Anatomy 34 Flashcards
What do the muscles in the posterior compartment of the leg primarily act as?
Plantarflexors of the foot at the ankle joint and flexors of the toes
What are the muscles in the posterior compartment of the leg innervated by?
Tibial nerve
What are the 3 superfical muscles found in the posterior compartment of the leg?
Gastrocnemis
Soleus
Plantaris
What do the tendons of the gastrocnemius, soleus and plantaris insert into?
The calcaneus via the calcaneal (Achilles) tendon
Which muscle out of the superficial muscles in the posterior compartment of the leg is the most superficial?
Gastrocnemius
What does the gastrocnemius attach via?
2 heads to the distal femur
What movements can the gastrocnemius execute?
Can flex the knee in addition to plantarflexing the
ankle
What is the soleus?
Large, flat muscle that lies deep to gastrocnemius
What is the soleus attached to?
Soleal line
What is important about contraction of the soleus?
Contraction of soleus compresses the deep veins of the leg and is important for venous return
What is plantaris?
Very small muscle that lies close to the popliteal fossa
What does plantaris give rise to?
A very long, thin tendon which merges with the Achilles tendon
What are the 4 deep muscles in the posterior compartment of the leg?
Popliteus
Tibialis posterior
Flexor hallucis longus (FHL)
Flexor digitorum longus (FDL)
Where do the tendons of the Tibialis posterior, Flexor hallucis longus (FHL) and Flexor digitorum longus (FDL) travel?
Travel posterior to the medial malleolus
Where do the tendons of the Tibialis posterior, Flexor hallucis longus (FHL) and Flexor digitorum longus (FDL) insert into?
The plantar surface of the bones of the foot
Where does the popliteus lie?
In the popliteal fossa
What is the popliteus attached to?
Tibia and the femur
What movement does the popliteus allow?
It allows for a small degree of rotation of the knee.
When the knee is flexed from full extension, popliteus slightly rotates the knee before flexion begins
What movements does the tibialis posterior execute?
Plantarflexes and inverts the foot
What do the tendons of the tibialis posterior attach to?
Multiple bones in the foot
What movement does the flexor hallucis longus execute?
Flexes the big toe via its insertion into the distal phalanx
Also plantarflexes the foot
What does the flexor digitorum longus give rise to?
4 tendons that insert into the distal phalanges of toes 2-5
What is the primary action of the flexor digitorum longus?
Flexion of the toes, but it also plantarflexes the foot
What intrinsic muscles are found in the sole of the foot?
Abductors of the big and little toes,
Flexors of the toes,
Adductor of the big toe,
Lumbricals and
Interossei.
How are the muscles in the sole of the foot arranged?
Arranged in 4 layers and mirror those of the palm
What are the muscles in the sole of the foot innervated by?
Medial and lateral plantar nerves
What are the medial and plantar nerves branches of?
They are the terminal branches of the tibial nerve
What does the popliteal artery bifurcate into?
Anterior and posterior tibial arteries
What does the posterior tibial artery supply?
Posterior compartment of the leg and sole of the foot
What does the posterior tibial artery give rise to?
Fibular artery, which supplies the lateral compartment
Where does the posterior tibial artery travel?
Posterior to the medial malleolus, along with the tendons of tibialis posterior, FHL and FDL to enter the plantar aspect of the foot.
The artery is palpable here, but it is not as easy to palpate as the dorsalis pedis artery
What does the posterior tibial artery bifurcate into in the foot?
Medial and lateral plantar arteries, which supply the sole of the foot
What do branches of the dorsalis pedis artery anastomose with?
Branches of the plantar arteries
What is the deep plantar arch?
Important vessel formed by the lateral plantar artery and a branch of the dorsalis pedis.
What arteries supply the forefoot and toes?
Metatarsal and digital arteries
What veins unite to form the popliteal vein?
The posterior tibial, anterior tibial and fibular arteries accompanied by deep veins.
What veins drain most of the blood from the foot?
Superficial veins
Where can superficial veins usually be seen?
Over the dorsum of the foot
What does the dorsal venous network drain medially to?
Great saphenous vein
What does the dorsal venous network drain laterally to?
Small saphenous vein
What does the small saphenous enter in the popliteal fossa?
Popliteal vein
What does the great saphenous meet in the femoral triangle?
Femoral vein
What nerve innervates all the muscles in the posterior compartment of the leg and plantar surface of the foot?
