Department of Human Anatomy KNMU

THE NERVES AND VESSELSOF THE PELVIC GIRDLE AND

FREE LOWER LIMB

Slide-lecture for students of the 6 Faculty of Medicine

Lector – associate professor Zharova Nataliya

2015

PLAN:

• LUMBAR, SACRAL, COCCYGEAL SPINAL NERVES• THE LUMBAR PLEXUS• THE SACRAL PLEXUS• THE COCCYGEAL PLEXUS• ARTERIES OF THE PELVIC GIRDLE• ARTERIES OF FREE LOWER LIMB• VEINS OF THE PELVIC GIRDLE• VEINS OF FREE LOWER LIMB

LUMBAR, SACRAL, COCCYGEAL SPINAL NERVES • Each spinal nerve arise in the area of the intervertebral foramen as

the result of merging of the anterior and posterior roots of the spinal cord. The principal trunk of spinal nerve escapes from the intervertebral foramen and gives rise to 4 branches:

– anterior, posterior, meningeal, communicating. Lumbar spinal nerves: • anterior branches form lumbal plexus, • posterior branches – medial – supply m. multifidus, m.interspinalis; – lateral – supply m. sacrospinalis, mm. intertransversarii;• meningeal branches – returns to the vertebral canal to supply the

spinal meninges;• communicating branches – pass to the ganglia of sympathetic

trunk.

THE LUMBAR PLEXUS, PLEXUS LUMBALIS (Тh12 — L4)

• The lumbar plexus is formed from the anterior branches of three upper lumbar spinal nerves and a part of the anterior branches 12-th thoracic spinal nerve and anterior branches 4-th lumbar spinal nerve.

• It resides within the lumbar region in between the transverse processes of related lumbar vertebrae posterior and in depth of the psoas major.

• Inferiorly, the lumbar plexus communicates with the sacral plexus. Most of the rami arise from behind the lateral border of the psoas major; one ramus traverses the muscle (the genitofemoral nerve) and one branch arises from behind the medial border of the muscle (the obturator nerve).

The branches of the lumbar plexus

1. muscular branches2. iliohypogastric

nerve3. ilioinguinal nerve4. genitofemoral

nerve5. lateral cutaneous

nerve 6. of thigh7. obturator nerve8. femoral nerve

The branches of the lumbar plexus

1. the muscular branches supply both psoas muscles, the quadratus lumborum, the lumbar intertransversarii

2. the iliohypogastric nerve supplies all abdominal muscles, the skin of hypogastrium and the skin of the gluteal region (its superolateral portion)

3. the ilioinguinal nerve terminates within the skin of the pubic region and the scrotum (the labia majora) and gives some branches to both oblique muscles and the transversus abdominis

4. the genitofemoral nerve The genital branch enters the inguinal canal where runs posterior to the spermatic cord (the round ligament of uterus). It supplies the cremaster, the dartos muscle, the skin of scrotum (the labia majora) and the skin of superomedial surface of thigh. The femoral branch passes through the vascular space below the inguinal ligament to a small upper portion of the femoral triangle

5. the lateral cutaneous nerve of thigh

Skin of the lateral surface of thigh

6. the obturator nerve It arises from behind of the medial border of the psoas major and runs along the lesser pelvis wall to enter the obturator canal that leads the nerve to the thigh. Within the thigh, the nerve resides in between the adductors and splits into the anterior and the posterior branches. The nerve supplies the neighboring adductors, the pectineus, the gracilis, the obturator externus and the joint capsule of the hip joint.

7. the femoral nerve Is the greatest branch of the lumbar plexusTopography of the femoral nerve

The nerve arises from behind the lateral border of the psoas major and proceeds to the thigh region via the muscular space. Within the thigh region, the nerve resides in the femoral triangle laterally from the femoral artery.

The branches of the femoral nerve

1. the muscular branches

supply the quadriceps femoris and the pectineus

2. the anterior cutaneous branches

penetrate the fascia and terminate in the skin of anteromedial area of thigh

3. the saphenous nerve

It enters the adductor canal together with the femoral artery and the femoral vein. In the thigh are, the nerve gives no branches; the first branch to arise is the infrapatellar branch.

It supplies the skin of the medial surface of knee joint and of the patellar area. Apart from this, the nerve supplies the skin of the medial aspect of shin and foot up to the great toe.

