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What is the musculoskeletal system? A complete guide

The musculoskeletal (MSK) system describes the interconnected network of bones, muscles, and connective tissue within the human body.

    Together, your muscles, bones, and all of the different types of connective tissue in-between work to let you move and interact with the world around you. The 206 bones that makeup your skeleton give your body a frame, while also protecting your organs and contributing to the function of your immune system. Your skeletal muscles let you move, your smooth muscles aid with digestion and other bodily functions, and your cardiac muscle allows your heart to pump more than 2.5 billion times throughout your lifetime. 

    Your musculoskeletal system begins developing four weeks after conception, and supports you your whole life. Protecting your musculoskeletal health in turn protects your ability to do what you love. 

    The muscular component of the MSK system is made up of... 

    • Skeletal muscle
    • Smooth muscle
    • Cardiac muscle
    • Connective tissue (tendons, fascia, etc.)

    The skeletal component of the MSK system is made up of... 

    • Bones
    • Cartilage
    • Ligaments
    • Bursae

    What does the musculoskeletal system do?

    As it says in the name, your musculoskeletal system is made up primarily of your muscles and bones (as well as all of the other associated, in-between tissues like tendons and ligaments). You may not know it, but your MSK system does more than just let you lift weights at the gym!

    Although the primary function of your MSK system is to make your body move, your muscles and bones are also involved in a variety of other essential bodily functions. 

    Most people don’t realise that they have three different types of muscle in their body: skeletal muscle, cardiac muscle, and smooth muscle. In addition to helping you move, skeletal muscles provide 85% of your body’s heat, and even work to warm you up when you’re cold by making you shiver. Your cardiac muscle (found in your heart) starts contracting when you are only weeks old and keeps your heart pumping for your entire life. And your smooth muscle can be found in over half of your different bodily systems, working tirelessly to do things like help you digest food and regulate your blood pressure.

    Muscles mainly function by doing something called “contracting.” In order to contract, they need to have lots of calcium ions available. Luckily, there are calcium stores in the other part of your MSK system: your bones!

    In addition to containing calcium reserves to regulate blood calcium levels, your skeleton has a variety of functions. Your bones protect some of your most important and delicate organs, including your heart, lungs, and brain, while also providing sturdy attachment sites for all of your powerful muscles. One function of bones that many people are not aware of is their role in immune system function. The production of new blood cells occurs within your bone marrow, and results in the production of new white blood cells (as well as red blood cells and platelets). So next time you get over a cold, be sure to thank your MSK system!

    How is the musculoskeletal system structured?

    The general structure of the musculoskeletal system is in the name: it is a system made of muscles and bones. However, it’s a bit more complicated than that! Let’s take a look at skeletal muscle, bone, and everything in-between.

    There are many different types of joints in the body, but in general you can think of a joint as two bones with connective tissue structures in-between. Ligaments are sturdy bands of connective tissue that run between bones, whereas joint capsules can be thought of as bags of connective tissue that contain fluid within joints. Some joints, like your knees, shoulders, and hips, have cartilage on the joint surface, whereas other joints, like the ones at the front of your chest and pelvis, have a fibrous disc. 

    Skeletal muscle has connective tissue both within it and around it. Tendons are thought by many people to just connect muscle to bone, but there are many tendons in the human body that extend within muscle to help generate extra power. Some tendons need to glide extra smoothly within a muscle, so they have an extra layer of connective tissue wrapped around them as well.

    Instead of having a tendon, some muscles (like your biceps brachii) have a type of attachment called an aponeurosis, which can be thought of as a broad and flat, tendon-like attachment that attaches directly to other muscles and connective tissue. 

    Caring for not only your bones and muscles, but also for all of the connective tissue in-between is a key way to protect your muscle and joint health long-term. 

    Different types of muscle

    When people think of “muscle” usually the first thing that comes to mind are quads, biceps, and abs. However, those are examples of only one of the three types of muscles in your body. Let’s take a look at the different types of muscles in your body below.

    Skeletal muscle

    When people think of muscle, this is the type that comes to mind - even if they don’t know the name of it. Two of the key features of skeletal muscle is that it attaches to bones and produces voluntary movement through a process called contraction. Like cardiac muscle, skeletal muscle is striated. This means that it looks stripy under a microscope due to how the muscle fibres are organised. 

    Skeletal muscle should only contract when you want it to. An involuntary contraction in skeletal muscle is commonly referred to as a spasm or a cramp, and usually happens as a result of the muscle being injured or excessively fatigued (although sometimes muscle cramps and spasms happen due to vitamin and mineral deficiencies or disease processes). 

    Cardiac muscle

    It may not be the biggest muscle in your body, but you literally couldn’t live without this one! Your heart is made of a special type of muscle cell called “cardiomyocyte” and it has its own special properties that make it able to meet the HUGE demand of contracting tirelessly almost every second for your entire lifetime. Like skeletal muscle, cardiac muscle is striated. But unlike skeletal muscle, contraction of your cardiac muscle is involuntary. 

    Smooth muscle

    Smooth muscle is the unsung hero of some of your most important bodily functions, such as breathing, bowel and bladder function, and regulating blood pressure. It is located within the walls of hollow organs, within blood vessels, and throughout your respiratory, urinary, and digestive tracts. Unlike skeletal and cardiac muscle, smooth muscle is not striated. Like cardiac muscle, skeletal muscle contracts involuntarily, and it is thanks to this property that you can do things such as digest food without even having to think about it! 

