circulation of the lower limb

Question 1

starting point:
1. where does oxygenated blood which supplies the lower limb come from?

2. where does the abdominal aorta terminate?
3. at what landmark do the common iliac arteries give rise to external + internal iliac arteries?
4. what do the external and internal iliac arteries do?

Answer 1

1. Oxygenated blood is ejected by the left ventricle
   - to the Ascending aorta
   - to the aortic arch
   - to the descending aorta (thoracic and abdominal)
2. The abdominal aorta terminates into left and right common iliac arteries
3. At sacroiliac joint, common iliac arteries give rise to External and Internal iliac arteries
4. External iliac artery supplies the majority of the lower limb while Internal iliac also contributes

Question 2

internal iliac artery: branches

1. what are the 4 branches of the internal iliac artery?
2. where do they pass through?

Answer 2

1. Superior gluteal artery
   - Passes from the pelvic cavity to the gluteal region via the greater sciatic foramen, above piriformis muscle
2. Inferior gluteal artery
   - Enters the gluteal region via the greater sciatic foramen, below piriformis muscle
3. Internal pudendal artery
4. Obturator artery
   - Lies on lateral wall of pelvis and passes through obturator canal

Question 3

external iliac artery -> femoral artery:

1. where does the external iliac artery pass through?
2. what does the external iliac artery become?
3. where is the pulse of the external iliac artery felt?
4. while the artery descends in the femoral triangle, what 4 branches does it give off?
5. where does the femoral artery enter and pass into?

Answer 3

1 + 2. the external iliac artery passes under the inguinal ligament and becomes the femoral artery

3. the pulse is found inferior to the mid-inguinal point
4. while the femoral artery descends it gives off:
   - superficial epigastric artery
   - superficial circumflex iliac artery
   - external pudendal arteries
   - profunda femoris artery (deep artery of the thigh)
5. the femoral artery enters the adductor canal to pass into the popliteal fossa

Question 4

femoral artery -> profunda femoris:

1. what branches does the profunda femoris give off?
2. where are there rich numbers of anastomoses?
3. what does the profunda femoris supply?

Answer 4

1. • medial circumflex femoral artery
     - lateral circumflex femoral artery
     - 3-4 perforators
2. there are rich anastomoses around the hip with the gluteal vessels (with branches of internal iliac artery) and around the knee
3. the profunda femoris supplies the posterior compartment of the thigh

Question 5

blood supply of the hip joint:

1. what are the 4 arteries of the trochanteric anastomosis?
2. what do the trochanteric anastomosis provide circulation for?
3. what are the 4 arteries of the cruciate anastomosis?
4. what do the cruciate anastomosis provide circulation for?

Answer 5

1. Trochanteric anastomosis
   - Medial circumflex femoral artery (and retinacular branches)
   - Lateral circumflex femoral artery
   - Superior gluteal artery
   - Inferior gluteal artery
2. the trochanteric anastomosis provides circulation around the head of the femur
3. Cruciate anastomosis
   - First perforator
   - Inferior gluteal artery
   - Lateral circumflex femoral artery
   - Medial circumflex femoral artery
4. The function of the cruciate anastomosis is to provide an alternative route for the blood supply of the lower limb when there is a blockage of the blood flow between the external iliac and femoral arteries

Question 6

blood supply of the hip joint:

1. what are the two possible fractures of the hip joint?
2. what may be affected by the fracture of the femoral neck?
3. what are retinacular vessels?

Answer 6

1. subcaptial fracture (more medial) and interochanteric fracture (more lateral)
2. the blood supply of femoral head may be affected by the fracture of the femoral neck
3. retinacular arteries are branches of the medial and lateral circumflex femoral arteries that extend to the head of the femur within retinacuar folds of synovial membrane surrounding the neck of the femur. Collectively, these arteries provide the main blood supply to the femoral head.

Question 7

popliteal artery:

1. between what two structures is the popliteal artery?
2. what is a main characteristic of the popliteal artery?
3. where can the pulse be felt?
4. what does the popliteal artery give rise to?
5. how does the popliteal artery exit the popliteal fossa?
6. how does the popliteal artery terminate?
7. what does the popliteal artery supply?
8. when may it be compromised?

Answer 7

1. Between Hiatus tendineus and lower border of popliteus muscle
2. Deepest structure in the popliteal fossa and so it is therefore difficult to get the pulse
3. it can be found (difficultly) at the medial aspect of the popliteal fossa
4. Gives rise to 5 genicular branches
5. Exit the popliteal fossa by passing through tendinous arch of soleus
6. Ends as the posterior and anterior tibial arteries.
7. Supplies the knee joint.
8. may be compromised in dislocation of the knee and in fractures of the lower femur, it is also the second most common site of aneurysm

Question 8

blood supply of the knee joint:

1. what are the 4 categories of arteries supply the knee joint?
2. what are the specific arteries within each group?

Answer 8

5 Genicular branches of popliteal artery
- superior lateral genicular artery
- inferior lateral genicular artery
- superior medial genicular artery
- middle genicular artery
- inferior medial genicular artery

Branches of the femoral artery

Branch of the profunda femoris
- descending branch of lateral circumflex femoral artery

A branch from the anterior tibial artery join and form genicular anastomosis
- anterior tibial recurrent artery

Question 9

collateral circulation:

1. in what two ways, does blood continue to reach the popliteal artery when there is a blockage between the external iliac artery and femoral artery?

