Dermatomes, Myotomes and Spinal Nerve Plexuses

Question 1

Lateral mesoderm gives rise to

Answer 1

Splanchnic- circulatory system and viscera

Somatic- body cavity

Question 2

When do the limb buds start to appear

Answer 2

During week 4

Question 3

Skin of trunk and skin of limbs are innervated by segmental or plexus nerves

Answer 3

Trunk- segmental nerves

Skin of limbs- 3 spinal nerves form one plexus

Question 4

What is a myotome

Answer 4

All of the muscles that are innervated by a single efferent anterior root. Most muscles are composed of more than one myotome

Question 5

Femoral nerve levels

Answer 5

L2-4

Question 6

Obturator nerve levels

Answer 6

L2-4

Question 7

Sciatic nerve, tibial nerve and common fibular nerve levels

Answer 7

Sciatic/tibial- L4-S3

Common fibular- L4-S2

Question 8

Lateral femoral cutaneous nerve levels

Answer 8

L2-3

Question 9

Posterior femoral cutaneous nerve levels

Answer 9

S1-S3

Question 10

Which nerves are part of the lumbosacral plexus

Answer 10

Subcostal
Genitofemoral
Iliohypogastric
Iliolinguinal
Lateral femoral cutaneous
Obturator
Femoral

Question 11

Which nerves are part of the sacral plexus

Answer 11

Superior/inferior gluteal
Sciatic
Tibial
Common fibular
Posterior femoral cutaneous
Pudendal