9/25 Development Of Musculature - Dennis

Question 1

What rises from paraxial mesoderm? 4

Answer 1

Somites

Question 2

What gives rise to muscle of the trunk? 4

Answer 2

Myotomes

Question 3

What gives rise to cartilage? 4

Answer 3

Sclerotomes

Question 4

Where do sclerotomes begin and end? 5

Answer 4

Begin as a portion of the sclerotome and are then released and move inferior to the sclerotome

Question 5

Once the somite opens and becomes linear what are the different layers from superficial to deep? 6

Answer 5

Dermatomes —> myotome —> Syndetome (tendons) —> sclerotome

Question 6

What does the myotome differentiate into? 7

Answer 6

Epidermis

Hypomere

Question 7

What does the epimere give rise to? 7

Answer 7

Deep epaxial muscle (dorsal rami):
—> erector spinae
—> transversospinalis

Question 8

What does the hypomere give rise to? 7

Answer 8

Hypaxial muscle (ventral rami):
—> lateral body wall
—> ventral body wall

Question 9

What are the four Hypaxial divisions? 9

Answer 9

Cervical myotomes

Thoracic myotomes

Lumbar myotomes (Quadratus lumborum)

Sacrococcygeal myotomes (pelvic floor musculature)

Question 10

What occurs in Poland Syndrome? 10

Answer 10

Absence of pectoralis minor

Partial loss of pectoralis major

Question 11

What occurs in Prune-Belly Syndrome? 11

Answer 11

Partial/complete absence of abdominal musculature

Cryptorchidism (failure for one or both testes to descend)

Malformation of urinary tract/bladder

Question 12

Within a sclerotome, what do the ventral, dorsal, and lateral cells become? 12

Answer 12

Ventral cells —> vertebral body

Dorsal cells —> vertebral arch & spine

Lateral cells —> vertebral transverse processes and ribs

Question 13

What occurs during sclerotomal break-up? 13, 14

Answer 13

Sclerotome is split by a spinal nerve into a rostral (superior) segment and a caudal (inferior) segment

A posterior, caudal segment joins with a superior, rostral segment to form a vertebrae

Question 14

Where would you find a C4 nerve root? 14

Answer 14

Above the C4 vertebrae (true for all vertebrae)

Question 15

What does the centrum develop from? 15

Answer 15

Immediately caudal sclerotomes?

Question 16

What gives rise to intervertebral discs? 15

Answer 16

Add

Question 17

As the vertebral column develops what does the notochord expand and turn into? 18

Answer 17

The nucleus purposes

Question 18

What comes to surround the nucleus pulposus and is wedged between vertebrae? 18

Answer 18

Annulus fibrosus

Question 19

What do the sternal bars give rise to? 19

Answer 19

Manubrium

sternebrae (segments of the sternal body)

Xiphoid process

Question 20

What decides the shape of each vertebrae and determines where the transition point between vertebrae will be? 20

Answer 20

Hox genes

Hox10 - forms the thoracic/Lumbar boundary

Question 21

What problem can cervical ribs cause? 22

Answer 21

Can impinge:
—> Brachial plexus
—> subclavian artery

Question 22

What syndrome is associated with impingement of the subclavian artery? 22

Answer 22

Thoracic outlet syndrome

Question 23

What malformation shows a depressed sternum that is sunken posteriorly?

Answer 23

Pectus excavatum

Question 24

What malformation causes bilateral flattening of the chest with an anteriorly projecting sternum? 22

Answer 24

Pectus carinatum

Question 25

Do concept map

Answer 25

Slide 24