Bones and Joints - Final Exam

Question 1

How many bones to adult humans have?

Answer 1

206

Question 2

How much body weight do the bones attribute?

Answer 2

12%

Question 3

How much bone is replaced annually?

Answer 3

10%

Question 4

Periosteum

Answer 4

Outer layer of fibrous tissue surrounding bone

Question 5

Cortical bone

Answer 5

Hard layer of bone surrounding inner cancellous bone

Question 6

Cancellous bone

Answer 6

Spongy bone

Question 7

Medullary layer

Answer 7

Primarily in long bone
Inside cancellous bone
Reticular or lace formation
Supports bone marrow

Question 8

Bone marrow

Answer 8

Makes blood cells

Question 9

Cells of the bone (3)

Answer 9

1. Osteoclast
2. Osteoblast
3. Osteocyte

Question 10

Osteoid

Answer 10

Calcified type I collagen

Question 11

Osteoclast

Answer 11

Used to remodel bone

Resorb osteoid

Question 12

Osteoblast

Answer 12

Make osteoid and control mineralization of bone

Question 13

Osteocyte

Answer 13

Osteoblasts that have surrounded themselves with bone

Involved in mineralization and sense mechanical forces

Question 14

Epiphys

Answer 14

End of long bones, associated with cartilage cap and joint

Question 15

Metaphysis

Answer 15

Contains growth plate

Changes radically during growth

Question 16

Diaphysis

Answer 16

Central portion of bone

Question 17

Two mechanisms of bone formation

Answer 17

Endochondral ossification

Intramembranous ossification

Question 18

Endochondral ossification

Answer 18

Long bones

Cartilage makes bone bigger first, then turned into bone

Question 19

Intramembranous ossification

Answer 19

Flat bones

Fibrous tissue is taken up and calcified

Question 20

Functions of bones

Answer 20

Support muscles, facilitate movement
Protect organs
Site of bone marrow
Storage of calcium and phosphate

Question 21

Vitamin D functions (3)

Answer 21

1. Increased Ca absorption by intestine
2. Resorption of Ca by kidneys
3. Bone mineralization (calcification of osteoid)

Question 22

Cause of Vitamin D deficiency (3)

Answer 22

1. Lack of exposure to sunlight
2. Inadequate intake
3. Abnormal intestinal absorption

Question 23

Vit D deficiency

Answer 23

Osteopenia (osteomalacia)

Question 24

Osteopenia

Answer 24

Decreased mineralization of bone
Bones are soft, pliable
Increased fractures
Rickets in children

Question 25

Osteoporosis

Answer 25

``` Reduction of bone mass Often multifactorial Cortical and medullary bone is lost Fracture risk increases (can be caused by body weight alone, vertebrae, hips and distal radius) Primary or secondary ```

Question 26

Primary osteoporosis

Answer 26

Idiopathic | Older age, menopause, diet/lifestyle, low initial bone mass

Question 27

Secondary osteoporosis (5)

Answer 27

Due to identifiable cause 1. Hormone inbalances (menopausal women) 2. Dietary insufficiency 3. Drugs (steroids) 4. Tumours (hormone production or direct bone destruction) 5. Immobilization

Question 28

Fractures

Answer 28

Disruption of bone structure Usually due to trauma Complete or incomplete Simple, comminuted, open/compound, complicated, pathogenic

Question 29

Complete fracture

Answer 29

Through entire thickness of bone

Question 30

Incomplete fracture

Answer 30

Through partial thickness of bone

Question 31

Simple fracture

Answer 31

One fracture

Question 32

Comminuted fracture

Answer 32

Multiple fractures

Question 33

Closed fracture

Answer 33

Skin intact

Question 34

Open/compound fracture

Answer 34

Skin disrupted

Question 35

Complicated fracture

Answer 35

Infected

Question 36

Pathologic fracture

Answer 36

Due to abnormal bone (osteoporosis, tumour)

Question 37

Fracture healing (4)

Answer 37

1. Blood fills gap left by fracture and clots (hematoma) 2. Inflammatory cell, fibroblasts, and new capillaries use clot framework and ingrow (granulation tissue) 3. Soft tissue becomes woven bone (bony callus) 4. Matures and subjected to physical/weight bearing stress - remodelling to become like regular bone, but only 70% of former strength

Question 38

Osteomyelitis

Answer 38

Infection of bone Usually bacterial (occasionally fungal, rarely viral) Tries to wall off infection by making more bone, with necrotic tissue in center, can have sinus formation Difficult to treat (surgery, amputation)

Question 39

Causes of osteomyelitis (3)

Answer 39

1. Direct inoculation/trauma (stabbed into bone) 2. From adjacent joint (septic joint) 3. Haematogenously (by blood)

Question 40

Bone tumors

Answer 40

Rare Benign (osteoma) or malignant (osteosarcoma) Mainly in children or young adults Each bone tumour has preferred site

Question 41

Osteosarcoma

Answer 41

Most common primary bone malignancy Occurs in children/adolescents Common in metaphysis of long bones Tumour of osteoblasts, making disorganized osteoid Typically metastatic at presentation (lungs) Treated with chemotherapy and surgery 60-70% live 5 years post-treatment

Question 42

Joint

Answer 42

Connection between 2 or more bones Allows movement, support and structure Two types

Question 43

Two types of joints

Answer 43

1. Synarthroses - little to no movement | 2. Synovial - allow movement

Question 44

Synovial joints

Answer 44

Bones covered in cartilage Non-boney surfaces covered with synovial cells that produce fluid Surrounded by capsule made of connective tissue/tendons May have meniscus (fibrous tissue that absorbs shock)

Question 45

Osteoarthritis

Answer 45

