final exam skeletal system

Question 1

each somite divides into 2 parts:

Answer 1

dermamyotome- derma and myo

sclerotome- skeleton

Question 2

what forms the somites?

Answer 2

mesoderm

Question 3

dividing somite is made up of mesodermal cells that give rise to?

Answer 3

mesenchyme

Question 4

condensation of mesenchyme gives rise to formation of

Answer 4

bone models and selective gene activity begins

Question 5

3 areas of mesenchymal development

Answer 5

paraxial-> somite-> lateral mesoderm

Question 6

cartilage bones

Answer 6

replace provisional cartilage and are remaining bones of body

Question 7

membrane bones

Answer 7

make up the face and cranial roof and develop from skeletal mesenchyme

Question 8

what is the cartilaginous vertebral body that replaces notochord

Answer 8

centrum- 2 CHONDRIFICATION CENTERS

Question 9

vertebral arches do not unite to form spinous processes until

Answer 9

3rd month after birth

Question 10

when does ossification of vertebra begin?

Answer 10

9th week, all centers present by 5th month except sacral and coccyx

Question 11

what are the ossification centers at puberty?

Answer 11

5: 1 at tip of spinous processes
1 at each tip of transverse processes
2 on rim of epiphyseal center

Question 12

mesenchymal bands= sternal bars of?

Answer 12

sternum

Question 13

chondrification of limbs start at?

Answer 13

5th and 6th week

Question 14

upper limbs rotate

Answer 14

laterally

Question 15

lower limbs rotate

Answer 15

medially

Question 16

which bone ossifies before any other bone in the body?

Answer 16

clavicle

Question 17

congenital malformations of the skeleton

Answer 17

chondrodystrophies- abnormal development of cartilage

Question 18

cartilage stage in these bones can grow rapidly to match growth of fetus

Answer 18

inter-cartilagenous or endochondral

Question 19

2 types of neurocranium development

Answer 19

neurochondrocranium

neuromembranocranium

Question 20

neurochondrocranium at 6 weeks

Answer 20

nasals, orbitals, temporals

Question 21

neuromembranocranium- fontanelles and sutures**

Answer 21

2 parietals, 2 frontals, 1 vomer, 2 nasals, 2 lacrimals

Question 22

closure times of fontanelles

Answer 22

anterior- end of second year, largest
anterolateral- 2-3 mo
posterolateral- end of 1st year

Question 23

splanchochondrocranium- bones of the face

Answer 23

visceral, pharyngeal, brachial arches

Question 24

1st visceral arch

Answer 24

mandibular

Question 25

1st arch

Answer 25

palate, maxilla, meckels cartilage, incus, malleolus

Question 26

2nd arch

Answer 26

stapes, cranial half of hyoid, lesser horn

Question 27

3rd arch

Answer 27

caudal half of hyoid, greater horn

Question 28

4 and 6 arch

Answer 28

cartilage of larynx

Question 29

vertebral column comes from

Answer 29

somite mesenchyme sclerotome

Question 30

intersegmental development gives the vertebra:

Answer 30

1 muscle attachment | 2 nerve emergence

Question 31

chondrification begins in

Answer 31

7th week in cranial vertebra and follows down

Question 32

slow growth of cartilage and bone ossification is called

Answer 32

achondroplasia syndrome

Question 33

3 characteristics of achondroplasia syndrome

Answer 33

1 small stature 2 megalocephaly 3 skeletal issues

Question 34

hypochondroplasia syndrome is

Answer 34

a mild form of achondroplasia

Question 35

clavicle agenesis or no clavicle

Answer 35

cleidocranial dysostosis

Question 36

2 type of spina bifida

Answer 36

occulta- can't see | cystica- can see, meninges only

Question 37

2 types of congenital scoliosis

Answer 37

1 numerical variations | 2 morphological variations

Question 38

all sutures closing prematurely and symmetrically

Answer 38

oxycephaly

Question 39

metatopic suture- triangle looking

Answer 39

trigonocephaly

Question 40

when sutures close asymmetrically

Answer 40

plagiocephaly

Question 41

when sagittal sutures close prematurely

Answer 41

scaphocephaly

Question 42

coronal sutures- large wide short

Answer 42

acrocephaly

Question 43

complete absence of limbs

Answer 43

amelia

Question 44

absence of reduction of proximal part of limbs

Answer 44

phocomelia

Question 45

absence of reduction of distal part of limbs

Answer 45

meromelia

Question 46

hypoplasia and fusion of lower limbs

Answer 46

sympodia

Question 47

duplication of distal part of limbs

Answer 47

dichiria

Question 48

presence of extra digits

Answer 48

polydactyly

Question 49

fusion of digits

Answer 49

syndactyly

Question 50

shortness of digits

Answer 50

brachydactyly

Question 51

long digits with extra phalanges

Answer 51

hyperphalangism