Lecture 9.3

Question 1

Where is the lumbar plexus located?

Answer 1

Within psoas major

Question 2

Where is the sacral plexus located?

Answer 2

Deep to piriformis

Question 3

What division of spinal nerves forms the lumbar plexus?

Answer 3

Ventral rami (L 1 - 4)

Question 4

What nerves run out of lateral border of psoas major?

Answer 4

Ilioinguinal, iliohypogastric, and femoral nerve

Question 5

What nerve runs onto anterior surface of psoas?

Answer 5

Genitofemoral nerve

Question 6

What nerve runs medially to psoas major?

Answer 6

Obturator nerve

Question 7

What does the genitofemoral nerve supple?

Answer 7

Genital genitofemoral nerve supplies the spermatic cord

Femoral genitofemoral nerve supplies skin over the femoral triangle

Question 8

Which nerve runs under the inguinal ligament and divides into many divisions right after?

Answer 8

femoral nerve

Question 9

Where does the lateral cutaneus nerve run after it leaves psoas?

Answer 9

through the inguinal ligament right under ASIS.

Question 10

What is the pneumonic to remember the nerves of the lumbar plexus?

Answer 10

I (twice) Get Laid On Fridays
I= Ilioinguinal + Iliohypogastric
G= Genitofemoral
L= Lateral Cutaneous Nerve
O= Obturator
F= femoral

Question 11

What are the branches of the sacral plexus?

Answer 11

Parietal (exits sciatic foramen into gluteal region)

Visceral (innervates pelvic viscera)

Question 12

Where does the femoral nerve split into all it’s braches?

Answer 12

In the femoral triangle right after the inguinal ligament

Question 13

What are the boundaries of the femoral triangle?

Answer 13

Superiorly: Inguinal ligament
Medially: adductor longus
Laterally:sartorius

Question 14

What muscles does the femoral nerve innervate?

Answer 14

Quads, sartorius, and pectineus

Question 15

What sensory branches does the femoral nerve form and what do they innervate?

Answer 15

anterior cutaneous branch; innervates anteromedial thigh
saphenous; innervates medial leg and foot up to the first MT/P joint
Also sends articular branches to hip and knee

Question 16

What are the contents of the femoral triangle?

Answer 16

femoral nerve, artery, and vein.

Femoral vein is contained within the femoral sheath which contains dead space for the vein to expand.

Question 17

What is a femoral hernia?

Answer 17

Occurs when abdominal contents fall into the femoral sheath.

Question 18

What muscle innervates articularis genus?

Answer 18

femoral nerve

Question 19

What nerve innervates the lateral part of the thigh?

Answer 19

Lateral cutaneus nerve

Question 20

What nerve innervates the gap that the femoral nerve leaves on the medial thigh?

Answer 20

obturator nerve

Question 21

What are the branches of the saphenous nerve at the medial leg called?

Answer 21

medial crural cutaneous branches of the saphenous nerve

Question 22

What spinal nerves form the femoral nerve?

Answer 22

L2, 3, 4; Posterior divisions of lumbar plexus

Question 23

What spinal nerves form the obturator nerve?

Answer 23

L2, 3, 4 Anterior divisions

Question 24

Where does the pectineus originate and insert and what are it’s functions?

Answer 24

Origin: pectineal line
Insertion: Pectineal line of the femur
Innervation: femoral nerve, with 20% of the population have a branch of the obturator nerve)

Question 25

What nerve innervates hamstrings? Be as specific as possible

Answer 25

Tibial portion of sciatic nerve for semitendinosus, semimembranosus, + long head of biceps femoris.
Fibular portion of sciatic nerve for short head of biceps femoris.

Question 26

What nerve is responsible for cutaneous innervation of posterior thigh?

Answer 26

Posterior cutaneous nerve

Question 27

What spinal nerves form the sciatic nerve?

Answer 27

L 4, 5, S 1->3 anterior and divisions

Question 28

What structure/s is/are vulnerable from posterior dislocation of hip joint?

Answer 28

Sciatic nerve

Question 29

Where does the tibial nerve travel after the popliteal fossa?

Answer 29

Posterior to tibialis posterior and anterior to soleus -> moves to foot behind the medial malleolus to form the plantar nerves

Question 30

What are the motor innervations of the tibial nerve?

Answer 30

Muscles of posterior leg and sole of the foot

Question 31

What is the name of the foot’s nerve divisions that innervate the sole of the foot

Answer 31

Medial calcaneal nerve
Medial plantar nerve
Lateral plantar nerve

Question 32

What are the sensory divisions of the tibial nerve and what to they innervate?

Answer 32

The sural nerve (innervates posterolateral leg and lateral foot)
Medial calcaneal, medial plantar, lateral plantar (innervate the sole of the foot)

Question 33

What are the structures behind the medial malleolus?

Answer 33

Tom Dick And Very Naughty Harry

Tibialis Posterior, FDL, posterior tibial Artery, great saphenous Vein, tibial Nerve, and FHL

Question 34

What spinal nerves form the Common Fibular Nerve?

Answer 34

L4,5 S1,2

Question 35

Where in the popliteal fossa does the common fibular nerve pass?

Answer 35

medial to biceps tendon and then superficial to gastrocnemeus lateral head.

Question 36

Where does the common fibular nerve split into its terminal branches?

Answer 36

Right after passing the head of the fibula. This occurs near the fibularis longus.

Question 37

The common fibular nerve gives a communicating branch to which nerve?

Answer 37

lateral sural nerve.

Question 38

What does the deep fibular nerve innervate?

Answer 38

the anterior compartment muscles

skin of the big toe cleft.

Question 39

What does the superficial fibular nerve innervate?

Answer 39

lateral compartment muscles

skin of anterolateral leg and dorsum of the foot.

Question 40

What does the sural nerve innervate?

Answer 40

the posterolateral leg skin

Question 41

Where in the leg does the deep fibular nerve run?

Answer 41

Near the interosseus membrane and then passes through the extensor retinaculum to supply the hallucis cleft

Question 42

What nerve is the sural nerve a branch of?

Answer 42

tibial nerve

Question 43

What is significant to remember about Lateral Cutaneous Nerve and Posterior Cutaneous Nerve?

Answer 43

They emerge directly from the plexus and innervate the skin.