Ossification

Question 0

Perichondrium

Answer 0

Double-layered connective tissue sheath covering most cartilage

Question 1

Lacuna

Answer 1

Cartilage, singular. Chondrocyte occupies a lacuna

Question 2

Articulate cartilage

Answer 2

Hyaline cartilage that covers bones at joints. Has no perichondrium blood vessels or nerves

Question 3

Appositional growth

Answer 3

Chondroblasts in perichondrium add new cartilage to outside edge of existing cartilage

Question 4

Interstitial growth

Answer 4

Chondrocytes within tissue divide and add more matrix between existing cells

Question 5

Hydroxyapatite

Answer 5

65% of bone. Inorganic. Calcium phosphate crystal.

Question 6

Ruffled boarder

Answer 6

Osteoclasts. SpecialIzed reabsorption area

Question 7

Lacunae

Answer 7

Plural, bone networking. Osteocytes

Question 8

Canaliculi

Answer 8

Spaces occupied by osteocyte processes. Little canals

Question 9

Osteochondral progenitor cells

Answer 9

Stem cells that become either osteoblasts or Chondroblasts

Question 10

Woven bone

Answer 10

Random colleges fibers. Appear in fetal development and bone repair.

Question 11

Lamellar bone

Answer 11

Mature bone organized in thin sheets

Question 12

Trabeculae

Answer 12

Spongy bone. Interconnecting rods or plates. Spaces filled with marrow and vessels

Question 13

Central canals

Answer 13

Parallel to axis of bone. Lined with endosteum and contain blood vessels nerves and connective tissue

Question 14

Concentric lamellae

Answer 14

Circular layers of matrix that surround a central canal

Question 15

Osteon

Answer 15

Haversian system: central canal, associated concentric lamellae, osteocytes.

Question 16

Circumferential lamellae

Answer 16

Outer surface of compacts bone.

Question 17

Interstital lamellae

Answer 17

Parts of circumferential lamellae left during bone remodeling

Question 18

Perforating canals

Volkmann canals

Answer 18

Allows blood vessels through the periosteum and medullary cavity

Question 19

Bone shapes

Answer 19

Long. Flat. Short. Irregular

Question 20

Perforating fibers

Answer 20

Sharpey fibers. Bundles of collagen fibers that strengthen the attachment of tendons and ligaments.

Question 21

Endosteum

Answer 21

Single layer of cells that lines internal surfaces of cavities in bone

Question 22

Intramembranous ossification

Answer 22

Week 8. Done by 2 years. Skull, mandible, diaphysis of clavicle. Osteoprogentor cells become osteoblasts. Begin at center of ossification. Move outward

Question 23

Endochondral ossification

Answer 23

Week 8. End 18-20 yrs old. Base of skull, part of mandible, epiphysis of clavicle, most of skeleton. Osteochondral progenitor cells become Chondroblasts, form hyaline cartilage model. Blood invades, Osteochondral progenitor cells in perichondrium become osteoblasts.

Question 24

Bone collar

Answer 24

During endochondral ossification, osteoblasts produce compact bone on surface of cartilage model-bone collar

Question 25

Primary ossification center

Answer 25

Diaphysis-spongy bone

Question 26

Growth in bone length steps

Answer 26

Zone of resting, zone of proliferation, zone of hypertrophy, zone of calcification

Question 27

Vitamin D

Answer 27

Absorption of calcium from intestines

Question 28

Rickets

Answer 28

Reduced mineralization of bone matrix

Question 29

Osteomalacia

Answer 29

Softening of bones due to calcium depletion

Question 30

Vitamin C

Answer 30

Necessary for collagen synthesis by osteoblasts.

Question 31

Scurvy

Answer 31

Vitamin C deficiency. Ulceration and hemorrhage anywhere collagen synthesis is not occurring. Teeth fall out

Question 32

Growth hormone

Answer 32

Anterior pituitary. Stimulates interstitial cartilage growth and Appositional growth

Question 33

Thyroid hormone

Answer 33

Needed for growth, otherwise may be a small individual

Question 34

Sex hormones

Answer 34

Estrogen causes quicker closure of the epiphyseal plate

Question 35

Steps of bone repair

Answer 35

1. Hematoma formation 2. Callus formation- internal then external 3. Callus ossification- replaced by woven spongy bone 4. Bone remodeling- new compact bone

Question 36

Parathyroid hormone

Answer 36

Elevates blood calcium levels

Question 37

Calcitonin

Answer 37

From thyroid gland, reduces blood calcium levels. Inhibits osteoclasts