SUPERFICIAL VEINS OF LOWER LIMB (N512, N513)

Great Saphenous Vein

On the anterior thigh, it travels through the Fossa Ovalis, after which it merges with the Femoral Vein.

As you go down the leg, it wraps medially around to the posterior aspect of the knee.

Then it comes back anteriorly to the medial malleolus of the ankle, where it anastomoses with the Lesser Saphenous Vein.

Lesser Saphenous Vein: Runs up the posterior leg.

It anastomoses with the Great Saphenous Vein around the ankle.

DEEP VEINS OF LOWER LIMB:

For the most part, the deep veins run with the deep arteries.

(N485) Popliteal Vein: Around the back of the knee, this vein is very important clinically.

BLOOD CLOT in POPLITEAL VEIN ------> Femoral Vein ------> External Iliac ------> IVC ------> Right Heart ------> Lungs ------>

Pulmonary Embolism! -- not good.

The Lesser Saphenous Vein feeds into the Popliteal Vein around the posterior aspect of the thigh.

The Popliteal Vein feeds into the Femoral Vein.

SCIATIC NERVE and Branches (N508): Largest peripheral nerve in body.

Innervates the posterior thigh. Divides into two principle branches at the Popliteal Fossa usually, but may occur a foot proximal to it.

Common Peroneal Nerve, which divides into

Deep Peroneal Nerve -- Motor to medial leg

Superficial Peroneal Nerve -- Motor to lateral leg

Lateral Sural Cutaneous -- Cutaneous innervation to lateral leg.

Tibial Nerve (N509) -- Posterior leg

It may arise above, through, or below the Piriformis muscle in the hip.

FEMORAL NERVE and Branches:

Anterior Cutaneous Branches -- Anterior Cutaneous innervation of thigh

Saphenous Nerve -- Anteromedial innervation of leg

LUMBAR PLEXUS (N468): L2, L3, L4 primarily.

Lateral Femoral Cutaneous Nerve

Femoral Nerve

Obturator Nerve

SACRAL PLEXUS (N469): L4, L5, S1, S2, S3 primarily.

Superior and Inferior Gluteal Nerves

Sciatic Nerve

Tibial

Common Peroneal

Nerve to the Piriformis

MULTIPLE SPINAL LEVELS: Generally we should know that different movements of the same limb utilize different spinal levels.

Generally the anterior compartment has a slightly higher spinal level than the posterior compartment, in the lower limb.

DERMATOME PATTERN OF LOWER LIMB (N511):

We almost get a Barber-Pole Effect with the different spinal levels as you travel down the lower limb.

LUMBAR generally covers the anterior leg.

SACRAL generally covers the posterior leg.

CUTANEOUS INNERVATION OF THIGH and LEG:

Posterior Femoral Cutaneous Nerve innervates the posterior thigh.

It comes directly off the Sacral Plexus.

Branches of the Femoral innervate the anterior thigh.

Saphenous Nerve: Innervates the medial part of the leg and foot.

It comes off the Femoral Nerve.

It only travels with the Saphenous Vein in the Leg -- not in the thigh!! In the thigh, the Saphenous Nerve has a different path than the

corresponding vein.

It gives residual innervation to the foot. If you lose the Tibial Nerve (from the Sciatic), you won't lose all of your sensation in the foot -- because

of the Saphenous.

CLINICAL (N510B) -- Cutaneous innervation of the Deep Peroneal Nerve is assessed at the web of skin between the first and second toes. This is a common

way to assess lower-damage from an injury.

HERNIATED SPINAL DISKS: Pinching a nerve in the nerve-root of the spinal chord, due to an outward herniation of the nucleus pulposus in the spinal

column.