Nervouse System Of Lower Limb

Question 1

What is the neurological supply to the lower limb made up of?

Answer 1

Spinal nerves emanating from the vertebral column

Question 2

At what vertebral level do the spinal nerves supplying the lower limb exit the vertebral column?

Answer 2

4th lumbar vertebra (L4)

Question 3

What is the name of the group of nerves that supply the lower limb?

Answer 3

Lumbo-sacral plexus

Question 4

Where does the lumbo-sacral plexus lie in relation to the vertebral column?

Answer 4

Anterior-lateral to the vertebral column, within the bony pelvis

Question 5

What do spinal nerves connect the central nervous system to?

Answer 5

Effector organs (receptors, muscles, glands)

Question 6

How do spinal nerves emerge from the vertebral column?

Answer 6

Via the intervertebral foramina between adjoining vertebrae

Question 7

At what level does the spinal cord itself end?

Answer 7

Near the level of L2

Question 8

What descends to reach their respective foramina before leaving the vertebral column?

Answer 8

Nerves of the lower lumbar, sacral, and coccygeal vertebrae

Question 9

What is the group of nerves that descends from the lower lumbar and sacral levels called?

Answer 9

Cauda equina

Question 10

What are the two points where a spinal nerve arises from the spinal cord?

Answer 10

A posterior (dorsal) root and an anterior (ventral) root

These roots unite to form a spinal nerve.

Question 11

What type of axons does the posterior root of the spinal nerve contain?

Answer 11

Sensory axons

These axons are responsible for touch and sensation.

Question 12

What type of axons does the anterior root of the spinal nerve contain?

Answer 12

Motor axons

These axons are involved in the activation of muscles.

Question 13

What type of nerves do spinal nerves originate as?

Answer 13

Mixed nerves

This is because they contain both sensory and motor axons.

Question 14

What are the branches of the spinal nerve called?

Answer 14

Rami

Shortly after leaving the intervertebral foramen, the spinal nerve separates into these branches.

Question 15

What does the ventral ramus supply?

Answer 15

Muscles and structures of upper and lower limbs, plus lateral and ventral surfaces of the trunk

The ventral ramus further divides into anterior and posterior divisions.

Question 16

What is the lumbar plexus made up of?

Answer 16

The ventral rami of L1-L4

This plexus supplies various nerves to the lower body.

Question 17

What does the ilioinguinal nerve (L1) supply?

Answer 17

Skin of superior medial thigh

This is one of the nerves originating from the lumbar plexus.

Question 18

What does the genitofemoral nerve (L1-L2) supply?

Answer 18

Skin over middle anterior thigh

Question 19

What does the lateral femoral cutaneous nerve supply?

Answer 19

Skin over lateral, anterior, and posterior thigh

Question 20

What is the function of the femoral nerve?

Answer 20

Flexors of thigh, extensors of leg, skin over anterior and medial thigh, medial side of leg and foot

Question 21

What does the obturator nerve supply?

Answer 21

Adductor muscle group and skin over medial aspect of thigh

Question 22

What is the sacral plexus made up of?

Answer 22

Ventral rami of L4-L5, S1-S4

The sacral plexus is a network of nerves in the lower back that supplies the pelvis and lower limbs.

Question 23

What nerves contribute to the superior gluteal nerve?

Answer 23

L4-L5, S1

The superior gluteal nerve innervates the gluteus medius, gluteus minimus, and tensor fascia latae.

Question 24

What is the function of the inferior gluteal nerve?

Answer 24

Innervates gluteus maximus

The inferior gluteal nerve is made up of fibers from L5, S1-S2.

Question 25

Which nerve is responsible for the sensation of the skin over the superior posterior thigh and superior calf?

Answer 25

Posterior femoral cutaneous nerve ## Footnote This nerve originates from S1-S3.

Question 26

What two components make up the sciatic nerve?

Answer 26

Tibial and common peroneal nerves ## Footnote The sciatic nerve is formed from L4-L5, S1-S3.

Question 27

What muscles does the tibial nerve innervate?

Answer 27

Gastrocnemius, plantaris, soles, popliteus, tibialis posterior, FDL, FHL ## Footnote The tibial nerve arises from L4-L5, S1-S3.

Question 28

What are the muscles innervated by the medial plantar nerve?

Answer 28

Abductor hallucis, FDB, FHB ## Footnote The medial plantar nerve also provides sensation to the skin over the medial two-thirds of the plantar surface.

Question 29

Which nerve innervates the remaining intrinsic foot muscles?

Answer 29

Lateral plantar nerve ## Footnote The lateral plantar nerve also supplies sensation to the skin over the lateral third of the plantar surface.

Question 30

What are the branches of the common peroneal nerve?

Answer 30

Superficial and deep branches ## Footnote The common peroneal nerve arises from L4-L5, S1-S2.

Question 31

What does the superficial peroneal nerve innervate?

Answer 31

Peroneus longus and brevis ## Footnote It also provides sensation to the skin over the distal third of the anterior leg and the dorsum of the foot.

Question 32

What muscles does the deep peroneal nerve innervate?

Answer 32

Tibialis anterior, EHL, peroneus tertius, EDL, EDB ## Footnote The deep peroneal nerve also provides sensation to the skin over the first and second inter-digital space.