Chapter 6

Question 1

BONE/OSSEUS TISSUE
WHAT IS IT, HOW IS IT MADE

Answer 1

connective tissue in which the matrix is hardened by calciumphosphate and other minerals

Question 2

Diaphysis

Answer 2

the shaft of a bone (also called the Body)

Question 3

Epiphysis

Answer 3

the end(s) of a bone

Question 4

Articular (Hyaline) cartilage

Answer 4

covers the ends of moveable bones

Question 5

Periosteum

Answer 5

fibrous membrane that covers the outer portion of a
bone, tendons attach here, highly innervated

Question 6

Medullary (Marrow) cavity

Answer 6

space inside bone that contains marrow

Question 7

Endosteum

Answer 7

the lining of the medullary cavity

Question 8

Epiphyseal plate

Answer 8

area that contains hyaline cartilage in growing
bone, area that causes bone to elongate, becomes ossified (bone) in adults

Question 9

Osteogenic cell

Answer 9

a stem cell that differentiates to become an
Osteoblast

Question 10

Osteoblast

Answer 10

cells that lay down collagen fibers and matrix
to form bone

Question 11

Osteocyte

Answer 11

mature osteoblast, bone cells, sense the various stressors on bone

Question 12

Osteoclast

Answer 12

bone dissolving cells

Question 13

Matrix

Answer 13

• mostly Hydroxyapatite, a calcium phosphate salt, and some calcium
  carbonate
• organic portion is mostly collagen

Question 14

Compact bone

Answer 14

• densely packed bone, usually located in the outer diaphysis

Question 15

Osteon = Haversian System is the

Answer 15

• the basic structural unit of compact bone

Question 16

Central (Haversian) canal

Answer 16

located at the center of the Osteon, contains vessels and
nerves

Question 17

Concentric lamellae

Answer 17

• concentric layers of matrix that surround the Central canal

Question 18

Lacuna

Answer 18

the space that houses a osteocyte

Question 19

Canaliculi

Answer 19

• “tiny canals” that connect lacuna

Question 20

Perforating (Volkmann) canal

Answer 20

channels that contain vessels and nerves, connect adjacent osteons and osteons to the outer surface of bone

Question 21

Spongy bone

Answer 21

loosely packed bone, usually found inside of the epiphysis
a. Trabeculae
- thin plates of calcified tissue that provide a lattice
appearance to spongy bone

Question 22

Red Bone Marrow

Answer 22

hemopoietic tissue (produces formed elements of the blood,
ex. RBC, WBC, Platelets

Question 23

Yellow Bone Marrow

Answer 23

Adipose tissue, not hematopoietic

Question 24

Bone Developmentis is called

Answer 24

Ossification or Osteogenesis = formation of bone
- Two methods:

Question 25

Intramembranous ossification produces

Answer 25

produces flat bones, ex. skull, clavicle - bone develops from membranes

Question 26

Endochondral ossification

Answer 26

produces most bones - hyaline cartilage matrix is laid down initially, then ossification occurs replacing this cartilage

Question 27

Remodeling

Answer 27

The change of the size and shape of bones to accommodate the changing forces applied to the skeleton.

Question 28

Interstitial growth

Answer 28

Adding matrix. When this occurs in the hyaline cartilage of the epiphyseal plate, the bone grows in length.

Question 29

Appositional growth

Answer 29

Deposition onto the surface of bone. Increases the diameter of a bone.

Question 30

Calcium and Phosphate Homeostasis.

Answer 30

Normal range of blood calcium = 9.2 to 10.4 mg/dL

Question 31

Hypocalcemia

Answer 31

low blood calcium, muscle is unable to relax, tetany

Question 32

Hypercalcemia

Answer 32

high blood calcium, nerves and muscles are slow torespond; weakness, sluggish reflexes, poss. cardiacarrest

Question 33

Calcitriol

Answer 33

a form of vitamin D, is stimulated by absorption of UV light - this hormone raises blood calcium by: a. Increasing absorption in the Small Intestine. b. Stimulates calcium removal from bones (Osteoclast). c. Causing the Kidney to retain calcium in the blood.

Question 34

Calcitonin

Answer 34

released by the Thyroid gland - this hormone lowers calcium level in the blood by: a. Inhibiting Osteoclast. b. Stimulate Osteoblast (places calcium into bone)

Question 35

Parathyroid hormone (PTH)

Answer 35

this hormone raises the blood calcium level by: a. Stimulating Osteoclast. b. Causing the Kidneys to retain calcium in the blood. c. Stimulates the production of Calcitriol. d. Decreases Osteoblast activity.

Question 36

Fracture

Answer 36

Any disruption in the continuity of a bone. - During normal fracture repair, the bone forms a hard callus that is often stronger than the original bone.

Question 37

Steps associated with fracture repair, step 1

Answer 37

Hematoma forms around fracture site

Question 38

Steps associated with fracture repair, step 2

Answer 38

Granulation tissue forms - hematoma becomes infiltrated with capillaries, fibroblasts, macrophages, osteoclasts, osteogenic cells

Question 39

Steps associated with fracture repair, step 3

Answer 39

Callus formation - fibroblasts lay down collagen, "soft callus" is formed which is made up of fibrocartilage

Question 40

Steps associated with fracture repair, step 4

Answer 40

Remodeling - bone tissue is laid down replacing cartilage, this forms the bony (hard) callus - initially spongy bone is laid down, the outer portion of the bone is converted (remodeled) into compact(cortical) bone

Question 41

Osteoporosis

Answer 41

Loss of bone mass, making them more susceptible to fracture. Associated with aging. _