Circulation and Nerves of the Lower Limb Flashcards
What is the pathway of oxygenated blood to the lower limb?
Oxygenated blood is ejected by the left ventricle to the Ascending aorta -> aortic arch -> descending aorta (thoracic and abdominal)
The abdominal aorta terminates into left and right common iliac arteries.
At sacroiliac joint, common iliac arteries give rise to External and Internal iliac arteries.
External iliac artery supplies the majority of the lower limb while Internal iliac also contribute.
What are the branches of the internal iliac artery?
Superior gluteal artery
Inferior gluteal artery
Internal pudendal artery
Obturator artery
Where does the superior gluteal artery lie?
Passes from the pelvic cavity to the gluteal region via the greater sciatic foramen, above piriformis muscle
Where does the inferior gluteal artery lie?
enters the gluteal region
via the greater sciatic foramen, below piriformis muscle
Where does the obturator artery lie?
lies on lateral wall of pelvis and passes through obturator canal
Where does the external iliac artery become the femoral artery?
External iliac artery passes under the inguinal ligament and becomes femoral artery
Where may one find the pulse of the femoral artery?
Inferior to midpoint of the inguinal point
Where does the femoral artery run?
Descends in the femoral triangle while giving off four branches
Enters Adductor canal to pass into the popliteal fossa
What are the four branches of the femoral artery?
- Superficial epigastric artery
- Superficial circumflex iliac artery
- External pudendal arteries
- Profunda femoris artery (deep artery of thigh)
Describe the supply of the profunda femoris?
There are rich anastomoses around the hip with the gluteal vessels (with branches of internal iliac) and around the knee.
Supplies the posterior compartment of the thigh
What does the profunda femoris give off?
– Medial circumflex femoral artery
– Lateral circumflex femoral artery
– 3-4 perforators.
What vessels make up the trochanteric anastomosis in the hip joint?
- Medial circumflex femoral artery
- Lateral circumflex femoral artery
- Superior gluteal artery
- Inferior gluteal artery
What vessels make up the Cruciate anastomosis in the hip joint?
- Medial circumflex femoral artery (and retinacular branches) - Lateral circumflex femoral artery - Obturator artery (and artery to head of femur)
What may impact on the blood supply to the femoral head?
fracture of the femoral neck.
Note the retinacular vessels passing on the neck to the head
What type of protection does the blood supply of the thigh have against damage to a blood vessel?
Its collateral circulation
If there is a blockage between the femoral artery and external iliac artery, blood can reach the popliteal artery through a host of other vessels
What vessels allow blood to reach the popliteal artery when there is a blockage between the femoral artery and external iliac artery?
– internal iliac -> inferior gluteal artery -> a perforating branch of the profunda femoris artery -> the lateral circumflex femoral artery -> its descending branch -> the superior lateral genicular artery -> the popliteal artery
– Via the anastomoses between obturator artery and branches of profunda femoris
Where is the origin of the popliteal artery?
Between Hiatus tendineus and lower border of popliteus muscle
Why is it difficult to get. pulse from the popliteal artery?
Deepest structure in the popliteal fossa
If you were to find a pulse from the popliteal artery, where would you find it?
Medial aspect of the popliteal fossa
How many branches does the popliteal artery have?
Gives rise to 5 genicular branches
Where does the the popliteal artery exit the popliteal artery?
Exit the popliteal fossa by passing through tendinous arch of soleus
What does the popliteal artery turn into?
Ends as the posterior and anterior tibial arteries
What does the popliteal artery supply?
The knee joint
What are some clinical considerations of the popliteal artery?
Second most common site of aneurysm
May be compromised in dislocation of the knee and fractures of the lower femur
Describe the blood supply to the knee joint
5 Genicular arteries from popliteal artery
Branches of the femoral artery
Branches of the profunda
femoris
A branch from the anterior tibial artery join and form genicular anastomosis
What are the 5 genicular arteries from the popliteal artery?
Superior lateral genicular artery Inferior lateral genicular artery Superior medial genicular artery Middle genicular artery Inferior medial genicular artery
What branch from the anterior tibial artery joins and forms genicular anastomosis to supply the knee joint?
