LE: Nerves and Blood Vessels

Question 1

• Arises from the lumbar plexus and enters the thigh through the obturator foramen.
  
  • Divides into anterior and posterior branches.

Answer 1

Obturator Nerve (L2-L4)

Question 2

Anterior branch of Obturator Nerve (L2-L4) innervates?

Answer 2

adductor longus,
adductor brevis,
gracilis,
pectineus muscles.

Question 3

Descends between the adductor longus and adductor brevis muscles

Answer 3

Anterior branch of Obturator Nerve (L2-L4)

Question 4

Descends between the adductor brevis and adductor magnus muscles.

Answer 4

Posterior branch of Obturator Nerve (L2-L4)

Question 5

Posterior branch of Obturator Nerve (L2-L4) innervates?

Answer 5

Obturator externus
Adductor brevis
Adductor magnus

Question 6

Arises from the lumbar plexus within the substance of the psoas major, emerges between the iliacus and psoas major muscles, and enters the thigh by passing deep to the inguinal ligament and lateral to the femoral sheath.

Answer 6

Femoral Nerve (L2-L4)

Question 7

Femoral nerve gives rise to __; ___ to the hip and knee joints; and __, including the anterior femoral cutaneous nerve and the saphenous nerve, which descends through the femoral triangle and accompanies the femoral vessels in the adductor canal.

Answer 7

muscular branches
articular branches
cutaneous branches

Question 8

It causes a weakness of adduction and a lateral swinging of the limb during walking because of the unopposed abductors

Answer 8

Damage to the obturator nerve

Question 9

It causes impaired flexion of the hip and impaired extension of the leg resulting from paralysis of the quadriceps femoris

Answer 9

Damage to the femoral nerve

Question 10

• Arises from the sacral plexus and enters the buttock through the greater sciatic foramen above the piriformis.
  
  • Passes between the gluteus medius and minimus muscles and divides into numerous branches.

Answer 10

Superior Gluteal Nerve (L4-S1)

Question 11

What does Superior Gluteal Nerve (L4-S1) innervate?

Answer 11

gluteus medius and minimus,
tensor fasciae latae,
hip joint

Question 12

It causes a characteristic motor loss, resulting in weakened abduction of the thigh by the gluteus medius, a disabling gluteus medius limp, and gluteal gait.

Answer 12

Injury to the superior gluteal nerve

Question 13

• Arises from the sacral plexus and enters the buttock through the greater sciatic foramen below the piriformis.
  
  • Divides into numerous branches.

Answer 13

Inferior Gluteal Nerve (L5-S2)

Question 14

What does Inferior Gluteal Nerve (L5-S2) innervate?

Answer 14

gluteus maximus

Question 15

• Arises from the sacral plexus and enters the buttock through the greater sciatic foramen below the piriformis.
  
  • Runs deep to the gluteus maximus and emerges from the inferior border of this muscle.
  • Descends on the posterior thigh.

Answer 15

Posterior Femoral Cutaneous Nerve (S1-S3)

Question 16

What does Posterior Femoral Cutaneous Nerve (S1-S3) innervate?

Answer 16

skin of the buttock, thigh, and calf, as well as scrotum or labium majus (BTC(SLM))

Question 17

Arises from the sacral plexus and is the largest nerve in the body.

Answer 17

Sciatic Nerve (L4-S3)

Question 18

Sciatic Nerve divides at the superior border of the popliteal fossa into the __, which runs through the fossa to disappear deep to the gastrocnemius, and the __, which runs along the medial border of the biceps femoris and superficial to the lateral head of the gastrocnemius.
• Enters the buttock through the greater sciatic foramen below the piriformis.
• Descends over the obturator internus gemelli and quadratus femoris muscles between the ischial tuberosity and the greater trochanter.
• Provides articular branches to the hip and knee joints.

Answer 18

Tibial nerve

Common peroneal nerve

Question 19

What does Sciatic nerve innervate by its tibial division, except for the short head of the biceps femoris, which is innervated by its common peroneal division?

Answer 19

Hamstring muscles

Question 20

It causes impaired extension at the hip and impaired flexion at the knee, loss of dorsiflexion and plantar flexion at the ankle, inversion and eversion of the foot, and peculiar gait because of increased flexion at the hip to lift the dropped foot off the ground.

Answer 20

Damage to the sciatic nerve

Question 21

○ Arises as the smaller terminal portion of the sciatic nerve at the apex of the popliteal fossa, descends through the fossa, and superficially crosses the lateral head of the gastrocnemius muscle.
○ Passes behind the head of the fibula, then winds laterally around the neck of the fibula, and pierces the peroneus longus, where it divides into the deep peroneal and superficial peroneal nerves.

Answer 21

Common Peroneal (Fibular) Nerve (L4-S2)

Question 22

Is vulnerable to injury as it winds around the neck of the fibula, where it also can be palpated.