    Musculoskeletal disorders

    Just like any other system in your body, your musculoskeletal system can be negatively affected by poor lifestyle choices, injury, and disease, and how it affects you can range from a small annoyance to a life-limiting dysfunction. Let’s go through a few of the ways that your MSK system can stop working as normal.

    Mechanical vs. systemic disorders

    Mechanical disorders are things like tendinitis, muscle tears, bone fractures, and arthritis. They are MSK injuries that have a MECHANICAL cause (such as falling or wear-and-tear over time), and are not a result of disease in other bodily systems.

    Systemic disorders are things such as rheumatoid arthritis, Parkinson’s disease, and cancer that are caused by more complex systemic processes and usually require medical treatment that targets the specific system(s) involved. 

    Figuring out whether or not an injury is mechanical in nature or systemic is one of the main reasons why it’s important to get muscle and joint injuries assessed by a qualified healthcare professional, since something as seemingly straightforward as back pain can (in some instances) have a more serious systemic cause. 

    Acquired vs. congenital 

    An acquired injury or illness is something that happens to you over your lifespan, whereas a congenital injury is something that you are born with. There are a ton of congenital MSK disorders that can affect how you move throughout your life. They range from things such as a curvature of the spine called “scoliosis” (which is generally quite treatable) to more serious diseases like the various types of muscular dystrophy. Diagnosis of congenital MSK disorders is important as some congenital disorders are easier to treat before puberty. 

    An example of acquired musculoskeletal disease is osteoarthritis. Over time (often decades) injury to the tissue within a joint results in changes within the joint that make it more vulnerable to reinjury, and more sensitive to pain. Osteoarthritis is common in older populations and is typically explained to patients as a medical term for the “wear and tear” that happens to joints due to ageing.

    Illness and injury happen, but healthy lifestyle choices and good nutrition with supplementation where appropriate are your best defence to keeping your MSK system working to let you do what you love. 

    How can I support my musculoskeletal system naturally?

    One of the coolest things about your musculoskeletal system is how changeable it is! Your ENTIRE skeleton remodels and rebuilds itself in your first year of life, and then continues this process of breaking down (resorption of calcium) and rebuilding at a rate of about 10% per year throughout adulthood. Your muscles are the most metabolically active tissue in your body, and rely on having nutrients readily available both for constant upkeep as well as healing after injury. 

    Let’s look at a few of the ways that you can support your MSK system, naturally:


    Collagen is found within and throughout your entire MSK system. Notably, it forms the contact surface between bones within many of the joints of your body and its incredibly smooth surface helps the bones to glide against each other without restriction. It also helps to keep your skin supple and smooth. 

    Although taking collagen might seem like a straightforward thing to do, it’s not that simple. Just because you take something doesn’t mean that it actually gets absorbed. Collagen is made up of large chains that are difficult for your body to process and absorb. A hydrolysed collagen supplement is one where the big collagen chains have been broken down into tiny collagen chains that are easy for your body to absorb. There is evidence that hydrolysed collagen supplements (like Zooki) result in better absorption and bioavailability, which means that what you are taking is actually ending up IN your joints, skin, and everywhere else that it is needed.

    Vitamin C

    People often hear “vitamin C” and immediately think of how it helps to support your immune system, but did you know that vitamin C plays a big role in the health of your muscles and joints? Vitamin C has been shown to positively affect collagen absorption and remodelling, which is a key part of maintaining the health of your tendons, ligaments, and other connective tissue structures. 


    Curcumin is the active component of turmeric, and research has shown it to have a positive effect on decreasing inflammation and sensitivity to pain. Unlike tablet curcumin supplements which require piperine to aid absorption, Zooki’s Liposhield™ version is easier to absorb and gentle on your digestion.

    Omega 3

    Omega 3 supplements (commonly referred to as “fish oil”) have been in the news a lot recently over the past decade, and research is still very much ongoing. What is clear is that taking a high quality omega 3 supplement does contribute positively to decreasing inflammation and pain, especially for individuals with musculoskeletal conditions. It also seems to increase protein synthesis to help support muscle growth and repair. 


    Supporting the health of your muscles, joints, and bones through strategic supplementation helps to protect every other aspect of your health. Although a healthy lifestyle with adequate exercise, sleep, and good nutrition is key, supplementation can play a big role in supporting and protecting your musculoskeletal health. 


    1. How many bones? Every bone in my body

    2. Heart rate, lifespan, and mortality risk

    3. Formate assay in body fluids

    4. Introduction to the muscular system

    5. Physiology, Smooth Muscle

    6. Bone function, dysfunction and its role in diseases including critical illness. International journal of biological sciences

    7. Clinically Oriented Anatomy

    8. Osteoarthritis

    9. Wheeless' textbook of orthopaedics.

    10. A randomised controlled trial on the efficacy and safety of a food ingredient, collagen hydrolysate, for improving joint comfort 

    11. Effect of vitamin C on collagen structure of cardinal and uterosacral ligaments during pregnancy

    12. Efficacy and safety of Meriva®, a curcumin-phosphatidylcholine complex, during extended administration in osteoarthritis patients

    13. Curcumin maintenance therapy for ulcerative colitis 

    14. Comparative absorption of curcumin formulations

    15. Omega-3 polyunsaturated fatty acids augment the muscle protein anabolic response to hyperinsulinaemia-hyperaminoacidaemia in healthy young and middle-aged men and women 





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