Clinical applications

Injury to the femoral nerve leads to paralysis of the quadriceps femoris and thus to inability to extend the knee joint. When walking, the victim is unable to with hold extension of leg and the foot strikes against the ground with its entire surface. Injury to the obturator nerve affects abduction of thigh and crossing of legs.

THE SACRAL PLEXUSTopography of the sacral plexus

• The sacral plexus is the greatest of all nervous plexuses in the human body. It arises from merged upper four sacral nerves, the fifth lumbar nerve and a part of the fourth lumbar nerve, the fourth and the fifth lumbar nerves merge into a single lumbosacral trunk, that descends to the lesser pelvis cavity and joins the sacral nerves. The lowest portion of the sacral plexus formed of the fifth sacral nerves and the coccygeal nerve is the coccygeal plexus.

• The sacral plexus appears as a thick triangular plate adherent to the pelvic wall (namely to the piriformis). The branches given quit the lesser pelvis via the suprapiriform and the infrapiriform foramina as the short and the long branches.

• The greatest nerve of the plexus is the sciatic nerve.

The short branches The long branches

1.the muscular branches

supply the piriformis, the obturator internus, both gemelli and the quadratus femoris

1.The posterior cutaneous nerve of thigh

runs via the infrapiriform foramen to skin of the posterior surface of thigh

2.the superior gluteal nerve

runs via the suprapiriform foramen to the gluteus medius, the gluteus minimus and the tensor fasciae latae

2.The sciatic nerve

The principal trunk of the nerve gives off the muscular branches to the posterior group of muscles of thigh (to the semitendinosus, the semimembranosus and the long head of biceps femoris).

3.the inferior gluteal nerve

runs via the infrapiriform foramen to the gluteus maximus and the joint capsule of the hip joint

4.the pudendal nerve

The nerve supplies the external anal sphincter and other perineal muscles together with related skin

Topography of the sciatic nerve

The nerve quits the lesser pelvis cavity via the infrapiriform foramen and runs on below the gluteus maximus. Somewhat below the escape point, the nerve enters in between the ischial tuberosity and the greater trochanter, proceeds onto the quadratus lumborum surface and finally becomes evident within the thigh region, arising from under the lower border of the gluteus maximus. Within the thigh region, the nerve runs deep in between the neighboring muscles. Clinical applications. Chilling of the area related to the nerve results in neuritis of the sciatic nerve (sciatica). The state features painful sensation within the ischial area and the posterior portion of the thigh. The condition may even feature sensory and motor disorders.

On reaching the upper angle of the popliteal fossa, the nerve splits into the terminal branches:

- the tibial nerve and - the common fibular nerve.

• Topography of the tibial nerveThe tibial nerve arises directly from the sciatic nerve and runs vertically down to the popliteal fossa. Within the fossa, the nerve occupies the most superficial position with respect to neighboring popliteal artery and popliteal vein. From the popliteal fossa, the nerve proceeds to the cruropopliteal canal. On escaping from the canal, the nerve loops around the medial malleolus and gives some branches to the ankle joint.

Below the flexor retinaculum, the tibial nerve gives off its terminal branches — the medial and the lateral plantar nerves.1.muscular

branchessupply all posterior muscles of shin (the igastrocnemius, the soleus, the plantaris, the popliteus etc.)

2.medial sural cutaneous nerve

It runs laterally and merges with the lateral sural cutaneous nerve (from the common fibular nerve) to form the sural nerve

3.sural nerve supplies skin of the posterolateral surface of shin and the lateral aspect of foot up to the little toe

4.medial plantar nerve

- common plantar digital nerves

- proper plantar digital nerves.

They supply the medial aspect of foot, the toes 1 through 3 and a medial half of the fourth toe. The muscular branches of the nerve supply the flexor digitorum brevis, all muscles of great toe and two lumbricals (1 and 2).

5.lateral plantar nerve-superficial branch-deep branch

They supply the lateral aspect of foot, the fifth toe and a lateral half of the fourth toe. The deep branch supplies all interossei, two lumbricals, the adductor hallucis, and the lateral head of flexor hallucis brevis.

• Clinical applications • Injury to the tibial nerve

results in paralysis of pertaining flexors. The foot thus becomes permanently extended and the toes may resemble the claws.

Topography of the common fibular nerve

• From the arise point, the nerve runs laterally to reach the head of fibula. At that point, the nerve enters between the heads of the fibularis longus and slits into the superficial and the deep fibular nerves.

• Yet within the popliteal fossa, the nerve gives the lateral sural cutaneous nerve that merges with the medial sural cutaneous nerve to form the sural nerve. Very often, the nerves merge at the lower third of shin or even run separately.

