

Three 4th-layer muscles ADducting toes 3-5 (PAD); lateral plantar n.

Dorsal interossei

Four 4th-layer muscles ABducting toes 2-4 (DAB); lateral plantar n.

Extensor digitorum brevis

Dorsal foot muscle assisting toe extension; deep fibular n. (L5-S1).

Extensor hallucis brevis

Dorsal foot muscle assisting great-toe extension; deep fibular n.

Great saphenous vein

Longest vein; union of dorsal vein of great toe & dorsal venous arch; ascends medially to drain into femoral vein via saphenous opening.

Small saphenous vein

Superficial vein from dorsal vein of little toe; ascends posterior to lateral malleolus to empty into popliteal vein.

Perforating veins

Valved vessels that shunt blood from superficial to deep veins, preventing backflow.

Deep fibular (peroneal) nerve

Branch of common fibular nerve innervating anterior leg muscles & dorsum of foot extensors; L4-S1 sensory web space between toes 1-2.

Superficial fibular nerve

Branch of common fibular nerve supplying lateral leg muscles & most dorsum foot skin; L5-S2.

Tibial nerve

Medial branch of sciatic nerve innervating posterior leg & plantar foot muscles; gives medial & lateral plantar nerves.

Obturator nerve

Lumbar plexus nerve (L2-L4) supplying medial thigh adductors and skin.

Superior gluteal nerve

Sacral plexus nerve (L4-S1) to gluteus medius, minimus & tensor fasciae latae.

Inferior gluteal nerve

Sacral plexus nerve (L5-S2) to gluteus maximus.

Cutaneous nerves of thigh

Include lateral, anterior & posterior cutaneous branches from lumbar & sacral plexuses supplying thigh skin.

Medial calcaneal branches

Sensory branches of tibial nerve supplying skin of heel.