Answer 22

Common Peroneal (Fibular) Nerve (L4-S2)

Question 23

Common Peroneal (Fibular) Nerve (L4-S2) gives rise to the __, which supplies the skin on the lateral part of the back of the leg, and the __ to the knee joint.

Answer 23

lateral sural cutaneous nerve

recurrent articular branch

Question 24

It is intermittent or continuous pain perceived as originating in an absent (amputated) limb.

Answer 24

Phantom limb pain

Question 25

It may occur as a result of frac ture of the head or neck of the fibula because it passes behind the head of the fibula and then winds laterally around the neck of the fibula. The nerve damage results in foot drop (loss of dorsiflexion) and loss of sensation on the dorsum of the foot and lateral aspect of the leg and causes paralysis of all muscles in the anterior and lateral compartments of the leg (dorsiflexor and evertor muscles of the foot).

Answer 25

Damage to the common peroneal (fibular) nerve

Question 26

Arises from the common peroneal (fibular) nerve in the substance of the peroneus longus on the lateral side of the neck of the fibula; thus, it is less vulnerable to injury than the common peroneal nerve.

Answer 26

Superficial Peroneal (Fibular) Nerve (See Cutaneous Nerves, Superficial Veins, and Lymphatics: I. H.)

Question 27

What does Superficial Peroneal (Fibular) Nerve innervate?

Answer 27

peroneus longus and brevis muscles

skin on the lateral side of the lower leg and the dorsum of the foot

Question 28

§ Arises from the common peroneal (fibular) nerve in the substance of the peroneus longus on the lateral side of the neck of the fibula (where it is vulnerable to injury but less vulnerable than the common peroneal nerve).
§ Enters the anterior compartment by passing through the extensor digitorum longus muscle.
§ Descends on the interosseous membrane between the extensor digitorum longus and the tibialis anterior and then between the extensor digitorum longus and the extensor hallucis longus muscles.

Answer 28

Deep Peroneal (Fibular) Nerve

Question 29

what does Deep Peroneal (Fibular) Nerve innervate?

Answer 29

anterior muscles of the leg and then divides into a:
lateral branch - supplies the extensor hallucis brevis and extensor digitorum brevis,
medial branch - accompanies the dorsalis pedis artery to supply the skin on the adjacent sides of the first and second toes

Question 30

It causes no foot drop but does cause loss of eversion of the foot.

Answer 30

Damage to the superficial peroneal (fibular) nerve

Question 31

It results in foot drop (loss of dorsiflexion) and hence a characteristic high-stepping gait.

Answer 31

Damage to the deep peroneal (fibular) nerve

Question 32

• Descends through the popliteal fossa and then lies on the popliteus muscle.
  
  • Terminates beneath the flexor retinaculum by dividing into the medial and lateral plantar nerves

Answer 32

Tibial Nerve (L4-S3)

Question 33

What does Tibial Nerve (L4-S3) give branches to?

Answer 33

three articular branches (which accompany the medial superior genicular, middle genicular, and medial inferior genicular arteries to the knee joint [MSg,Mg,MIg])
muscular branches (posterior muscles of the leg)
medial sural cutaneous nerve
medial calcaneal branch (skin of the heel and sole)
articular branches (ankle joint)

Question 34

It causes loss of plantar flexion of the foot and impaired inversion resulting from paralysis of the tibialis posterior and causes a difficulty in getting the heel off the ground and a shuffling of the gait. It results in a characteristic clawing of the toes and sensory loss on the sole of the foot, affecting posture and locomotion.

Answer 34

Damage to the tibial nerve

Question 35

○ Arises beneath the flexor retinaculum, deep to the posterior portion of the abductor hallucis muscle, as the larger terminal branch from the tibial nerve.
○ Passes distally between the abductor hallucis and flexor digitorum brevis muscles and innervates them.
○ Gives rise to common digital branches

Answer 35

Medial Plantar nerve

Question 36

What does the common digital branches of medial plantar nerve innervate?

Answer 36

divide into proper digital branches which supply the:
flexor hallucis brevis
first lumbrical
skin of the medial three and one-half toes.

Question 37

○ Is the smaller terminal branch of the tibial nerve.
○ Runs distally and laterally between the quadratus plantae and the flexor digitorum brevis, innervating the quadratus plantae and the abductor digiti minimi muscles.
○ Divides into a superficial branch and a deep branch

Answer 37

Lateral Plantar Nerve

Question 38

What does the superficial and deep branches of lateral plantar nerve innervate?

Answer 38

superficial branch - flexor digiti minimi brevis

deep branch - plantar and dorsal interossei, lateral three lumbricals, adductor hallucis

Question 39

• Arises from the internal iliac artery, passes between the lumbosacral trunk and the first sacral nerve, and enters the buttock through the greater sciatic foramen above the piriformis muscle.
  
