Limbs 4 Flashcards
What is the name of the plexus which innervates the lower limb
Lumbosacral plexus
What are the three main nerves of the lumbar plexus
- Lateral cutaneous nerve of the thigh
- Femoral nerve
- Obturator nerve
What are the roots of the lumbosacral trunk and what is its purpose?
L4 and L5
- Provides fibres to the sacral plexus
Name nerves 1-6 on this diagram of the sacral plexus?
1) Superior Gluteal Nerve
2) Inferior gluteal nerve
3) Sciatic nerve
4) Common peroneal part
5) Tibial part
6) Posterior cutaneous nerve of the thigh
What does the femoral nerve supply?
Anterior compartment of the thigh
- Iliacus
What does the obturator nerve supply?
Medial adductor compartment of the thihg
How does the obturator nerve pass into the lower limb?
Passes inferiorly through the obturator foramen, by piercing obturator memebrane
How does the sciatic nerve reach the LL?
Passesfrom the interior of the pelvis through the greater sciatic forament into the gluteal nerve
Here it gives fibres to the piriformis
Then it travels deep to the gluteus max. and then to posterior thigh.
What is the terminal branch of the femoral nerve and describe its course and what does it supply
The saphenous nerve
- The adductor canal
- Cutaneous nerve supplying the anteromedial knee, leg and the medial foot
What is the passage of the femoral nerve?
- Descends through the pelvis
- Passes under the inguinal ligament into the femoral triangle where it divides to give its branches
WHat do the anterior and posterior branches of the obturator nerve supply?
The adductor muscles and an area of skin on the medial surface of the thigh
WHat is the relation of the superior gluteal nerve to the piriformis
Superior to piriformis
(opposite w inferior gluteal nerve)
What structures does the superior gluteal nerve supply?
- Gluteus medius and minimus
- Tensor fasciae latae
What structures does the inferior gluteal nerve supply?
- Gluteus maximus ONLY
What is the anatomical relation between the sciatic nerve, posterior cutaneous nerve of the thigh and the piriformis?
SCiatic nerve and PCN are inferior to the piriformis
Which nerve supplies the hamstring muscles
Sciatic nerve
What are the terminal branches of the sciatic nerve?
- Common peroneal nerve
- Tibial nerve
How do the terminal branches of the sciatic nerve enter the leg?
Pass in the popliteal fossa (space behind knee)
Where does the sciatic nerve split into its terminal branches
The distal part of the thigh
What is the course of the common peroneal nerve and what is its clinical significance?
- Leave popliteal fossa
- Courses laterally to wind around the neck of fibula just inferior to its head
- Here it can be palpated and is susceptible to injury
Where does the common peroneal nerve bifurcate and what is the names of its terminal branches
At the head of the fibula
Superficial peroneal nerve
Deep peroneal nerve
What does the superficial peroneal nerve supply?
- Lateral muscles of leg
- Skin of dorsum of foot
What is the supply of the deep peroneal nerve?
- Anterior muscles of leg
- Skin of cleft between 1st and 2nd toes
How does the tibial nerve pass into the leg
Through the popliteal fossa
What does the tibial nerve supply in the leg?
- Both superficial and deep muscle compartments of the posterior leg
What happens to the tibial nerve at the ankle?
- Veers medially, posterior to medial malleolus,
- passes under plantar aponeurosis
- where it bifurcates to form its termnal branches
What are the terminal branches of tibial nerve?
Lateral and medial plantar nerves
What are autonomous sensory zones?
Regions of non-overlapping sensory supply from an individual spinal root
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```What is the clinical importance of autonomous snesory zones?
Pain and abnormal sensation in each zone can be attributed to a single spinal root
What does the Nerve to quadratus supply?
- External rotators
- Inferior gemellus
What does the nerve to obturator internus supply?
External rotators
Superior gemellus
Which nerve supplies the hamstring part of adductor magnus with origin on the ischial tuberosity?
Tibial part of the sciatic nerve
Which nerves supply cutaenous innervation to 1-4
1) Obturator nerve
2) Femoral nerve (anterior cutaneous nerves of thigh)
3) Femoral nerve (saphenous nerve)
4) Common peroneal (fibular) nerve
Which nerves supply cutaenous innervation to 5-8
5) Medial plantar nerve
6) Lateral cutaneous nerve of thigh (lumbar plexus)
7) Posterior cutaneous nerve of thigh (from sacral plexus)
8) Common peroneal nerve (lateral cutaneous nerve of calf)
Which nerves supply cutaenous innervation to 9-12
9) Common fibular nerve (SUPERficial branch)
10) Tibial nerve (sural nerve)
11) Lateral plantar nerve
12) Posterior rami (L1 to L3)
Which nerves supply cutaenous innervation to 13-17
13) Posterior rami (S1 to S3)
14) Obturator nerve
15) Femoral nerve (saphenous nerve)
16) Tibial nerve (sural nerve)
17) Tibial nerve (medial calcaneal branches)
What is the clinical importance of the lower limb arteries?
- Assessing vascular health
- Angiograms
- Angioplasty
What is the root of most of the lower limb arteries?
Left and right iliac arteries
How do the left and right common iliac arteries arise?
Bifurcation of the abdominal aorta at the iliac crest
Which arteries does the bifurcation of the common iliac arteries form?
Internal and external iliac arteries