7

Question 1

from mesoderm or ectoderm proliferate and
aggregate;

Answer 1

Mesenchymeal (chondrogenic) cells

Question 2

become round and enlarged and are now termed

Answer 2

Chondroblasts

Question 3

secrete amorphous ground substance

Answer 3

Chondroblasts

Question 4

to form the cartilage matreix

Answer 4

collagen
fibers

Question 5

Originates from paraxial mesoderm, somatic mesoderm or ectomesenchyme

Answer 5

Bone

Question 6

occurs in most bones of the axial skeleton and
appendicular skeleton.

Answer 6

Endochondral bone development

Question 7

Cartilage model

Answer 7

ossification

Question 8

chondroblasts secrete matrix to produce a cartilage model of the
future bone; the model is surrounded by

Answer 8

perichondrium

Question 9

Addition of layers of bone matrix reduces the intertrabecular spaces and the cancellous
bone in the diaphysis is converted into a

Answer 9

Compact bone

Question 10

creating
a smooth surface lubricated by

Answer 10

synovial fluid in the joint cavity

Question 11

Osteoblasts also secrete calcium to the osteoid to
form

Answer 11

bone trabecula

Question 12

me non-secretory and are now termed osteocytes.
Osteocytes present cytoplasmic processes that radiate into the matrix through tiny bone
channels called

Answer 12

Canaliculi

Question 13

A bone with large intertrabecular spaces is classified as

Answer 13

cancellous or spongy bone

Question 14

The intertrabecular spaces are occupied by blood-forming cells
(red bone marrow) and are also called

Answer 14

marrow spaces or marrow cavities

Question 15

Joints must move during in utero and postnatal
development to prevent

Answer 15

ankylosis

Question 16

Sclerotomal mesenchymal cells lateral to the thoracic vertebrae differentiates into

Answer 16

cartilaginous ribs

Question 17

which are eventually destroyed and replaced by

Answer 17

bony ribs ( cancellous bone)

Question 18

The sternum develops differently, from 2 longitudinal aggregations of somatic
mesaenchyme (somatic mesoderm) called

Answer 18

sternal bars

Question 19

. The two (2) sterna bars fuse in the
ventral midline and become segmented to form

Answer 19

eight (8) sternebrae

Question 20

lateral deviation of vertebral column

Answer 20

Scoliosis

Question 21

sagittal deviation of vertebral column in a fixed position

Answer 21

Kyphosis

Question 22

sagittal deviation of vertebral column in a fixed extended position.

Answer 22

Lordosis

Question 23

abnormal twisting of the cervical vertebral column

Answer 23

Torticolis or wry neck

Question 24

absence of vertebral arch

Answer 24

Spina bifida

Question 25

spina bifida of several adjacent vertebrae.

Answer 25

Rachischisis

Question 26

spina bifida covered by skin and subcutis.

Answer 26

Spina bifida occulta

Question 27

The cartilaginous structures fuse and ossify to form the bones of the

Answer 27

floor of the skull.

Question 28

does not ossify

Answer 28

Nasal capsule

Question 29

ethmoid and bone around the pituitary gland

Answer 29

Prechordal cartilage

Question 30

base of occipital

Answer 30

Parachordal cartilage

Question 31

temporal bone

Answer 31

Otic capsule

Question 32

Intramembranous bones articulate by means of fibrous joints called

Answer 32

Sutures

Question 33

Widened suture areas, at the corners of growing bones are called

Answer 33

Fontanels

Question 34

develops from outward growth of ectomesenchymal tissue located rostral to the cranium and pharynx.

Answer 34

Face

Question 35

Ectomesenchymal cells around prosencephalon completely envelop the prosencephalon to form the

Answer 35

frontonasal prominence

Question 36

located between VC1 and VC2, becomes the external auditory meatus.

Answer 36

VC1 or hyomandibular cleft

Question 37

are overshadowed by the expanding hyoid arch and fuse to form a cervical sinus that later disappears w/out a trace.

Answer 37

VC2 to VC4

Question 38

cleft lip caused by failure of fusion of medial nasal and maxillary processes.

Answer 38

Cheiloschisis

Question 39

cleft palate caused by failure of medial palatine processes to fuse

Answer 39

Palatoschisis

Question 40

no opening

Answer 40

Branchial cyst

Question 41

opening to exterior

Answer 41

branchial sinus

Question 42

Openings to interior and exterior

Answer 42

branchial fistula

Question 43

Primordia of enamel organs escape to the exterior and develop tooth structures anchored on the parietal bone or base of the ear.

Answer 43

Heterotropic polyodontia

Question 44

loss of a specific part of a limb

Answer 44

Limb reduction

Question 45

presence of one or more extra digits.

Answer 45

Limb Duplication

Question 46

inherited; systemic premature ossification of physes of extremeties.

Answer 46

Achondroplasia (dwarfism; Dachshund)

Question 47

complete absence of a limb.

Answer 47

Amelia

Question 48

absence of a part of a limb.

Answer 48

Meroromelia

Question 49

complete absence of limb.

Answer 49

Acromelia

Question 50

Absence of half or one or more segments of a limb

Answer 50

Hemimelia

Question 51

reduced size of a limb.

Answer 51

Micromelia

Question 52

absence of one or more proximal segments, a consequence of pregnant women taking thalidomide in the late 1950’s.

Answer 52

Phocomelia

Question 53

fused digits

Answer 53

Syndactyly

Question 54

shortened or stumpy digits.

Answer 54

Brachydactyly

Question 55

absence of one or more digits.

Answer 55

Ectrodactyly

Question 56

presence of one or more extra digits. This is common in pig and cat.

Answer 56

Limb Duplication

Question 57

one or more extra digits

Answer 57

Polydactyly

Question 58

partial or complete duplication of one limb

Answer 58

Bimelia

Question 59

limb growing from the back of the animal

Answer 59

Notomelia (noto=back)

Question 60

crooked limb. Gr. gryposis=crooked) - can results from malformed joints, denervation, abnormal muscle tension, or impaired mobility in utero.

Answer 60

Arthrogryposis

Question 61

abnormal maturation of the hip joint that results in formation of a shadow acetabulum and flattened femoral head.

Answer 61

Hip Dysplasia

Question 62

permanent fixation of a joint caused by immobility of the fetus in utero.

Answer 62

Ankylosis