CH 12--DISEASES OF BONES--Bone 1/Disorders of Growth & Maturation

Question 1

BONE CELLS
3 types of cells
1. __________: bone-forming (present on surface)
2. _________: mature, adult, main type (able to form &
resorb bone)
3. __________: bone-destroying

Answer 1

Osteoblasts

Osteocytes

Osteoclasts

Question 2

NORMAL STRUCTURE & FUNCTION

Periosteum– (dense outer connective tissue layer)
endosteum– (lining medullary cavities)
***Arranged lamellae are seen in NORMAL healthy bone

_________bone – is haphazard arrangement of lamellae with an ↑ number of osteocytes and is usually present with pathology.

Answer 2

Woven

Question 3

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ marrow in:
1--ribs
2--vertebrae
3--pelvic bones
4--most proximal portions of the long bones

Intramembranous = ossification (bones of the skull)
Endochondral ossification = (limb bones)

Answer 3

Hematopoietic

Question 4

HORMONAL CONTROL

Three main hormones regulate calcium & phosphate
metabolism:
1. _____________ hormone – bone resorption
2. _____________ – inhibits movement of calcium from bone
to blood
3. Vitamin D – absorption of calcium from the intestines
↓ vitamin D leads to ________ in children &
Osteomalacia in adults

Answer 4

Parathyroid

Calcitonin

Rickets

Question 5

DISORDERS OF GROWTH & MATURATION
4 different groups:

1. Delayed \_\_\_\_\_\_\_\_\_ maturation disorders
 Cretinism 
 Morquio's disease
2. Bone Modeling disorders
 osteopetrosis
3. Epiphyseal plate disorders
Achondroplasia
 Scurvy 
Asymmetrical cartilage growth 
 Kyphoscoliosis 
 Osteomalacia
4. Delayed \_\_\_\_\_\_ Maturation disorders
 Osteogenesis imperfecta

Answer 5

cartilage

Bone

Question 6

CONGENITAL BONE DISORDERS (hereditary)–1

1-OSTEOGENESIS IMPERFECTA (Ol) (______ ____ disease)

Etiology:
a—-Hereditary disorder of collagen synthesis leading to
formation of abnormal lamellar collagen.

b—-Insufficient synthesis of type _____collagen

Answer 6

Brittle bone

I

Question 7

CONGENITAL BONE DISORDERS (hereditary)–2

1-OSTEOGENESIS IMPERFECTA (Ol) (Brittle bone disease)
Prevalence:
Estimate range from 20,000 to 50,000

TREATMENT:
- No cure for OI
- A surgical procedure called “_________” is frequently considered for individuals with OI by inserting metal rod through the length of long bones to strengthen them & prevent &/or correct deformity.
- ________ as much as possible to promote muscle & bone strength.
- maintain healthy weight, nutritious diet, avoid smoking, excessive
alcohol and caffeine consumption & taking steroid medications (all
of which may deplete bone & exacerbate bone fragility)

Answer 7

rodding

Exercise

Question 8

CONGENITAL BONE DISORDERS (hereditary)–3

2- OSTEOPETROSIS—(Alber’s Schönberg disease) or
“_______ _________ disease”

a •Hereditary abnormality of _________ (rare disease)
b •___________and sclerosis of bones = INCREASED
density of the skeleton
c • Obliteration in the medullary cavity = anemia
d • Despite the “too much” bone, it breaks easily
(pathological fractures)
e. • Less bone resorption resulting in a net bone
OVERGROWTH
f • Bone deformities and nerve compression
manifestations (reduction of neural foramina, deafness)

Two patterns:
1. Malignant—- become evident in-utero and infancy ,
autosomal recessive
2. benign—- adult, autosomal dominant

Answer 8

Marble bone

osteoclasts

Overgrowth

Question 9

CONGENITAL BONE DISORDERS (hereditary)–4

3- ACHONDROPLASIA

a. DECREASED cartilaginous growth
b. DWARFISM
c. Long bones are SHORT and relatively THICK

Epidemiology:

• It is the most common of a group of _______ _______ characterized by abnormal body proportions
• Only 20% of cases have a positive family history
• 80% is thought to be due to genetic mutation
• 1 in every 20,000 live births

Answer 9

growth defects

Question 10

CONGENITAL BONE DISORDERS (hereditary)–5

3- ACHONDROPLASIA

Manifestations:
- Normal membranous ossification → normal skull,
facial bones & axial skeleton
- Limbs → much ________ than normal
- Narrow foramen magnum and spinal canal may →
accumulation of too much fluid in brain (hydrocephalus)
- High risk of repeated middle ear infection → hearing
loss.

*****Treatment:
- There is NO specific treatment for achondroplasia.
- Related abnormalities, including spinal stenosis and spinal cord compression, and _________ should be treated
when they cause problems.

Answer 10

shorter

hydrocephalus

Question 11

CONGENITAL BONE DISORDERS (hereditary)–6

4-Osteochondroma
(Hereditary Multiple Exostosis)
a. An osteochondroma is a benign (noncancerous) tumor that develops during childhood or adolescence. It is an abnormal growth that forms on the surface of a bone near the growth plate.

Features:
a—— benign masses
b——The cross-sectional appearance of an osteochondroma shows the cap of calcified cartilage overlying poorly organized __________ bone.
c—–This bone growth, though ______, can sometimes
cause problems of pain and irritation that leads to removal surgically.

Answer 11

cancellous

benign