Lecture 46 - Leg anatomy Flashcards
tibia function and landmarks:
- Weightbearing bone
1. Condyles (medial and lateral)
2. Soleal line
3. Intercondylar eminence
4. Medial malleolus
5. Tibial tuberosity
fibula function and landmarks
- A slender lateral bone of the leg for muscle attachments
1. Head
2. Neck
3. Lateral malleolus
connects tibia and fibula
interosseous membrane
Saphenous Nerve - nerve level and supplies:
- L3 & L4
- Supplies skin on the medial side of the leg
Sural Nerves - from where and what are its branches?
-branches of tibial and common peroneal nerves
-Branches:
medial sural cutaneous n - runs b/w 2 heads of gastrocnemius
lateral sural cutaneous n - lateral part of leg
sural communicating n -
sural nerve
medial sural cutaneous n - branch of?
branch of tibial nerve
lateral sural cutaneous n - is a branch of?
branch of common peroneal nerve
sural communicating n - is a branch of and joins what nerve?
- A branch of the lateral sural cutaneous
- Joins with the medial sural cutaneous (becomes the sural n)
sural nerve - formed by what?
-Formed by the junction of the medial sural and the communicating sural cutaneous nerves
Superficial peroneal nerve - is a branch of what, goes through where and supplies what?
- branch of common peroneal
- Courses through lateral compartment
- Supplies skin of anterolateral leg and dorsum of foot
Superficial veins
• Great Saphenous: -Begins at the foot -Ascends along the medial side of the leg -Drains into the femoral vein -Contains 10-12 valves (more in the leg) • Small Saphenous -Begins at the lateral side of the foot -Ascends along the posterior medial leg -Drains into the popliteal vein posterior to the knee joint
Crural Fascia - what is it and what are its parts?
- Deep fascia of the leg
- Continuation of the fascia lata inferior to the kneepu
- Attached to the anterior and medial borders of tibia (does not go bw the tibia and the skin of leg)
- Gives rise to the following septa and retinacula
- Parts:•Anterior intermuscular(crural) septum; •Posterior intermuscular (crural) septum; •Transverse intermuscular (crural) septum; •Superior extensor retinaculum (thickening of deep fascia); • Inferior extensor retinaculum; • Flexor retinaculum
Compartments of the leg and what forms these compartments
- ant, lateral, post
- Formed by the: 1) intermuscular septa attached to the fibula 2) the interosseous membrane extending from the fibula to the tibia
Anterior Compartment - muscles, nerve, arteries
-Dorsiflexor (extensor-toes up) compartment
-Located anterior to Interosseous membrane (IO), between the anterior intermuscular septum and tibia
-Muscles pass anterior to the ankle joint
1. MUSCLES: dorsiflexors of the ankle and extensors of the toes
-Tibialis Anterior: Tibia and IO membrane – med. cuneiform and 1st Met; Tibialis anterior strain; Shin splints; Strongest dorsiflexor
-Extensor Hallucis Longus: Fibula and IO membrane – distal phalanx 1st toe; Deepest muscle in the anterior comp.
-Extensor Digitorum Longus: Tibia, fibula and IO membrane – middle and distal phalanges toe 2-5
-Peroneus Tertius: Fibula and IO membrane – 5th metatarsal base
2. NERVE- Deep peroneal nerve (ranch of common peroneal)
3. ARTERIES
-Anterior Tibial artery: A branch of the popliteal a; Enters the anterior compartment by passing through the superior part of the interosseous membrane; Gives rise to the following branches in the leg:
• Tibial recurrent
• Anterior medial malleolar
• Anterior lateral malleolar
• Dorsalis pedis: At the ankle joint the anterior tibial a changes its name to dorsalis pedis to supply the foot
Lateral Compartment - muscles, nerve, arteries:
- Everter compartment (smallest)
- Bounded by the fibula, anterior and posterior intermuscular septa and deep fascia
1. MUSCLES: Peroneus longus: lateral fibula – Base 1st met and medial cuneiform - Peroneus brevis: lateral fibula – Tuberosity 5th met.
2. NERVES: Superficial peroneal nerve (also thorugh superficial fascia to become cutaneous in the foot)
3. ARTERIES Branches of peroneal artery (from the posterior compartment) - Branches of the anterior tibial artery (from the anterior compartment)
Posterior Compartment - muscles, nerves, arteries
-Muscles produce plantar flexion and inversion of the foot
-Flexor compartment
-Largest of the three compartments
-Divided into a superficial and a deep compartment by the transversae intermuscular septum
1. MUSCLES: Gastrocnemius: lateral and medial condyles of femur – calcaneus; Flex leg at the knee joint; Plantar flex foot
-Soleus: fibula, soleal line of tibia – calcaneus; Anti-gravity muscle; No action on knee; Fibers continuously active during
standing
-Triceps surae: Gastrocnemius and soleus together; Generate 95% of plantar flexion force; Large size human characteristic
-Plantaris: lateral supracondylar line of femur – calcaneus; Absent 5-10%; Separate attachment; Organ of proprioception
-Popliteus: lateral condyle of femur – superior to soleal line of tibia; Unlocks knee joint by laterally rotating femur 5 degrees
-Flexor hallucis longus: fibula and IO membrane.- base 1st distal phalanx
-Flexor digitorum longus: tibia inferior to soleal line – bases distal phalanges toes 2-5
-Tibialis posterior: Tibia, fibula and IO membrane. – navicular, cuneiforms, cuboid ,bases of 2-4 met
2. NERVES of the posterior compartment: Tibial nerve (L4-S3)
3. ARTERIES of the posterior compartment
-Posterior tibial: A branch of the popliteal a; Gives rise to the following branches: •Circumflex fibular; • Peroneal (Perforating branch of peroneal; Communicating artery; Posterior lateral malleolar artery;Posterior lateral calcaneal artery)
• Nutrient: Largest nutrient artery in the body
• Muscular
• Posterior medial malleolar
• Communicating: Joins posterior tibial and peroneal arteries
• Medial calcaneal (posterior)
• Medial plantar
• Lateral plantar
Tibial nerve levels:
L4-S3
Venous return
- Activity of the Triceps surae
- Calf pump
- Superficial veins
- Perforating veins
- Incompetent valve
- Varicosities
small saphenous drains into the
popliteal v
common peroneal n is very superficial and gets cut… what happens?
- paralysis of ant and lateral compartment muscles
- cant dorsiflex
