Anatomy 3 Nerves and blood vessels of lower limb
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Status: v103 Time: 2025-04-01 Tags: lecturenotes MSK Anatomy Links: The Lower Limb
tasks:
Content:
Flashcarding directives spinal root origins of the big 5 nerves origins and comments surrounding the lumbar and sacral plexae the different splittings of the nerves into all the parts what muscle is innervated by what nerve myotomes dermatomes arteries of the lower leg veins of the lower leg comments relating to the femoral triangle popliteal fossa and tarsal tunnel paths of muscles
NBs and summary Most of the nerves and arteries correspond to a particular compartment of the lower limb
Summary
• Gluteal region • Gluteus medius, minimus & TFL: superior gluteal nerve and vessels • Gluteus maximus: inferior gluteal nerve and vessels • Femoral triangle • Contents: (lateral to medial) femoral nerve, femoral artery, femoral vein, lymph nodes (NAVY) • Adductor canal and hiatus: fascial canal for femoral artery and vein becoming popliteal artery and vein • Popliteal fossa: tibial nerve, popliteal vein, popliteal artery (superficial to deep) • Tarsal tunnel: tibialis posterior, FDL, posterior tibial artery, posterior tibial vein, tibial nerve, FHL • Summary of compartmental neurovascular supply of thigh and leg • Veins • Deep veins – the same name as artery • Superficial veins – great saphenous & small saphenous veins
Objectives:
- Discuss the innervation of the lower limb muscles
- Describe the dermatomes, myotomes and cutaneous distribution of the lower limb
- Describe and understand the arterial supply of the lower imb
- discuss important neurovascular landmarks of the lower limb
- femoral triangle
- popliteal fossa
- tarsal tunnel
- describe and understand the venous drainage of the lower limb
- describe and understand the lymphatic drainage of the lower limb
- discuss the clinical anatomy and implications related to the neurovascular distribution of the lower limb
Rambles:
Nerve supply of the lower limb
spinal cord recap
dorsal is sensory ventral is motor spinal nerve is mixed info
rootlets come off the spinal cord combine to form roots, dorsal and ventral combine to form the spinal nerve split to form dorsal and ventral rami dorsal supplies deep back muscles joints and skin ventral rami form plexuses and innervate the limbs
ventral rami can also split into anterior and posterior divisions
Nerves and plexuses
Cervical nerves (C1-C8) cervical plexus (C1-C4) brachial plexus(C5-T1) Thoracic nerves (T1-T12) intercostal nerves(T1-T11) Lumbar nerves (L1-L5) Lumbar plexus (L1-L4) Sacral (S1-S5) Sacral plexus (L4-S4) Coccygeal (Co1) Coccygeal plexus (S4-Co1)
Lower limb is supplied via the lumbosacral plexus
lumbar plexus
sacral plexus lumbosacral trunk formed of L4 and L5 connect the lumbar plexus to the sacral plexus
Nerves of note
- Femoral nerve (L2-L4) anterior and posterior division
- Obturator nerve (L2-L4) anterior and posterior division
- Superior gluteal nerve (L4 - S1) Lumbosacral trunk (L4-L5) connects lumber plexus with sacral plexus
- Inferior gluteal nerve (L5-S2)
- Sciatic Nerve (L4-S3) (common fibular l4-s2 and tibial l4-s3)
for femoral and obturator nerve the limbs are supplied by the posterior division as there is a rotation of limb in utero
Femoral Nerve
Formed from the L2-L4 posterior divisions Motor supply: supplies the anterior thigh muscles (anterior compartment)
- illicus
- psoas major is innervated by ventral rami of L1-L3
- pectineus
- sartorius
- vastus lateralis
- rectus femoris
- vastus intermedius
- vastus medialis Sensory: skin of anterior and medial thigh medial side of leg - saphenous nerve
Obturator Nerve
Formation: L2-L4 anterior divisions Motor supply: medial thigh muscles (medial compartment)
- obturator externus
- adductor magnus (Also supplied by the tibial nerve) Sensory supply: Skin of the medial thigh region
Superior gluteal nerve
Formation: L4-S1 Motor supply:
- gluteus medius
- gluteus minimus
- TFL Sensory supply:
Inferior gluteal nerve
Formation:L5-S2 Motor supply: Gluteus maximus
Sciatic nerve
Tibial
Formation:L4-S3 Motor supply:
- Posterior compartment of leg and thigh
- intrinsic muscles of the foot (sole of foot)
- medial and lateral plantar nerve Sensory supply:
Common Fibular
Formation: L4-S2 Motor supply:
- Anterior compartment of the leg (Deep fibular Nerve)
- Lateral compartment of the leg (Superficial fibular nerve)
Nerve sensory distribution of the lower leg
Dermatomes and myotomes
Dermatome: area of skin supplied by a single nerve or spinal level Myotome: region of skeletal muscle innervated by a single nerve of spinal level
Dermatomes of the lower limb
Myotomes of the lower limb
Arterial supply of the lower limb
Abdominal trunk common left common iliac artery internal and external iliac arteries
as the external iliac artery passes through the inguinal ligament it makes the femoral artery
the femoral artery turns into the popliteal artery at the popliteal fossa
popliteal artery splits into the anterior and posterior tibial artery
fibular artery branches off the posterior tibial artery
anterior tibial artery turns into the dorsalis pedis posterior tibial artery splits into the medial and lateral planter arteries
dorsalis pedis medial and lateral plantar arteries then all form the plantar arch and plexus
Thigh
| Compartment | Arterial supply |
|---|---|
| Anterior | Deep femoral artery |
| Posterior | Deep femoral artery |
| Medial | Deep femoral artery + obturator artery |
Leg
| Compartment | Arterial supply |
|---|---|
| Anterior | Anterior tibial artery |
| Posterior | Posterior tibial artery |
| Lateral | Fibular/peroneal artery |
| Thigh | |
|---|---|
| Anterior | Femoral nerve |
| Posterior | Tibial nerve |
| Medial | obturator nerve |
| Leg | |
| Anterior | Deep fibular nerve |
| Posterior | Tibial nerve |
| Lateral | Superficial fibular nerve |
Important transition zones in the lower leg inguinal ligament + femoral triangle important as well as the femoral sheath contains the Nerve Artery Vein and lYmphatics (lymphatics are in the femoral canal)
femoral sheath forms into the adductor canal and passes anterior to posterior through the adductor hiatus. Made of Fascia
Popliteal fossa diamond shaped space which bares passage for the popliteal artery vein and tibial and common fibular nerves
Tarsal tunnel cable management for the foot
stablilises and positions (anterior to posterior): TIbialis posterior tendon Flexor Digitorum Longus Posterior Tibial Artery Posterior Tibial Vein Tibial Nerve Flexor Hallucis Longus
Clinical relation: feel the pulse at the femoral triangle, popliteal fossa, posterior tibial pulse, Dorsalis pedis
Venous drainage
basically same route backwards plus inferior vena cava, great and small saphenous veins
Lymphatic drainage the Inguinal lymph nodes are the main lymph nodes of the lower limb 2 in the popliteal fossa and maybe 1 at the attachement point of the tibialis anterior