Bone Disease

Question 1

(Of an immature or stem cell) capable of giving rise to several different cell types

Answer 1

Pluripotent

Question 2

Pluripotent (mesenchymal) stem cells that can form 3 cell types: Osteoblasts, chondroblasts, fibroblasts

Answer 2

Osteoprogenitor cells

Question 3

Bone forming cells

Answer 3

Osteoblasts

Question 4

Cartilage forming cells

Answer 4

Chondroblasts

Question 5

Collagen forming cells

Answer 5

Fibroblasts

Question 6

These cells synthesize the ‘organic’ bone matrix (osteoid), which constitutes 35% of bone

Answer 6

Osteoblasts

Question 7

When osteoblasts become embedded in the organic matrix they have secreted a ___ is formed

Answer 7

Osteocyte

Question 8

These cells will synthesize the initial template of long and irregular bones, being replaced eventually by osteoblasts.

Answer 8

Chondroblasts

Question 9

A large multinucleate bone cell that absorbs bone tissue during growth and healing.

Answer 9

Osteoclast

Question 10

____ are formed by the fusion of many cells derived from circulating monocytes (WBC) in the blood. These in turn are derived from bone marrow.

Answer 10

Osteoclasts

Question 11

The normal arrangement of bone matrix

Answer 11

Lamellar bone

Question 12

___ bone is “pre-bone”, an early stage of repair, or abnormal bone reacting to disease processes.

Answer 12

Woven

Question 13

Small channels in the bone that transmit blood vessels from the periosteum (outside) into the bone that communicate with the Haversian canals

Answer 13

Volkmann’s canals

Question 14

Small tubes in the outermost region of bone that allow blood vessels and nerves to travel through them.

Answer 14

Haversian Canals

Question 15

Any of the thready processes of the periosteum that penetrate the tissue of the superficial lamellae of bones

Answer 15

Sharpey’s fibers

Question 16

A dense layer of vascular connective tissue enveloping the bones, except at the surfaces of the joints.

Answer 16

Periosteum

Question 17

Which bone cell type produces RankL (growth regulator protein)

Answer 17

Osteocytes

Question 18

The thyroid gland secretes _____, which decreases osteoclast activity, and in turn, decreases blood calcium

Answer 18

Calcitonin

Question 19

What hormone will INCREASE osteoclast activity, and therefore increase blood calcium levels?

Answer 19

Parathyroid Hormone (PTH)

Question 20

The calcitonin/PTH processes are in balance up to age __, after that osteoclast is resorption slightly predominates and bone mass is lost at an estimated .5% per year.

Answer 20

40

Question 21

Organic bone matrix

Answer 21

Osteoid

Question 22

The osteoid (organic bone matrix) is made up of __% type 1 collagen

Answer 22

90%

Question 23

___ bone matrix is composed of calcium hydroxyapatite crystals (65% of bone)

Answer 23

Inorganic

Question 24

__% of the body’s calcium is in the bone

Answer 24

99%

Question 25

The two types of bone formation?

Answer 25

- Intramembranous | - Endochondral

Question 26

____ hormone is primarily responsible for managing calcium levels in the blood

Answer 26

Parathyroid (PTH)

Question 27

When blood calcium levels are LOW, the calcium sensor (on the surface of cells in the parathyroid gland) is _____ (Active/Inactive), which will cause PTH to be RELEASED

Answer 27

Inactive

Question 28

Name 3 things that PTH does:

Answer 28

1. Activates osteoclasts 2. Increases kidney reabsorption of Ca2+ 3. Stimulates increased activation of Vitamin D3 (which enhances gut absorption of calcium)

Question 29

___ bone formation is where bone is formed from a mesenchymal fibrous matrix and results in the formation of FLAT bones (no cartilage intermediary)

Answer 29

Intramembranous

Question 30

___ bone formation is when bone is formed on a cartilage matrix template (the major means of long bone formation, which then elongates after birth)

Answer 30

Endochondral

Question 31

Defective formation of bone

Answer 31

Dysostoses

Question 32

Digits that are fused together (all phalanges present - webbing)

Answer 32

Syndactyly

Question 33

Extra digits

Answer 33

Polydactyly

Question 34

Short digits

Answer 34

Brachydactyly

Question 35

The presence of cells of an abnormal type within a tissue. Also, abnormal growth or development of a tissue or organ.

Answer 35

Dysplasia

Question 36

Most common form of dwarfism

Answer 36

Achondroplasia

Question 37

Preaxial polydactyly refers to:

Answer 37

Extra thumb/great toe

Question 38

An extra little finger or toe is called?

Answer 38

Postaxial polydactyly

Question 39

Achondroplasia (most common form of dwarfism) is a fibroblast growth factor receptor mutation carried by the ____ (mother/father)

Answer 39

Father

Question 40

Genetic problems related to bone mass (osteopetrosis/porosis) are because of problems related to what protein?

