Devo of Vertebral Column, Ribs and Sternum Flashcards Preview

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Flashcards in Devo of Vertebral Column, Ribs and Sternum Deck (21)
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1

How does the scleratome form? 

Cells in the ventromedial/ventral half of the somite are influenced by Shh and noggin 

In response, the ventral somite cells express Pax1 and Pax9 -- induces proliferation and epithelium to mesenchyme transformations 

The newly formed mesenchymal cells is the scleratome 

2

How does scleratome mesenchyme become a vertebrae? 

Resegmentation: the cranial half of one somite merges with the caudal half of the next adjacent somite

As a result, vertebrae become intersegmental with respect to the orignal somite segmental pattern.

Skeletal muscles derived from dermomyotomes can span adjacent vertebrae 

3

What does the central subdomain of scleratome tissue produce? 

Pedicle

Proximal rib

4

What does the Ventral subdomain of scleratome tissue produce? 

Vertebral body, IV disc

5

What does the Dorsal subdomain of scleratome tissue produce? 

Dorsal part of neural arch, spine

6

What does the Lateral subdomain of scleratome tissue produce? 

Distal rib

7

What does the Somitocoel subdomain of scleratome tissue produce? 

Vertebral joints, IV disc, proximal ribs

8

Cells from the cranial half of scleratome contribute to: 

Vertebral body, small parts of neural arch and distal rib 

9

Cells from the caudal half of the scleratome contribute to: 

Vertebral body, transverse process, most of neural arch and proximal part of main part of distal rib 

10

What do cells from the cranial and caudal parts of the scleratome form? 

Cranial half forms vertebral body, small parts of neural arch and distal rib 

 

Caudal half forms vertebral body, transverse process, proximal rib, main part of distal rib and main part of neural arch 

11

What gene determines the type of vertabra that will form and where it will form? 

Hox genes 

And retinoic acid 

12

By what method do vertebra become bone? 

Endochondral ossification 

13

How do the ribs form? 

Costal processes expand laterally 

Proximal portion of rib forms from cells of central scleratome and somitocoel 

Distal portion is derived from lateral scleratome cells 

14

How does the sternum form? 

Begins independently as cartilage bars on either side of midline

Derived from Somatic mesoderm

Bars fuse after embryo folding 

Secondary segmentation forms Sternebrae

Refusion of sternebrae forms body of sternum 

Cranial most sternebrae forms manubrium

Xiphoid process forms at caudal end

 

15

What is hemivertebrae? 

A remainder of a vertebra that did not form completely 

16

What is spina bifida? 

Series of conditions where one or a few adjacent vertebrae have unfused spinous processes 

Spina bifida occulta is the mildest form, asymptomatic 

17

What is sacrilization? 

Occurs if fifth lumbar vertebrae is incorporated into sterum 

18

What is Kippel-Feil sequence?

AKA brevicollis

Rare, recessive 

Characterized by presence of several fused cervical vertebrae

Neck is shortened, low nuchal hair line

Limited spine mobility 

Associated with genitourinary and cardiopulmonary defects and hearing loss 

19

What is scoliosis? 

Abnormal curvature of the spine 

Congenital form may be caused by hemivertebrae 

Seven times more common in females 

20

What is lumbarization? 

When the first sacral vertebra is not included in the sacrum 

21

What is Rachischisis? 

A condition where many or all vertebrae have unfused spinous processes