MSK Blood supply and lymphatics of the lower limb

Question 1

Name the arteries in each region of the lower limb

Answer 1

Thigh and gluteal region:

• femoral artery (contination of external iliac artery that forms femoral artery when it crosses under inguinal ligament)
• obturator artery (arises from internal iliac artery)

Leg:

• popliteal artery (forms posterior and anterior tibial arteries at lower border of popliteal fossa)
• fibular artery arises from posterior tibial artery

Foot:

• dorsalis pedis artery (continuation of anterior tibial artery)
• posterior tibial artery

Question 2

Describe the branches of the femoral artery

Answer 2

In the femoral triangle the femoral artery gives off the profunda femoris artery which descends posteriorly giving off 3 branches:

1. Perforating branches (perforate adductor magnus) and supply medial and posterior
2. Lateral femoral circumflex - wraps around anterior lateral side of femur and supplies lateral muscles
3. Medial femoral circumflex - wraps around posterior femur suppling head and neck of femur.

Femoral artery continues down anterior thigh via adductor canal. Femoral artery moves through the adductor hiatus - it is now the popliteal artery.

Question 3

Describe the branches of the obturator artery

Answer 3

Descends via the obturator canal to reach the medial thigh and then bifurcates into 2 branches:

• anterior branch supplies adductors
• posterior branch supplies some of the deep gluts

Question 4

Describe the branches of the popliteal artery

Answer 4

At the lower border of the popliteal fossa the popliteal artery terminates by dividing into ant and post tibial arteries.

The posterior tibial artery continues along the posterior muscles and accompanies the tibial nerve in entering the foot via the tarsal tunnel.
The fibular artery arises from the posterior tibial artery in the proximal leg which supplies lateral muscles.

The anterior tibial artery passes anteriorly between tibia and fibular and moves into foot where it becomes the dorsalis pedis artery

Question 5

Describe the arterial supply of the foot

Answer 5

The dorsalis pedi artery (derived from the anterior tibial artery) passes over dorsal aspect of tarsal bones and then moves towards sole of the foot. It anastamoses with layeral plantar artery to form the deep plantar arch.
Supplies tarsals and dorsal part of metatarsals

The posterior tibial artery enters foot via tarsal tunnel and splits into lateral and medial plantar arteries. These supply toes via deep planar arch

Question 6

What are the pulse points of the lower limb?

Answer 6

Femoral pulse - palpated at mid inguinal point
Popliteal pulse (hardest to find) lies deep in pop fossa, so leg needs to be slightly flexed to relax fascia
Dorsalis pedis pulse - palpate dorum of foot lateral to hallucis longus tendon

Question 7

Name the major deep veins of the lower limb

Answer 7

Foot:
Dorsal venous arch (some veins from the arch form the anterior tibial vein)
Medial and plantar veins which combine to form post tibia and fibula veins

Leg:
ant + post Tibial and fibular veins
These all combine to form popliteal vein

Thigh:
Femoral vein
Deep vein of the thigh (profunda femoris vein)
At inguinal ligament - turns into external iliac vein

Gluteal region:
Inferior and superior gluteal veins which drain into the internal iliac vein

Question 8

Name the superficial veins of the lower limb

Answer 8

Great & small saphenous vein

Question 9

At what location doe the anterior and posterior tibial vein and fibular veins combine to form the popliteal vein?
Where does the popliteal vein change into the femoral vein?

Answer 9

Posterior surface of the knee

Once it has entered the thigh

Question 10

What is the anatomical course of the posterior tibial vein as it enters the leg?

Answer 10

Enters the leg posterior to the medial malleolus

Question 11

What is deep vein thrombosis and what is a possible complication?

Answer 11

The formation of a blood clot in the deep veins of the lower limb causing blockage
Causes pain swelling and tenderness
The main complication is a pulmonary embolism

Question 12

What is the anatomical course of the great saphenous vein?

Answer 12

Formed by dorsal arches of foot
Passes anterior to medial malleolus and travels medially up the leg
Passes posterior to medial condyle at the knee
Terminates by draining into femoral vein inferior to inguinal ligament
(can be harvested for use in coronary artery bypass)

Question 13

What is the anatomical course of the small saphenous vein?

Answer 13

Formed by dorsal arches of foot
Passes posterior to lateral malleolus and travels up posterior leg
Empties into popliteal fossa

Question 14

What are varicose veins?

What are the treatments?

Answer 14

Valves in the veins become incompetent so blood flows back into superficial veins
There is an increased pressure cause veins to become dilated

There can be a brown pigments and ulceration of the surrounding tissue

Treatments:

• move the saphenous systems
• reconstruct the valves
• tie off the affected valves

Question 15

What is the anatomical course of the superficial lymphatic vessels of the leg?

Answer 15

Medial vessels - follow the anatomical course of the great saphenous vein
Originate on dorsal surface of foot and travel up medial leg, passing behind medial condyle of femur
Ends in the groin where they drain into sub inguinal nodes

Lateral vessels - follow the course of the small saphenous vein
Arise from lateral surface of foot and accompany small saphenous vein to popliteal fossa and join the medial group

Question 16

What is the anatomical course of the deep lymphatic vessels of the leg?

Answer 16

Far fewer the superficial
Accompany deep arteries of lower leg
3 main groups - anterior tibial, posterior tibial and peroneal
Enter the popliteal lymph nodes

Question 17

What are the lymphatic nodes of the lower leg?

Answer 17

Inguinal nodes are found in the upper femoral triangle.
2 groups determined by their position to the level of termination of the great saphenous vein:
- superficial nodes, directly below ing ligament
- subinguinal nodes (superficial and deep)

Popliteal nodes are found embedded in fat in the popliteal fossa.
Efferent vessels of pop nodes pass alongside femoral vessels to empty into the deep inguinal nodes

Question 18

What is lymphadenopathy?

Answer 18

An abnormality in size, number or consistency of any lymphatic nodes in the body. Usually in response to infection, malignancy or auto-immune condition