Answer 40

LRP-5 (Low density lipoprotein receptor related protein 5)

Question 41

HYPER-activation of LRP-5 is called _____ and results in too much osteoblast activity

Answer 41

Osteopetrosis

Question 42

INACTIVATION of LRP-5 is called osteoporosis and results in too much osteo____ activity

Answer 42

Clast (resorption (breakdown) of bone)

Question 43

In achondroplasia what part of the body is NOT affected?

Answer 43

Skull (grows via intramembranous growth --no cartilaginous cells involved)

Question 44

Brittle bone disease

Answer 44

Osteogenesis imperfecta

Question 45

___ is due to abnormal Type 1 Collagen synthesis which causes skeletal fragility

Answer 45

Osteogenesis Imperfecta

Question 46

Abnormal type 1 collagen synthesis can affect other tissues, such as the eyes, as well. What clinical sign will be seen in the eyes if they are affected?

Answer 46

Blue sclera

Question 47

Other names for this include Albers-Schonberg Disease and Marble Bone Disease

Answer 47

Osteopetrosis (very hard bone)

Question 48

What similar result is occurring with osteopetrosis and osteogenesis imperfecta (but for completely different reasons)?

Answer 48

Bones are brittle and fracture easily

Question 49

The most severe type of osteopetrosis is ____

Answer 49

Infantile malignant osteopetrosis

Question 50

Increased cranial bone structure because of osteopetrosis can lead to ____ of the cranial nerves

Answer 50

Entrapment

Question 51

Long-term corticosteroid use (Ex: Asthma) and Hyperparathyroidism (autonomous overproduction of PTH) are secondary causes of ____

Answer 51

Osteoporosis

Question 52

Inadequate availability of Vitamin D

Answer 52

Osteomalacia

Question 53

In osteoporosis, the activity of what bone cell is dominating ("winning")?

Answer 53

OsteoCLASTS (increased bone resorption)

Question 54

In osteoporosis, there is a decrease in bone _____, while there is normal/close to normal bone quality

Answer 54

QUANTITY

Question 55

In osteoporosis, ___ bone is affected more than ___ bone (cortical, cancellous)

Answer 55

Cancellous, cortical

Question 56

A cancer of plasma cells (cancer of the bone marrow = weakens bones) is called?

Answer 56

Multiple myeloma

Question 57

Both hyper and hypothyroidism play a role in bone health because of the role of Vitamin __ in osteoblast and osteoclast activity.

Answer 57

D2

Question 58

Vitamin __ is responsible for calcium absorption in the bowel

Answer 58

D3

Question 59

Name for Vitamin D3?

Answer 59

Calciferol

Question 60

Vitamin D deficiency can cause osteomalacia (making bad bone). In children this is called ____

Answer 60

Rickets

Question 61

Osteomalacia results from defective ____ of the osteoid bone matrix (due to lack of vitamin D)

Answer 61

Mineralization

Question 62

On a chest X-Ray of a child, one may notice a bulbous appearance at the costochondral junction of the ribs due to cartilage overgrowth and metaphyseal splaying. This is known as ____ of Rickets

Answer 62

Rachitic Rosary

Question 63

In hyperparathyroidism (increased levels of PTH) ___ bone is affected more than ___ bone (cortical, cancellous)

Answer 63

Cortical, cancellous

Question 64

Osteopenia

Answer 64

Bone loss

Question 65

In hyperparathyroidism, "reflex" osteoblast activity in response to bone loss can decrease marrow space and create a "___ jersey" appearance on X-Ray (lucent bone density between the vertebral endplates). It can also create ___ tumors-to be seen usually on the 2nd and 3rd digits on X-Ray

Answer 65

Rugger, brown

Question 66

Paget Disease (Osteitis Deformans) is due to a dysfunction of what bone cell?

Answer 66

Osteoclasts

Question 67

Name the three stages of Paget Disease:

Answer 67

1. Osteolytic stage (increased osteoclast activity) 2. Mixed stage (osteoblasts try to "keep up" w/osteoclast activity) 3. Osteosclerotic stage ("burn-out" where osteoblasts make a lot of extra bone that is not structurally sound)

Question 68

Paget's Disease is polyostotic in __% of cases, affecting multiple bones. The other __% of cases are monostotic where it only affects one bone.

Answer 68

85%, 15%

Question 69

____ disease is a childhood hip condition where the blood supply to the femoral head is interrupted causing it to stop growing (avascular necrosis)

Answer 69

Legg-Calve-Perthes

Question 70

Avascular necrosis occurs in 15-30% of ___ fractures (carpal bone), making it a very common (maybe the most common) place to see AVN. Almost always involves the PROXIMAL POLE

Answer 70

Scaphoid