Lower Limb Neurovasculature Flashcards
Which spinal segments make up the lumbar plexus
L1 to L4
What are the first two branches of the lumbar plexus? Which spinal do they come from?
iliohypogastric and ilioinguinal
L1
Where do iliohypgastric and ilioinguinal nerves travel? What do they supply?
they slip into the neurovascular plane between abdominal muscles, supplying the abdo wall
What is the motor supply of iliohypogastric and ilioinguinal nerves
the lower most fibres of IOM and TA, which is the roof of inguinal canal
Why do pregnancy women sometimes feel pins and needles down the lateral side of the thigh?
The increased body size can cause compression of lateral cutaneous nerve just adjacent to the ASIS, causing sensory abnormalities
Which lumbar segments give rise to lateral cutaneous nerve of the thigh?
L2 and L3
Which lumbar segments give rise to genitofemoral nerve?
L1 - femoral branch
L2 - genital branch
Which nerve supplies the spermatic cord?
genital branch of the genitofemoral nerve
What does the femoral branch of the genitofemoral nerve supply?
the skin over the femoral triangle
T/F Femoral nerve is from the posterior division of the ventral rami
True, posterior division supplies the extensors
T/F Femoral nerve supplies the psoas as it is a muscle of the anterior compartment
False, psoas gets segmental supply from the nerves within
Which muscles does the femoral nerve supply?
quads, sartorius, lateral compartment of the pectineus
What is the sensory terminal branches of femoral nerve?
intermediate and medial cutaneous nerves of the thigh
saphenous nerve
What does the saphenous nerve supply?
the sensory component medially along the knee, leg and ankle, right down to the first metatarsal
T/F Femoral nerve supplies all of the sensory component for anterior and medial part of the thigh
False, femoral branch of genitofemoral supplies the supero-medial thigh, and obturator supplies a patch of the medial side just above the knee
Which compartment does the obturator supply?
medial compartment of the thigh
T/F Obturator nerve divides into the anterior and posterior divisions before giving suppy to gracilis
False, it supplies the gracilis, then split into anterior and posterior divisions
Which muscles does the anterior division of obturator travel between
adductor longus and adductor brevis
Which muscles does the posterior division of obturator travel between
adductor brevis and adductor magnus
What is the sensory supply of the obturator nerve?
pelvic peritoneum
medial side of thigh just above the knee
Which nerve roots make up the sacral plexus
ventral nerves of S1-4, plus L5, and the leftover of L4
Which muscle is a useful landmark for the sacral plexus
piriformis
Which muscles does 1) superior gluteal nerve 2) inferior gluteal nerve supply?
1) gluteus medius and minimus
2) gluteus maximus
Is posterior cutaneous nerve of the thigh a branch of the sciatic?
No
T/F Sciatic nerve has both anterior and posterior division fibres
True, anterior and posterior of L4, L5, S1-S3
When does sciatic nerve divide into its terminal branches
at the apex of the popliteal fossa, 2/3 way down the thigh
T/F Posterior dislocation of the hip joint will damage the sciatic nerve
True
What are the sensory branches of the femoral nerve?
medial and intermediate cutaneous branches
saphenous branch
T/F the terminal branches of sciatic nerve arises from the same segment and division of the sacral plexus
False, tibial nerves gets the anterior division of L4,L5, S1-3
Common fibular gets posterior division of L4,L5, S1, S2
Describe the course of descend of the tibial nerve in the leg
from the popliteal fossa, it slips beneath and soleal arch, between the superficial and deep posterior compartments
T/F The tibial nerve is posterior to the lateral malleolus
False, it is posterior to the medial malleolus
What is the sensory branch off the tibial nerve?
sural nerve, supplying the skin over the posterior compartment
What does the tibial nerve divide into at the foot
Medial and lateral plantar nerves for the sole
Describe the course of the common fibular nerve from the popliteal fossa
travels medial to biceps, to the lateral side of the knee and winds around the fibula. Then it turns medially and sink into the substance of tibialis anterior
What is the sensory branch off the common fibular at the leg region?
the communicating sural nerve
T/F Common fibular nerve is deep to the lateral head of gastrocnemius
False, it is superficial. Its superficial location makes it prone to injury
What can happen if we fracture the head of fibula
lose motor and sensory supply by the common fibular nerve, and you get a foot drop
What does the deep fibular nerve supply?
motor for the anterior compartment and EDB
sensory to the triangle between 1st and 2nd toes
T/F Deep fibular nerve travels along the interosseous membrane
True
What does the superficial fibular nerve supply?
motor to lateral compartment and sensory to lower lateral leg and dorsum of foot
The superficial fibular nerve initially runs deep in the lateral compartment. When does it become superficial?
After supplying fibularis longus and brevis
What is the major branch of femoral artery
profunda femoris
How does profunda femoris travel?
It travels with adductor magnus, sending off perforating branches
T/F Femoral artery and profunda femoris both enter the posterior compartment of the thigh
False, femoral artery does, at the adductor hiatus. Profunda femoris stays in the anterior compartment
The ascending branch of profunda femoris supplies the head of the femur. What are the names of the two branches?
medial circumflex
lateral circumflex
What are the branches of popliteal artery?
geniculate branch around the knee
Splits into anterior and posterior tibial at the inferior border of popliteus
What the femoral sheath contain?
femoral artery, femoral vein
femoral nerve is NOT included
T/F femoral vein lies medial to the femoral artery in the femoral sheath
True, so it can expand into the femoral canal
Where is the femoral ring?
at the top of the femoral canal
what is directly posterior to the femoral ring?
pectineus
Why does strangulation often occur to the herniated content through the femoral ring?
Because the boundary of the femoral ring is especially rigid
Which major neurovascular structures can be found in the popliteus?
popliteal artery, popliteal vein, tibial nerve
T/F Popliteal vein is the most superficial structure in the popliteal neurovascular bundle
False, tibial nerve is
Which nerve does the anterior tibial artery travel with?
deep fibular nerve, along the interosseous membrane
Which branch comes off the posterior tibial artery?
fibular artery, going to the evertor compartment
Which artery becomes the dorsalis pedis artery after crossing the extensor retinaculum
anterior tibial artery
Does posterior tibial artery travel medially or laterally at the ankle?
medially
How does compartment haematoma lead to increased compartmental pressure?
initial bleeding + the oedema from ischaemia
What are the five P’s of compartment syndrome
pain pale pulseless parasthetic paralysed
T/F Deep veins often run in pairs (vena commitantes)
True
Which veins does the dorsal venous arch drain into?
medially, into the great saphenous vein
laterally, into short saphenous vein
T/F the drainage pathway between dorsal venous arch and great saphenous vein is posterior to the medial malleolus
False, it is anterior to the medial malleolus
From an anterior view, when does the great saphenous vein disappear from view
at the level of the knee
How does great saphenous vein drain into deep venous structure?
at the superior thigh, through the saphenous opening in the fascia lata and join with the femoral vein
how does short saphenous drain into deep venous structure
at the superior leg, pierce the fascia to join up with anterior and posterior tibial veins, and eventually join the popliteal vein
What happens to the superficial veins when there is defect in the communicating valves
veins are engorged, tortuous and full of blood
Why do you get brown pigmentation and varicose ulcers with defects in communicating valves?
Due to increased capillary pressure, squeezing blood into soft tissue
