week 12- MSK

Question 1

skeleton is composed of 2 tissues

Answer 1

• bone

- cartilage

Question 2

skeleton is composed of 3 cell types

Answer 2

• osteoblasts
• osteoclasts
• chondrocytes

Question 3

skeletal tissue derive from 3 embryonic cell lineages

Answer 3

1. cranial neural crest
2. paraxial mesoderm
3. lateral plate mesoderm

Question 4

CRANIOFACIAL SKELETON, CALVARIUM, MIDFACE, MANDIBLE AND TEETH DERIVE FROM

Answer 4

cranial neural crest cell

Question 5

axial skeleton derived from

Answer 5

paraxial mesoderm

Question 6

limbs derive from

Answer 6

lateral plate mesoderm

Question 7

notochord and neural tube form in week

Answer 7

3

Question 8

intraembryonic mesoderm lateral to the notochord and neural tube thicken to form 2 longitudinal columns of ____

Answer 8

paraxial mesoderm

Question 9

appear as bead-like elevations along the dorsolateral surface of the embryo.

Answer 9

somites

Question 10

somites differentiate into 2 parts:

Answer 10

1. ventromedial part

2. dorsolateral part

Question 11

ventromedial part is the ___ and ___

Answer 11

sclerotome vertebra and ribs

Question 12

dermomyotome from the

• myoblasts (muscle cells)
• dermis (fibroblasts)

Answer 12

dorsolateral part

Question 13

neural plate fuse to form the neural tube and is made from

Answer 13

ectoderm

Question 14

limb buds start to develop in week 6, as clusters of ___ cells covered by ___

Answer 14

mesenchymal

ectoderm

Question 15

Limbs develop in a ____ sequence

Answer 15

proximodistal

Question 16

the __and ___ form first, followed by ___ and ___, ___ and ___, metacarpal and matatarsal, and finally phalanges

Answer 16

1. humerus & femur
2. radius & ulna
3. tibial & fibula

Question 17

osteogenesis begins in the __ and ___ by 8 weeks

Answer 17

clavicle & mandible

Question 18

by __-__ weeks, the primary ossification centers of the long bones formed

Answer 18

11-12

Question 19

___ are primary ossification centres

Answer 19

diaphysis

-shaft of long bones

Question 20

___ are secondary ossification centres

Answer 20

epiphysis

-ends of long bones

Question 21

epiphysis form __ or articulation with another bone

Answer 21

joints

Question 22

most secondary ossification centres develop ___

Answer 22

after birth

Question 23

prenatally, ___ epiphysis are visible at 32-35 weeks

Answer 23

distal femoral

Question 24

prenatally, ___ epiphysis are visible by 34-35 weeks

Answer 24

proximal tibia (sometimes prox humerus)

Question 25

Visualization of these epiphyses aids in the determination of fetal ___ maturity in late pregnancy

Answer 25

lung

Question 26

limbs are fully developed and primary ossification centers image at __ weeks

Answer 26

10

Question 27

metacarples and phalanges of hands imaged ___

Answer 27

second trimester

Question 28

most severe skeletal anomalies picked up on US at

Answer 28

19-20 weeks

Question 29

mild forms of anomalies expressed __ in pregnancy

Answer 29

later

Question 30

most common measured long bone

Answer 30

femur (leg bone)

Question 31

echogenicity of the femur

Answer 31

equally hyperechoic

Question 32

__ has similar appearance to femur

Answer 32

humerus (arm where bicep is)

Question 33

tibia is __ than ___ and oriented medially

Answer 33

thicker | fibula

Question 34

fibula lies

Answer 34

laterally

Question 35

distal radius and ulna should end at __ point

Answer 35

the same

Question 36

ulna is __ than radius

Answer 36

longer

Question 37

tibia is the __ bone

Answer 37

front/ medial of leg

Question 38

fibula is the ___ bone

Answer 38

lateral of leg

Question 39

normal appearance of fetal hand is __ hypoechoic carpal bones, 5 ___ metacarpal bones, 5 digits of ___ lengths

Answer 39

unossified hyperechoic varrying

Question 40

hand should always be seen in __ and ___

Answer 40

flexion | extension

Question 41

foot has 5 __ bones

Answer 41

tarsal

Question 42

technical factors that inhibit sonogrpaher ability to visualize fetal limbs

Answer 42

- not enough amniotic fluid - too much amniotic fluid - limbs in NEAR field

Question 43

Polyhydramnios

Answer 43

too much fluid in baby swimming pool

Question 44

__ weeks LMP start to grow limbs, ___ weeks LMP can see hands / feet

Answer 44

6 | 8