Movement Lecture 4 - Neurovasculature of the lower limb Flashcards
Which artery is the continuation of the external iliac artery in the thigh, and what is the anatomical boundary where this change occurs?
External iliac artery becomes the femoral below the inguinal ligament
What is the blood supply for the anterior compartment of the thigh?
Femoral artery
Where does the profunda femoris artery branch from and what is its alternative name?
Femoral artery
AKA The deep artery of the thigh
How many perforating arteries are given off by the profunda femoris artery and what do they supply?
Four
Posterior compartment of the thigh
Which muscle do the superior and inferior gluteal arteries pass either side of to enter the gluteal region?
Piriformis
Where do the gluteal arteries branch from?
Internal iliac artery
Which artery branches from the internal iliac and supplies the medial compartment of the thigh?
Obturator artery
Branches from which two arteries anastamose around the femur so blood can bypass an occlusion?
Internal iliac and profunda femoris
How many genicular branches are given off by the popliteal artery and what are their names?
Five
Lateral and medial superior
Middle
Lateral and medial inferior
What structures are formed by the genicular branches of the popliteal artery and what is their function?
Genicular anastamoses
Allow blood supply to the leg to be maintained when the knee is flexed
What are the two terminal branches of the tibial artery, and which one perforates the interosseus membrane?
Anterior tibial artery (perforates interosseus membrane)
Posterior tibial artery
Which artery supplies the lateral compartment of the leg and where does it branch from?
Fibular artery branches from the posterior tibial
What are the terminal branches of the anterior tibial artery and which one runs more medially on the dorsum of the foot?
Dorsalis pedis and lateral tarsal
Dorsalis pedis is medial
What is the artery formed by the anastamosis of the terminal branches of the anterior tibial artery?
Arcuate artery
Which artery does the deep plantar artery of the foot branch from?
Dorsalis pedis
What are the terminal branches of the posterior tibial artery?
Medial and lateral plantar arteries
Which terminal branch of the posterior tibial artery anastamoses with the deep plantar artery, and what is this anastamosis called?
Lateral plantar artery
Deep plantar arch
The femoral pulse point can be found just inferior to a point half way between which two structures?
Anterior superior iliac spine
Pubic tubercle
What is the deepest structure in the popliteal fossa?
Popliteal artery
How should the knee be positioned to best feel a popliteal pulse?
Flexed
Which anatomical features can the posterior tibial pulse be found halfway between?
Medial malleolus and heel
Which tendon is the dorsalis pedis pulse found just lateral to?
Extensor hallucis longus tendon
Name two clinical procedures that the femoral artery is used for
Arterial blood gases in cases of poor perfusion
Minimally invasive surgery - used as point of entry for catheter, then advance up the arterial tree to reach the target organ
What are the six “P” symptoms of acute ischaemia in the lower limb?
Pain Perishingly cold Pallor Paralysis Paraesthesia Pulseless
What is paraesthesia?
Pins and needles
Name three potential complications of chronic ischaemia
Tissue loss
Ulceration
Gangrene
Which side of the foot has a venous arch and what does this drain into?
Dorsal venous arch drains into the great saphenous vein
Does the great saphenous vein lie anterior or posterior to the medial malleolus?
Anterior
Which general regions of the leg do the great and short saphenous veins drain?
Great - medial and anterior
Short - lateral and posterior
What do the palmar veins of the foot drain into?
Short saphenous vein
Name three things that aid venous return in the lower limb
Valves
Muscle contraction
Deep fascia acts as “compression stocking”
What are the main deep veins of the leg?
Anterior and posterior tibial
Fibular
What is special about the deep veins of the leg, compared to those of the thigh?
They are venae comitantes
What do the deep veins of the leg join to form, and where does this drain?
Popliteal vein, drains into the femoral vein
What can happen to the saphenous veins as a result of a proximal venous obstruction?
Varicose veins - increased pressure means they become dilated and incompetent
What complications can result from the breakdown of varicose veins?
Bleeding
Ulceration
Which veins in the lower limb can be used for emergency IV access in the event of trauma?
Great saphenous vein
Femoral vein
What is the mortality rate for untreated DVT and what complication is this due to?
1-2% mortality rate from pulmonary embolism
What are some risk factors for DVT?
Pregnancy Immobility Sepsis IV drug use in femoral vein Recent surgery Malignancy
What are the nerve roots of the lumbar and sacral plexuses?
Lumber plexus = L1 - L4
Sacral plexus = L4 - S5
What is the name of the structure that is formed by parts of both the lumbar and sacral plexuses, and what are its spinal nerve roots?
Lumbosacral trunk
L4, L5
What is the nerve supply to the anterior thigh, and what are its spinal nerve roots?
Femoral nerve
L2, L3, L4
What is the nerve supply to the medial thigh, and what are its spinal nerve roots?
Obturator nerve
L2, L3, L4
What is the nerve supply to the posterior thigh, and what are its spinal nerve roots?
Tibial nerve
L4 - S3
What is the exception to the tibial nerve innervating the posterior compartment of the thigh - which muscle, nerve and spinal nerve roots?
Short head of biceps femoris
Common fibular nerve
L4 - S2
Does the femoral nerve pass anterior or posterior to the inguinal ligament?
Posterior
What is the terminal branch of the femoral nerve and what does it supply?
Saphenous nerve
Medial skin of the thigh
(via adductor hiatus)
Where does the sciatic nerve bifurcate?
Distal thigh
What are the terminal branches of the obturator nerve?
Anterior and posterior branches
Which muscles separate the two terminal branches of the obturator nerve?
Obturator externus
Adductor brevis
Which quadrant of the gluteal region should intramuscular injections be given into to avoid iatrogenic sciatic nerve injury?
Superolateral
What are the terminal branches of the common fibular nerve and what do they supply?
Deep fibular nerve supplies anterior leg
Superficial fibular nerve supples lateral leg
Where is the fibular nerve most vulnerable to injury and what would be the symptoms of this?
Where it wraps around the neck of the fibula
Foot drop, affected gait and loss of sensation on the dorsum of the foot
What does the tibial nerve innervate before bifurcating?
Posterior compartment of the leg
Where does the tibial nerve bifurcate, and what are its terminal branches?
Deep to the flexor retinaculum
Medial and lateral plantar nerves
Which nerve innervates the dorsal intrinsic foot muscles?
Deep fibular nerve
Divide the plantar intrinsic foot muscles into those innervated by the medial plantar nerve and those innervated by the lateral plantar nerve
Medial plantar nerve: abductor hallucis, flexor digitorum brevis, flexor hallucis brevis and first lumbrical
Lateral plantar nerve: all others
Which toes receive innervation on their plantar skin from the medial plantar nerve, and which from the lateral plantar nerve?
Medial plantar innervates medial 3 1/2
Lateral plantar innervates lateral 1 1/2