• Clinical applications• Injury to the fibular nerve leads to

inability to extend and to pronate the foot. The foot in this case hangs down and laterally.

The branches of the common fibular nerve

1.The superficial fibular nerve-medial dorsal cutaneous nerve-lateral dorsal cutaneous nerve

Both nerves supply the respective areas of the dorsal surface of foot. It also leaves some muscular branches to the fibulares muscles while running within the musculoperoneal canal.

2.The deep fibular nerve

Within the shin, the nerve supplies the anterior group of muscles (the tibialis anterior, the extensor digitorum longus and the extensor hallucis longus) and the joint capsule of ankle joint.

THE COCCYGEAL PLEXUS

• The coccygeal plexus is composed of the anterior branches of the fourth and fifth sacral and the cocygeal nerves. It gives rise to the thin anococcygeal nerves which join with the posterior branch of the coccygeal nerve and innervate the skin at the top of the coccyx and of the anus.

THE COMMON ILIAC ARTERY The abdominal aorta diverges at sharp angle (60-70°) to give rise to the common iliac arteries. Each artery descends laterally to reach the respective sacroiliac joint. There, the arteries give rise to the external and internal iliac arteries.

THE INTERNAL ILIAC ARTERY

Relations of the internal iliac artery

• The internal iliac artery arises from the common iliac artery and descends to the lesser pelvis. The artery is the principal nourishing vessel for this region.

• The artery gives off numerous branches, both

• parietal and visceral.

The parietal The visceral branches of the internal iliac artery:

1. the iliolumbar artery

2. the lateral sacral arteries

3. the obturator artery:

- acetabular branch,

- pubic branch.

4. the superior gluteal artery

5. the inferior gluteal artery

1. the umbilical artery a)an opened part - the superior vesical arteriesb)an obliterated part2. the inferior vesical artery - In males, the artery gives branches to the seminal glands and prostate; in females — to the vagina;3. the a. ductus deferentis (in male) the uterine artery (in female)- vaginal branch,- ascending branch,- ovarian branches,- tubal branches; 4. the middle rectal artery. The middle rectal artery supplies the inferior part of the rectum, anastomosing with the superior and inferior rectal arteries, supplying the seminal glands and prostate (or the vagina); 5.the internal pudendal artery

1) the inferior rectal artery, passes to the anus;2) the artery of bulb of penis supplies the respective bulb of penis;3) the dorsal artery of penis (clitoris) passes below skin (to the penis or

clitoris respectively);4) the deep artery of penis (clitoris) take the same route as the latter

arteries yet deeper;5) the perineal artery supplies the perineal muscles and skin;6) the posterior labial branches and the posterior scrotal branches supply

the spective external genitals.

The external iliac artery descends on the medial aspect of the psoas major and quits the lesser pelvis via the vascular space. Within the femoral triangle, the artery becomes continuous with the femoral artery. The external iliac artery gives the branches as follows:- the inferior epigastric artery arises from the main trunk above the inguinal ligament and then ascends medially along the internal surface of the anterior abdominal wall occupying the lateral umbilical ligament. Then the artery enters the rectus sheath and ascends along its posterior surface to reach the umbilical ring. Here it anastomoses with the superior hypogastric artery.In the beginning, the artery gives off - the pubic branch anastomoses with the same branch of the obturator artery; -a. cremasterica (in male) or a. ligamentum teres uteri (in female);- the deep circumflex iliac artery runs laterally along the inguinal ligament and the iliac crest. It supplies the iliacus and the muscles of abdominal wall.

THE EXTERNAL ILIAC ARTERY

THE FEMORAL ARTERY, ARTERIA FEMORALIS• The femoral artery arises directly

from the external iliac artery. The arteries are delimited by the inferior border of the inguinal ligament.

• On leaving the vascular space, the artery appears within the femoral triangle together with the femoral nerve (found laterally) and the femoral vein (found medially).

• Pulsation of the artery is palpable below the inguinal ligament in the area related to the vascular space. Within the femoral triangle, the artery runs along the iliopectineal groove and then along the femoral groove. From the femoral groove, the artery proceeds to the adductor canal, which leads it to the popliteal fossa. Here it becomes continuous with the popliteal artery.

• Clinical applications. The deep artery of thigh is of great importance for collateral circulation. Intrinsic anastomoses and intersystem anastomoses (with the internal iliac and popliteal arteries) provide good conditions for collateral circulation, which is vital in occlusions of femoral artery.

