The Muscular System These are the major muscles of the body… Deltoids Trapezius Pectorals Biceps Triceps Latissimus Dorsi Abdominals Gluteals Quadriceps Hamstrings Gastrocnemius Skip to labelled diagram Front View Back View

These are the major muscles of the body… The Muscular System These are the major muscles of the body… Deltoids Trapezius Pectorals Biceps Triceps Latissimus Dorsi Abdominals Gluteals Quadriceps Hamstrings Gastrocnemius Front View Back View

Muscle Types of the Body Every movement in the body depends upon muscles to take place. Within the body, there are 3 types of muscle: 1. Cardiac Muscle 2. Involuntary Muscle 3. Voluntary Muscle

1. Cardiac Muscle The cardiac muscle works without you thinking about it - there is no conscious control. Even when asleep it is capable of constant, automatic and rhythmical contractions. It is only found in the walls of the heart, which has it’s own blood supply provided by the coronary artery. When it contracts, the heart pumps blood to the lungs and around the rest of the body.

Cardiac Muscle - Structure

2. Involuntary Muscle Involuntary muscle works without you thinking about it - there is no conscious control. Also known as smooth muscle. Found in the walls of arteries, veins, stomach and intestine. Artery Vein Small Intestine

Involuntary Muscle - Structure Smooth Muscle

3. Voluntary Muscle You have full conscious control over voluntary muscles. However they can also be involved in involuntary reflexes. They are also known as striated or skeletal muscle. They are attached to bone and cause the skeleton to move. Examples include the triceps and hamstrings. They are the largest group of muscles in the body.

The Structure of Skeletal Muscle Skeletal muscle is wrapped in a tough covering called perimysium, which is slippery to allow muscles next to each other to move. All muscles narrow at each end into tough cords called tendons. These attach the muscle to bone. Tendons

Voluntary Muscle - Structure

Antagonistic Muscle Pairs Movement of the arm at the elbow Skeletal muscles work across a joint and are attached to the bones by strong cords known as tendons. They work in pairs, each contracting or relaxing in turn to create movement. Movement of the arm at the elbow

The Origin and Insertion When a muscle contracts, only one bone moves leaving the other stationary. The points at which the tendons are attached to the bone are known as the origin and the insertion. The origin is where the tendon of the muscle joins the stationary bone(s). The insertion is where the tendon of the muscle joins the moving bone(s). Origin The arm is being flexed. Insertion The radius and ulna are the moving bones. The humerus and scapular are stationary bones.

Flexion (Bending) of the Arm The muscle doing the work (contracting) and creating the movement is called the agonist or prime mover. The muscle which is relaxing and letting the movement take place is called the antagonist. Antagonist (Triceps relax) Agonist or Prime Mover (Biceps contract)

Extension (Straightening) of the Arm Locate and name the following parts involved in the extension of the arm: Agonist (prime mover) Antagonist Origin Insertion Any Bones Scapula Origin Triceps: agonist (prime mover) contracting muscle Biceps: antagonist relaxing muscle Radius Humerus Carpals Insertion Phalanges Metacarpals Ulna