LOCOMOTOR SYSTEM: IMPORTANCE, FUNCTIONS AND PARTS (WITH PICTURES) - ANATOMY AND PHYSIOLOGY - 2025

The musculoskeletal system, musculoskeletal system or musculoskeletal system is the organic system that gives the body the ability to move using the muscular systems and the skeleton.

The importance of the locomotor system is that it is responsible for providing form, stability, movement and support to the body.

The osteoarticular system and the muscular system are formed; skeletal bones, cartilage, muscles, tendons, ligaments, joints, and connective tissue, which hold organs in place and hold body tissues together.

The bones of the skeletal system protect the internal organs of the body, support the body's weight, and serve as the primary source of phosphorus and calcium absorption.

In order for bones to move, they have to be attached. That is why they are connected by the joints and muscle fibers and also by connective tissues such as tendons and ligaments. In the case of cartilage, they prevent bones from constantly rubbing against each other.

You can also see the human nervous system: structure and functions, as one would not work without the other.

Components of the locomotor system

1- Bones

There are 206 bones in the human body that serve some main functions. One of the most important is the support of the entire body, including a support network of soft tissues and organs.

Bones, in turn, store minerals and lipids such as calcium - which is the most abundant mineral in our body. 99% is in the skeleton. In addition to this, there are lipid reserves in the bone marrow, where the yellow marrow is found.

Bones are also involved in the process of making blood cells, especially red blood cells. Also white blood cells and other blood elements are produced in the red marrow, which fills the internal cavity of the bones.

The skeleton protects the organs of the body, for example, the rib cage where the heart and lungs meet. The skull protects the brain; the vertebrae to the spinal cord and the pelvis the reproductive organs in men and women.

Bones also have a particular structure. A compact part that is what is on the outside of the bone and a "spongy" part that is on the inside. This ratio depends on the shape of the bone.

Bone growth begins in cartilage, through the process known as ossification. As bones, like the rest of the body, are in constant change, physical activity is important to stimulate their maintenance and strength.

2- Joints

Types of joints.

They are another essential part of the locomotor system. They correspond to two interconnected bones and determine the compromise between stability and range of motion.

• Tendons. They attach the muscles to the bone.
• Ligaments. They join bones to bones.
• Skeletal muscles. They contract to pull on tendons and move skeletal bones. They also maintain body posture and position, support soft tissues, protect the sphincters of the digestive and urinary systems, and maintain body temperature.
• Nerves. They control the contraction of skeletal muscles, interpret sensory information, and coordinate the activities of organ systems in the body.

3- Cartilage

They are a type of connective tissue, a substance with a firm gel texture. There are three types of cartilage in the body, depending on their location.

Hyaline cartilage is the most common, and generates firm but flexible structures, such as the tips of the ribs, and part of the nasal septum.

Also articular cartilage, which covers the ends of the bones within the joint. The others are elastic cartilage and fibrocartilage. The latter is in charge of resisting compression and limiting relative movements, such as that found in the knee joints, vertebrae and pubic bones.

Functions of the locomotor system

Muscles of the locomotor system

The locomotor system acts with all its components in its functions: movement, support and stability of the body. In this way, muscles and skeleton work together to move the body.

The more muscles involved in a joint, the greater the range of motion is, as is the case with the shoulder joint.

In the bones that are part of the locomotor system, there is red marrow, which produces red blood cells and also some cells of the white series, such as granulocytes.

As the human being grows, the presence of red marrow begins to decrease and the amount of yellow marrow increases in the bones, which corresponds to fat.

In adults, red marrow is usually present in the ribs, vertebrae, hip bones, and sternum. On the other hand, the radius, tibia, ulna and fibula contain more fat inside.

In the case of blood loss, the bones increase the amount of red marrow so that more red cells can form.

The locomotor system provides movement and stability and the skeletal muscles are constantly making small adjustments to hold the body in stationary positions.

The tendons stretch over the joints to keep it stable. This can be evident in joints such as the knee and shoulder. They also produce much more subtle movements, such as facial expressions, eye movements, and breathing.

Another fundamental function is the maintenance of body temperature, by the action of skeletal muscles. In this process, blood plays an important role, absorbing heat from inside the muscles and redirecting it to the surface of the skin.

Musculoskeletal diseases

There are some diseases and disorders that can directly affect the function of the locomotor system and cause failures in its functioning, which in turn generate detriment to the functions of the human body.

These diseases are potentially debilitating and difficult to diagnose, due to the interrelation of the locomotor system with the rest of the internal organs in the body.

In humans, the main cause of diseases of the locomotor system is poor nutrition. Joint discomfort such as arthritis are also very common. Some symptoms are pain, difficulty in movement and, in more severe cases, complete immobility.

In some cases, when the joint has suffered too much damage, surgery is recommended to repair the condition. This can be done through a prosthesis that replaces the section of the joint or bone that has been damaged.

New advances in medicine have increasingly improved joint replacement prostheses, the most common being those for the hips and knees, two joints that tend to wear out with age. Other joint prostheses may be required in shoulders, fingers, and elbows.

Although the prostheses so far have a duration of a certain number of years, especially in the case of young patients, they are currently testing different materials such as carbon fiber that would increase the duration of the prostheses.

Importance of the locomotor system

The locomotor system is very important because it allows humans and other vertebrate animals to carry out physical activities and interact with their environment, in addition to other vital functions.

The locomotor system works in coordination with the central nervous system, which allows muscle contraction to take place.

For the musculoskeletal system to function properly, it is necessary for the nervous system to generate the orders that make its movement possible. The brain sends the order to the nervous system and the latter coordinates the movement of the locomotor system.

Some of the elements that make the locomotor system essential for life are listed below:

-Support: the muscular bone apparatus gives structural support to the whole body, giving it its external appearance.

-Protects our internal organs: many soft tissues and organs of the body are surrounded by skeletal elements. For example, the rib cage protects the lungs and heart, the skull protects the brain, the vertebrae protects the spinal cord, and the pelvis protects the organs of the reproductive system.

-Firmness and resistance: gives the body firmness and resistance to any movement that requires strength.

-Mechanics of the body: the locomotor system works like a set of levers. Muscles provide force, joints act as fulcrums, and bones act like moving parts that can change the power and direction of force generated by the muscles.

-Energy storage: bones store lipids (fats) as energy reserves in spaces filled with yellow marrow. They also make blood cells and accumulate calcium. The calcium salts of bone are a valuable mineral reserve for the body.

-Temperature regulator: the muscles of the system help to maintain the temperature of the body.

-They give expression: the muscles of the locomotor system also provide motor responses through more subtle movements that result in various facial expressions, chewing and swallowing food, eye movements and breathing.

-Regulate the passage of substances: the muscles also work on the entrances and exits of organs such as those of the digestive and excretory systems, regulating the passage of substances and preventing them from returning. Some of the most important muscle rings in the locomotor system are the sphincters. These control the excretion of fecal matter and urine.

-Coating: cartilage is very important in the locomotor system because they cover the bone endings of the joints and condition the surfaces of the bones to prevent wear and tear that may cause friction. They dampen the percussion produced by jumping or walking.

-Keep everything in place: the function of the ligaments that are present in all the joints of the locomotor system is important, since they help to keep the bones in place, preventing dislocations. Ligaments are also very important for organs like the bladder and uterus to stay in place.

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