Lower extremity blocks (new)

Question 1

Match each nerve with its corresponding nerve roots:
femoral
lateral femoral cutaneous
posterior femoral cutaneous
sciatic
L2-L4
L2-L3
S1-S3
L4-S3

Answer 1

Femoral: L2-L4
Lateral Femoral cutaneous: L2-L3
Posterior femoral cutaneous: S1-S3
Sciatic: L4-S3

Question 2

What plexuses innervate the lower extremities?

Answer 2

Lumbar plexus: L1-L4 (T12 contribution in ~50% of the population
sacral plexus: L4-S4

Question 3

The lumbar plexus gives rise to 6 nerves:

Answer 3

iliohypogastric nerve
ilioinguinal nerve
genitofemoral nerve
lateral femoral cutaneous nerve
obturator nerve
femoral nerve (largest branch)

Question 4

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

Answer 4

I Invariably Get Lazy on Fridays

Question 5

The sacral plexus gives rise to the following 5 major nerves:

Answer 5

superior gluteal nerve
inferior gluteal nerve
posterior cutaneous nerve
pudendal nerve
sciatic nerve

Question 6

What is the pneumonic to remember the sacral plexus?

Answer 6

SIPPS

Question 7

The foot and ankle are innervated by the following 5 nerves:

Answer 7

saphenous nerve
sural nerve
superficial peroneal nerve
deep peroneal nerve
posterior tibial nerve

Question 8

The obturator nerve originates from

Answer 8

L2-L4

Question 9

The lateral femoral cutaneous nerve originates from

Answer 9

L2-L3

Question 10

The femoral nerve originates from

Answer 10

L2-L4

Question 11

The iliohypogastric nerve originates from

Answer 11

L1

Question 12

The ilioinguinal nerve originates from

Answer 12

L1

Question 13

The genitofemoral nerve originates from

Answer 13

L1-L2

Question 14

The pudendal nerve originates from

Answer 14

S2-S4

Question 15

The lumbar plexus forms within the ____________ and passes in front of the

Answer 15

psoas muscle and; quadratus lumborum muscle

Question 16

The lateral femoral cutaneous nerve forms at the

Answer 16

midpoint of the psoas muscle

Question 17

The femoral nerve forms near the

Answer 17

middle and lower third of the psoas muscle

Question 18

The femoral nerve divides into

Answer 18

anterior and posterior branches- posterior: saphenous nerve which courses through the adductor canal

Question 19

The obturator nerve forms near the

Answer 19

medial border of the psoas muscle at the level of the sacroiliac joint

Question 20

This nerve is often injury in patients undergoing extensive pelvic surgery:

Answer 20

obturator nerve

Question 21

The sacral plexus forms

Answer 21

anterior to the psoas major

Question 22

The sacral plexus arises from

Answer 22

L4-S3

Question 23

The largest nerve in the body is the

Answer 23

sciatic nerve

Question 24

The sciatic nerve arises from

Answer 24

L4-S3

Question 25

The sciatic nerve divides into

Answer 25

the tibial nerve & common peroneal nerve

Question 26

The tibial nerve gives rises to

Answer 26

the terminal branch: posterior tibial nerve

Question 27

The common peroneal nerve gives rise to

Answer 27

3 terminal branches: deep peroneal nerve, superficial peroneal nerve, and sural nerve

Question 28

The coccygeal plexus encompasses

Answer 28

S4-Co

Question 29

The primary nerves of the coccygeal plexus include

Answer 29

pudendal
inferior anal
perineal

Question 30

The lumbar plexus provides sensory and motor innervation to the

Answer 30

lower abdominal wall
anteriomedial thigh
knee

Question 31

The sacral plexus provides sensory and motor innervation to the

Answer 31

gluteal region
posterior thigh
lower leg
& foot

Question 32

What nerve would assess hip flexion?

Answer 32

femoral nerve

Question 33

What nerve would assess hip extension?

Answer 33

sciatic nerve

Question 34

What nerve assesses knee flexion?

Answer 34

sciatic nerve

Question 35

What nerve assess knee extension?

Answer 35

femoral nerve

Question 36

What nerve is responsible for plantar flexion?

Answer 36

tibial nerve

Question 37

What nerve is responsible for dorsiflexion?

Answer 37

peroneal nerve

Question 38

What nerve is responsible for eversion?

Answer 38

superficial peroneal nerve

Question 39

What nerve is responsible for inversion?

Answer 39

deep peroneal nerve

Question 40

Peripheral nerves are either

Answer 40

pure sensory or combined sensory-motor

Question 41

Sensory only nerves include

Answer 41

lateral femoral cutaneous
saphenous
sural

Question 42

The sensory region of the pudendal nerve is the

Answer 42

perineum
anal canal + external sphincter

Question 43

The sensory region of the posterior tibial nerve is the

Answer 43

plantar surface of the foot

Question 44

The sensory region of the superficial peroneal nerve is the

Answer 44

dorsal surface of the foot

Question 45

The sensory region of the deep peroneal nerve is the

Answer 45

web space between big toe and 2nd toe

Question 46

The sensory region of the sural nerve is the

Answer 46

lateral aspect of the foot

Question 47

Describe how to assess motor function of the femoral nerve

Answer 47

Hip–> flexion + rotation (lateral)
knee–> extension + flexion (minor contribution from sartorius)

Question 48

Describe how to assess motor function of the obturator nerve.

Answer 48

Hip–> ADDuction + flexion+ extension

Question 49

Describe how to assess motor function of the pudendal nerve.

Answer 49

Anal sphincter tone

Question 50

Describe how to assess motor function of the sciatic nerve.

Answer 50

Hip–> extension
knee–> flexion

Question 51

Describe how to assess motor function of the tibial nerve.

Answer 51

Toe–> ABduction+ extension+ flexion
ankle–> plantar flexion

Question 52

Describe how to assess motor function of the superficial peroneal nerve.

Answer 52

Ankle–> eversion

Question 53

Describe how to assess motor function of the deep peroneal nerve.

Answer 53

ankle–> inversion + dorsiflexion