Musculoskeletal: Anatomy - Fascia, veins, lymphatics, efferent vessels, and cutaneous nerves of lower limb Flashcards
Superior boundaries of the fascia lata
Anterior: pubic tubercle, body of pubis, pubic arch, inguinal ligament, Scarpa fascia (deep membranous layer of inferior abdominal wall)
Posterolateral: iliac crest
Posteromedial: sacrum, coccyx, sacrotuberous ligament, ischial tuberosity/ischiopubic ramus
Inferior boundaries of the fascia lata
Continuous with exposed parts of bones around knee, and deep fascia of leg inferior to knee
What forms the iliotibial tract?
Lateral fascia lata reinforced by additional longitudinal fibres (shared aponeurosis of tensor fasciae latae and gluteus maximus)
What are the compartments of the thigh? How are they formed and which is the strongest of the intermuscular septa?
Anterior, medial and posterior compartments
Forms by fascia lata and three intermuscular septa which attach to the linea aspera of the femur
Lateral intermuscular septum is strongest
What is the saphenous opening? Describe its margins
Hiatus in fascia lata located inferolateral to pubic tubercle
Medial margin is smooth; superior, lateral and inferior form sharp cresenteric edge called the falciform margin
What closes the saphenous opening?
Cribiform fascia
Where is the deep fascia of the leg thickest?
Proximal part of anterior aspect of leg
Where does the deep fascia of the leg attach proximally?
Anterior and medial borders of tibia (continuous with periosteum)
Describe the compartments and septae of the leg
Anterior (dorsiflexor), posterior (plantarflexor) and lateral (fibular) compartments
Anterior and posterior intermuscular septa divide lateral from anterior and posterior compartments respectively
Transverse intermuscular septum separates superficial and deep plantarflexors
Do superficial veins have valves?
Yes but more numerous in deep veins
Two major superficial veins in lower limbs
Great and small saphenous veins
Describe the course of the great saphenous vein
Formed by union of dorsal vein of great toe and dorsal venous arch of foot
Ascends anterior to medial mal
Passes posterior to medial femoral condyle
Anastamoses with small saphenous vein
Traverses saphenous opening
Empties into femoral vein
How many valves are in the great saphenous vein? Where are they typically located?
10-12
Typically located inferior to perforating veins
6 tributaries received by great saphenous vein
- Accessory saphenous (from medial and posterior tributaries of thigh)
- Lateral cutaneous veins
- Anterior cutaneous veins
- Superficial circumflex iliac
- Superficial epigastric
- External pudendal
Describe the course of the small saphenous vein
Arises on lateral foot from union of dorsal vein of the little toe and dorsal venous arch
Ascends posterior to lateral mal (as continuation of lateral marginal vein)
Passes along lateral border of calcaneal tendon
Penetrates deep fascia in midline of fibula
Ascends between heads of gastrocnemius
Empties in popliteal vein in popliteal fossa
What are perforating veins? What features assist in their function?
Veins that originate from the superficial veins and penetrate the deep fascia, carrying blood to the deep veins
Contain valves that allow one-way flow (from superficial to deep) and penetrate at an oblique angle so that they are compressed during muscle contraction: contributing to venous return via the musculovenous pump
Describe the pattern of deep veins in the lower limb
Paired, frequently interconnecting veins flanking the major arteries and their branches
Contained within a vascular sheath with the artery (pulsation of artery helps to move blood in vein)
Three deep veins of the leg
- Anterior tibial
- Medial plantar -> posterior tibial
- Lateral planta -> fibular
Where do the three deep veins of the leg drain to?
Popliteal vein -> femoral vein -> terminal portion of femoral vein + profunda femoris -> external iliac vein
Describe the lymphatic drainage of the lower limb
Superficial:
- Lymphatics accompanying great saphenous: superficial inguinal lymph nodes -> external iliac lymph nodes (some to deep inguinal nodes)
- Lymphatics accompanying small saphenous: popliteal lymph nodes
Deep:
- From leg: popliteal lymph nodes -> deep lymphatic vessels of thigh -> deep inguinal lymph nodes -> external and common iliac lymph nodes -> lumbar lymphatic trunks
How many nerves provide cutaneous innervation to the lower limb? List them and describe the area they innervate
18
- Superior clunial nerves: superior and central buttocks
- Medial clunial nerves: medial buttocks and intergluteal cleft
- Inferior clunial nerves: inferior buttocks (overlying gluteal fold)
- Lateral cutaneous branch of subcostal: hip region inferior to anterior iliac crest, anterior to greater trochanter
- Lateral cutaneous branch of iliohypogastric: superolateral buttocks
- Femoral branch of ilio-inguinal: medial femoral triangle
- Genitofemoral*: femoral branch supplies lateral femoral triangle, genital branch supplies anterior scrotum or labia major
- Lateral cutaneous nerve of thigh: anterolateral thigh
- Anterior cutaneous branches of femoral nerve: anteromedial thigh
- Cutaneous branch of obturator nerve: middle part of medial thigh
- Posterior cutaneous nerve of thigh: posterior thigh and popliteal fossa
- Saphenous nerve: medial leg and foot
- Superficial fibular nerve: anterolateral leg and dorsum of foot (excluding web space between 1st and 2nd toes)
- Deep fibular nerve: web space between 1st and 2nd toes
- Sural nerve: posterolateral leg and lateral margin of foot
- Medial plantar nerve: medial sole, and plantar aspect, sides and nail beds of medial 3.5 toes
- Lateral plantar nerve: lateral sole, and plantar aspect, sides and nail beds of lateral 1.5 toes
- Calcaneal nerves: skin of heel
*for purposes of recalls this supplies the skin over the femoral triangle
Describe the lower limb dermatomes
What four tributaries join the great saphenous vein at the saphenous opening?
Four veins corresponding to four cutaneous branches of femoral artery:
1. Superficial circumflex iliac
2. Superficial epigastric
3. Superficial external pudendal
4. Deep external pudendal
Five branches of the common fibular nerve. Where and how does it terminate?
- Sural communicating nerve
- Lateral sural cutaneous nerve
- Superior genicular nerve
- Inferior genicular nerve
- Recurrent genicular nerve
Ends by dividing into deep and superficial fibular nerves in substance of peroneus longus
