1.1.4. Dermatomes of the Lower Limb

Question 1

What is a Dermatome?

Answer 1

A strip of Skin that is innervated by a single Spinal Nerve

Question 2

1. In Clinical Practice, what can conform to Dermatomes?
2. What can cause this?

Answer 2

1. Areas of sensory loss
2. a) Injuries of the Spinal Cord
3. b) Injuries of the individual Nerve Root

Question 3

What happens when there is injury to a Peripheral Nerve, containing many Nerve Roots?

Answer 3

Sensory loss will occur corresponding to the area of distribution of that specific Cutaneous Nerve

Question 4

What does Nerve Root L1 Supply?

Answer 4

The Anterior Groin Area

Question 5

What does Nerve Root L2 Supply?

Answer 5

1. The Superior part of the Thigh
2. The Lateral part of the Thigh
3. The Area of Skin just above the Buttocks

Question 6

What does Nerve Root L3 Supply?

Answer 6

1. The Medial part of the Thigh
2. The Inferior part of the Thigh
3. The Anterior Knee

Question 7

What does Nerve Root L4 Supply?

Answer 7

1. The Anteriomedial part of the Calf
2. The Posteromedial part of the Calf
3. The Medial part of the Ankle

Question 8

What does Nerve Root L5 Supply?

Answer 8

1. The Anterolateral part of the Calf
2. The Posterolateral part of the Calf
3. The Anterior part of the Ankle
4. The Anteior part of the Foot
5. The First 3 Toes (Big Toe - Middle Toe)
6. The Distal-Medial part of the Sole of the Foot

Question 9

What does Nerve Root S1 Supply?

Answer 9

1. The Lateral part of the Ankle
2. The Last 2 Toes (4th Toe and Little Toe)
3. The Lateral part of the Foot
4. The Majority of the Sole of the Foot

Question 10

What does Nerve Root S2 Supply?

Answer 10

1. The Posterior part of the Ankle
2. The Posterior part of the Calf
3. The Posterior part of the Knee
4. The Posterior part of the Thigh

Question 11

What does Nerve Root S3 Supply?

Answer 11

1. The Genital Region
2. The Buttock Region

Question 12

What does Nerve Root S4, S5 and Ccx1 Supply?

Answer 12

The Peri-Anal Area