Chapter 6 - Bone Tissue & Skeletal System

Front 1

Bone are make up of several different types of tissue working together: (7)

Back 1

Bone Tissue

Cartilage

Dense Connective Tissue - Ligaments

Epithelium

Various blood forming tissues

Adipose tissue

Nervous tissue

Front 2

Each individual bone in a ____ because ___

Back 2

organ, made up of several tissues

Front 3

Bones along with cartilage make up ____ system

Back 3

skeletal

Front 4

The skeletal system performs five basic functions:

Back 4

1. Support

2. Storage of Minerals & Lipids

3. Blood Cell Production

4. Protection

5. Leverage

Front 5

Skeletal system stores:

Back 5

Minerals and Lipids. Bones store and release several minerals, especially calcium and phospate. The yellow marrow of adult dones is a site of triglyceride storage

Front 6

The ___ marrow of adult dones is a site of _____ storage

Back 6

yellow, triglyceride

Front 7

Hemopoiesis

Back 7

Blood cell production - red & white blood cells and other blood elements are produced in the red marrow of bones

Front 8

The skeletal system protects....

Back 8

many organs by bony coverings (e.g. skull -> brain)

Front 9

Leverage of skeletal system

Back 9

bones assist skeletal muscles to produce movement

Front 10

Structure of a long bone (7)

Back 10

1. Diaphysis

2. Epiphysis

3. Metaphysis

4. Medullary Cavity

5. Periosteum

6. Endosteum

7. Articular Cartilage

Front 11

Diaphysis

Back 11

the tubular shaft of the bone, includes a layer of solid, compact bone

Front 12

Epiphysis

Back 12

the expanded areas at ends of the bone (consists mostly of spongy bone)

Front 13

Metaphysis

Back 13

the areas between the epiphysis and diaphysis. Areas where a long bone can grow in length.

Front 14

Medullary Cavity

Back 14

the space within the diaphysis that contains the yellow marrow in adult long bones

Front 15

Periosteum

Back 15

connective tissue covering the surface of the bone. Contains osteoprogenitor cells that allow bones to grow in diameter or thickness, not in length.

Front 16

Endosteum

Back 16

lining of marrow cavity, contains some osteoprogenitor cells and connective tissue

Front 17

Articular Cartilage

Back 17

at the ends of long bone, reduces friction and absorbs shock at the joints

Front 18

Flat Bone

Back 18

resembles a spongy bone sandwich with layer of compact bone covering a core of spongy bone. (e.g.. parietal bone, pelvic bone)

Front 19

Bone Matrix

Back 19

Very dense and is composed of 33% collagen fibers and 67% inorganic components (mostly calcium salts)

Front 20

Osteogensis

Back 20

The process of creating bones

Front 21

Different types of bone cells (4)

Back 21

Osteoprogenitor

Osteoblast

Osteocyte

Osteoclast

Front 22

Osteoprogenitor

Back 22

unspecialized stem cells of bone tissue. Stem cell divides to form another stem cell and a daughter cells that differentiates.

Front 23

Osteoblast

Back 23

Cells that responsible for calcification

Front 24

Osteocyte

Back 24

mature bone cells (the most abundant bone cells). As osteoblasts surround themselves completely with matrix they turn into osteocytes. Osteocytes no longer secrete matrix. They maintain bone metabolism (i.e. exchange of nutrients and wastes with blood

In event of bone damage osteocytes can convert back to osteoblasts or osteoprogenitor cells to participate in repair

Front 25

Osteoclasts

Back 25

giant cells that remove and recycle bone matrix

- can release acids and enzymes that digest bone matrix as part of normal growth, repair or for mineral homeostasis

-they are not related to the first 3 cell types, they are a type of macrophage

Front 26

Homeostasis of Bone

Back 26

Osteoclasts are constantly removing matrix, and osteoblasts are always adding it. Balance between is essential. If the osteoclasts remove calcium salts too fast, the bone can weaken.

