Chapter 7

Question 1

Components of the skeletal system

Answer 1

Bones of the skeleton, cartilage, ligaments, and other connective tissues

Question 2

Functions of Bones

Answer 2

Support and protection, movement (anchor points), hemopoiesis (forms blood cells), Storage of mineral and energy reserves

Question 3

Compact Bone

Answer 3

Compact bone is dense connective bone tissue; appears white, smooth, and solid; 80% of bone mass
(Dense or cortical bone)

Question 4

Spongy Bone

Answer 4

Located internal to compact bone; appears porous; 20% of bone mass; absorbs shock (concellous or trabecular bone)

Question 5

Mesenchyme

Answer 5

Loosely organized embryonic connective tissue that gives rise to skin, blood, and bone

Question 6

Epiphysis

Answer 6

The knobby region at the end of long bones; proximal and distal; composed of an outer thin layer of compact bone and an inner region of spongy bone;

Question 7

Diaphysis

Answer 7

elongated shaft that provides leverage and major weight support; compact bone with thin spicules of spongy bone extending inward

Question 8

Metaphysis

Answer 8

Region of mature bone between diaphysis and epiphysis

Question 9

Epiphyseal Plate

Answer 9

a thin layer of hyaline cartilage in the metaphysis; provides continued lengthwise bone growth;

Question 10

Epiphyseal Line

Answer 10

The remnant of the epiphyseal plate in adults

Question 11

Medullary Cavity

Answer 11

hollow, cylindrical space within the diaphysis; contains red bone marrow in children; contains yellow bone marrow in adults

Question 12

Periosteum

Answer 12

Tough sheath covering outer surface of bone; outer fibrous layer of dense irregular connective tissue; high density of collagen; protects bone from surroundings; anchors blood vessels and nerves to bone surface; attachment site for ligaments and tendon

Question 13

Endosteum

Answer 13

Covers all internal surfaces of bone within medullary cavity; contains osteoprogenitor cells, osteoblasts, and osteoclasts

Question 14

Osteon

Answer 14

the basic unit of structure of compact bone: haversian canal and concentrically arranged lamellae

Question 15

4 types of bone cells

Answer 15

osteoprogenitor/osteogenic cells, osteoblasts, osteocytes, osteoclasts

Question 16

Osteoprogenitor Cells

Answer 16

Early stem cells for bones; located in periosteum and endosteum; derived from mesenchyme

Question 17

Osteoblasts

Answer 17

Builds the bone matrix; synthesizes and secretes osteoid

Question 18

Osteocytes

Answer 18

Mature bone cells; detect mechanical stress on bone;

Question 19

Osteoclasts

Answer 19

break down bone

Question 20

Cartilage Components

Answer 20

Collagen fibers, elastic fibers, chondrocytes, chondroblasts, Lacunae, Perichondrium

Question 21

Collagen fibers

Answer 21

strong, flexible, and resistant to stretching, unbranched fibers

Question 22

Elastic Fibers

Answer 22

branching wavy fibers that stretch and recoil easily, help structures return to normal shape after stretching

Question 23

Chondrocytes

Answer 23

Mature cartilage cells that occupy small spaces called lacunae; chondroblasts that have become encased within the matrix

Question 24

Chondroblasts

Answer 24

secrete cartilage matrix

Question 25

Lacunae

Answer 25

Small empty spaces

Question 26

Perichondrium

Answer 26

dense irregular connective tissue; covers cartilage and helps maintain its shape

Question 27

Hyaline cartilage

Answer 27

Covers the ends of some bones, cartilage within growth plates, model for the formation of most bones, attaches ribs to the sternum, Resilient and flexible, Avascular and contains no nerves, Good shock absorber; embedded in a gel-like ground substance

Question 28

Elastic Cartilage

Answer 28

Flexible, springy cartilage; numerous densely packed elastic fibers; ensure tissue is resilient and flexible; chondrocytes closely packed; surrounded by a perichondrium; found in the external ear and the epiglottis

Question 29

Fibrocartilage

Answer 29

Weight-bearing cartilage that withstands compression; forms intervertebral discs, forms cartilage pads of the knees, and numerous parallel collagen fibers; larger chondrocytes in lacunae; no perichondrium

Question 30

Ligaments

Answer 30

Bone to bone (like to like)

Question 31

Tendons

Answer 31

Muscle to Bone

Question 32

Appositional growth

Answer 32

Bone growth in diameter; occurs within the periosteum; bone matrix deposited within layers parallel to the surface

Question 33

Osteopenia

Answer 33

Insufficient ossification; osteoblast activity declining; vertebrae, jaw bones, epiphyses losing large amount of mass

Question 34

Osteoporosis

Answer 34

Reduced bone mass sufficient to compromise normal function; occurs in more older women than older men

Question 35

Stress Fracture

Answer 35

Thin break caused by increased physical activity; bone experiences repetitive loads

Question 36

Pathologic Fracture

Answer 36

Occurs in bone weakened by disease

Question 37

Simple Fracture

Answer 37

broken bone not penetrating the skin

Question 38

Compound fracture

Answer 38

One or both ends piercing overlying skin

Question 39

Intramembranous Ossification

Answer 39

Dermal ossification, begins when mesenchyme becomes thickened with capillaries, produces the flat bones of the skull, some of the facial bones, mandible, central part of the clavicle

Question 40

Endochondral Ossification

Answer 40

replacement of hyaline cartilage with bone