Chapter 6 - Skeleton System

Question 1

Appositional Growth

Answer 1

Growth in bone width after birth; thickens the bones.

Occurs on cartilage s outside contour (perichondrium). Starts when stem cells at the edge of the perichondrium are converted into chondroblast.

Question 2

Osteoblast

Answer 2

Create bone matrix

Question 3

Osteocyte

Answer 3

Mature bone cell that is surrounded by bone matrix.

Maintain the bone matrix and found inside the lacunae

Question 4

Osteoclast

Answer 4

Remove bone tissue to shape the bone

Question 5

Osteoprogenitor Cells

Answer 5

Stem/germ cells that give rise to osteoblast

Question 6

Interstitial Growth

Answer 6

Growth in length at the epiphyseal plate after birth

Process ends between 12 - 25 years

Question 7

Zones of the Epiphyseal Plate

Answer 7

1. Proliferation Zone - cartilage cells undergo mitosis
2. Hypertrophic Zone - older cartilage cells enlarge
3. Calcification Zone - matrix is calcified
4. Ossification Zone - new bone formation

Question 8

Osteogenesis

Answer 8

Bone growth that start before birth:

1. Intramembranous ossification - ends 1-2 years after birth
2. Endochondral ossification - ends in early adulthood

Question 9

Factors Affecting Bone Growth

Answer 9

Nutrition and Hormones

Question 10

Effects of PTH

Answer 10

Increases Blood Ca+, by:

1. Stimulates osteoclast activity
2. Increases Ca absorption by intestines by promoting Vitamin D synthesis
3. Increase Ca reabsorption from urine

Question 11

Effects of Calcitonin

Answer 11

Decreases Blood Ca+

Stimulates osteoblast activity

Question 12

Compound Fracture

Answer 12

Breaks skin of the bone

Question 13

Simple Fracture

Answer 13

Skin does not break

Question 14

Incomplete Fracture

Answer 14

Partial break, not all the way

Question 15

Complete Fracture

Answer 15

Break all the way through the bone

Question 16

Comminuted Fracture

Answer 16

complete break with more than 2 pieces

Question 17

Bone Matrix

Answer 17

1. Ground Substance (organic - Osteoid)
   - Proteoglycans
2. Protein Fibers (organic - Osteoid)
   - Collagen
3. Calcium Phosphate Crystals (inorganic)
   - Must be ingested, deposited to the bone via blood

Question 18

Intramembranous ossification

Answer 18

Also referred to as dermal ossification. Examples of bones created through this process are flat bones of the skull, mandible (lower jaw), and ribs.

Question 19

Endochondral ossification

Answer 19

Linear growth of cartilage. Occurs within the cartilage itself. Starts with the division of chondrocytes within the lacuna into two identical cells.

Question 20

Fossa

Answer 20

Flattened, shallow depression or recess in the bone surface

Question 21

Canal

Answer 21

Rather large passageway through a bone

Question 22

Fissure

Answer 22

Elongated, narrow, cleft or slit-like opening through a bone

Question 23

Foreman

Answer 23

Small, rounded passageway through a bone, through which vessels and nerves pass

Question 24

Sulcus

Answer 24

Deep narrow groove

Question 25

Sinus

Answer 25

Hollow space, cavity, or chamber in a bone, normally filled with air

Question 26

Trochlea

Answer 26

Smooth grooved structure shaped like a pulley

Question 27

Condyle

Answer 27

Large, smooth rounded prominence

Question 28

Epicondyle

Answer 28

Adjoining projection to a condyle

Question 29

Tubercle

Answer 29

Small rounded projection

Question 30

Trochanter

Answer 30

Large, rough projection

Question 31

Tuberosity

Answer 31

Large protrusion (located at the proximal and lateral aspect of the shaft of the femur).