  • Runs deep to the gluteus maximus muscle and divides into a superficial branch and a deep branch,
  • Anastomoses with the lateral and medial circumflex and inferior gluteal arteries.

Answer 39

Superior Gluteal Artery

Question 40

What does the superficial and deep branches of Superior Gluteal Artery supply?

Answer 40

superficial branch - gluteus maximus and anastomoses with the inferior gluteal and lateral sacral arteries
deep branch - gluteus medius and minimus muscles, tensor fasciae latae.

Question 41

• Arises from the internal iliac artery, usually passes between the first and second sacral nerves, and enters the buttock through the greater sciatic foramen below the piriformis.
  
  • Enters the deep surface of the gluteus maximus and descends on the medial side of the sciatic nerve, in company with the posterior femoral cutaneous nerve.
  • Enters the cruciate anastomosis and also anastomoses with the superior gluteal, internal pudendal, and obturator arteries.

Answer 41

Inferior Gluteal Artery

Question 42

What does inferior gluteal artery supply?

Answer 42

gluteus maximus,
lateral rotators of the hips,
hamstrings (upper part),
hip joint

Question 43

• Arises from the internal iliac artery in the pelvis and passes through the obturator foramen, where it divides into anterior and posterior branches.
  
  • May arise from the external iliac or inferior epigastric artery, which may pass toward the pelvic brim along the medial margin of the femoral ring.

Answer 43

Obturator Artery

Question 44

Descends in front of the adductor brevis muscle and gives rise to muscular branches.

Answer 44

Anterior branch of obturator artery

Question 45

Gives rise to the acetabular branch, which enters the hip joint through the acetabular notch, ramifies in the acetabular fossa, and sends an artery to the head of the femur, which is an important source of blood to the femoral head in children. It may or may not persist in adults, or it may be insufficient to sustain the viability of the femoral head; thus, ischemic necrosis gradually takes place.

Answer 45

Posterior branch of obturator artery

Question 46

It is defined as the vascular anastomoses between the obturator and external iliac systems. A vascular anastomosis between pubic branches of the obturator artery and of the external iliac (or inferior epigastric) artery is called the corona mortis because these vessels in the retropubic area are hard to distinguish and can be injured in groin or pubic surgery, leading to massive uncontrolled bleeding. Since a venous connection is more probable than an arterial one, surgeons dealing with inguinal and femoral hernias should avoid venous bleeding and need to be aware of these anastomoses and their proximity to the femoral ring. An aberrant obturator artery may arise from the external iliac or inferior epigastric artery and is vulnerable during surgical repair of a femoral hernia.

Answer 46

Corona mortis (crown of death)

Question 47

• Begins as the continuation of the external iliac artery distal to the inguinal ligament, descends through the femoral triangle, and enters the adductor canal.
  
  • Has a palpable pulsation, which may be felt just inferior to the midpoint of the inguinal ligament.
  • Is vulnerable to injury because of its relatively superficial position in the femoral triangle.

Answer 47

Femoral Artery

Question 48

1. Runs subcutaneously upward toward the umbilicus.
2. Runs laterally almost parallel with the inguinal ligament.
3. Emerges through the saphenous ring, runs medially over the spermatic cord (or the round ligament of the uterus), and sends inguinal branches and anterior scrotal (or labial) branches.
4. Passes medially across the pectineus and adductor longus and is distributed to the skin of the perineum, scrotum, or labium majus.

Answer 48

1. Superficial Epigastric Artery
2. Superficial Circumflex Iliac Artery
3. Superficial External Pudendal Artery
4. Deep External Pudendal Artery

Question 49

• Arises from the femoral artery within the femoral triangle.
  * Descends in front of the pectineus, adductor brevis, and adductor magnus muscles but behind the adductor longus muscle.
  * Gives rise to the medial and lateral femoral circumflex and muscular branches.
  * The first perforating artery sends an ascending branch, which joins the cruciate anastomosis of the buttock.

Answer 49

Profunda Femoris (Deep Femoral) Artery

Question 50

What does the four perforating arteries of Profunda Femoris (Deep Femoral) Artery supply?

Answer 50

adductor magnus

hamstring muscles

Question 51

• Arises from the femoral or profunda femoris artery in the femoral triangle.
  * Runs between the pectineus and iliopsoas muscles, continues between the obturator externus and adductor brevis muscles, and enters the gluteal region between the adductor magnus and quadratus femoris muscles.
  * Gives rise to muscular branches and an acetabular branch to the hip joint and then divides into an ascending branch, which anastomoses with branches of the superior and inferior gluteal arteries, and a transverse branch, which joins the cruciate anastomosis.

Answer 51

Medial Femoral Circumflex Artery

Question 52

It is clinically important because its branches run through the neck to reach the head, and it supplies most of the blood to the neck and head of the femur except for the small proximal part that receives blood from a branch of the obturator artery.

