What Are the 5 Main Functions of the Muscular System?

Reviewed on 5/12/2021
muscular system
The five main functions of the muscular system are movement, support, protection, heat generation and blood circulation

The muscular system is like a machine that converts chemical energy from food into mechanical energy. The five main functions of the muscular system are movement, support, protection, heat generation and blood circulation:

1. Movement

  • Skeletal muscles pull on the bones causing movements at the joints.
  • Skeletal muscles pull on the soft tissues of the face causing facial expressions.
  • Movement caused by the respiratory muscles enables breathing.

2. Support

  • Muscles of the body wall support the internal organs.
  • As these muscles lose their tone, the internal organs of the abdominal-pelvic cavity may bulge outward as seen in some individuals as they age.

3. Protection

  • Skeletal muscles, particularly of the body wall, cushion the body's internal organs (abdominal cavity) from force applied to the exterior of the body. 

4. Heat generation

  • Heat is a waste product of muscle metabolism, which helps maintain an internal body temperature of 98.6 F.
  • Shivering is a mechanism of the muscular system that generates heat to warm an overly cooled body.

5. Blood circulation

  • Cardiac muscles aid pumping action of the heart by aiding blood circulation.

What are the types of muscles in the muscular system?

The muscular system consists of skeletal, smooth and cardiac muscles:

  1. Skeletal muscles: These create movement in the body. There are nearly 700 skeletal muscles and make up about 40% of a person’s body weight.
  2. Smooth muscles: These are involuntary muscles that line the walls of the blood vessels and viscera (organs in the abdominal cavity).
  3. Cardiac muscles: These cause the heart to contract and expand properly.

What are the functions of skeletal muscle fibers?

Skeletal muscle fibers are categorized into two types, slow-twitch fiber and fast-twitch fiber. These perform different functions:

Slow-twitch fibers

  • Contract at a slow rate. 
  • Play a vital role in endurance or aerobic activities such as cross-country or long-distance races.

Fast-twitch fibers

  • Contract at a fast rate. 
  • Produce explosive power and perform fast repetitive contractions.
  • Mainly used in 100-meter races or sprints, high jumps, weightlifting, basketball and football.
  • Play a vital role in performing anaerobic activities.

What foods are good for the muscular system?

Nutrient-rich food is important for the muscular system to function properly. Foods that contribute to a strong muscular system include:

  • Meat, poultry, milk, eggs and seafood all contain amino acids essential for the body. Dairy products help strengthen the bones and muscles with nutrients such as calcium, vitamin D, phosphorus and potassium.
  • Whole grains, fruits and vegetables contribute to a healthy muscular and skeletal system. 
    • As carbohydrates are broken down into glucose, they increase insulin levels in the blood, which causes adenosine triphosphate (ATP) to be carried to the muscles around the body. These nutrients give the muscles the ability to function properly.
    • Infused with tons of antioxidants, fruits like grapes form nitric oxide in the body and help to maintain heart health. Citrus fruit, blueberries, oatmeal, soy, potatoes, legumes and avocado are also beneficial for muscles and contribute to overall health. 
    • Vegetables drastically reduce the risk of cardiovascular disease, lower cholesterol and eliminate free radicals that lead to aging and cancer.
  • Unsaturated fats such as omega-3 in fish oil, olive oil, peanut oil and soy oil (to name a few) keep the cells nourished.
    • Healthy fats prevent or reduce inflammation and function as a reserve fuel source when carbohydrates are depleted.
    • Omega-3 fatty acids lower the risk of arrhythmia (irregular heartbeats) and prevent plaque accumulation in the arteries. The American Heart Association advises eating fish twice a week.
  • Chocolate with 60%-70% cocoa reduces the risk of nonfatal heart attacks and stroke. Dark chocolate components include flavonoids called polyphenols which can reduce blood pressure, clotting and inflammation.


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The Muscular System: https://www.shsu.edu/~bio_mlt/Chapter10.html Muscular and Skeletal Systems:


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