a. The bones of your body form your skeleton. The skeleton forms the
framework of your body. The bones that form the ribcage and the pelvis act to protect
internal organs such as the heart, lungs, and intestines. The skull protects the brain.
The spine (backbone) protects the spinal cord, a system of nerves that sends messages
from the brain to all parts of the body and transmits messages from all parts of the body
to the brain.
b. Muscles are attached to bones by tendons. These muscles contract and
relax, causing your bones to move. This allows you to sit, stand, run, turn your head,
pick up an object with your fingers, and so forth.
c. When two bones meet, they form a joint. The ends of the bones are covered
with cartilage, which prevents the bones from actually rubbing against each other. The
bones are connected to each other by ligaments. Most joints are mobile (allow
movement). For example, your arm and forearm meet at the joint known as the elbow.
Some joints are relatively fixed, such as those in your coccyx (tailbone) and skull.
d. Bones are surrounded by blood vessels and nerves. When a bone is
fractured (broken), damaged nerves and blood vessels cause pain and loss of blood.
TYPES OF FRACTURES
A fracture occurs when a bone is broken. The break may only be a crack in the
bone (incomplete fracture) or the bone may be broken into two separate parts (complete
fracture). Any fracture can be serious. A fracture of a large bone like the femur can
result in a significant loss of blood that, in turn, can result in hypovolemic shock.
Complete fractures are also dangerous because the sharp ends of the fractured bone
can injure muscle tissues, nerves, and blood vessels. A fracture can cause discomfort,
disability, and even death. An incomplete fracture is treated as though it were a
complete fracture. Fractures are usually classified as open or closed.
a. Closed Fracture. A closed fracture (figure 6-1 A) is a fracture in which the
skin is not broken. A closed fracture may result in significant loss of blood due to
internal bleeding (bleeding into surrounding body tissues or into a body cavity) even
though no blood is visible.