The Muscular System What do skeletal muscles do? How do muscles work?

The Muscular System Muscle is an organ that can relax and contract, and provides the force to move your body parts.

Tim and Moby film

Muscular system There are more than 630 muscles in your body. On average, your body weight is 40% muscle. Muscles consists of million of fibers packed with protein. Not all proteins are identified yet.

The Amazing Muscle The job of a muscle is to move the body. Without muscles the skeleton couldn’t move. Muscle help to move the mouth to form speech, help to blink, digest food, breathe, pump the heart and allow a person to smile.

Functions of the Muscular System Produce movement Maintain posture and body position Support soft tissue Guard entrances and exits Maintain body temperature

To move or not to move 1.  Voluntary muscles – muscles that you are able to control 2. Involuntary muscles – muscles that you cannot control

Muscle Groups Each muscle belongs to one of three categories: Skeletal muscles, Smooth muscle, and cardiac muscle.

Three types of muscle Skeletal Cardiac Smooth

Skeletal muscle characteristics Large muscles Maintain posture Facilitate (help with) locomotion Move jointed bones Joined to bones by tendons

Heart muscle cells behave as one unit Found only in the heart Cardiac muscle Main muscle of heart Heart muscle cells behave as one unit Found only in the heart Involuntary

Found in walls of internal organs Involuntary movement Smooth muscle Found in walls of internal organs Involuntary movement

Tendon ~ strong, tough connective tissue cord, connect muscle to bone Example *Achilles Tendon (attaches to calf muscle and heel bone)

Skeletal muscle action produces movements at synovial joints Skeletal muscle action produces movements at synovial joints. Usually one end of the muscle is attached to a relatively immovable or fixed on side of a joint, while the other end of the muscle is attached to a movable end or origin.

Types of body movement Flexor Extensor Abduction Adduction Hyperextension Dorsiflexion Rotation circumduction Let’s look at each one

Flexion (Flexor) ~ decreasing the angle between two bones and body part

Extension ( Extensor) ~ increasing the angle between two bones and body part

Abduction-moving of a body part away from the central axis of the body . Adduction-moving of a body part toward the central axis of the body.

Hyperextension-Extension of a bodily joint beyond its normal range of motion.

Dorsiflexion-the act of bending backward (of the body or a body part

Rotation-The act or process of turning around a center or an axis.

Circumduction-The circular movement of a limb.

Do you know who I am? Hint: I’m the governor of Cal.

Of muscular system, now let’s look at the skin. The End Of muscular system, now let’s look at the skin.

Advance science only Before we begin let’s watch a dancer perform and see how the different system work together to make a great perfomance. http://www.youtube.com/watch?v=DmUhiCaTm3k http://www.youtube.com/watch?v=tpAEkZqOVX0

Integumentary System The bodily system consisting of the skin and its associated structures, such as the hair, nails, sweat glands, and sebaceous glands.

The skin is one of the more versatile in our body, the skin is vital in maintaining homeostasis.

Protective layer for the body Helps us to maintain homeostasis Integumentary system Functions: Protective layer for the body Helps us to maintain homeostasis Helps us to react to our environment

The skin is composed of layers and is known as the body’s largest organ: This lead to the development of skin grafts and transplants. Let’s learn to the components of the skin.

Epidermis The outer, protective, nonvascular layer of the skin of vertebrates, covering the dermis.

Seen here in a scanning electron micrograph, the epidermis is a tough coating formed from overlapping layers of dead skin cells, which continually slough off and are replaced with cells from the living layers beneath. The epidermis is the outermost of three layers that make up the skin.

Dermis The dense inner layer of skin beneath the epidermis, composed of connective tissue, blood and lymph vessels, sweat glands, hair follicles, and an elaborate sensory nerve network.

Accessory organs They are recognized as important in the protective mechanism of the human body. Nail, hair follicles, sebaceous glands, melanin, sudoferous glands, eccrine glands and sweat glands. Let’s look at each one.

Sebaceous gland A cutaneous gland that secretes sebum (usually into a hair follicle) for lubricating hair and skin 

pertaining to, or affecting the skin. cutaneous gland pertaining to, or affecting the skin.

Producing or secreting sweat Sudoriferous Gland Producing or secreting sweat

The fat layer lying just beneath the dermis Subcutaneous tissue The fat layer lying just beneath the dermis

a small cavity, sac, or gland which holds the hair. Follicle a small cavity, sac, or gland which holds the hair.

Melanin any of a class of insoluble pigments, found in all forms of animal life, that account for the dark color of skin, hair, fur, scales, feathers, etc.

Eccrine glands Any of the numerous small sweat glands distributed over the body's surface that produce a clear aqueous secretion