Atlas of Anatomy

27 Neurovasculature

Arteries of the Lower Limb

Fig. 27.1 Arteries of the lower limb
Right limb, anterior (A) and posterior (B) views.

Fig. 27.2 Arteries of the sole of the foot
Right foot, plntar view

Clinical

Femora I head necrosis

Dislocation or fracture of the femoral head (e.g., in patients with osteoporosis) my disrupt the anastomoses between the foveal artery and the femoral neck vessels, resulting in femoral head necrosis.

Fig. 27.3 Arteries of the femoral head
Right hip joint, anterior view.

Fig. 27.4 Arteries of the thigh and leg
Right leg.

Veins & Lymphatics of the Lower Limb

Fig. 27.5 Veins of the lower limb
Right limb, anterior view.

Fig. 27.6 Veins of the sole of the foot
Right foot, plantar view.

Fig. 27.7 Veins of the leg
Right leg, posterior view.

Fig. 27.8 Clinically important perforating veins
Right leg, medial view.

Fig. 27.9 Superficial lymphatics
Right limb. Arrows indicate the main directions of lymphatic drainage.

Fig. 27.10 Lymph nodes and drainage
Right limb, anterior view.

Lumbosacral Plexus

The lumbosacral plexus supplies sensory and motor innervation to the lower limb. It is formed by the anterior (ventral) rami of the lumbar and sacral spinal nerves, with contributions from the subcostal nerve (T12) and coccygeal nerve (Co1).

Fig. 27.11 Lumbosacral plexus
Right side, anterior view.

Nerves of the Lumbar Plexus

Fig. 27.12 Sensory innervation of the inguinal region
Right male inguinal region, anterior view.

Fig. 27.13 Nerves of the lumbar plexus
Right side, anterior view with the anterior abdominal wall removed.

Nerves of the Lumbar Plexus: Obturator & Femoral Nerves

Fig. 27.14 Obturator nerve: Sensory distribution
Right leg, medial view.

Fig. 27.15 Obturator nerve
Right side, anterior view.

Fig. 27.16 Femoral nerve
Right side, anterior view.

Fig. 27.17 Femoral nerve: Sensory distribution
Right limb, anterior view.

Nerves of the Sacral Plexus

Fig. 27.18 Sensory innervation of the gluteal region
Right limb, posterior view.

Fig. 27.19 Posterior femoral cutaneous nerve: Sensory distribution
Right limb, posterior view.

Fig. 27.20 Emerging sacral nerve
Horizontal section, superior view.

Fig. 27.21 Nerves of the sacral plexus
Right limb.

Clinical

Small gluteal muscle weakness

The small gluteal muscles on the stance side stabilize the pelvis in the coronal plane. Weakness or paralysis of the small gluteal muscles from damage to the superior gluteal nerve (e.g., due to a faulty intramuscular injection) is manifested by weak abduction of the affected hip joint. In a positive Trendelenburg's test, the pelvis sags toward the normal, unsupported side. Tilting the upper body toward the affected side shifts the center of gravity onto the stance side, thereby elevating the pelvis on the swing side (Duchenne's limp). With bilateral loss of the small gluteals, the patient exhibits a typical waddling gait.

Nerves of the Sacral Plexus: Sciatic Nerve

The sciatic nerve gives off several direct muscular branches before dividing into the tibial and common fibular nerves proximal to the popliteal fossa.

Fig. 27.22 Common fibular nerve: Sensory distribution

Fig. 27.23 Common fibular nerve
Right limb, lateral view.

Table 27.6 Common fibular nerve (L4-S2)
Nerve	Innervated muscles	Sensory branches
Direct branches from Sciatic n.	Biceps femoris (shortsciatic head)	–
Superficial fibular n.	Fibularisbrevisand longus	Medial dorsal cutaneous n. Intermediate dorsal cutaneous n.
Deep fibular n.	Tibialis anterior Extensors digitorum brevis and longus Extensors hallucis brevis and longus Fibularis tertius	Lateral cutaneous n. of big toe Medial cutaneous n. of 2nd toe.

Fig. 27.24 Tibial nerve
Right limb.