Front 27

Two types of bone

Back 27

Compact, Spongy

Front 28

Osteons

Back 28

How compact bone is arranged with very little space between them. Each contain osteocytes arranged in concentric layers around a central canal that contains blood vessels.

All are aligned in the same direction, along lines of stress. Thus the shaft does not bend, even when extreme force is applied to either end.

Front 29

Spongy Bone

Back 29

Has no osteon. Consists of trabeculae surrounding many red marrow filled spaces. Found where bones are not heavily stressed, mostly in short, flat, irregular shaped bones and in the epiphyses of long bones. Spongy bone tissue is light and support/protects the red bone marrow

Front 30

Two ways bones of the body are formed

Back 30

Endochondral & Intra membrane ossification

Front 31

Intra Membrane Ossification

Back 31

Happens between membranes, forms skull

Front 32

6 steps of Endochondral Ossification

Back 32

Step 1

chondrocytes in the center of hyaline cartilage enlarge & form struts which begin to calcify. Then the enlarged chondrocytes die, leaving cavities in the cartilage

Step 2

Blood vessels grow around the edges of cartilage; cells in the perichondrium change to osteoblasts, producing a layer of superficial bone around the shaft which will continue to grow & become compact bone (appositional growth)

Step 3

Blood vessels enter the cartilage, bringing osteoblasts, spongy bone develops at the primary ossification center

Step 4

Remodeling creates a marrow cavity, bone replaces cartilage at the metaphyses

Step 5

Capillaries & osteoblasts enter the epiphyses, creating secondary ossification centers

Step 6

Epiphyses fill with spongy bone, cartilage remaining within the joint cavity is the articulation cartilage (Hyaline cartilage only in this phase)

Front 33

Canaliculi

Back 33

Arms reaching out to other cells from osteocytes

Front 34

Where do Osteocytes live?

Back 34

Lacunae

Front 35

Functions of Osteocytes

Back 35

Maintain matrix - protein and mineral content

Help repair damaged bone

Front 36

Ways that calcium concentration is balanced in blood stream.

Back 36

Calcium & Phosphate absorbed from diet by intestines

Kidneys remove calcium

Osteoblast use up calcium, Osteoclasts release calcium

Front 37

Three main phases of bone growth and remodelling in humans:

Back 37

1.Birth to Adolescence - more bone is produced than is lost due to resorption

2.Young Adults - the rates of boneproduction and reabsorption are about the same (appx. 20% is recycled and replaced each year)

3.Middle-age to elderly - bone mass decreases because more bone is reabsorbed than is produced

Front 38

Osteoporosis

Back 38

the weakening of bones due to decreased deposition of calcium. Common in the elderly.

Front 39

Two reasons women are particulary at risk of getting osteoporosis:

Back 39

1. Have less bone mass to begin with. Thin, petite women are at most risk

2. The reproductive hormones contribute to bone decomp,and estrogen production declines at menopause, while testosterone is produced in men throughout life, with only as slight decline as they age.

Front 40

Prevention of osteoporosis

Back 40

1,500mg of dietary calcium daily

Weight bearing exercise - stress increases bone mass

Older adults: estrogen replacement therapy and/or drug called fosamax, which blocks resorption of bone by osteoclasts

Front 41

Bone is a _______ _______ for _____

Back 41

storage reservoir, minerals

Front 42

How much of calcium & phosphates in body is stored in bones

Back 42

99%

Front 43

What body functions need calcium ions (3)

Back 43

- nerve and muscle cells need calcium

- many enzymes only work with calcium

- needed for blood clotting

Front 44

Small chages in blood calcium level can cause (2)

Back 44

Heart to stop (calcium level too high)

Nervous convulsions (calcium level too low)

Front 45

Parathyroid hormone

Back 45

increases levels of calcium in bloodstream

- osteoclasts breakdown bone

- calcitriol increase intestine absorbtion

- kindey increase calcitriol and stimulates calcium reabsorbtion at kindeys (less calcium lost in urine)`