Tibial nerve
Where does the tibial nerve travel?
Posterior to the medial malleolus along with the tendons of tibialis posterior, FHL and FDL
What does the tibial nerve divide into as it enters the sole of the foot?
Medial and lateral plantar nerves
What does the medial and plantar nerves innervate?
All the intrinsic muscles in the plantar aspect of the foot
What nerves innervate the skin of the foot?
● The tibial nerve innervates most of the skin on the plantar surface of the foot.
● The common peroneal (fibular) nerve and its branches innervate the skin over the anterolateral leg and dorsum of the foot.
How can sensation be examined?
● the territories of the peripheral nerves
● the dermatomes
What territory of skin does the femoral nerve supply?
Anterior thigh and anteromedial leg (via the saphenous nerve)
What territory of skin does the obturator nerve supply?
Medial thigh
What territory of skin does the common peroneal nerve supply?
Anterolateral leg and dorsum of the foot
What territory of skin does the superficial peroneal nerve supply?
Lower anterolateral leg, most of the dorsum of the foot
What territory of skin does the deep peroneal nerve supply?
1st interdigital cleft
What territory of skin does the tibial nerve supply?
Sole of the foot
What dermatome regions are innervated by L1?
The region over the inguinal ligament
What dermatome regions are innervated by L3?
The lower anterior thigh and the medial aspect of the knee
What dermatome regions are innervated by L4?
On the anterior surface of the lower limb, the lateral aspect of the lower thigh, knee and upper leg.
The dermatome extends obliquely, inferiorly and medially, to cover the anterior knee, the anteromedial leg, the dorsum of the medial aspect of the foot and the skin over the dorsum and plantar surface of the big toe.
What dermatome regions are innervated by L5?
On the anterior surface of the lower limb, laterally the dermatome covers the lower two-thirds of the leg, excluding the skin over the lateral ankle.
The dermatome extends obliquely, inferiorly and medially to cover the dorsum of the middle of the foot and the dorsum of toes 2-4.
The nerve innervates a corresponding region of skin on the sole of the foot (the skin in the middle of the foot and over the plantar surface of toes 2-4).
Posteriorly, the nerve innervates a vertical strip of skin laterally, extending from the buttock to the upper leg.
What dermatome regions are innervated by S1?
Posteriorly, the nerve innervates a vertical strip of skin in the middle of the thigh, extending over the lateral part of the posterior leg, the lateral aspect of the ankle, the lateral aspect of the dorsum and sole of the foot and the skin over the dorsum and plantar aspect of the little toe
What dermatome regions are innervated by S2?
Posteriorly the nerve innervates a vertical strip of skin over the medial thigh and leg, extending onto the medial aspect of the sole of the foot, but excluding the plantar surface of the big toe (which is innervated by L4)
How is sensation tested for the dermatomes of the leg?
- L1: region over the inguinal ligament
- L2: upper anterior thigh
- L3: medial aspect of the knee
- L4: anteromedial leg
- L5: anterolateral leg
- S1: 5th digit / lateral side of the foot
What is deep vein thrombosis (DVT)
Thrombus, or clot, can develop in the deep veins of the leg. Venous return from the leg is impaired, causing swelling, pain, redness and warmth of the affected leg.
It is important to recognise and treat DVT, as the clot may migrate proximally and enter the pulmonary circulation, causing pulmonary embolism – a potentially fatal condition.
What is compartment syndrome?
Because the deep fascia and intermuscular septa do not stretch, swelling in one of the compartments of the leg (e.g., oedema, bleeding) increases pressure in the compartment and compresses muscles, nerves and blood vessels.
Once the pressure exceeds capillary perfusion pressure, ischaemia and infarction of the tissues occurs if not treated promptly by releasing the fascia (fasciotomy).
What is achilles tendon rupture?
The typical mechanism of injury is a sudden, forceful plantarflexion of the ankle, such as pushing off from the ground to jump or run.
Patients present with pain and altered gait, as they cannot plantarflex the foot to push-off from the ground when walking.
On examination, they cannot plantarflex the foot against resistance
What is gout?
Gout can affect any joint, but typically first presents at the first metatarsophalangeal joint.
The joint becomes swollen, red and warm, and is extremely painful
What is Plantar fasciitis?
This is inflammation of the plantar aponeurosis and is associated with high-impact activity, such as running.
It causes pain on the plantar surface of the foot.
