Muscular System
Myology is the science that studies muscular system, their physical structure, function, the connections between different muscle groups and their diseases and injuries. The knowledge of muscle physiology can be utilized to evaluate the potential effectiveness of various endurance and resistance training techniques. Any movement that we make requires the functioning of related muscles to complete the action.
Introduction
Understanding the muscle names helps describe shapes, location, and actions of various muscles.The classification and nomenclature of muscles have been done on several basis.
- Based on the control of the nervous system on the muscular movement ( Voluntary & Involuntary Muscles)
- Muscles are named based on their shape( Example: Deltoid is a thick triangular muscle covering the shoulder joint and is used for moving the arm away from the body.
- Nomenclature is also based on the type of movement supported by the muscle (Example: Flexor, Extensor ). The muscles that decrease the angle between bones are called flexor muscles. The muscles that increase the angles between bones are called extensor muscles.
In case of Biceps & Triceps, the prefix bi indicates that the muscle has two origins and tri indicates three origins.
Naming is also based on the location of attachment of a muscle. The sternocleidomastoid muscle is a two-headed neck muscle, which is attached to the manubrium of sternum, the clavicle (-cleido-), and the mastoid process of the temporal bone.
The muscles of human body are widely classified into three types:-
Skeletal Muscle
- Attaches to the bones via tendons and contracts to move bones
- Voluntary
- Striated Appearance
Smooth Muscle
- Form the walls of organs and tubes ( stomach, blood vessels, intestine)
- Involuntary
- Smooth Appearance
Cardiac Muscle
- Forms the walls of the heart.
- Involuntary
- Smooth Appearance
Role of Individual Muscles During Exercise
Agonist Muscles
- These are the muscles responsible for a particular movement.
- It is also called the Prime Mover.
- Example: Pectoralis major, deltoid and triceps are used in a bench press and they are called Agonists.
Synergist
- These muscles assist the movement indirectly. They act to stabilize joints around which a movements is occurring.
- During forearm flexion, the biceps brachii is the prime mover. It is assisted by the brachialis, for the movement and brachialis is called a synergist in this action.
Antagonist Muscles
- These muscles oppose the action done by another muscle.
- While the agonist muscle contract, the movement is opposed by relaxation of another muscle which acts as the Antagonist.
- Example: During flexion at the elbow, biceps contract and triceps relaxes, during extension at an equivalent joint, triceps contract, and biceps relax.
Origin and Insertion of a Muscle
Origin of a Muscle: The end of a skeletal muscle that is attached to another structure (usually a bone) in a fixed position.
Insertion of a Muscle: The end of a skeletal muscle that is attached to the structure (usually a bone) that is moved when the muscle contracts.
The end of the muscle that attaches to the bone being pulled is called the muscle’s insertion and the end of the muscle attached to a fixed, or stabilized, bone is called the origin.
