Origin Insertion And Action Of Muscles With Pictures Pdf
If you have ever studied human anatomy, you probably know that muscles are responsible for creating movement in the body. But have you ever wondered how muscles actually work? Understanding the origin, insertion, and action of muscles is key to understanding how we move. In this article, we will explore the basics of muscle anatomy and physiology and provide a comprehensive guide on origin, insertion, and action of muscles with pictures PDF.
What Are Muscles?
Muscles are specialized tissues that are responsible for movement, posture, and stabilization. They are composed of muscle fibers that are bundled together and surrounded by connective tissue. There are three types of muscles in the body:
- Skeletal muscles: these are attached to bones and are responsible for voluntary movement.
- Smooth muscles: these are found in the walls of internal organs and blood vessels and are responsible for involuntary movement.
- Cardiac muscles: these are found in the walls of the heart and are responsible for pumping blood.
How Do Muscles Work?
Muscles work by contracting and relaxing. When a muscle contracts, it shortens and pulls on the bones to create movement. When a muscle relaxes, it lengthens and allows for movement to occur. Muscles work in pairs, with one muscle contracting while the opposing muscle relaxes. This creates a pulling action that moves the bones and creates movement.
Origin and Insertion of Muscles
The origin of a muscle is the point where it attaches to a stationary bone. The insertion of a muscle is the point where it attaches to a moving bone. When a muscle contracts, it pulls on the insertion bone, which moves towards the origin bone.
For example, let's look at the bicep muscle. The origin of the bicep muscle is the scapula, or shoulder blade. The insertion of the bicep muscle is the radius bone in the forearm. When the bicep muscle contracts, it pulls on the radius bone, which moves towards the scapula.
Action of Muscles
The action of a muscle is the movement that it creates when it contracts. Muscles can create a variety of movements, including:
- Flexion: this is when a joint is bent, such as when you lift your arm to your shoulder.
- Extension: this is when a joint is straightened, such as when you lower your arm back down.
- Abduction: this is when a limb is moved away from the body, such as when you lift your leg to the side.
- Adduction: this is when a limb is moved towards the body, such as when you lower your leg back down.
- Rotation: this is when a bone rotates around its axis, such as when you turn your head from side to side.
Examples of Muscles and Their Origin, Insertion, and Action
Here are a few examples of muscles and their origin, insertion, and action:
Bicep muscle
Origin: Scapula
Insertion: Radius bone in the forearm
Action: Flexion of the elbow joint
Quadriceps muscle
Origin: Femur bone
Insertion: Patella and tibia bones
Action: Extension of the knee joint
Trapezius muscle
Origin: Occipital bone and spine of the thorax
Insertion: Acromion process and spine of the scapula
Action: Elevation and retraction of the scapula
Conclusion
Understanding the origin, insertion, and action of muscles is key to understanding how we move. When a muscle contracts, it shortens and pulls on the bones to create movement. When a muscle relaxes, it lengthens and allows for movement to occur. Muscles work in pairs, with one muscle contracting while the opposing muscle relaxes. This creates a pulling action that moves the bones and creates movement. By knowing the origin, insertion, and action of each muscle in the body, we can better understand how our bodies move and function.
