Embryonic

Question 1

What is the functionality of the sclerotome

Answer 1

vertebral and axial bones

Question 2

what is the functionality of the myotome

Answer 2

muscle of body wall and limbs

Question 3

what is the functionality of the dermatone

Answer 3

deep dermis of body

Question 4

what creates the posterior root ganglion

Answer 4

neural crest cells

Question 5

How do sensory neurons travel to dermatomes

Answer 5

by following the motor axon that have reached the corresponding myotome

Question 6

The sclerotome mesenchyme

Answer 6

surrounds notochohrd and neural tube and creates a loose model of vertebra and ribs

Question 7

Chondrification centers

Answer 7

form in the sclerotome and start to replace it with cartilage in the 6th week then bone in 7th week

Question 8

primary ossification centers

Answer 8

vertebral body, (centrum), pedicle and lamina

Question 9

secondary centers of ossification

Answer 9

spinal and transverse processes aas well as annular epiphyses (lining of vert body)

Question 10

spina bifida

Answer 10

failure of ossification or failure of spinous process to form at all

Question 11

spina bifida occulta

Answer 11

failure of the neural arch specifically the spinous process to ossify.

Question 12

meningocele

Answer 12

meningies and CSF herniate in the hole left by failed neural arch

Question 13

meningimyelocele

Answer 13

same as meningiocele but with spinal chord and roots

Question 14

rachischisis

Answer 14

failure of neural tube to fold properly and neural arch cannot form

Question 15

hox gene

Answer 15

fused L5 or unfused S1

Question 16

how long in spinal chord in embryo

Answer 16

all the way down

Question 17

how long is spinal chord in 6 month gestation

Answer 17

S1 level

Question 18

how long in spinal chord in newborn

Answer 18

L3-L2 level

Question 19

how long is spinal chord in adult

Answer 19

L1 level

Question 20

muscle agenesis

Answer 20

no muscle formation

Question 21

myostatin

Answer 21

inhibits growth of muscle, mutations cause over muscling

Question 22

what migrates into the upper limb bud

Answer 22

the C4-T2 myotomes and dermatomes

Question 23

what migrates into the lower limb buds

Answer 23

myotomes and dermatomes from t4-s3

Question 24

Where do limb bones come from

Answer 24

lateral mesoderm

Question 25

what causes carved out digits in hand

Answer 25

apoptosis between finger areas

Question 26

syndactyly

Answer 26

webbed fingers or toes

Question 27

sirenomelila

Answer 27

complete or partial fusal of lower limbs

Question 28

amelia and what causes it

Answer 28

absence of one or more limbs cause by FGF8 gene absence or misexpression

Question 29

meromelia and what causes

Answer 29

partial absence of a frere limb and absence or misexpression of FGF8

Question 30

Phocomelia

Answer 30

absence of intermediate sections of extremities

Question 31

polydactyly is _____ and is caused by ______

Answer 31

extra digits caused by sonic hedge hog protein over expression