THE MUSCULAR SYSTEM

LEARNING OBJECTIVES

State the function of the Muscular System.

To describe the structure and workings of the muscular system.

To identify the major muscles of the human body.

To describe the effects of physical activity in the muscular system.

The muscular system is made up of all the muscles in the

body.

FUNCTIONS OF THE MUSCULAR SYSTEM

Facilitate movement of the body when they contract and pull on bones.

Maintain good posture.

Produce heat as they work, which helps to maintain body temperature.

Types of muscles in the body……….

Skeletal Muscles or voluntary muscles

These are the muscles which are attached to bones.

They are controlled voluntarily, i.e. you can consciously causes them to contract or relax

Cardiac Muscles The heart is made up pf mainly cardiac muscles.

Smooth or involuntary muscles.

These make up the walls of hollow structures like the digestive tract and blood vessels.

You cannot consciously cause them to contract or relax. There movements are involuntary.

WHAT ARE THE PARTS OF A SKELETAL MUSCLE?

Skeletal muscles are connected to bones by tendons. Most are connected across two bones that form a joint.

The skeletal muscle had three main parts:

* The point of origin

*The point of insertion

* The body of the muscle

THE POINT OF ORIGIN This is where the end of the muscle is attached to the bone that remains relatively stable during movement of that muscle

THE POINT OF INSERTION

This is where the other end of the muscle is attached to the other bone that moves when the muscle contracts.

THE BODY OF THE MUSCLE

This is the main part of the muscle which contracts and relaxes.

What types of movements are produced by skeletal muscles?

FLEXION A movement that brings the bones of a joint together. (bending)

EXTENSION A movement that increases the angle between two bones at a joint. (straightening)

ABDUCTION A movement of a part away from the midline of the body.

ADDUCTION A movement of a part toward the midline of the body.

ROTATION A movement around an axis.

What are the effects of exercise on the Muscular System.

Makes muscles stronger and more efficient.

Improves muscle tone which is the readiness of the muscles to respond even when they are relaxed.

Encourages good posture that enables muscles to work efficiently and can help prevent injuries.

Increases the size of muscle hypertrophy.

Reduces the risk of atrophy which is the wasting away of muscle due to lack of use.