Bones of the Skeletal System Support the Body and Help You Move. They Give Your Body Shape

Bones of the skeletal system support the body and help you move. They give your body shape.

200 bones in the skeletal system and this system contain more than just bones but other structures that connect and protect the bones and that support other functions of the body.

Bones provide support and without bones our bodies would be similar to gelatin (jell-o). Bones help you sit, stand and throw things when Mr. Moore is not looking.

Irregular bones: Example is pelvis and vertebrae

Flat bones: sternum and cranium-protects and supports organs

Long bones: Supports weight and allows movement-humerus and femur

Short bones: supports weight and allows for many small movements. Example would me the tarsals and the carpals

MOVEMENT

Skeletal and muscular systems work together to help move your body. Bones can move because they are attached to muscles.

PROTECTION

Feel your stomach and then your head. Bones protect internal structures like the brain. Ribs protect the heart and lungs as does the sternum.

PRODUCTION AND STORAGE

Another function of bones is to produce and store materials needed by your body. RBC’s are produced inside your bones. Bones store fat and calcium. Calcium is needed for strong bones as well as many cellular processes. It is released from bones into the blood when needed and is also collected from the blood and stored into the bones when there is a surplus. If too much calcium is taken from the bones, they become weak.

STRUCTURE OF BONES

A bone is an ORGAN composed of living tissue. There are two types of bone tissue: spongy and compact.

Compact bone tissue: The hard, outer parts of the bone are made of compact bone tissue which is a dense web of fibers. Long bones like the arm are mostly made up of compact bone. At the ends of bones is the spongy bone tissue.

Spongy bone tissue: the small holes in the tissue make it look like a sponge which also makes it less dense. It is very vascular which makes it a great site for metabolic activity and nutrient exchange. A short bone like the ones in the wrist are spongy bones.

Bone marrow: this is located inside most bones and it is a soft tissue. There are two kinds. Red marrow is the tissue where RBC’s are made and is found in the spongy end of long bones and in some flat bones like the ribs. Yellow bone marrow stores fat and is found in the longest part of long bones. At birth, all of the bone marrow in the human body is red. As a person ages, the bone marrow at the center of long bones is slowly converted to yellow bone marrow, made mostly of fat cells, which does not synthesize blood cells. The bone marrow of a typical adult is half red and half yellow. However, yellow bone marrow can be converted back to red bone marrow if necessary, in the case of severe blood loss.

CARTILAGE: Cartilage is a flexible connective tissue found in many parts of the body. It can bend a bit, but resists stretching. Its main function is to connect bones together and prevent the surfaces of articulating bones from rubbing against each other causing friction. It is also found in the joints, the rib cage, the ear, the nose, the throat and between the bones of the back.

PERIOSTEUM

The membrane that surrounds the bone. This thin tissue contains blood vessels and nerves as well as cells that produce new bone tissue. Periosteum nourishes bones and help them function and grow properly, as well as heal after injury.

FORMATION OF BONES

Before you were born your skeleton was made up of mostly cartilage. During infancy and childhood that cartilage was gradually replaced by bone. The long bones in children and young teens have growth plates which are regions that produce new cells. A growth plate produces cartilage that is then replaced by bone tissue. It is the weakest part of the adolescent bone. Growth continues until adulthood when most of the cartilage has turned to bone.

BREAKS

A doctor might be able to tell whether a bone is broken simply by looking at the injured area. But the doctor will order an X-ray to confirm the fracture and determine what type it is. Getting an X-ray to look at the broken bone won't take long.

However, a fracture through the growing part of the bone (called the growth plate) may not show up on X-ray. If this type of fracture is suspected, the doctor will treat it even if the X-ray doesn't show a break.

Kids' bones are more likely to bend than break completely because they're softer. Fracture types that are more common in kids include:

buckle or torus fracture: one side of the bone bends, raising a little buckle, without breaking the other side

greenstick fracture: a partial fracture in which one side of the bone is broken and the other side bends (this fracture resembles what would happen if you tried to break a green stick)

Mature bones are more likely to break completely. A stronger force will also result in a complete fracture of younger bones. A complete fracture may be a:

closed fracture: a fracture that doesn't break the skin

open (or compound) fracture: a fracture in which the ends of the broken bone break through the skin (these have an increased risk of infection)

non-displaced fracture: a fracture in which the pieces on either side of the break line up

displaced fracture: a fracture in which the pieces on either side of the break are out of line (which might require surgery to make sure the bones are properly aligned before casting)

Other common fracture terms include:

hairline fracture: a thin break in the bone

single fracture: the bone is broken in one place

segmental: the bone is broken in two or more places in the same bone

comminuted fracture: the bone is broken into more than two pieces or crushed

Doctors take xrays to see what kind of fracture it is and then set the bone which is putting the bone in its normal position. After your bone has been set, the next step is usually putting on a cast to keep the bone in place for the 1 to 2 months it will take for the break to mend.With breaks in larger bones or when a bone breaks in more than two pieces, the doctor may need to put in a metal pin — or pins — to help set it. For this operation, you'll receive anesthesia so you'll be asleep and not feel any pain. When your bone has healed, the doctor will remove the pin or pins.

ARTHRITIS

Arthritis is a disease in which the joints become irritated or inflamed, such as when cartilage in joints is damaged or wears away. Arthritis is most common in adults but may affect children.

OSTEOPOROSIS

This causes bones to weaken and become brittle. It is most common in women over the age of 50. Most common areas of break are the hip, spine and wrist.

Gender. Women get osteoporosis more often than men.

Age. The older you are, the greater your risk of osteoporosis.

Body size. Small, thin women are at greater risk.

Ethnicity. White and Asian women are at highest risk. Black and Hispanic women have a lower risk.

Family history. Osteoporosis tends to run in families. If a family member has osteoporosis or breaks a bone, there is a greater chance that you will too.

Other risk factors are:

Sex hormones. Low estrogen levels due to missing menstrual periods or to menopause can cause osteoporosis in women. Low testosterone levels can bring on osteoporosis in men.

Anorexia nervosa. This eating disorder can lead to osteoporosis.

Calcium and vitamin D intake. A diet low in calcium and vitamin D makes you more prone to bone loss.

Medication use. Some medicines increase the risk of osteoporosis.

Activity level. Lack of exercise or long-term bed rest can cause weak bones.

Smoking. Cigarettes are bad for bones, and the heart, and lungs, too.

Drinking alcohol. Too much alcohol can cause bone loss and broken bones.

Ways to avoid osteoporosis:

Eat a diet rich in calcium and vitamin D

Exercise

Not drink in excess or smoke.

JOINTS

A joint is where two or more bones meet. They provide flexibility and allow the skeleton to move. Bones are connected to other bones by ligaments. When joints move, ligaments stretch and keep bones from shifting away from each other. Ligaments connect not protect bones (cartilage does).

Immovable joints

Sutures of the skull

Movable joints

These allow movement in a wide range of motion

Ball and socket-allows bones to move and rotate in nearly all directions (hip and shoulders)

Hinge joint-allows back and forth in a single direction (fingers, elbows and knees)

Pivot-allow bones to rotate (neck, lower arm below the elbow)

HEALTHY BONES

Exercise, calcium and vitamin D.

HOMEOSTASIS

Because bones supply calcium to your nerves, muscles and heart, a healthy skeletal system is important to maintain homeostasis. Bones allow you to respond to unpleasant stimuli like mosquitos.