The human musculoskeletal system (हाड़ पिंजर प्रणाली) also is known as the locomotor system, and previously the activity system is an organ system that gives humans the ability to move using their muscular and skeletal systems. The musculoskeletal system provides form, support, stability, and movement to the body. Complex issues and injuries involving the musculoskeletal system are usually handled by a physiatrist (specialist in physical medicine and rehabilitation) or an orthopedic surgeon. Siddha Spirituality of Swami Hardas Life System wishes our readers to read about the musculoskeletal system, meaning, function, types of various muscles, and clinical significance for wellbeing.
Musculoskeletal system Meaning (हाड़ पिंजर प्रणाली का अर्थ)
The musculoskeletal system is composed of two systems – the muscular system and the skeletal system – but is commonly referred to as ‘musculoskeletal’ because of the main common functions of the said two systems, which are, movement and support. The musculoskeletal system is made up of hard and soft tissues. The hard tissue includes bones and cartilages (articular cartilages), while the soft tissues are the muscles, tendons, synovial membranes, joints capsule, and ligaments.
Musculoskeletal system Function (हाड़ पिंजर प्रणाली का कार्य)
Primarily, the roles of the musculoskeletal system are movement and support, but the system also performs the following functions:
- Protection of vital structures
- Provision of body forms
- Storage of salts e.g. calcium
- Formation and supply of new blood cells
Essentially the skeletal part of the system pertains to the arrangement of bones, and how they join to one another to form joints that permit and limit specific movements. This part also outlines the factors that influence the stability of some of those joints. For example, a joint with good bony congruence (joint with bones fitting well together) is most likely to be more stable than one with poor bony congruence.
On the other hand, the muscular portion of the musculoskeletal system primarily describes the movements produced at joints, which as a basic principle, is based on the location of a muscle in relation to the joint and attachment to bones forming the joint. For example, a muscle lying anterior to two or more bones, and also crossing the joint formed by those bones anteriorly will produce the movement – “flexion” at that joint when it is contracted.
Types of various muscles (विभिन्न मांसपेशियों के प्रकार)
The skeletal system serves many important functions; it provides the shape and form for the body, support, and protection, allows bodily movement, produces blood for the body, and stores minerals. The number of bones in the human skeletal system is a controversial topic.
Humans are born with over 300 bones; however, many bones fuse together between birth and maturity. As a result, an average adult skeleton consists of 206 bones. The number of bones varies according to the method used to derive the count. While some consider certain structures to be a single bone with multiple parts, others may see it as a single part with multiple bones. There are five general classifications of bones. These are:
- Long bones
- Short bones
- Flat bones
- Irregular bones
- Sesamoid bones
The human skeleton is composed of both fused and individual bones supported by ligaments, tendons, muscles, and cartilage. It is a complex structure with two distinct divisions: the axial skeleton, which includes the vertebral column, and the appendicular skeleton.
Skeletal Function (कंकाल संबंधी कार्य)
The skeletal system serves as a framework for tissues and organs to attach themselves to. This system acts as a protective structure for vital organs. Major examples of this are the brain being protected by the skull and the lungs being protected by the rib cage.
Located in long bones are two distinctions of bone marrow (yellow and red). The yellow marrow has fatty connective tissue and is found in the marrow cavity. During starvation, the body uses the fat in yellow marrow for energy. The red marrow of some bones is an important site for blood cell production, approximately 2.6 million red blood cells per second in order to replace existing cells that have been destroyed by the liver. Here all erythrocytes, platelets, and most leukocytes form in adults. From the red marrow, erythrocytes, platelets, and leukocytes migrate to the blood to do their special tasks.
Another function of bones is the storage of certain minerals. Calcium and phosphorus are among the main minerals being stored. The importance of this storage device helps to regulate mineral balance in the bloodstream. When the fluctuation of minerals is high, these minerals are stored in bone; when it is low it will be withdrawn from the bone.
There are three types of muscles:
- Skeletal, and
Smooth muscles are used to control the flow of substances within the lumens of hollow organs and are not consciously controlled. Skeletal and cardiac muscles have striations that are visible under a microscope due to the components within their cells. Only skeletal and smooth muscles are part of the musculoskeletal system and only the skeletal muscles can move the body.