The branches of the femoral artery:1. The superficial epigastric artery arises

near the very beginning of the femoral artery and passes in front of the inguinal ligament under the skin to the region of the navel.

2. The superficial circumflex artery runs along the inguinal ligament to the skin in the region of the superior anterior iliac spine.

3. The external pudendal arteries usually two in number, branch out in the region of the hiatus saphenus and lead medially to the skin of the external genital organs and lower surface of the abdomen.

4. The descending artery of the knee branches off from the femoral artery on its way in the adductor canal and, exiting through the anterior wall of this canal with n. saphenus, supplies m. vastus medialis with blood and participates in the formation of the arterial network of the knee joint.

5. The deep femoral artery is the main vessel through which the thigh is supplied with blood.

The branches of the deep femoral artery: 1) a. circumflexa femoris medialis passes

medially and upward and gives off the branches to the m. pectineus, to the adductor muscles, to the hip joint, to m. iliopsoas, m. obturatorius externus, m. piriformis, m. quadriceps femoris.

2) a. circumflexa femoris lateralis passes laterally under m. rectus femoris and gives off the branches to m.quadriceps, m. sartorius and to the knee joint.

3) aa. perforantes (three in number) branch off the posterior surface of the deep femoral artery and supply posterior muscles of the thigh.

Clinical applications. The deep artery of thigh is of great importance for collateral circulation. Intrinsic anastomoses and intersystem anastomoses (with the internal iliac and popliteal arteries) provide good conditions for collateral circulation, which is vital in occlusions of femoral artery.

THE POPLITEAL ARTERY, ARTERIA POPLITEA

The popliteal artery is a direct continuation of the femoral artery. It occupies the popliteal fossa together with the vein of the same name (it runs laterally and posteriorly). Upon reaching the leg region, the artery enters the cruropopliteal canal and gives off its two terminal branches — the anterior and posterior tibial arteries.

The popliteal artery gives off five genicular arteries.

The popliteal artery gives off five genicular arteries:1. the superior (medial and lateral) genicular arteries arise above the femoral epicondyles. Each artery rounds the respective epicondyle and passes to the anterior surface of knee joint. Their branches form the genicular anastomosis;2. the middle genicular artery penetrates the posterior wall of the joint capsule of knee joint and terminates within the cruciform ligaments;3. the inferior (medial and lateral) genicular arteries arise below the femoral epicondyles. Each artery rounds the respective epicondyle and passes to the anterior surface of knee joint.

The genicular arteries supply the knee joint and neighboring muscles. They form a wide anastomosis around the knee joint — the genicular anastomosis.

THE ANTERIOR TIBIAL ARTERY Relations of the anterior tibial artery• The anterior tibial artery arises from the

popliteal artery within the cruropopliteal canal. It quits the canal via the anterior outlet (the opening in the interosseous membrane) and descends to the foot together with the deep fibular nerve. Upon reaching the ankle joint, the artery comes out from under the extensors tendons. Then the artery proceeds to the dorsal surface of foot to become continuous with the dorsal artery of foot.

The branches of the anterior tibial artery:• the posterior tibial recurrent artery becomes

evident on the posterior surface of leg; it ascends to join the genicular anastomosis;

• the anterior tibial recurrent artery arises opposite to the latter artery. It also joins the genicular anastomosis;

• the anterior (medial and lateral) malleolar arteries descend to the respective ankles. They participate in formation of the medial and lateral malleolar networks.

• muscular branches supply the anterior muscles of the leg.

THE DORSAL ARTERY OF FOOTRelations of the dorsal artery of footThe dorsal artery of foot is a direct continuation of the anterior tibial artery. It runs between the tendons of the extensor hallucis longus and the extensor digitorum longus.

The branches of the dorsal artery of foot:1. the lateral and 2. medial tarsal arteries run to the respective aspects of foot;3. the arcuate artery arises at the bases of metatarsals and runs laterally to anastomose with the lateral tarsal artery. The arch formed gives off the dorsal metatarsal arteries (2 through 5), which split into the dorsal digital arteries; the first dorsal metatarsal artery arises directly from the dorsal artery of foot. It gives off three dorsal digital arteries to both aspects of the great toe and to the medial aspect of the second toe;4. the deep plantar artery is the 2nd terminal branch of the dorsal artery of foot; there it anastomoses with the lateral plantar artery to form the deep plantar arch.

