Skeletal

Question 1

Unspecialized stem cells derived from mesenchyme cells of the mesoderm

Answer 1

Osteoprogenitor cells

Question 2

Bone building cells

Answer 2

Osteoblasts

Question 3

Mature bone cells that develop from osteoblasts

Answer 3

Osteocytes

Question 4

Cytoplasmic processes which penetrate the bony matrix

Answer 4

Canaliculi

Question 5

Involved in bone resorption

Answer 5

Osteoclasts

Question 6

Forms the external layer of all bones; makes up the bulk of long bones

Answer 6

Compact bone

Question 7

Functional unit of compact bone

Answer 7

Osteon

Question 8

Found at the expanded heads of long bones; fills most irregular bones

Answer 8

Spongy bone

Question 9

An irregular latticework of thin columns of bones

Answer 9

Trabeculae

Question 10

Contains a blood vessel involved in the common nutrition of the osteon

Answer 10

Haversian canal

Question 11

Rings of calcified matrix that surrounds the Haversian canal

Answer 11

Concentric lamellae

Question 12

Concentric layers that surround the central canal; formed by osteoblast

Answer 12

Interstitial lamellae

Question 13

Direct conversion of mesenchymal tissue into bone

Answer 13

Intramembranous ossification

Question 14

Growing cartilage is systematically replaced by bone to form the growing skeleton

Answer 14

Endochondral ossification

Question 15

Called ‘armored fishes’ because they had so much dermal bone

Answer 15

Ostracoderms

Question 16

Cartilage-replacement bone from sclerotome

Answer 16

Somatic endoskeleton

Question 17

Associated with gill arches and derivatives, derived from neural crest cells

Answer 17

Visceral endoskeleton

Question 18

Non-mesodermal source of bone development

Answer 18

Neural crest cells

Question 19

Most primitive form of scales; found in sharks

Answer 19

Placoid scale

Question 20

Found in gar; grow in size as the fish ages

Answer 20

Ganoid scale

Question 21

Thin, circular scales covered by a thin layer of epidermis and mucus

Answer 21

Cycloid scale

Question 22

Most advanced of all the scale forms; has tiny comb like protrusions on the posterior of the scale

Answer 22

Ctenoid scale

Question 23

A bony structure that forms the head of the vertebrates

Answer 23

Cranial skeleton