Fig. 27.25 Tibial nerve: Sensory distribution
Right lower limb, posterior view.

Table 27.7 Tibial nerve (L4–S3)
Nerve	Innervated muscles	Sensory branches
Direct branches from sciatic n.	Semitendinosus Semimembranosus Biceps femoris (long head) Adductor magnus (medial part)	–
Tibial n.	Triceps surae Plantaris Popliteus Tibialis posterior Flexor digitorum longus Flexor hallucis longus	Medial sural cutaneous n. Medial and lateral calcaneal branches Lateral dorsal cutaneous n.
Medial plantar n.	Adductor hallucis Flexor digitorum brevis Flexor hallucis brevis(medial head) 1st and 2nd lumbricals	Proper plantar digital nn.
Lateral plantar n.	Flexor hallucis brevis (lateral head) Quadratus plantae Abductor digiti minimi Flexor digiti minimi brevis Opponens digiti minimi 3rd and 4th lumbricals 1st and 3rd plantar interossel 1st to 4th doral interossel Adductor hallucis	Proper plantar digital nn.

Superficial Nerves & Vessels of the Lower Limb

Fig. 27.26 Cutaneous innervation: Anterior view
Right limb.

Fig. 27.27 Superficial cutaneous veins and nerves
Right limb.

Fig. 27.28 Cutaneous innervation: Posterior view
Right limb.

Topography of the Inguinal Region

Fig. 27.29 Superficial veins and lymph nodes
Right male inguinal region, anterior view. Removed: Cribriform fascia about the saphenous hiatus.

Fig. 27.30 Inguinal region
Right male inguinal region, anterior view.

Fig. 27.31 Lacunae musculorum and vasorum
Right inguinal region, anterior view.

Table 27.8 Structures in the inguinal region
Region	Boundaries	Contents
1 Lacuna musculorum	Anterior superior iliac spine Inguinal ligament Iliopectineal arch	Femoral n. Lateral femoral cutaneous n. Iliacus Psoas major
2 Lacuna vasorum	Inguinal ligament Iliopectineal arch Lacunar ligament	Femoral a. and v. Genitofemoral n. (femoral branch) Rosenmiiller's lymph node
3 External inguinal ring	Medial crus Lateral crus Reflex inguinal ligament	Ilioinguinal n. Genitofemoral n. (genital branch) Spermatic cord

Topography of the Gluteal Region

Fig. 27.32 Gluteal region
Right gluteal region, posterior view.

Fig. 27.33 Gluteal region and ischianal fossa
Right gluteal region, posterior view. Removed: Cluteus maximus and medius.

Topography of the Anterior & Posterior Thigh

Fig. 27.34 Anterior thigh
Right thigh, anterior view.

Fig. 27.35 Posterior thigh
Right thigh, posterior view.

Topography of the Posterior & Medial Leg

Fig. 27.36 Posterior compartment
Right leg, posterior view.

Fig. 27.37 Popliteal region
Right leg, posterior view.

Fig. 27.38 Posterior compartment: Medial view
Right foot.

Topography of the Lateral & Anterior Leg

Fig. 27.39 Neurovasculature of the leg: Lateral view
Right limb. Removed: Origins of the fibularis longus and extensor digitorum longus.

Clinical

Compartment syndrome

Muscle edema or hematoma can lead to a rise in tissue pressure in the compartments of the leg. Subsequent compression of neurovascular structures may cause ischemia and irreversible muscle and nerve damage. Patients with anterior compartment syndrome, the most common form, suffer excruciating pain and cannot dorsiflexthe toes. Emergency incision of the fascia of the leg may be performed to relieve compression.

Fig. 27.40 Neurovasculature of the leg and foot: Anterior view
Right limb with foot in plantar flexion.

Topography of the Sole of the Foot

Fig. 27.41 Neurovasculature of the foot: Sole
Right foot, plantar view.

Fig. 27.42 Neurovasculature of the foot: Cross section
Coronal section, distal view.

Transverse Sections of the Thigh & Leg

Fig. 27.43 Windowed dissection
Right limb, posterior view.

Fig. 27.44 Transverse sections
Right limb, proximal (superior) view.