Anterior tibial recurrent artery
What branches of the profunda femoris supply the knee joint?
Descending branch of the lateral circumflex femoral artery
Where does the anterior tibial artery lie?
Anterior tibial artery descends from the popliteal artery, deep to the anterior compartment muscles, accompanied by deep fibular [peroneal] nerve
What does the anterior tibial artery supply?
the anterior compartment muscles
What artery does the anterior tibial artery become?
The dorsalis pedis artery
Where does the anterior tibial artery become the dorsalis pedis artery?
Inferior to extensor retinaculum, it
becomes the dorsalis pedis artery
Describe the dorsalis pedis artery
The dorsalis pedis − Arcuate branch − 1st dorsal metatarsal branch • Dorsal digital arteries Dorsalis pedis pulse is felt in the first intermetatarsal space
Where does the posterior tibial artery lie?
Accompanies the tibial nerve as it descends deep to the soleus muscle.
What arteries do the posterior tibial artery give off?
Gives off the fibular, circumflex fibular, and nutrient arteries
What does the posterior tibial artery supply?
Supplies the muscles of the posterior compartment of the leg (plantar flexors)
What does the posterior tibial artery become?
Becomes the medial and lateral plantar arteries after running posterior to the medial malleolus
Where can one find the pulse of ht posterior tibial artery?
behind the medial malleolus
Describe the lateral and medial plantar arteries?
The medial and lateral plantar arteries supply the sole of the foot along with their branches: superficial and deep plantar arches, respectively.
The deep arch gives rise to plantar digital arteries of the phalanges.
Where do the superficial veins of the lower limb originate?
Originate from the dorsal venous network of the foot and dorsal veins of foot
What are the superficial veins of the lower limb?
Great (long) saphenous vein
Small (short) saphenous vein
Where does the great (long) saphenous vein lie?
ascends 2.5 cm anterior to the medial malleolus, posterior to medial condyle of femur (Hands breadth behind the patella)
Pierces the fascia lata to join the femoral vein.
Where does the small (short) saphenous vein lie?
ascends posterior to lateral malleolus and penetrates the deep fascia of the leg in the popliteal fossa.
Merges with deep veins to form the popliteal vein.
Where do the deep veins of the lower limb lie?
They ascend internal to the deep fascia of the lower limb
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)
Where does the femoral vein lie?
Femoral vein ascends in the adductor canal from the popliteal vein, it enters the femoral sheath and ends as the external iliac vein
Where does the femoral vein receive drainage from?
It receives drainage from profunda femoris, great saphenous and other small branches
Describe venous blood flow
Venous flow is from superficial to deep veins, via perforators
Arterial pulsation, negative intra-thoracic pressure and contraction of muscles (Muscle pump) all help venous return to the heart, against gravity.
Valves prevent backflow
Where do superficial lymph vessels lie?
Superficial lymph vessels accompany the superficial veins
Where do the lymph vessels drain to?
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
The lymph vessels accompanying the small saphenous vein enter the popliteal lymph nodes.
Deep lymph vessels accompany deep veins and enter the popliteal lymph nodes, accompany femoral vein to the deep inguinal nodes.
Where are superficial inguinal nodes found?
In a “T” along inguinal ligament and saphenous vein
Where do the superficial inguinal nodes receive lymph from?
– Anterior abdominal wall (under umbilicus) – skin of back (below iliac crests) – Perineum – Gluteal region – Superficial Lower limb
What is the femoral canal and ring?
Femoral canal is a short and conical space between the medial wall of the femoral sheath and the femoral vein
Contains deep inguinal lymph nodes
Where are the deep inguinal nodes found?
In the femoral triangle, medial to femoral vein
Where do the deep inguinal nodes 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
Where do the deep and superficial inguinal nodes drain to?
external iliac nodes common iliac nodes lumbar lymph nodes cisterna chyli thoracic duct Pirogov’s venous angle (left) venous system
What plexuses are found in the hip?
