Back and limb dev

Question 1

tissue sources for intervertebral discs

Answer 1

paraaxial mesoderm

Question 2

direction of dev of vert.

Answer 2

cranio>caudal

Question 3

Tissue dev from the side of somites (3)

Answer 3

1. dorsolateral - dermomyotome - dermis
2. dorsal and ventral - myotome - striated muscle
3. ventromedial - sclerotome -

Question 4

tissue dev from side of myotome

Answer 4

1. dorsal - back muscle

2. ventral - rest of body muscle

Question 5

3 sclerotome directions and their devs.

Answer 5

1. ventomedial - vert. bodies and disc
2. dorsomedial - neural acrches and meninges
3. ventrolateral - transverse process and ribs

Question 6

Disc are segmental or intersegmental

Answer 6

segmental

Question 7

vert. are segmental or intersegmental

Answer 7

inter

Question 8

defects of sclerotome dev (3)

Answer 8

1. hemivert. - lacking somite dev on one side
2. fusions
3. spina bifida - vert arch not formed

Question 9

types of neural tube spina bifida (2)

Answer 9

2. myloschisis - open spinal cord

3. mylomeninggocele - produces sac out skin

Question 10

types of vert spina bifida (3)

Answer 10

1. occulta - small gap
2. meningocele
3. meningomyelocele

Question 11

2 areas of interaction for limb dev

Answer 11

lateral mesoderm and wolfian plate

Question 12

expression of what leads to limb bud dev

Answer 12

FGF-10

Question 13

where does and apical ectodermal ridge (AER) form ?

Answer 13

where dorsal and ventral ectoderm meet

Question 14

3 types of org. involved in limb dev. and area and their signal modelcules

Answer 14

1. proximodistal - AER - FGF
2. craniocaudal - ZPA - SHH
3. dorsoventral - ectoderm - Wnt-7

Question 15

Features of proximodistal org.

Answer 15

cells leaving later become more distal

Question 16

probs of proximodistal org

Answer 16

lack of limb dev - paddle limbs

Question 17

features of craniocaudal dev.

Answer 17

which side up and down

Question 18

probs of craniocaudal dev.

Answer 18

mirror-image duplications

Question 19

features of dorsoventral dev

Answer 19

makes flexors and extensors

Question 20

signal molecules of AER and ZPA

Answer 20

AER - FGF

ZPA - SHH

Question 21

what signal and what tissue start limb bud

Answer 21

FGF-10 in mesoderm

Question 22

toe that is on side of ZPA

Answer 22

little toe or finger

Question 23

what are predecessors of limb tissues

Answer 23

muscles - myotomes

limb bud mesenchyme - bones, tendons, blood vessels