Front 46

Calcitonin

Back 46

Reduces calcium blood levels

- inhibits osteoclasts (does not effect osteoblasts)

- intestines stop absorbing extra calcium

- suppress absorption in kidneys (more calcium in urine)

Front 47

Fracture

Back 47

any break in a bone

Front 48

Types of Fractures (8)

Back 48

1. Colles Fracture

2. Potts fracture

3. Comminuated fracture

4.Epiphyseal fracture

5. Sprial Fracture

6. Compression fracture

7. Displaced fracture

8. Transverse fracture

Front 49

Most common fractures when seniors fall?

Back 49

Colles Fracture, Hip Fracture

Front 50

Type of fracture only occurs in children

Back 50

Greenstick fracture

Front 51

Physician that deals with the correction of deformities of bones:

Back 51

Orthopedist

Front 52

Fractures are broadly categorized as: (2)

Back 52

closed (simple), open (compound)

Front 53

Closed fracture

Back 53

- does not protrude through the skin

Front 54

Open Fracture

Back 54

broken ends of bone stick out through skin. Are more dangerous than closed fractures due to the possibility of infection and uncontrolled bleeding.

Front 55

Three treatments of bone fractures

Back 55

1. Realignment of the bone fragments (reduction)a. closed reduction - manual manipulation is enough b. open reduction - surgery is required with screws, plates, wires, rods

2. Immobilization to maintain realignment - cast, sling, splint, bandage, etc.

3. Restoration of function - happens with time and may require physiotherapy

Front 56

Repair of Fracture (4)

Back 56

1. Formation of a fracture hematoma that closes off the injured blood vessels. Inflammation occurs in response to dead bone cells, and phagocytes and osteoclasts remove dead or damaged tissue and microbes.

2. Formation of a callus. Cells of the peristeum and endosteum activate and migrate into the fracture zone. External callus of cartilage and bone encircle the bone at level of fracture. Internal callus of spongy bone also forms within the marrow cavity

3. Osteoblasts replace the cartilage of the external callus with spongy bone (cast would be removed at this stage)

4. Bone remodelling - osteoclasts and blasts remodel the calluss until the bone regains its original shape. May last 4 months to well over a year.

Front 57

Achondroplasia

Back 57

- Little people

- different protions due to unusual cartilage formation.99% of case, fibroblast growth factor receptor has a single mutation

Front 58

Rickets

Back 58

child has abnormal bone formation resulting from inadequte calcium in bones. Bones are soft and bendable and may have bow legs. Vitamin D lacking.

Front 59

Osteomalacia

Back 59

adult version of rickets. does not result in loe bowing but similar to rickets and treat in similar fashion. Common in countries where women fully cover their body (no sunlight)

Front 60

Gigantism

Back 60

bone grow longer as a child

Front 61

Acromegaly

Back 61

bones grow longer later in life

Front 62

Tall man in the world

Back 62

Robert Wadlow - 8'11" died at 22yrs

Front 63

Pituitary Dwarfism

Back 63

short bones but proportional

Front 64

Cleft Palate

Back 64

a split of opening in the bony plate or roof of the mouth. Occurs when the maxillary bones and palatine bones do not fuse properly. Hard to nurse if baby has because of extra air.

Front 65

Marfan's Syndrome

Back 65

limbs are extremely long and slender, results from excessive catilage formation at the epiphyseal plates. Defective elastic fibers in connective tissue is also present in other body organs, and these patients have weakened blood vessels

Front 66

Spina Bifida

Back 66

congenital defect of the vertebral column where vertebrae do not align properly and the spinal cord may protrude through openings between adjacent vertebrae. Research has shown that taking folic acid supplements during pregnancy reduce the risk of having a baby with a birth defect like spina bifida.

Front 67

Scoliosis

Back 67

Lateral curvature of the spine/ Idiopathic