Lumbar and sacral (lumbosacral) plexuses (ventral rami of L1 – S4)
What do the lumbar and sacral (lumbosacral) plexuses supply?
Supply the lower limbs, parts of the abdominal wall, pelvis and perineum
What are the major nerves arising from the lumbar and sacral plexuses?
The largest nerves from these plexuses entering the thigh are the femoral nerve (L2-4) and the sciatic nerve (L4-S3)
What nerve root ganglion make up the lumbar plexus?
L1-4
Where is the lumbar plexus?
The lumbar plexus is formed within
the psoas major muscle and anterior to the transverse processes of the lumbar vertebrae.
What types of nerves are present in the lumbar plexus?
Has motor and sensory branches
What nerve root ganglion make up the femoral nerve?
L2-4
Where does the femoral nerve lie?
Descends behind the inguinal ligament
Passes through the femoral triangle in the thigh.
What branches do the femoral nerve give off?
Gives off muscular, anterior cutaneous femoral and saphenous branches
What is the sensory innervation of the femoral nerve?
- Hip joint
- Knee joint
- Skin on the anterior surface of the thigh (by
the anterior cutaneous femoral branch) - Skin of the medial leg and foot (by the
saphenous nerve).
What is the motor innervation of the femoral nerve?
- Iliacus
- Muscles in the anterior compartment of the thigh
• Quadriceps femoris
• Sartorius
• Pectineus
What nerve ganglions make up the saphenous nerve?
L3-4
Where does the saphenous nerve lie?
The terminal cutaneous branch
Enters the adductor canal with femoral
vessels
Pierces the medial wall of the adductor canal and becomes superficial
Accompanies the greater saphenous vein in the leg
What clinical considerations should one have about the saphenous nerve?
Saphenous nerve may be at risk in venous access or varicose vein surgery
What parts of the skin do the saphenous nerve supply?
Supplies the skin on the medial surface of the knee, anteromedial surface of leg and medial malleolus
Where does the obturator nerve lie?
Travels anteriorly on lateral pelvic wall towards obturator canal
Passes through obturator canal and enters the medial aspect of the thigh
What nerve root ganglion make up the obturator nerve?
L2-4
What is the sensory innervation of the obturator nerve?
- Hip joint
- Upper half of medial thigh
- Knee joint
What is the motor innervation of the obturator nerve?
- Obturator externus
- Muscles in the medial compartment of the thigh
• Adductor magnus*
• Adductor longus
• Adductor brevis
• Gracilis
What nerve root ganglion make up the sacral plexus?
Formed by anterior rami of L4 and L5 (the lumbosacral trunk) + S1-4
Where is the sacral plexus located?
Located on the surface of the posterior pelvic wall, deep to the piriformis muscle.
What are the gluteal nerves?
Superior gluteal nerve (L4 –S1)
Inferior gluteal nerve (L5 -S2)
Where does the superior gluteal nerve lie?
Exits pelvis through suprapiriform space
Runs laterally between the gluteus medius
and minimus
What does the superior gluteal nerve supply?
Supplies gluteus medius, gluteus minimus and tensor fasciae latae
Where does the inferior gluteal nerve lie?
Exits pelvis through infrapiriform space
What does the inferior gluteal nerve supply?
Innervates gluteus maximus
Where does the sciatic nerve enter the gluteal region?
Enters the gluteal region through the infrapiriform space
Where does the sciatic nerve lie?
Descends deep to gluteus maximus, midway between the ischial tuberosity and the greater trochanter, behind the hip joint
What nerve root ganglion supply the sciatic nerve?
L4-S3
What are some clinical considerations with the nerovascular structures of the buttocks?
Remember intragluteal injections should only be performed in the superolateral quadrant of the buttock, away from the majority of neurovascular structures
What branches do the sciatic nerve give off?
The sciatic nerve usually gives off its terminal branches at the apex of the popliteal fossa but in some cases can branch near the piriformis (12%)
− Tibial nerve
− Common fibular [peroneal] nerve
What is the sensory innervation of the sciatic nerve?
Hip joint
What is the motor innervation of 5th sciatic nerve?