Answer 9

1. iliac artery to
2. inferior gluteal artery to
3. a perforating branch of the profunda femoris artery to
4. the lateral circumflex femoral artery
5. its descending branch
6. the superior lateral genicular artery
7. the popliteal artery

or

• via the anastomoses between the obturator artery and branches of profunda femoris

Question 10

anterior tibial artery -> dorsalis pedis:

1. what is the anterior tibial artery accompanied by?
2. what does it supply?
3. when does it terminate and become the dorsalis pedis artery?
4. what kind of branch is the dorsalis pedis?
5. where is the dorsalis pedis felt?

Answer 10

1. the anterior tibial artery descends, deep to the anterior compartment muscles accompanied by the deep fibular (peroneal) nerve
2. it supplies the anterior compartment muscles
3. it terminates inferior to the extensor retinaculum and it becomes the dorsalis pedis artery
4. the dorsalis pedis is an arcuate branch as well as the the 1st dorsal metatarsal branch and flows into dorsal digital arteries
5. the dorsalis pedis pulse is felt in the first intermetatarsal space

Question 11

posterior tibial artery:

1. what does the posterior tibial artery accompany?
2. what does it give off?
3. what does it supply?
4. when does it terminate?
5. where can the pulse of the posterior tibial artery be felt?

Answer 11

1. the posterior tibial artery accompanies the tibial nerve as it descend deep to the soleus muscle
2. it gives off the fibular, circumflex fibular, and nutrient arteries
3. it supplies the muscles of the posterior compartment of the leg (plantar flexors)
4. it terminates and becomes the medial and lateral plantar arteries after running posterior to the medial malleolus
5. the pulse of the posterior tibial artery can be felt behind the medial malleolus

Question 12

lateral and medial plantar arteries:

1. what do the medial and lateral plantar arteries supply?
2. what does the deep arch give rise to?

Answer 12

1. the medial and latera plantar arteries supply the sole of the foot along with their branches: superficial plantar arches (medial plantar arteries) and deep plantar arches (lateral plantar arteries)
2. the deep arch gives rise to plantar digital arteries of the phalanges

Question 13

superficial veins of the lower limb:

1. where do the superficial veins originate from?
2. where does the great (long) saphenous vein ascend and pierce through?
3. where does the small (short) saphenous vein ascend and penetrate through and merge with?

Answer 13

1. superficial veins originate from the dorsal venous network of the foot and dorsal veins of foot
2. Great (long) saphenous vein ascends 2.5 cm anterior to the medial malleolus, posterior to medial condyle of femur (Hands breadth behind the patella) and pierces the fascia lata to join the femoral vein.
3. Small (short) saphenous vein ascends posterior to lateral malleolus and penetrates the deep fascia of the leg in the popliteal fossa and merges with deep veins to form the popliteal vein.

Question 14

deep veins of the lower limb:

1. where do the deep veins of the lower limb ascend to?
2. what are ‘vena comitantes’?
3. where does the femoral vein ascend to and terminate as?
4. where does the femoral vein receive drainage from?

Answer 14

1. They ascend internal to the deep fascia of the lower limb.
2. Vena comitantes generally occur as paired veins travelling with the arteries of the same name, within vascular sheaths with the artery (i.e. anterior and posterior tibial veins)
3. Femoral vein ascends in the adductor canal from the popliteal vein, it enters the femoral sheath and ends as the external iliac vein.
4. It receives drainage from profunda femoris, great saphenous and other small branches.

Question 15

venous blood flow:

1. what is the order of venous flow?
2. what 3 things help venous return to the heart, against gravity?
3. what do valves do?

Answer 15

1. Venous flow is from superficial to deep veins, via perforators
2. Arterial pulsation, negative intra-thoracic pressure and contraction of muscles (Muscle pump) all help venous return to the heart, against gravity
3. Valves prevent backflow

Question 16

lymph drainage of the lower limbs:

1. what do superficial lymph vessels accompany?
2. where do the lymph vessels accompanying the great saphenous vein drain to? and eventually lead to?
3. where do the lymph vessels accompanying the small saphenous vein drain to?
4. where do the deep lymph vessels drain to?

Answer 16

1. Superficial lymph vessels accompany the superficial veins
2. The lymph vessels accompanying the great saphenous vein drain to the superficial inguinal lymph nodes leading to the deep inguinal nodes then the external iliac nodes
3. The lymph vessels accompanying the small saphenous vein enter the popliteal lymph nodes.
4. Deep lymph vessels accompany deep veins and enter the popliteal lymph nodes, accompany femoral vein to the deep inguinal nodes.

Question 17

superficial inguinal nodes:

1. what structure is formed by the superficial inguinal nodes?
2. what 5 places do the superficial inguinal nodes receive lymph from?

Answer 17

1. “T” along inguinal ligament and saphenous vein
2. Receive lymph from:
   Anterior abdominal wall (under umbilicus)
   Skin of back below iliac crests
   Gluteal region
   Perineum
   Superficial Lower limb

Question 18

femoral canal & ring:

what is the femoral canal?

what does it contain?

Answer 18

1. Femoral canal is a short and conical space between the medial wall of the femoral sheath and the femoral vein
2. it contains deep inguinal lymph nodes

Question 19

deep inguinal nodes:

1. where are deep inguinal nodes located?
2. what 3 places do they receive lymph from?

Answer 19

1. In the femoral triangle, medial to femoral vein
2. Receive lymph from:
   - Lower limb (deep lymph vessels accompanying the femoral vessels, including from popliteal nodes)
   - Superficial inguinal nodes (some can proceed directly to external iliac nodes)
   - External genitalia

Question 20

iliac lymph nodes:

where do deep and superficial inguinal nodes drain to? (7)

Answer 20

Deep and Superficial Inguinal nodes drain to
1. external iliac nodes
2. common iliac nodes
3. lumbar lymph nodes
4. cisterna chyli
5. thoracic duct
6. Pirogov’s venous angle (left)
7. venous system