Lecture 8: Posterior Thigh Flashcards
What is the origin of all “hamstring” muscles?
Ischial tuberosity
All hamstring muscles are supplied by perforating branches of what artery?
Profunda femoris a.
[in addition, inferior gluteal a. supplies several small branches to muscles attached to the ischial tuberosity]
The femoral a. continues as what artery as it enters the popliteal fossa?
Popliteal a.
What muscles are considered the hamstrings?
Semitendinosus m.
Biceps femoris long head
Semimembranosus m.
Origin of semitendinosus
Ischial tuberosity
Insertion of semitendinosus
Medial surface of tibia
Action of semitendinosus m.
Extension of thigh, flexion of leg
Innervation of semitendinosus m.
Tibial division of sciatic n.
What muscle passes medial to the biceps fmoris and posterior to semimembranosus, then diverges medially from biceps above the knee?
Semitendinosus m.
The tendon of semitendinosus m. travels posterior to knee joint and curves anteriorly to insert into the upper part of the medial surface of the tibia, just posterior to the insertion of the _______ and _______ muscles
Gracilis; sartorius
Origin of biceps femoris long head
Ischial tuberosity
Insertion of biceps femoris long head
Lateral tibial condyle and head of fibula
Innervation of biceps femoris long head
Tibial divison of sciatic n.
Origin of biceps femoris short head
Lateral lip of linea aspera of femur
Insertion of biceps femoris short head
Lateral tibial condyle and head of fibula
Innervation of biceps femoris short head
Peroneal division of sciatic n.
What is the function of biceps femoris?
Thigh extension, leg flexion
Origin of semimembranosus
Ischial tuberosity (arises by long, flat tendon)
Insertion of semimembranosus
Medial and posterior surfaces of medial condyle of the tibia
Innervation of semimembranosus
Tibial division of sciatic n.
Action of semimembranosus
Thigh extension and leg flexion
Muscle origin, insertion, action, and innervation:
Semitendinosus m.
Origin: ischial tuberosity
Insertion: medial tibia
Actions: extension of thigh, flexion of leg
Innervation: tibial n.
Muscle origin, insertion, action, and innervation:
Biceps femoris long head
Origin: ischial tuberosity
Insertion: lateral tibial condyle + head of fibula
Action: thigh extension/leg flexion
Innervation: tibial n.
Muscle origin, insertion, action, and innervation:
Biceps femoris short head
Origin: lateral lip of linea aspera (femur)
Insertion: lateral tibial condyle and head of fibula
Action: thigh extension/leg flexion
Innervation: peroneal n.
Muscle origin, insertion, action, and innervation:
Semimembranosus m.
Origin: ischial tuberosity
Insertion: medial and posterior surfaces of medial condyle of tibia
Action: thigh extension/leg flexion
Innervation: tibial n.
The popliteal fossa is a primarily ____-filled space posterior to the knee joint
Fat
What muscle is superficial and superolateral in the popliteal fossa?
Biceps femoris
What muscles are superficial and superomedial in the popliteal fossa?
Semimembranosus and semitendinosus
[semitendinosus is lateral to semimembranosus]
What muscles are superficial, inferolateral and inferomedial in the popliteal fossa?
Lateral and medial heads of gastrocnemius
What muscles are superficial and posterior in the popliteal fossa?
Skin and popliteal fascia - these form the roof of popliteal fossa
What anatomical structures form the superior border of the floor of the popliteal fossa?
Medial and lateral supracondylar lines of the femur
What anatomical structure forms the inferior border of the floor of the popliteal fossa?
Soleal line of tibia
What forms the superior floor of the popliteal fossa?
Popliteal surface of the tibia
What forms the central floor of the popliteal fossa?
Posterior aspect of joint capsule of the knee
What forms the inferior floor of the popliteal fossa?
Investing popliteus fascia covering the popliteus muscle inferiorly
What are the contents of the popliteal fossa?
Termination of small saphenous v.
Popliteal a. and its branches
Popliteal v. and its tributaries
Tibial and common fibular nn.
Posterior cutaneous n. of the thigh
Popliteal LNs and vessels
Popliteal fascia
What vein terminates in the popliteal fossa?
Small saphenous v.
What does the femoral a. become when it passes through the adductor hiatus?
Popliteal a.
Where does the popliteal a. terminate?
It bifurcates into anterior and posterior tibial arteries
The _______ branches of the popliteal a. form an anastomotic network supplying the knee joint.
What is the anatomic significance of these branches?
Genicular
These will maintain the blood supply to the leg during knee flexion, which may kink the popliteal a.
The popliteal v. is a continuation of what vein? What artery does it tend to follow?
It is a continuation of the posterior tibial v.
Follows closely with the popliteal a.
Superiorly, the popliteal v. becomes the ______ vein, where it traverses the adductor hiatus
Femoral
Which tributary of the popliteal v. pierces the popliteal fascia?
Small saphenous v.
Which 3 nerves are associated with the popliteal fossa?
Tibial n.
Common peroneal (fibular) n.
Posterior cutaneous nerve of the thigh
What is the difference between the superficial and deep lymph nodes found in the popliteal fossa?
Superficial - small, lie in superficial fascia
Deep - surround vessels and receive lymph from joint capsule of knee and lymphatic vessels accompanying deep veins of the leg
The lymphatic vessels of the popliteal fossa accompany _______ vessels to drain into the deep _____ lymph nodes
Femoral; inguinal
The popliteal fascia is continuous with _________ superiorly, and _________ inferiorly
Fascia lata
Deep fascia of leg
What is the primary function of the popliteal fascia?
Forms protective covering for neurovascular structures
What structures lie deepest in the popliteal fossa?
Arteries - these lie directly on the popliteal surface of the femur, joint capsule, and investing fascia
The sciatic n. ends at the superior angle of the popliteal fossa by dividing into tibial and common peroneal nn.
The tibial n. is medial and supplies motor function to what muscles?
Soleus
Gastrocnemius
Plantaris
Popliteus
What nerve supplies the skin covering the popliteal fossa?
Posterior cutaneous nerve of the thigh
What typically occurs in patients who have paralyzed posterior hamstrings? Why?
They fall forward because the hamstrings typically maintain more tone than the gluteus maximus
[all muscles arising from the ischial tuberosity assist in gluteus maximus in thigh extension]
How do the hamstring muscles limit flexibility?
Their length limits the ability for free simultaneous flexion of the thigh and extension of the leg (touching your toes)
[sharp flexion of the thigh produces flexion of the leg as a result of resistance of the hamstrings; extension of leg produces extension of thigh for same reason]
