Hand in 13.1/13.2 Notes

Bone and Joint Problems13.3 and 13.4

Bone Fracture•A fracture is a

break in a bone.• There are three

most common types of fractures

Greenstick fracture: a partial break in a bone; common in babies and young children due to the

cartilage the bone does not break completely.

Closed fracture: occurs when the bone breaks completely but the broken ends do not pierce the

skin.

Open fracture: also called compound fracture; the broken ends of the bone pierce the skin surface.

Other Common Breaks

Joint Injuries

Sprain: most common joint injury; a tear in a ligament caused by stretching it too far

Dislocation: the end of one bone is pulled out of the joint and the ligaments are severely stretched or torn.

Bursitis: an inflammation of a sac near a joint; the inflammation may be caused by an injury, an infection

, overuse, or repeated strain on a joint.

Arthritis: an inflammation of a joint.

Osteoarthritis: the cartilage in a joint gradually wear away, exposing the bone surfaces. The bones rub against each

other and against other tissues of the joint

Osteoporosis

• The thinning and weakening of the bones caused by the loss of calcium

from bone tissue.• Eventually the bones become so weak

and brittle that they fracture very easily from a fall, an impact or even

physical effort like lifting.

Scoliosis

•A sideways curve of the spine.

•Commonly develops during early adolescence.

•Signs include an uneven shoulder or hip level

Rickets

•A softening of the bones caused by inadequate amounts of vitamin D and calcium in the diet.•Occurs in children as their bones grow.•Can be treated by adding calcium and vitamin D to the diet.

MusclesChapter 13Section 4

Functions of Muscles

• There are more than 600 muscles in the body. • Movement: Move the bones, pump blood, and

control the size of the pupil in your eye. • Maintenance of Posture: Keeps the skeleton

upright.• Protection of Body Heat: The constant muscle

contractions in your body helps to maintain the normal body temperature.

Types of Muscle

• Skeletal Muscle: attached to the bones in your skeleton; produce all movements that you can control; also called voluntary muscles.• Smooth Muscle: produces movement in

your internal organs; also called involuntary muscles• Cardiac Muscles: a type of involuntary

muscle that forms the walls of the heart.

How Muscles Work

•Each muscle is capable of only two actions--contraction and relaxation.•Tendon; a cord of tissue that connects a muscle to a bone, made mostly of collagen

Muscle Tone

• The slight, but constant contraction of skeletal muscles• Poor muscle tone places

additional strain on your skeletal system, tendons and ligaments.• Regular exercise helps

maintain good muscle tone.

Muscle Injuries and Disorders

• Cramp: an intense and prolonged muscle contraction that causes pain.• Strain: a tear in a muscle or tendon• Tendonitis: the overuse of a muscle causing a

tendon to become inflamed,irritated and swollen.• Hernia: occurs when part of the intestine pushes

through the weak spot in the layer of the skeletal muscle that covers the abdomen and groin area.

Review 13.3

1. Identify the major differences between a closed fracture and an open fracture.

2. What are the three common symptoms of a sprain?

3. Osteoporosis starts to develop in middle age or later. What two factors can you control now to help prevent osteoporosis when you are older?

Review 13.41. Why are skeletal muscles also called

voluntary muscles?2. Why is good muscle tone

important?3. How often does cardiac muscle

work?