Chapter 6

Question 1

What is the name of a mature cartilage cell?

Answer 1

Chondrocytes

Question 2

What is a lacunae?

Answer 2

The space that a chondrocyte occupies in the cartilage matrix.

Question 3

Since cartilage is avascular, how does it receive nutrition and rid itself of waste?

What effect does this have on healing?

Answer 3

Diffusion through the matrix

Cartilage heals poorly

Question 4

Function of hyaline cartilage (2)

Answer 4

1. Provides stiff but somewhat flexible support

2. Reduces friction between bony surfaces

Question 5

Functions of elastic cartilage

Answer 5

Provides support, but tolerates distortion without damage and returns to original shape

Question 6

Functions of fibrocartilage (3)

Answer 6

1. Resists compression
2. Prevents bone-to-bone contact
3. Limits movement

Question 7

Location of hyaline cartilage (4)

Answer 7

1. Between the ribs, and bones of the sternum
2. Covering bone surfaces at synovial joints
3. Supporting larynx, trachea, and bronchi
4. Forming part of the nasal septum

Question 8

Location of Elastic cartilage (4)

Answer 8

1. Auricle of external ear
2. Epiglottis
3. Auditory canal
4. Cuneiform cartilages of the larynx

Question 9

Location of Fibrocartilage (3)

Answer 9

1. Pads within knee joints
2. Between pubic bones of the pelvis
3. Intervetebral discs

Question 10

What are the components found in the matrix of bone?

Answer 10

Calcium salts
Calcium phosphate
Lesser amounts of calcium carbonate Collagen fibers

Question 11

List the primary function of the skeletal system.

Answer 11

1. Support
2. Storage of minerals and lipids
3. Blood Cell Production
4. Leverage

Question 12

Matrix

Answer 12

Consists of extracellular fibers and calcium salts

Question 13

Lacunae

Answer 13

Small chambers where osteocytes and chondrocytes live

Question 14

Canaliculi

Answer 14

Passageways between lacunae for nutrient and waste exchange

Question 15

Periosteum

Answer 15

The connective tissue layer which surrounds the bone

Question 16

Osteocyte

Answer 16

The bone cell which maintains the matrix

Question 17

What attribute do the collagen fibers provide to bone?

Answer 17

Flexibility to the bone

Question 18

What attribute dose the hydroxyapatite provide to bone?

Answer 18

Stiffens the bone

Question 19

Maintain the protein and mineral content of the matrix.

Answer 19

Osteocytes

Question 20

Produce new bone matrix

Answer 20

Osteoblast

Question 21

Stem cells which can differentiate to make new osteoblasts

Answer 21

Osteogenic

Question 22

Break down or resorb matrix

Answer 22

Osteoclast

Question 23

What is the functional unit of bone?

Answer 23

Osteon

Question 24

Functions of red bone marrow

Answer 24

Forms blood cells

Question 25

Functions of yellow bone marrow

Answer 25

Adipose tissue for energy reserve

Question 26

What function does spongy bone provide in the epiphysis of a long bone

Answer 26

Distribution of weight

Question 27

Where is the periosteum located?

Answer 27

Superficial layer of compact bone

Question 28

What are the functions of the periosteum

Answer 28

1. Isolates the bone from surrounding tissues 2. Provides a route for the blood vessels and nerves 3. Takes part in bone growth and repair

Question 29

Where is the endosteum located

Answer 29

Lines the medullary cavity

Question 30

What are the functions of the endosteum

Answer 30

1. Bone growth 2. Bone repair 3. Bone remodeling

Question 31

Growth in the girth of a bone is termed _____ growth

Answer 31

Appositional

Question 32

Where is the primary ossification centers located in a long bone.

Answer 32

Diaphysis

Question 33

Where is the secondary ossification centers located in a long bone.

Answer 33

Epiphysis

Question 34

Growth in length of a bone occurs at what location

Answer 34

epiphyseal cartilage

Question 35

Epiphyseal plate vs epiphyseal line

Answer 35

Plate: New bone is produced Line: Occurs after epiphyseal closure happens and growth ends

Question 36

What bones are formed via intramembranous ossification.

Answer 36

Dermal bones - Skull, mandible, and clavicles

Question 37

What is bone remodeling

Answer 37

Continuously recycles and renews the organic and mineral components of the bone matrix

Question 38

What cells are involved in bone remodeling

Answer 38

Osteocytes, osteoclasts, and osteoblasts

Question 39

Why would a bone undergo remodeling

Answer 39

1. To repair microfractures in the bone 2. To maintain blood calcium levels in the correct range 3. To reinforce heavily-stressed regions of the bone

Question 40

Summarize the effects of exercise on the bone

Answer 40

Mineral crystals generate minute electrical fields. Osteoblasts are attracted to the electrical fields and begin to produce bone. Where tendons attach to the bone develops with exercise.

Question 41

What two minerals are present in the largest amounts in bone

Answer 41

Calcium | Phosphorus

Question 42

Function of the hormone: calcitriol

Answer 42

Increase calcium and phosphorus absorption

Question 43

Function of the hormone: Sex hormones

Answer 43

Stimulates osteoblast activity and synthesis of bone matrix

Question 44

Function of the hormone: Parathyroid hormone

Answer 44

Simulates osteoclast activity

Question 45

Function of the hormone: Calcitonin

Answer 45

In pregnant and nursing women, it decreases blood calcium ion levels and may aid calcium ion transfer to the fetus

Question 46

Where is the majority of calcium stored in the human body

Answer 46

Skeleton

Question 47

Describe negative feedback to maintain blood calcium levels - high blood calcium levels

Answer 47

Increased blood calcium levels causes the thyroid gland to release calcitonin. Calcitonin decreases osteoclasts and decreases the release of calcitriol, which is in the kidneys, slows the absorption of calcium in the small intestines. Calcitonin increases osteoblast and increases urine excretion of calcium.

Question 48

Describe negative feedback to maintain blood calcium levels - low blood calcium levels

Answer 48

Decreased blood calcium levels causes the parathyroid to release PTH. PTH decreases osteoblast and the excretion of calcium in the urine. PTH increases osteoclasts and causes the kidney's to release calcitroil. Which increases the absorption of calcium in the small intestines.

Question 49

Closed fracture

Answer 49

The break remains completely internal

Question 50

Open fracture

Answer 50

The fracture breaks through the skin

Question 51

Transverse fracture

Answer 51

Break a bone shaft across it's long axis

Question 52

First step in Fracture Repair

Answer 52

Fracture Hematoma Forms - Torn blood vessels hemorrhage and clots - Site becomes swollen, painful, and inflammed - Happens immediately

Question 53

Second Step in Fracture Repair

Answer 53

Callus Forms - Cells of the periosteum and endosteum undergo rapid division - Phagocytic cells clear debris - Osteoblasts begin forming spongy bone - Cartilage and bone material stabilizes the outside region of the break - Fibroblasts secrete collagen fibers to connect bone ends - Happens after about a week

Question 54

Third Step in Fracture Repair

Answer 54

Spongy Bone Formation - New trabeculae form a bony callus - Break can with stand normal muscle movement - Bony callus formation continues until firm union is formed in about 2 months

Question 55

Final Step in Fracture Repair

Answer 55

Compact Bone Formation | - Remodeled by osteoblasts and osteoclasts

Question 56

When osteopenia becomes severe enough to interfere with the normal functioning of bone, it is termed

Answer 56

Osteoporosis

Question 57

Why is severe osteoporosis less frequent in men than in women

Answer 57

Men - Produce testosterone until late in life | Women - Have a decline in estrogen after menopause