Muscle Diversity Muscle Anatomy of the Human Body Types of Body Movement

Muscle Diversity Muscle Anatomy of the Human Body Types of Body Movement

Muscle is derived from the Latin word, mus, meaning “little mouse”  b/c flexing muscles look like mice scurrying beneath the skin.  there are 600+ muscles in a human body. They are grouped into 3 types : Skeletal muscle – are muscle fibres that attach to the body’s skeleton. It helps form smoother body contour. Cardiac muscle – are muscle fibres that form the heart and its chamber walls. Smooth muscle – are muscle fibres that form the walls of hollow organs in our body. Eg. stomach, bladder etc…

Characteristic Skeletal Cardiac Smooth 1. Body location - Attached to bones or to skin on face - Walls of the heart- Walls of other hollow organs 2. Cell shape & appearance - single, very long, cylindrical, striated, and multinucleate - branching chains of cells, striated, and uninucleated - single, fusiform, no striations, and uninucleate 3. Regulation of contraction - voluntary; control via nervous system - involuntary; heart has pacemaker; NS - involuntary; NS; hormone, chemicals

Producing movement is a common function of ALL muscle types  muscle contraction and relaxation Skeletal muscle has three (3) additional functions: Maintaining Posture – skeletal muscles almost continuously making small adjustment after another we can have an erected posture despite being pulled by gravity. Stabilizing Joints – muscle tendons keep joints in place. Generating Heat – muscle uses ATP as energy to power contraction. Much of this escapes as heat which helps maintaining normal body temperature.

Frontalis Orbicularis oculi Orbicularis oris Deltoid Pectoralis major Biceps Rectus abdominis Brachioradialis Rectus femoris Fibularis longus Gastrocnemius Biceps femoris Gluteus maximus Triceps

Body movement occurs when muscles contract across a joint.  This means that the type of movement depends on the mobility/type of joint & how muscle is attached across that joint. Every muscle (600+) anchors to 2 ends.  One is called: origin (on immovable bone)  Other is called: insertion (movable bone) When muscle contracts, the insertion moves toward the origin. Some muscles have multiple origins and/or insertions. These combinations increase the flexibility of body movements.

1.Flexion – a movement that decreases the angle of the joint and bring two bones closer together. 2.Extension – a movement that increases the angle or distance. If it is greater than 180 degree, it is called hyperextension.

3.Rotation – movement of a bone around its longitudinal axis. This normally involves the ball-and-socket joints. 4.Supination & Pronation – rotation at the wrist to palm either facing up or down. 5.Dorsifexion & Plantar flexion – up and down movement of the foot at the ankle.