Cardiac muscles are found in the heart and are used only to circulate blood; like the smooth muscles, these muscles are not under conscious control.
Skeletal muscles are attached to bones and arranged in opposing groups around joints. Muscles are innervated, to communicate nervous energy to, by nerves, which conduct electrical currents from the central nervous system and cause the muscles to contract.
Contraction initiation (संकुचन दीक्षा)
In mammals, when a muscle contracts, a series of reactions occur. Muscle contraction is stimulated by the motor neuron sending a message to the muscles from the somatic nervous system. Depolarization of the motor neuron results in neurotransmitters being released from the nerve terminal. The space between the nerve terminal and the muscle cell is called the neuromuscular junction. These neurotransmitters diffuse across the synapse and bind to specific receptor sites on the cell membrane of the muscle fiber. When enough receptors are stimulated, an action potential is generated and the permeability of the sarcolemma is altered. This process is known as initiation.
A tendon is a tough, flexible band of fibrous connective tissue that connects muscles to bones. The extra-cellular connective tissue between muscle fibers binds to tendons at the distal and proximal ends, and the tendon binds to the periosteum of individual bones at the muscle’s origin and insertion. As muscles contract, tendons transmit the forces to the relatively rigid bones, pulling on them and causing movement. Tendons can stretch substantially, allowing them to function as springs during locomotion, thereby saving energy.
Joints, ligaments, and bursae (जोड़ों, स्नायुबंधन, और बर्सी)
The joints are structures that connect individual bones and may allow bones to move against each other to cause movement. There are three divisions of joints, diarthrosis which allows extensive mobility between two or more articular heads; amphiarthrosis, which is a joint that allows some movement, and false joints or synarthroses, joints that are immovable, that allow little or no movement and are predominantly fibrous. Synovial joints, joints that are not directly joined, are lubricated by a solution called synovial fluid that is produced by the synovial membranes. This fluid lowers the friction between the articular surfaces and is kept within an articular capsule, binding the joint with its taut tissue.
A ligament is a small band of dense, white, fibrous elastic tissue. Ligaments connect the ends of bones together in order to form a joint. Most ligaments limit dislocation or prevent certain movements that may cause breaks. Since they are only elastic they increasingly lengthen when under pressure. When this occurs the ligament may be susceptible to break resulting in an unstable joint.
Ligaments may also restrict some actions: movements such as hyperextension and hyperflexion are restricted by ligaments to an extent. Also, ligaments prevent certain directional movement.
A bursa is a small fluid-filled sac made of white fibrous tissue and lined with a synovial membrane. Bursa may also be formed by a synovial membrane that extends outside of the joint capsule. It provides a cushion between bones and tendons and/or muscles around a joint; bursa are filled with synovial fluid and are found around almost every major joint of the body.
Musculoskeletal system Clinical significance (हाड़ पिंजर प्रणाली का नैदानिक महत्व)
Because many other body systems, including the vascular, nervous, and integumentary systems, are interrelated, disorders of one of these systems may also affect the musculoskeletal system and complicate the diagnosis of the origin of the disorder. Diseases of the musculoskeletal system mostly encompass functional disorders or motion discrepancies; the level of impairment depends specifically on the problem and its severity.
Articular (of or pertaining to the joints) disorders are the most common. However, also among the diagnoses are primary muscular diseases, neurologic (related to the medical science that deals with the nervous system and disorders affecting it) deficits, toxins, endocrine abnormalities, metabolic disorders, infectious diseases, blood and vascular disorders, and nutritional imbalances.
Disorders of muscles from another body system can bring about irregularities such as:
- Impairment of ocular motion and control
- Respiratory dysfunction
- Bladder malfunction
Complete paralysis, paresis, or ataxia may be caused by primary muscular dysfunctions of infectious or toxic origin; however, the primary disorder is usually related to the nervous system, with the muscular system acting as the effector organ, an organ capable of responding to a stimulus, especially a nerve impulse.
One understated disorder that begins during pregnancy is Pelvic girdle pain, it is complex and multi-factorial and likely to be also represented by a series of sub-groups driven by pain varying from peripheral or central nervous system, altered laxity/stiffness of muscles, laxity to injury of tendinous/ligamentous structures to ‘mal-adaptive’ body mechanics.