Bone Development, Bone Homeostasis: Remodeling and Repair, Fractures

open reduction

surgical realignment of broke bone ends.

"Maturation" of newly formed (noncalcified) bone matrix takes about [10 days].

False; "maturation" takes about 12 days.

[Membrane] bones develop from hyaline cartilage structures.

False; Cartilage bones develop from hyaline cartilage structures.

Epiphyseal plates are made of [spongy bone].

False; Epiphyseal plates are made of hyaline cartilage.

[Osteocytes] produce collagen fibers that span the break.

False; Fibroblast produce the collagen fibers.

Large numbers of [osteocytes] are found in the inner periosteum layer.

False; Large numbers of mesenchymal cells/osteoblasts are found in the inner periosteum layer.

Osteoblasts from the [medullary cavity] migrate to the fracture site.

False; Osteoblasts from the periosteum cavity.

[Primary] ossification centers appear in the epiphyses.

False; Secondary ossification centers appear in the epiphyses.

The enzyme alkaline phosphatase encourages the deposit of [collagen fibers] within the matrix of developing bone.

False; alkaline phosphatase encourages the deposit of calcium salts within the matrix of developing bone.

In appositional growth, bone reabsorption occurs on the [periosteal] surface.

False; bone reaborption occurs on the endoseal surface.

When a bone forms from a fibrous membrane, the process is called [endochondral] ossification.

False; intramembrous ossification is the process when a bone forms from a fibrous membrane.

Nonbony debris at the fracture site is removed by [fibroblasts].

False; nonbony debris is removed by phagocytes.

The bony callus is composed of [compact] bone.

False; the bony callus is composed of spongy bone.

When blood calcium levels begin to drop below homeostatic levels, ____ is released, causing calcium to be released from bones.

Parathyroid hormone

When trapped in lacunae, osteoblasts change into [osteocytes].

True

A [hematoma] usually forms at a fracture site.

True

Deprived of nutrition, [osteocytes] at the fracture site die.

True

During endochondral ossification, the [periosteal bud] invades the deteriorating hyaline cartilage shaft.

True

The [fibrocartilaginous callus] is the first repair mass to splint the broken bone.

True

The organic bone matrix is called the [osteoid].

True

greenstick fracture

a break common in children; bone splinters, but break is complete.

spiral fracture

a common sports fracture

depressed fracture

a common type of skull fracture.

compound fracture

a fracture in which the bone ends penetrate through the skin surface.

compression fracture

a fracture in which the bone is crushed; common in the vertebral column.

simple fracture

also called a closed fracture.

Disuse such as that caused by paralysis or severe lack of exercise results in muscle and bone _____.

atrophy

spiral fracture

bone breaks from twisting forces.

simple fracture

bone is broken cleanly; the endsdo not penetrate the skin.

_______ causes blood calcium to be deposited in bones as calcium salts.

calcitonin

Astronauts must perform isometric exercises when in outer space because bones atrophy under conditions of weightlessness or lack of ______.

gravity

closed fracture

nonsurgical realignment of broke bone ends and splinting of bone.

comminuted fracture

often seen in the brittle bones of the elderly.

Immature, or matrix-depositing, bone cells are referred to as ______.

osteoblasts

Bone cells that liquefy bone matrix and release calcium to the blood are called ______.

osteoclasts

Mature bone cells, called _____, maintain bone in a visible state.

osteocytes

Large tubercles and/or increased deposit of bony matrix occur at sites of ______.

stress and/or tension