Ossification & Osteoclasts - Anatomy Final Exam

Ossification & Osteoclasts – Anatomy Final Exam

The key terms of Anatomy Final Exam include, Bone, Cartilage, Vitamin, Produce, Ossification, Osteoclasts, Fibrous, Joint, Increase.

Glucocorticoids increase bone ________; high levels of serotonin lead to _____ bone density.

formation, high
formation, low
loss, high
loss, low – correct

Which vitamin is required for the normal synthesis of collagen?

Vitamin D
Vitamin B
Vitamin A
Vitamin C – correct
Vitamin K

To trigger bone growth, growth hormone stimulates the:

liver to produce somatomedin. – correct
liver to produce calcitonin.
brain to produce serotonin.
parathyroid to produce parathyroid hormone.
thyroid to produce calcitriol.

Before beginning orthodontic treatment, a patient may have her wrist and hand x-rayed to determine her stage of growth. What long bone feature will the orthodontist use to assess this?

Osteon
Periosteum
Spongy bone
Epiphyseal plate – correct
Compact bone

The formation of bone from a cartilaginous model is termed:

mesenchymal ossification.
intramembranous ossification.
bone remodeling.
orthodontia.
endochondral ossification. – correct

When bone forms by intramembranous ossification, the ossification centers are within:

hyaline cartilage.
compact bone.
mesenchyme. – correct
elastic cartilage.
spongy bone.

Which bone forms by intramembranous ossification?

Zygomatic – correct
Radius
Axis
Hamate
First metatarsal

Which choice places the steps of intramembranous ossification in correct chronological order?
a: Formation of lamellar bone
b: Osteoid undergoes calcification
c: Ossification centers form
d: Formation of woven bone and its periosteum

b – a – c – d
c – b – d – a – correct
c – b – a – d
a – c – d – b
b – c – d – a

Endochondral ossification begins with a(n) _________ model.

mesenchyme
dense connective tissue
hyaline cartilage – correct
membranous
osteoid

When during human development does the process of ossification begin?

12 weeks after birth
12th-13th week of embryonic development – correct
8th-9th month of fetal development
3-4 months of age
10-25 years of age

The steps in the process of endochondral ossification are
a: Ossification center forms in the diaphysis.
b: Cartilage calcifies and a bone collar forms.
c: Ossification centers form in the epiphyses.
d: Bone replaces cartilage.
e: Epiphyseal plates ossify.
f: Cartilage model develops.
The correct chronological order for these steps is:

f. – b. – c. – d. – a. – e.
b. – c. – f. – a. – e. – d.
a. – c. – b. – d. – e. – f.
f. – b. – a. – c. – d. – e. – correct
a. – e. – c. – d. – b. – f.

During the process of endochondral ossification, chondrocytes in the cartilage model die. Why does this occur?

Blood supply to the cartilage is cut off by the developing periosteum.
Canaliculi connecting adjacent chondrocyte lacunae fuse.
Nutrients cannot diffuse to the chondrocytes through the calcified matrix. – correct
The developing bone collar secretes enzymes that destroy the chondrocytes.
Phagocytic osteoclasts in the new bone engulf and destroy the chondrocytes.

The zones found in an epiphyseal plate are
a: Calcified cartilage
b: Hypertrophic cartilage
c: Ossification
d: Resting cartilage
e: Proliferating cartilage
The correct order for these zones, beginning with the edge closest to the epiphysis and proceeding toward the diaphysis, is:

c – a – b – e – d
d – b – e – a – c
e – d – a – c – b
c – d – e – a – b
d – e – b – a – c – correct

Within which zone of the epiphyseal plate do cartilage cells undergo mitosis?

The zone closest to the medullary cavity
The zone closest to the epiphysis
The second closest bone to the medullary cavity
The second closest zone to the epiphysis – correct

Which is an accurate description of appositional bone growth?

Osteoblasts build bone at the circumferential lamellae while osteoclasts widen the medullary cavity. – correct
Osteoclasts build bone at the concentric lamellae while osteoblasts build bone at the interstitial lamellae.
Osteoblasts build bone at the concentric lamellae while osteoclasts build bone at the epiphyses.
Osteocytes build bone at the interstitial lamellae while osteoclasts expand the length of the medullary cavity.
Osteocytes and osteoclasts expand the bone at its epiphyses, chondrocytes construct cartilage.

Bone growth in which the bone increases in diameter is called:

interstitial growth.
epiphyseal growth.
appositional growth. – correct
endosteal growth.
cancellous bone growth.

Which is not true about bone remodeling?

It occurs throughout life.
It assists in the maintenance of calcium and phosphate levels in the body.
It occurs at both the endosteal and periosteal surfaces of the bone.
It occurs only at articular surfaces. – correct
It can occur in response to stress on a bone.

The type of bone tissue that is replaced more frequently is ________ bone; the part of the femur that is replaced more frequently is the __________.

compact, distal epiphysis
compact, diaphysis
spongy, distal epiphysis – correct
spongy, diaphysis

Mechanical stress of bones, such as that caused by weight lifting, is detected by:

osteocytes, which then communicate to osteoblasts to increase synthesis of osteoid. – correct
osteoclasts, which then communicate to osteocytes to increase the size of lacunae.
chondrocytes, which then trigger osteoblasts to increase bone in a lengthwise fashion.
osteoblasts, which then communicate to osteocytes and osteoclasts to deposit more hydroxyapatite.

The epiphyseal plates in the _________ are the last ones in the body to ossify.

femur
humerus
clavicle- correct
radius
tibia

Which hormone inhibits rather than stimulates bone growth?

Calcitonin
Estrogen and testosterone
Thyroid hormone
Parathyroid hormone- correct
Growth hormone