THE POSTERIOR TIBIAL ARTERYRelations of the posterior tibial arteryThe larger posterior tibial artery arises immediately

from the popliteal artery. The artery occupies the cruropopliteal canal

together with the tibial nerve. Within the canal, the artery runs along the deep muscles of leg anterior to the soleus. The artery quits the canal and passes medially from the calcaneal tendon immediately below the skin and fascia. Here, one can palpate pulsation of the artery.

The artery then rounds the medial malleolus, passes under the flexor retinaculum and eventually appears on the plantar surface of foot.

There it gives the lateral and medial plantar arteries.

The branches of posterior tibial artery:• muscular branches supply the posterior

muscles of the leg• medial malleolar branches• lateral malleolar branches• calcaneal branch• fibular artery• perforating branch

THE PLANTAR ARTERIESThe posterior tibial artery gives rise to the lateral and medial plantar arteries.

• The lateral plantar artery - it runs laterally to reach the lateral plantar groove. On reaching the 5th metatarsal bone, the artery declines medially and anastomoses with the deep plantar artery to form the deep plantar arch. The arch gives off four plantar metatarsal arteries which anastomose with the dorsal arteries by means of the perforating branches. The plantar metatarsal arteries become continuous with the common plantar digital arteries which in turn split into the plantar digital arteries proper. The latter arteries run along the aspects of toes.

•The medial plantar artery is smaller than the lateral; it runs along the medial plantar groove and reaches the base of great toe to anastomose with the lateral plantar artery. The plantar arch thus features anastomoses related to both vertical and horizontal planes.

• Clinical applications The arteries of lower limb are often affected by atherosclerosis and obliterating endarteritis, which feature pathological growth of connective tissue in the inner layer and lipid infiltration of vascular wall. The pathologies result in occlusion of the vessel affected. Collateral circulation may compensate slow progressing occlusion of the distal arteries yet occlusion of min trunks results in severe ischemia and even gangrene. Gangrene requires amputation of the limb. Treatment of the state nowadays includes various reconstructive and plastic surgeries.

THE VEINS OF LOWER LIMB

• The veins of the lower limb are subdivided into the superficial and deep. The double deep veins accompany the arteries.

• The superficial veins run below the skin and outside the proper fascia. The superficial veins give rise to the great and small saphenous veins. They arise from the dorsal and plantar venous networks of foot.

• The great saphenous vein, arises from the medial portion of the dorsal venous network of foot and ascend along the medial aspect of the leg and thigh . In the upper third of thigh, the vein runs along its anterior surface to reach the saphenous opening.

• On passing the saphenous opening, the vein joins the femoral vein. On the way to destination point, the vein receives numerous tributaries that anastomose with each other and with the tributaries of small saphenous vein and deep veins of lower limb.

The small saphenous vein, arises at the lateral aspect of foot. The vein rounds the lateral malleolus and ascends along the posterior surface of leg in between the heads of the gastrocnemius muscle. At the popliteal fossa, the muscle pierces the fascia and joins the popliteal vein. The small saphenous vein receives numerous tributaries that anastomose with the tributaries of the great saphenous vein and with the deep veins of thigh.

The deep veins accompany the pertaining arteries

(two veins accompany one artery):

• two anterior tibial veins,• two posterior tibial veins, • the anterior and • posterior tibial veins, • popliteal vein, • the femoral vein – resides

within the femoral triangle medially from the femoral artery. Upon passing through the vascular space, it becomes continuous with the external iliac vein. The greatest tributary of the femoral vein is the deep vein of thigh, vena profunda femoris.

• The deep veins anastomose

with each other and with the superficial veins. Both superficial and deep veins have numerous valves.

Blood is continuously shunted from the superficial veins in the subcutaneous tissue to deep veins via the perforating veins that penetrate the deep fascia. Vein grafts obtained by surgically harvesting parts of the great saphenous vein are used to bypass obstructions in blood vessels (e.g., an occlusion of a coronary artery or its branches). When part of the vein is used as a bypass, it is reversed so that the valves do not obstruct blood flow. Because there are so many anastomosing leg veins, removal of the great saphenous vein rarely affects circulation seriously, provided the deep veins are intact.

Muscular compression of deep veins assists return of blood to the heart against gravity.

Varicose veins form when either the deep fascia or the valves of the perforating veins are incompetent. This allows the muscular compression that normally propels blood toward the heart to push blood from the deep to superficial veins. Consequently superficial veins become enlarges and tortuous.

THE ENDTHANK FOR YOUR ATTENTION