14: Posterior Thigh, Poplitea Fossa

Question 1

Posterior thigh common origin (besides short head of biceps femoris)

Answer 1

Ischial tuberosity

Question 2

Posterior thigh common N

Answer 2

Tibial division of sciatic N

Question 3

Common A of posterior thigh

Answer 3

Thigh extension, leg flexion

Question 4

Four muscles of the posterior thigh

Answer 4

Semitendinosus, semimembranosus, biceps femoris, adductor magnus (hamstring portion)

Question 5

Semitendinosus O and I

Answer 5

O: ischial tuberosity
I: medial surface of tibia

Question 6

Semimembranosus O and I

Answer 6

O: ischial tuberosity
I: posterior medial condyle of tibia

Question 7

Distal tendon of semimembranosus - two parts

Answer 7

1. One attaches to medial tibial condyle

2. One blends with fascia -> becomes oblique popliteal ligament

Question 8

Biceps femoris long head O and I

Answer 8

O: ischial tuberosity
I: head of fibular

Question 9

Biceps femoris short head O and I

Answer 9

O: distal linea aspera
I: head of fibula

Question 10

Biceps femoris long and short head N

Answer 10

Long head: tibial N

Short head: common fibular N

Question 11

Adductor magnus hamstring portion O and I

Answer 11

O: ischial tuberosity
I: adductor tubercle on medial epicondyle of femur

Question 12

Adductor magnus hamstring portion A

Answer 12

Extend thigh

Question 13

Adductor magnus hamstring portion N

Answer 13

Tibial division of sciatic N

Question 14

Six muscles involved in boundaries of the popliteal fossa

Answer 14

1. Semitendinosus
2. Semimembranosus
3. Biceps femoris short head
4. Biceps femoris long head
5. Lateral head gastrocnemius
6. Medial head gastrocnemius

Question 15

Four contents of the popliteal fossa, superficial to deep

Answer 15

1. Tibial N
2. Popliteal V
3. LNs
4. Popliteal A and branches

Question 16

Three branches from the popliteal artery

Answer 16

1. Genicular branches
2. Anterior tibial A
3. Posterior tibial A

Question 17

Popliteal V formed from union of what?

Answer 17

Anterior tibial + posterior tibial V’s

Question 18

Where does the popliteal vein form?

Answer 18

Near inferior border of popliteus

Question 19

What vein terminates into the popliteal V?

Answer 19

Small saphenous V

Question 20

Where does the sciatic N become tibial and common fibular N’s?

Answer 20

Superior angle of popliteal fossa

Question 21

Two things supplied by tibial N?

Answer 21

Knee joint, posterior leg muscles

Question 22

Where is the common fibular N susceptible to injury?

Answer 22

Where it winds around the head/neck of the fibula

Question 23

What two things does the common fibular N terminate into?

Answer 23

Deep fibular N + superficial fibular N

Question 24

Three important sural N’s (cutaneous)

Answer 24

Medial sural cutaneous, sural communicating branch, lateral sural cutaneous

Question 25

What do the sural N’s supply?

Answer 25

Distal posterior leg, lateral aspect of foot and ankle

Question 26

What two nerves join together to form the sural N?

Answer 26

Lateral + medial sural cutaneous N’s

Question 27

What is the genicular anastomosis important for?

Answer 27

Circulation bypassing popliteal A (when knee is fully flexed for too long, narrowed popliteal A)

Question 28

What is supplied by the genicular anastomosis

Answer 28

Articular capsule, ligaments of the knee joint

Question 29

Seven arteries involved in the genicular anastomosis

Answer 29

1. Superior lateral genicular
2. Inferior lateral genicular
3. Superior medial genicular
4. Inferior medial genicular
5. Middle genicular
6. Descending genicular
7. Descending branch of lateral femoral circumflex

Question 30

Two branches of the descending genicular A

Answer 30

1. Muscular terminal branch

2. Saphenous branch

Question 31

Nerve of the LE most susceptible to injury

Answer 31

Common fibular N

Question 32

What happens if the common fibular N is injured?

Answer 32

Paralysis of all anterior and lateral crural muscles -> loss of dorsiflexion and eversion -> foot drop

Question 33

Describe a foot drop

Answer 33

Difficult to heel strike, pt has a high stepping gait/waddling gait, and if the leg is swung strongly forward it will strike with a clop