Skeletal System Part 2

Question 1

In embryo, what is the skeleton primarily made of?

Answer 1

Cartilage

Question 2

Ossification

Answer 2

Bone formation

Question 3

Osteoblasts

Answer 3

Bone forming cells.
Covers Hyaline cartilage.

Question 3

When cartilage is broken down, what does it produce?

Answer 3

Marrow

Question 4

Bone is a …… and a ……. tissue.

Answer 4

Dynamic & Active

Question 5

What are the two factors that remodel bones?

Answer 5

Calcium levels in the blood& pull of gravity & muscle on skeleton.

Question 6

Calcium Levels

Answer 6

When calcium levels drop below homeostatic levels, the parathyroid releases parathyroid hormone (PTH) to activate osteoclasts.
When calcium levels in the blood increase, calcium is deposited in the bone matrix.

Question 7

Pull of Gravity & Muscle on Skeleton

Answer 7

Stress of muscle pull away & gravity action on the skeleton determine where bone matrix is to be broken down or forms so that the skeleton can remain as strong & vital as possible.

Question 8

Osteoclasts

Answer 8

Giant bone-destroying cells in bones to release calcium.

Question 9

What are the two classifications of bones fractures?

Answer 9

Closed & Compound

Question 10

Closed Fracture

Answer 10

Does not penetrate the skin

Question 11

Compound Fracture

Answer 11

End of bones penetrate through the skin.

Question 12

Reductions

Answer 12

A realignment of the broken bone ends.

Question 13

Open Reductions

Answer 13

Surgery & the bone ends are secured together with pins or wires.

Question 13

Closed Reduction

Answer 13

Bone ends are coaxed back into position by physicians hands.

Question 14

Comminuted Fracture

Answer 14

Bone breaks into many fragments.
Most common in older people & brittle bones.

Question 15

Compression Fracture

Answer 15

Bone is crushed.
Common in porous bones.

Question 16

Depressed Fracture

Answer 16

Broken bone is pressed inward.
Typical of skull fractures.

Question 17

Impacted Fracture

Answer 17

Broken bone ends are forced into each other.
Commonly occurs when someone attempts to break a fall with an outstretched arm.

Question 18

Spiral Fracture

Answer 18

Ragged break occurs when excessive twisting forces are applied to a bone.
Common sports fracture.

Question 19

What are the stages of healing a bone fracture in order?

Answer 19

1. Hematoma
2. Fibrocartilage Callus Forms
3. Bony Callus Forms
4. Bone Remodeling Occurs

Question 20

Hematoma

Answer 20

Hematoma forms (blood-filled swelling)

Question 21

Fibrocartilage Callus Forms

Answer 21

Growth of new capillaries in the clotted blood at the site of damage.
Removal of dead tissue by phagocytes.
Contains cartilage, bony matrix, & colagen fibers.

Question 22

Bony Callus Forms

Answer 22

Osteoblasts & Osteoclasts migrate into the area and multiply.
Fibrocartilage callus is replaced by bony callus made of spongy bone.

Question 23

Bone Remodeling

Answer 23

Bony callus is remodeled in response to the mechanical stresses placed on it.
Forms a new permanent “patch” at the fracture site.