Muscular SystemMuscle Diversity

Muscle Anatomy of the Human BodyTypes of Body Movement

Muscular SystemMuscle Diversity

Muscle Anatomy of the Human BodyTypes of Body Movement

Overview of Muscle TissuesMuscle 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…

Comparison of muscle typesCharacteristic 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

Muscle Functions• 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.

Muscular System ComponentsFrontalis Orbicularis oculi

Orbicularis oris

DeltoidPectoralis major

BicepsRectus abdominis

Brachioradialis

Rectus femoris

Fibularis longusGastrocnemius

Biceps femorisGluteus maximus

Triceps

Mechanics of Body Movements• 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.

Types of Body Movement1. 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.

Types of Body Movement3. 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.