The Skeletal System: Your Body's Central Framework

Skeletal System

One of the important system of human body.

The skeletal system is your body’s central framework. 

It consists of bones and connective tissue, including cartilage, tendons, and ligaments. 

It’s also called the musculoskeletal system.

Major Functions:

• Allows movement: 

Your skeleton supports your body weight to help you stand and move. 

Joints, connective tissue and muscles work together to make your body parts mobile.

• Produces blood cells: 

Bones contain bone marrow. 

Red and white blood cells are produced in the bone marrow.

• Protects and supports organs: 

Your skull shields your brain, your ribs protect your heart and lungs, and your backbone protects your spine.

• Stores minerals: 

Bones hold your body’s supply of minerals like calcium and vitamin D.

Skeletal system consists of:

Bones, Cartilage, Joints, Ligaments, Tendons

Composition of Bones:

Collagen fibres and an inorganic bone mineral in the form of small crystals

Mineral component in bone: Hydroxyapatite (major component Calcium, Phosphorous: Ca₁₀(PO₄)₆(OH)₂)

Water: 10-20%

Skeleton Facts:

• Your skeleton is made of more than 200 bones
• The body has two types of bone: cortical bone, trabecular bone.
• Bones are filled with a spongy tissue.
• Babies are born with 300 bones.
• The smallest bone in the body is in your ear.
• The longest bone in the body is in your leg.
• More than half your bones are in your hands and feet.

You have 206 bones in total, and 106 of them are in your hands and feet.

• One bone isn’t connected to any other bones.

The hyoid bone, which is in your throat, is the only bone that doesn’t connect to a joint. The hyoid is responsible for holding your tongue in place.

• Most people have 12 ribs, but some have 13.

A 13th rib is rare — only 1 of people are born with it. In most people, this extra rib, called a cervical rib, can cause medical issues like neck pain. For that reason, people born with this extra rib often have it removed.

• The biggest joint in your body is your knee.
• Bones are strong, but teeth are stronger.
• Bones are natural healers.

Factors affecting bone health

The amount of calcium in your diet

A diet low in calcium contributes to diminished bone density, early bone loss and an increased risk of fractures.

Physical activity

People who are physically inactive have a higher risk of osteoporosis than do their more-active counterparts.

Tobacco and alcohol use

Research suggests that tobacco use contributes to weak bones. 

Similarly, regularly having more than one alcoholic drink a day for women or two alcoholic drinks a day for men may increase the risk of osteoporosis.

Sex

You're at greater risk of osteoporosis if you're a woman, because women have less bone tissue than do men.

Size

You're at risk if you are extremely thin (with a body mass index of 19 or less) or have a small body frame because you might have less bone mass to draw from as you age.

Age

Your bones become thinner and weaker as you age.

Race and family history

You're at greatest risk of osteoporosis if you're white or of Asian descent. 

In addition, having a parent or sibling who has osteoporosis puts you at greater risk — especially if you also have a family history of fractures.

Hormone levels

Too much thyroid hormone can cause bone loss. In women, bone loss increases dramatically at menopause due to dropping estrogen levels. 

Prolonged absence of menstruation (amenorrhea) before menopause also increases the risk of osteoporosis. 

In men, low testosterone levels can cause a loss of bone mass.

Eating disorders and other conditions

Severely restricting food intake and being underweight weakens bone in both men and women. 

In addition, weight-loss surgery and conditions such as celiac disease can affect your body's ability to absorb calcium.

Certain medications

Long-term use of corticosteroid medications, such as prednisone, cortisone, prednisolone and dexamethasone, is damaging to bone.

Other drugs that might increase the risk of osteoporosis include aromatase inhibitors to treat breast cancer, selective serotonin reuptake inhibitors, methotrexate, some anti-seizure medications, such as phenytoin (Dilantin) and phenobarbital, and proton pump inhibitors.

Keeping your skeletal system healthy:

• Get plenty of vitamin D and calcium in your diet (try milk, yogurt or almonds) to keep bones strong.
• Drink plenty of water to help keep tissues healthy.
• Exercise regularly to strengthen bones and joints.
• Stay at a healthy weight to avoid putting extra pressure on your bones and cartilage.
• Wear protective gear during contact sports such as football and hockey.
• Be cautious on stairs to avoid falls.

Conditions affecting skeletal health

• Arthritis: Age, injury, and medical conditions such as Lyme disease can lead to arthritis, a painful wearing down of joints.
• Fracture: Disease, a tumor, or trauma can put stress on a bone, causing it to break.
• Osteosarcoma: Cancer that forms in the bones can cause tumors that may weaken and break bones.
• Osteoporosis: Bone loss caused by not getting enough calcium can lead to fragile and brittle bones, known as osteoporosis.
• Sprains and tears: Age, disease and trauma can cause connective tissue to overstretch and tear.

Tips for keeping bones healthy

•    Include plenty of calcium in your diet. For adults ages 19 to 50 and men ages 51 to 70, the Recommended Dietary Allowance (RDA) is 1,000 milligrams (mg) of calcium a day. 
The recommendation increases to 1,200 mg a day for women age 51 and older and for men age 71 and older.
Good sources of calcium include dairy products, almonds, broccoli, kale, canned salmon with bones, sardines and soy products, such as tofu. 
If you find it difficult to get enough calcium from your diet, ask your doctor about supplements.
•    Pay attention to vitamin D. Your body needs vitamin D to absorb calcium. For adults ages 19 to 70, the RDA of vitamin D is 600 international units (IUs) a day. 
The recommendation increases to 800 IUs a day for adults age 71 and older.
Good sources of vitamin D include oily fish, such as salmon, trout, whitefish and tuna. 
Additionally, mushrooms, eggs and fortified foods, such as milk and cereals, are good sources of vitamin D. 
Sunlight also contributes to the body's production of vitamin D. 
If you're worried about getting enough vitamin D, ask your doctor about supplements.
•    Include physical activity in your daily routine. Weight-bearing exercises, such as walking, jogging, and climbing stairs, can help you build strong bones and slow bone loss.

•    Avoid substance abuse. Don't smoke. If you are a woman, avoid drinking more than one alcoholic drink each day. 
If you are a man, avoid drinking more than two alcoholic drinks a day.