Skeletal System

Overview

What is the skeletal system?

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.

Function

What does the skeletal system do?

The skeletal system has many functions. Besides giving us our human shape and features, it:

  • 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.

Anatomy

What are the parts of the skeletal system?

The skeletal system is a network of many different parts that work together to help you move. The main part of your skeletal system consists of your bones, hard structures that create your body’s framework — the skeleton. There are 206 bones in an adult human skeleton. Each bone has three main layers:

  • Periosteum: The periosteum is a tough membrane that covers and protects the outside of the bone.
  • Compact bone: Below the periosteum, compact bone is white, hard, and smooth. It provides structural support and protection.
  • Spongy bone: The core, inner layer of the bone is softer than compact bone. It has small holes called pores to store marrow.

The other components of your skeletal system include:

  • Cartilage: This smooth and flexible substance covers the tips of your bones where they meet. It enables bones to move without friction (rubbing against each other). When cartilage wears away, as in arthritis, it can be painful and cause movement problems.
  • Joints: A joint is where two or more bones in the body come together. There are three different joint types. The types of joints are:
    • Immovable joints: Immovable joints don’t let the bones move at all, like the joints between your skull bones.
    • Partly movable joints: These joints allow limited movement. The joints in your rib cage are partly movable joints.
    • Movable joints: Movable joints allow a wide range of motion. Your elbow, shoulder, and knee are movable joints.
  • Ligaments: Bands of strong connective tissue called ligaments hold bones together.
  • Tendons: Tendons are bands of tissue that connect the ends of a muscle to your bone.

Conditions and Disorders

What are some common conditions that can affect the skeletal system?

Many conditions can affect the bones, joints, and tissues that make up the skeletal system. Some happen as a result of disease or injury. Others develop due to wear and tear as you get older. Conditions that may affect the skeletal system can include:

  • 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.

Care

How can I keep my skeletal system healthy?

To keep your skeletal system strong and healthy, you should:

  • 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.

What happens when you break a bone?

Your healthcare provider will classify a fracture based on the way the bone breaks. Types of fractures include:

  • Stable (closed): The ends of the broken bones line up.
  • Stress fracture: Overuse causes a crack in the bone.
  • Open (compound): The broken bone breaks the skin.

If you break a bone, you’ll need an imaging test called an X-ray so your doctor can identify the type of fracture. Depending on the severity of the break, you’ll need to immobilize it (prevent it from moving) in a cast or brace for three to eight weeks. Broken bones can take several months to heal completely.

Frequently Asked Questions

When should I call my healthcare provider about an issue with my skeletal system?

Call your healthcare provider if pain, swelling, or stiffness in your bones or joints lasts more than a few days or interferes with your daily activities. Orthopedic doctors specialize in the skeletal system. These doctors can help you manage issues with:

  • Medical treatment, such as treating a fracture.
  • Lifestyle changes, such as exercise.
  • Medications like ibuprofen to relieve pain or Fosamax® (alendronic acid) to prevent bone loss.

If you suspect you may have broken a bone, go to the emergency room or see your healthcare provider. You’ll need treatment to make sure it heals properly.

Last reviewed by a Cleveland Clinic medical professional on 11/19/2019.

References

  • Merck Manual. Introduction to the Biology of the Musculoskeletal System. (https://www.merckmanuals.com/home/bone,-joint,-and-muscle-disorders/biology-of-the-musculoskeletal-system/introduction-to-the-biology-of-the-musculoskeletal-system) Accessed 11/20/2019.
  • National Cancer Institute. Introduction to the Skeletal System. (https://training.seer.cancer.gov/anatomy/skeletal/) Accessed 11/20/2019.

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