Ps2017 - Cga - Lab 10 (Posterior Compartment Of The Thigh, Popliteal Fossa & Posterior Compartment Of The Leg)

Front 1

Popliteal Artery (source, course)

Back 1

Source: A continuation of the femoral artery beginning at the adductor hiatus in the adductor magnus.

Course: The popliteal artery passes through the popliteal fossa to the leg and ends by bifurcating into the anterior and posterior tibial arteries. The popliteal artery gives rise to numerous genicular arteries that participate in a important anastomosis with arterial branches from the anterior thigh and leg.

Front 2

Genicular Arteries (source, course)

Back 2

Source: Genicular arteries are usually branches of the popliteal artery

Course: The genicular arteries participate in an important anastomosis with arterial branches from the anterior thigh and leg. This network of vessels around the knee provides collateral circulation capable of maintaining blood supply to the leg during full knee flexion.

Front 3

Posterior Tibial Artery (source, course)

Back 3

Source: One of the two terminal branches of the popliteal artery (the other being the anterior tibial artery). It continues on the same trajectory as the popliteal artery while the anterior tibial comes off at a 90 degree angle just below the popliteal fossa.

Course: The posterior tibial artery lies within the posterior compartment of the leg between the superficial and deep muscle groups. It is accompanied by the posterior tibial nerve. The fibular artery is a branch of the posterior tibial artery. The posterior tibial artery runs posterior to the medial malleolus after which it divides into the medial and lateral plantar arteries on the sole of the foot.

Front 4

Anterior Tibial Artery (source, course)

Back 4

Source: One of two terminal branches of the popliteal artery (the other being the posterior tibial artery). It comes off at a 90 degree angle just inferior to the popliteal fossa while the posterior tibial continues in the same trajectory as the popliteal artery.

Course: The anterior tibial artery passes from the posterior compartment to the anterior compartment through a gap in the superior part of the interosseous membrane. It is located between the tibialis anterior and the extensor digitorum longus. It changes its name at the ankle joint, midway between the malleoli, to the dorsalis pedis artery.

Front 5

Fibular (Peroneal) Artery (source, course)

Back 5

Source: Usually a branch of the posterior tibial artery, a terminal branch of the popliteal artery

Course: The fibular artery arises within the posterior compartment of the leg between the superficial and deep muscle groups. It descends just medial to the fibula and posterior to the flexor hallucis longus. The fibular artery give musuclar branches to the muscles in the posterior and lateral compartments of the leg.

Front 6

Sciatic Nerve (origin, path, branches, innervation)

Back 6

NOTES: The sciatic nerve does not innervate any muscles or skin (trick question!)

Origin: Sacral plexus (contains axons from L4-S3)

Path: Goes from the pelvis to the gluteal region by passing through the greater sciatic foramen inferior to the piriformis and deep to the gluteus maximus. It descends deep to biceps femoris and bifurcates into the tibial and common fibular (peroneal) nerves typically at the apex of the popliteal fossa although this bifurcation can alternatively occur in the gluteal region or posterior thigh.

Front 7

Tibial Nerve (origin, path, muscles innervated, skin innervated, branches)

Back 7

Origin: The medial, larger branch of the sciatic nerve (the other being the common fibular nerve; the bifurcation of the sciatic nerve is usually at the apex of the popliteal fossa; it has been shown that the posterior muscles of the thigh (except for the short head of the biceps femoris) are supplied by the tibial branch.

Path: Descends through the popliteal fossa and lies on popliteus; runs inferiorly on tibialis posterior with posterior tibial vessels; terminates beneath flexor retinaculum by dividing into medial and lateral plantar nerves.

Muscles Innervated (posterior compartments of the thigh and leg):
Biceps femoris (long head)
Semimembranous
Semitendinous
Gastrocnemius
Popliteus
Soleus
Plantaris
Tibialis posterior
Flexor digitorum longus
Flexor hallucis longus

Skin Innervated: None

Branches (you are not responsible for innervation of the foot): Medial plantar nerve & Lateral plantar nerve

Front 8

Common Fibular (Peroneal) Nerve (origin, path, muscles innervated, skin innervated, branches)

Back 8

Origin: The lateral, smaller terminal branch of the sciatic nerve (the other being the tibial nerve); the bifurcation of the sciatic nerve is usually at the apex of the popliteal fossa; it has been shown that the short head of the biceps is supplied by the common fibular branch.

