The Muscular System What is a Muscle A

The Muscular System

What is a Muscle? § A muscle is an organ that contracts and gets shorter, this provides the force to move your body parts.

Muscles of the Human Body § Body muscles perform many useful functions from movement to keep your heart beating. § Muscles are able to contract, or get shorter, and relax. § Contracting and relaxing muscles allow you to bend and straighten your arms and legs.

Types of Muscles § There are three types of muscles in the body. § Skeletal muscles are connected to bones to provide movement. They are striped or striated. § Smooth muscles form the walls of organs, such as the stomach and intestines. Smooth muscles are found in the digestive organs and blood vessel walls. § The Cardiac muscles keeps the heart beating. Theses are found only in the heart.

Muscles & Tendons § Muscles can also be classified as voluntary or involuntary muscles. § Voluntary muscles are attached to bones and you can control them to move your body. Ex: Deltoid Muscle § Involuntary muscles work on their own without you needing to think about them. Ex: Heart Muscle

Connections § Muscles are connected to bones using tendons. § When muscles contract, they pull on tendons attached to the bone. § Tendons can also connect muscles to muscles. § Tendons look like cables that are broad and flat.

Deltoid § The Deltoid muscles are located on the shoulders. § They provide the ability to move the shoulder and upper arm.

Pectoralis Major § The Pectoralis Major muscles are the major muscles in the chest. § They help to pull the arm and shoulder forward toward the body.

Abdominals (Stomach Muscles) § The Abdominals are major stomach muscles. § They help to pull in the abdomen. § They also help to lift the upper body when laying down.

Biceps § The Biceps are located in the front of the arm and they help to bend the arm. § When the biceps contracts it pulls the forearm toward the upper arm, bending the arm at the elbow.

Quadriceps § The Quadriceps are a large muscle, long muscle that extends from the top of the leg to the kneecap. § It is the strongest and leanest muscle in the human body.

Sartorius § The Sartious muscle is a long slender muscle that starts at the inner knee and ends at the hip. § It is the longest muscle in the human body.

Gastrocnemius § The Gastrocnemius muscles are located in the back of the lower leg. § These muscles help to lift the heal upward and to bend the foot and toes downward.