Answer 52

The medial femoral circumflex artery

Question 53

It is formed by an ascending branch of the first perforating artery, the inferior gluteal artery, and the transverse branches of the medial and lateral femoral circumflex arteries. The cruciate anastomosis bypasses an obstruction of the external iliac or femoral artery.

Answer 53

The cruciate anastomosis of the buttock

Question 54

• Arises from the femoral or profunda femoris artery and passes laterally deep to the sartorius and rectus femoris muscles.
  * Divides into three branches: an ascending branch, which forms a vascular circle with branches of the medial femoral circumflex artery around the femoral neck and also anastomoses with the superior gluteal artery; a transverse branch, which joins the cruciate anastomosis; and a descending branch, which anastomoses with the superior lateral genicular branch of the popliteal artery.

Answer 54

Lateral Femoral Circumflex Artery

Question 55

• Arises from the femoral artery in the adductor canal just before it passes through the adductor hiatus.

Answer 55

Descending Genicular artery

Question 56

Branches and its innervation of the descending genicular artery

Answer 56

articular branch (which enters the anastomosis around the knee) 
saphenous branch - superficial tissue and skin on the medial side of the knee.

Question 57

It is easily exposed and cannulated at the base of the femoral triangle just inferior to the midpoint of the inguinal ligament. The superficial position of the femoral artery in the femoral triangle makes it vulnerable to injury by laceration and gunshot wounds. When it is necessary to ligate the femoral artery, the cruciate anastomosis supplies blood to the thigh and leg.

Answer 57

femoral artery

Question 58

• Is a continuation of the femoral artery at the adductor hiatus and runs through the popliteal fossa.
  
  • Terminates at the lower border of the popliteus muscle by dividing into the anterior and posterior tibial arteries.
  • May be felt by gentle palpation in the depth of the popliteal fossa.
  • Is vulnerable to injury from fracture of the femur and dislocation of the knee joint.
  • Gives rise to five genicular arteries

Answer 58

Popliteal Artery

Question 59

Branches of Popliteal Artery:

1. passes deep to the biceps femoris tendon.
2. passes deep to the semimembranosus and semitendinosus muscles and enters the substance of the vastus medialis.
3. passes laterally above the head of the fibula and then deep to the fibular collateral ligament
4. passes medially along the upper border of the popliteus muscle, deep to the popliteus fascia.
5. pierces the oblique popliteal ligament and enters the knee joint.

Answer 59

1. Superior lateral genicular artery
2. Superior medial genicular artery
3. Inferior lateral genicular artery
4. Inferior medial genicular artery
5. Middle genicular artery

Question 60

• Arises from the popliteal artery at the lower border of the popliteus, between the tibia and the fibula.
  
  • Is accompanied by two venae comitantes and the tibial nerve on the posterior surface of the tibialis posterior muscle. Its pulsation is often palpable between the medial malleolus and the calcaneal tendon.
  • Gives rise to the peroneal (fibular) artery, which descends between the tibialis posterior and the flexor hallucis longus muscles and supplies the lateral muscles in the posterior compartment. The peroneal artery passes behind the lateral malleolus, gives rise to the posterior lateral malleolar branch, and ends in branches to the ankle and heel.
  • Gives rise also to the posterior medial malleolar, perforating, and muscular branches and terminates by dividing into the medial and lateral plantar arteries.

Answer 60

Posterior Tibial Artery

Question 61

• Is the smaller terminal branch of the posterior tibial artery.
  * Runs between the abductor hallucis and the flexor digitorum brevis muscles.
  * Gives rise to a superficial branch, which supplies the big toe, and a deep branch, which forms three superficial digital branches.

Answer 61

Medial Plantar Artery

Question 62

• Is the larger terminal branch of the posterior tibial artery.
  * Runs forward laterally in company with the lateral plantar nerve between the quadratus plantae and the flexor digitorum brevis muscles and then between the flexor digitorum brevis and the adductor digiti minimi muscles.
  * Forms the plantar arch by joining the deep plantar branch of the dorsalis pedis artery. The plantar arch gives rise to four plantar metatarsal arteries.

Answer 62

Lateral Plantar Artery

Question 63

Are the venae comitantes to the anterior and posterior tibial arteries.

Answer 63

Deep Veins of the Leg

Question 64

• Ascends through the popliteal fossa behind the popliteal artery.
  
  • Receives the small saphenous vein and those veins corresponding to the branches of the popliteal artery

Answer 64

Popliteal Vein

Question 65

• Accompanies the femoral artery as a continuation of the popliteal vein through the upper two thirds of the thigh.
  
  • Has valves, receives tributaries corresponding to branches of the femoral artery, and is joined by the great saphenous vein, which passes through the saphenous opening.

Answer 65

Femoral Vein