``` Degenerative joint disease Affects weight bearing joints (knee) Increased incidence with age and weight Due to wear and tear Cartilage damage Many symptoms ```

Question 46

Cartilage damage of osteoarthritis (5)

Answer 46

1. Exposed bone 2. Boney sclerosis (looks like ivory, called eburnation) 3. Cysts form in bone (fibrosis in bone marrow spaces) 4. New nodules of bone form, project into joint space and adjacent soft tissue 5. Inflammation and welling

Question 47

Eburnation

Answer 47

Boney sclerosis | Makes bone look like ivory

Question 48

Osteophytes

Answer 48

New nodules of bone | Project into joint spaces and adjacent soft tissue

Question 49

Symptoms of osteoarthritis (6)

Answer 49

1. Pain 2. Crepitus 3. Swelling, inflammation 4. Deformation 5. Loss of mobility 6. Stiffness ***improves with rest

Question 50

Crepitus

Answer 50

Cartilage degeneration

Question 51

Rheumatoid arthritis

Answer 51

Systemic autoimmume disease affecting synovial joints May affect any age group Synovium becomes markedly inflamed Inflammatory cells and fluid expand joint pace (pannus formation) Inflammation stimulates growth of vessels and proliferation of synovium, produce factors that induce injury to cartilage and bone Bone fusion (ankyloses) can appear

Question 52

Characteristic features of rheumatoid arthritis (3)

Answer 52

1. Chronic, symmetric inflammation of joints 2. Serologic evidence of autoimmune disorder 3. Extra-articular manifestations (splenomegaly, skin nodules)

Question 53

Symptoms of rheumatoid arthritis (5)

Answer 53

1. Pain 2. Joint deformity 3. Limited mobility (scarred into place) 4. Contractures 5. Stiffness (improves with movement)

Question 54

Pannus formation

Answer 54

Inflammatory cells and fluid expanding joint space

Question 55

Ankyloses

Answer 55

Bone fusion

Question 56

Gout

Answer 56

Disease due to hyperuricemia Deposition of uric acid crystals in various body sites (big toe) Primary or secondary Uric acid crystals are insoluble in tissue Lower temperatures encourage crystallization, which induce inflammation Acute or chronic

Question 57

Primary gout

Answer 57

Metabolic (increased uric acid production) | Renal (decreased uric acid excretion)

Question 58

Secondary gout

Answer 58

Malignancy, chronic kidney disease

Question 59

Acute gout

Answer 59

Pain, swelling, problems with mobility/walking, systemic symptoms Last days

Question 60

Chronic gout

Answer 60

``` Bone deformities Gouty tophi (tumour like masses) ```