Embryo3

Question 1

Paraxial Mesoderm derivatives

Answer 1

Vertebrae
Annulus fibrosus of intervertebral discs
Ribs
Neurocranium (occipital, parietal, petrous, posterior sphenoid)

Question 2

Lateral Plate Mesoderm derivatives

Answer 2

Pectoral girdle
Pelvic girdle
Limbs
Sternum (axial skeleton)

Question 3

Neural crest cell derivatives

Answer 3

Viscerocranium and hyoid bone
Neurocranium:
(Frontal bone
Squamous portion of temporal
Anterior sphenoid)

Question 4

Viscerocranium comes from ______ ossification

Answer 4

intramembranous

Question 5

Chondrocranium comes from _____ ossification

Answer 5

Endochondral

Question 6

Endochondral Ossification before birth

Answer 6

Early cartilage model
Primary ossification center
Secondary ossification center (vascular)

Question 7

Intramembranous ossification

Answer 7

Mesenchyme condenses
Osteoblast/clast
Bony spicules
Reorganize as osteons

Question 8

Chondrocranium includes

Answer 8

sphenoid
Petrous portion of temporal
Portion of occipital

Question 9

Fontanell

Answer 9

enlarged membranous space where more than 2 bones meet

Question 10

Largest Fontanelle

Answer 10

Anterior Fontanelle

Question 11

Scaphocephaly

Answer 11

premature closing of sagittal suture

Question 12

Brachycephaly

Answer 12

premature closing of coronal suture

Question 13

Paraxial mesoderm (sclerotome) forms all axial skeleton except

Answer 13

sternum and portion of skull

Question 14

Chondrification occurs at

Answer 14

6 weeks

Question 15

Ossification occurs at

Answer 15

7 weeks

Question 16

Ribs are lateral extension of

Answer 16

Costal processes of thoracic vertebrae

Question 17

Sternum develops during ___ week from

Answer 17

10th week from lateral plate somatic mesoderm

Question 18

Week 6 appendicular skeleton

Answer 18

Mesenchymal bone models undergo chondrification to form hyalline cartilage

Question 19

Achondroplasia

Answer 19

Most common skeletal dysplasia

distubance of endochondral ossification during fetal life at epiphyseal cartilage plates esp long bones

Question 20

Skeletal muscle derived from

Answer 20

paraxial mesoderm

Question 21

Cardiac muscle derived from

Answer 21

intraembryonic splanchnic mesoderm

Question 22

Smooth muscle derived from

Answer 22

intraembryonic splanchnic mesoderm

Question 23

Somites give rise to (3)

Answer 23

axial skeleton
Associated musculature (bold)
Overlying dermis of back

Question 24

Myoblasts
definition
Actively contract at

Answer 24

specialized mesoderm cells that fuse together to form skeletal muscle
Actively contract at 7 weeks

Question 25

Meromelia

Answer 25

absense of part of limb

Question 26

Amelia

Answer 26

absence of entire limb

Question 27

Polydactyly

Answer 27

extra digits

Question 28

Syndactyly

Answer 28

few digits

Question 29

Week 12

Answer 29

primary ossification centers in all long bones

Question 30

At birth

Answer 30

diaphysis completely ossified, epiphyses still cartilaginous

Question 31

Primaxial forms

Answer 31

Epaxial muscles:
back
intercostals
shoulder girdle

Question 32

Abaxial forms

Answer 32

Hypaxial muscles:
infrahyoid m.
pectoralis M and m  mm.
body wall mm.
limb mm.

Question 33

Ectoderm derived smooth muscle

Answer 33

Neuroectoderm: sphincter pupillae, dilator pupillae

Surface ectoderm: myoepithelial ells of mammary, salivary, sweat glands

Question 34

Limb buds emerge near end of __ week

Answer 34

4th week

Question 35

_______ sends signaling factors to nearby mesenchyme of ________ zone

Answer 35

Apical ectodermal ridge to progress zone

Question 36

Limb rotation

Answer 36

week 7