Path: The common fibular (peroneal) nerve follows the medial border of the biceps femoris and then winds around neck of fibula going deep to the fibularis (peroneus) longus, where it divides into the deep and superficial fibular nerves.

Muscle Innervated: Short head of biceps femoris

Skin Innervated: None

Branches: Superficial fibular nerve; Deep fibular nerve; Lateral sural cutaneous nerve

Front 9

Biceps Femoris Muscle (long and short heads) (attachments, innervation, actions)

Back 9

Proximal Attachments: Long head - Ischial tuberosity; Short head - Linea aspera of femur

Distal Attachment: Head of fibula

Innervation: Long head (tibial division of the sciatic nerve; short head (common fibular division of sciatic nerve)

Actions: Extension at the hip; Flexion at the knee; Lateral rotation at hip when knee is flexed

Front 10

Semitendinosus Muscle (attachments, innervation, actions)

Back 10

Proximal Attachment: Ischial tuberosity

Distal Attachment: Medial surface of superior part of the tibia

Innervation: Tibial nerve

Actions: Extension at the hip, flexion at the knee

Front 11

Semimembranosus Muscle (attachments, innervation, actions)

Back 11

Note: One of the hamstring muscles

Proximal Attachment: Ischial tuberosity

Distal Attachment: Medial condyle of the tibia

Innervation: Tibial nerve

Actions: Extension of the hip; flexion at the knee

Front 12

Hamstring portion of adductor magnus (attachments, innervation, actions)

Back 12

Proximal Attachment: Ischial tuberosity

Distal Attachment: Adductor tubercule of femur

Innervation: Tibial nerve

Actions: Contributes to extension at hip; adduction at hip

Front 13

Popliteus Muscle (attachments, innervation, actions)

Back 13

Proximal Attachments: Lateral condyle of the femur and the lateral meniscus

Distal Attachment: Posterior surface of the tibia superior to the soleal line.

Innervation: Tibial nerve

Actions: Flexion at the knee; Unlocks the extended knee by lateral rotation of the femur on a fixed tibia OR medial rotation of the tibia of an unplanted limb.

Front 14

Calcaneal (Achilles') tendon

Back 14

The calcaneal tendon is the common tendon for the gastrocnemius, soleus, and plantaris muscles attachment to the calcaneus.

Front 15

Soleus Muscle (attachments, innervation, action)

Back 15

Proximal Attachment: Posterior surface of the upper fibula and the soleal line of the tibia

Distal Attachment: Calcaneus via calcaneal tendon

Innervation: Tibial nerve

Action: Plantarflexion at the talocrural (ankle) joint

Front 16

Plantaris Muscle (attachments, innervation, action)

Back 16

Proximal Attachment: Lateral supracondylar line of the femur.

Distal Attachment: Calcaneus via calcaneal tendon

Innervation: Tibial nerve

Action: Plantarflexion at the talocrural (ankle) joint

Front 17

Gastrocnemius Muscle (attachments, innervation, actions)

Back 17

Proximal Attachments: Medial and lateral condyles of the femur.

Distal Attachment: Calcaneus via calcaneal tendon

Innervation: Tibial nerve

Actions: Flexion at the knee joint; Plantarflexion at the talocrural (ankle) joint; raises heel during walking

Front 18

Tibialis Posterior Muscle (attachments, innervation, action)

Back 18

Proximal Attachment: Posterior surface of the tibia inferior to the soleal line and posterior surface of the fibula.

Distal Attachments: Navicular, cuneiforms, cuboid, and metatarsals

Innervation: Tibial nerve

Action: Plantarflexes the ankle, inverts the foot, supports the medial longitudinal arch of the foot.

Front 19

Flexor Digitorum Longus Muscle (attachments, innervation, actions)

Back 19

Proximal Attachment: Posterior surface of tibia inferior to soleal line

Distal Attachments: Distal phalanges of lateral four digits

Innervation: Tibial nerve

Actions: Plantarflexion at the talucrural (ankle) joint; Flexion of the MP, PIP, and DIP joints of the lateral four digits.

Front 20

Flexor Hallucis Longus Muscle (attachments, innervation, actions)

Back 20

Proximal Attachment: Posterior surface of fibula

Distal Attachment: Distal phalanx of big toe

Innervation: Tibial nerve

Actions: Plantarflexion at the talocrural joint; Flexes big toe at MP and IP joints.