Development of Somites and the Nervous System Flashcards Preview

IUSM Anatomy KG > Development of Somites and the Nervous System > Flashcards

Flashcards in Development of Somites and the Nervous System Deck (16)
Loading flashcards...
1

Somites differentiate segmentally into what three parts?

Sclerotomes
Dermatomes
Myotomes

2

What part of the somite do the vertebral bodies form from?

Sclerotome

3

Sclerotomes will develop into vertebrae in the vicinity of what?

notochord

4

Why embroynically do spinal nerves exit between the vertebrae?

Sclerotomes split and recombine to produce intersegmental vertebrae

5

In the IV discs, what does the nucleus pulposus form from?

nucleus pulposus

6

In the IV discs, what does the anulus fibrosis form from?

Sclerotome cells

7

Where do ribs develop from?

Mesenchymal condensations called costal processes that are associated with vertebral arches

8

How does the sternum develop?

Fusion of 2 longitudinal bars of mesenchymal tissue, called sternal bars

9

The dermomyotome differentiates into the dermatome and myotome. What does the dermatome contribute to the development of?

Dermis of the neck, back, and trunk
(remember that most other dermis is derived from somatopleure)

10

_________ invade limb buds and form limb musculature

somitic myoblasts

11

Myotomes differentiate into _______ and ________ muscle

epimeric (dorsal) and hypomeric (ventral)

12

What gives rise to deep back muscles?

epimeres

13

What gives rise to muscles of lateral and ventral body wall, including intercostals, abdominal girdling muscles and rectus abdominus?

Hypomeres

14

What is piebaldism and what causes it?

Absence of melanocytes in the skin and hair, therfore unable to make melanin pigment.
A lack of migration of the neural crest prevents melanocyte formation

15

All ganglion in the body are derived from what?

neural crest

16

What are melanocytes derived from?

neural crest cells