- Muscles in the posterior compartment of thigh
• Hamstring muscles - Adductor magnus (in addition to the obturator nerve)
What nerves are found in the lateral compartment of the leg?
Superficial fibular nerve territory, evertors of foot
What nerves are found in the anterior compartment of the leg?
Deep fibular nerve territory, dorsiflexors of foot and toes
What nerves are found in the posterior compartment of the leg?
Tibial nerve, plantar flexors of foot and toes
What nerve root ganglion supply the tibial nerve?
L4-S3
Where does the tibial nerve lie?
Descends in the popliteal fossa, postero-lateral to the popliteal vessels
Passes into the sole behind medial malleolus, deep to the flexor retinaculum
What nerves arise form the tibial nerve?
Divides into the Medial and Lateral plantar nerves
What branch comes off the tibial nerve?
Gives off medial sural cutaneous branch (sensory)
What is the sensory innervation of the tibial nerve?
- Ankle joint
- Skin of the heel
What is the motor innervation of the tibial nerve?
- Hamstring muscles except short head of biceps femoris - Plantaris - Popliteus - Muscles in the superficial posterior compartment of the leg • Gastrocnemius • Soleus − Muscles in the deep posterior compartment • Tibialis posterior • Flexor hallucis longus • Flexor digitorum longus
What are the plantar nerves?
Medial plantar nerve
Lateral plantar nerve
Plantar digital nerves
What does the medial plantar nerve supply?
Supplies Abductor hallucis, Flexor hallucis brevis, Flexor digitorum brevis, Lumbrical 1
Sensory supply to anterior two-thirds of the
sole and adjacent surfaces of the medial 3.5 toes
What does the lateral plantar nerve supply?
Supplies all other plantar muscles
Sensory supply to skin on the lateral side of
the anterior two-thirds of the sole and the adjacent plantar surfaces of the lateral 1.5 digits
What nerve root ganglion make up the common fibular [peroneal] nerve?
L4-S2
Describe the path of the common fibular [peroneal] nerve
Is the smaller of the terminal branches
Descends laterally in the popliteal fossa.
Gives off lateral sural cutaneous branch (sensory)
Winds around the neck of the fibula
Divides into its terminal branches:
− Superficial fibular [peroneal] nerve
− Deep fibular [peroneal] nerve
What branch comes off the common fibular [peroneal] nerve?
Gives off lateral sural cutaneous branch (sensory)
What does the common fibular [peroneal] nerve supply?
- Short head of Biceps femoris
What forms the sural nerve?
Formed by lateral cutaneous sural branch from the common fibular nerve and medial cutaneous sural branch from the tibial nerve
What is the clinical importance of the sural nerve?
May be used as nerve graft
What does the sural nerve supply?
Supplies the skin on the lower
posterolateral surface of the leg and the lateral side of the foot (and little toe)
What nerve root ganglion make up the deep fibular nerve?
L4-5
What is the sensory innervation of the deep fibular nerve?
- Ankle joint
- Web space between the 1st and 2nd toes
What is the motor innervation of the deep fibular nerve?
- muscles in the anterior compartment of the leg • Tibialis anterior • Extensor hallucis longus • Extensor digitorum longus • Fibularis tertius - Extensor digitorum brevis - Extensor hallucis brevis
What is the sensory innervation of the superficial fibular nerve?
- Ankle joint
- Skin on anterior distal leg
- Skin on dorsum of foot
What is the motor innervation of the superficial fibular nerve?
- Muscles in the lateral compartment of the
thigh
• Fibularis longus
• Fibularis brevis
What are the nerve root ganglion that make up the superficial fibular nerve?
L5-S2
Describe the blood supply of the hip joint?
Cruciate anastomosis - Medial circumflex femoral artery (and retinacular branches) - Lateral circumflex femoral artery - inferior gluteal artery - first perforating branch of deep femoral artery
What may effect the blood supply of the femoral head?
Blood supply of femoral head may be affected by fracture of the femoral neck.
Note the retinacular vessels passing on the neck to the head
