Muslce System

Question 1

What is the somite division that develops the muscles and skin?

Answer 1

Dermamyotome

Question 2

what is the the process of muscle formation called?

Answer 2

Myogenesis

Question 3

Which layer doe the muscular system develop from?

Answer 3

Mesoderm

Question 4

What are the 3 classifications of muscle?

Answer 4

Skeletal, Smooth/Visceral, Cardiac

Question 5

What is skeletal muscle derived from?

Answer 5

Myotomes of somites, Mesenchyme of brachial arches, and mesenchyme of the limbs

Question 6

What are the two divisions of skeletal muscle?

Answer 6

1) the small dorsal division or epimre

2) large ventral division or hyopmere

Question 7

What is formed from the Epimer?

Answer 7

extensor musculature of the vertebral column and the dorsal primary rami

Question 8

What is formed from the hypomers?

Answer 8

muscles of the limbs and body wall and the ventral primary rami

Question 9

What is an example of change in direction of the muscle fibers during development?

Answer 9

• Latissimus dorsi (migration of whole muscle)
• Rectus abdominus (fusion of successive myotomes)
• sternohyoid (longitudinal splitting of the myotome)
• Oblique and transvers abdominals (tangential splitting of myotomes)
• Tensor Fascia Lata (Degeneration of myotomes)

Question 10

What are some of the muscles that form from the hyopmers in the cervical region?

Answer 10

• Scalenes
• part of trap
• part of SCM
• infrahyoid

Question 11

What muscles develop from the hypomers in the thoracic region?

Answer 11

• Intercostals

- Transverse Throacis

Question 12

What muscles develop from the hyopmere in the abdominal region

Answer 12

• psoas (major and minor)
• quadratus lumborum
• external/internal transverse abdominus
• rectus abdominus

Question 13

What is the significance of the ribs developmentally?

Answer 13

They allow the muscles of the chest wall to maintain their segments

Question 14

T/F: The nerves remain within the muscles even though the muscles will change direction.

Answer 14

True

Question 15

T/F: The muscle origin and insertion will change as the muscles change direction.

Answer 15

False. The origin and insertions of the muscles will stay the same even though the muscle ill change diection

Question 16

What muscles form from the 1st arch?

Answer 16

Teh muscles of mastication

• temporalis
• masseter
• pterygoid
• myelhyoid
• Ant. belly of digastric tensor tempani
• tensor veli palatini

Question 17

What muscles form from the 2nd arch?

Answer 17

The facial muscles

• orbicularis oculi
• obiculris oris
• risorius
• platysma
• occipitalis

Question 18

The muscle that develops from the 3rd arch

Answer 18

stylo-paryngeal muscle

Question 19

The muscles that develop from the 4th and 6th arch

Answer 19

• laryngeal
• palateine muscles
• part of SCM
• part of trap

Question 20

The innervation of the 1st brachial arch

Answer 20

Trigiminal nerve (CN V)

Question 21

Innervation of 2nd brachial arch

Answer 21

Facial N. (CN VII)

Question 22

Innervation of 3rd Brachial arch

Answer 22

Glossopharyngeal N. (CN IX)

Question 23

Innervation of the 4th and 6th brachial arch

Answer 23

Vagus N. (CN X) and Hypoglossal N. (CN XII)

Question 24

What do the limb buds originate from?

Answer 24

Muscular Mesenchyme

Question 25

The extensors muscles develop from which mesenchymal group?

Answer 25

Dorsal Group

Question 26

The flexor muscles develop from which mesenchymal group?

Answer 26

Ventral Group

Question 27

What does the smooth muscle derived from?

Answer 27

Splanchinic Mesoderm. Except the smooth muscle of the iris which develop from the neuroectoderm

Question 28

The cardiac musculature develops from which layer?

Answer 28

Splamchinc Mesoderm