Integumentary System

List at least three situations in which dogs pant List at least three situations in which dogs pant. How do humans respond to those same situations? Why do you think dogs pant? Do you know of any other animals that pant?

Functions of Skin Your skin, hair, and nails make up your integumentary system. Skin protects you by keeping water in your body and foreign particles out of your body. Protects underlying body parts from injury. Stores energy in the form of fat and vitamins. Nerve endings in your skin let you feel things around you. Skin helps regulate your body temperature. Skin also helps get rid of waste chemicals through perspiration.

Functions of Hair and Nails Hair is an outgrowth of protein; projected from the epidermis, though it grows from the hair follicles deep in the dermis. Nails which are made of a tough protein called keratin, are produced from living skin cells in the fingers and toes. Cutaneous glands include sweat, sebaceous, ceruminous, and mammary glands. Sweat glands produce sweat to regulate temperature. Sebaceous glands produce oil that keep skin and hair moist and soft. Ceruminous glands are in the are and produce earwax. Mammary glands are milk producing glands in the breast.

Layers of Skin Epidermis: The outermost layer of skin. Most cells in the epidermis are dead. Specialized cells produce pigment called melanin, which helps determine skin and hair color. 3 Main layers: Epidermis: has no blood vessels and the cells in the epidermis are constantly shedding. Dermis: Contains many blood vessels and new cells are continually forming to replace those lost from the epidermis. Subcutaneous: “under the skin” connects the skin to the muscle.

Layers of Skin Dermis: The thicker layer of skin that lies beneath the epidermis is the dermis. Capillaries- Tubes that carry blood as it circulates. Arteries bring oxygenated blood from the heart and lungs; veins return oxygen-depleted blood back to the heart and lungs. Lymph vessels- transports fluids from tissue to the blood system. Nerve endings 3 Main layers: Epidermis: has no blood vessels and the cells in the epidermis are constantly shedding. Dermis: Contains many blood vessels and new cells are continually forming to replace those lost from the epidermis. Subcutaneous: “under the skin” connects the skin to the muscle.

Layers of Skin Dermis: Hair follicles- a tube-shaped sheath that surrounds the part of the hair that is under the skin. It is located in the epidermis and the dermis. The hair is nourished by the follicle at its base (this is also where the hair grows). hair shaft - The part of the hair that is above the skin. Sweat and Sebaceous Glands Sweat glands produce sweat to regulate temperature. Sebaceous glands produce oil that keep skin and hair moist and soft. 3 Main layers: Epidermis: has no blood vessels and the cells in the epidermis are constantly shedding. Dermis: Contains many blood vessels and new cells are continually forming to replace those lost from the epidermis. Subcutaneous: “under the skin” connects the skin to the muscle.

Sweat & Sebaceous Glands sweat gland - (also called sudoriferous gland) a tube-shaped gland that produces perspiration (sweat). The gland is located in the epidermis; it releases sweat onto the skin. sebaceous gland - a small, sack-shaped gland that releases oily (fatty) liquids onto the hair follicle (the oil lubricated and softens the skin). These glands are located in the dermis, usually next to hair follicles.

Layers of Skin Subcutaneous Tissue: Layer between the dermis and the body's inner organs. Consist of fatty and fibrous tissue. Within the layer lies blood vessels and nerves. The fatty tissue serves to protect the inner organs and to maintain body's temperature. Also fat is necessary as an efficient store for energy. 3 Main layers: Epidermis: has no blood vessels and the cells in the epidermis are constantly shedding. Dermis: Contains many blood vessels and new cells are continually forming to replace those lost from the epidermis. Subcutaneous: “under the skin” connects the skin to the muscle.

Hair Grows from the epidermis to cover part of the body. Serves to cushion and protect the area it covers. Protects skin from ultraviolet light. Regulates temperature Composed of a protein called keratin and pigments which give it color. 2 Parts: The shaft which is about the skin and the root which is beneath the skins surface. A hair forms at the bottom of a tiny sac called a hair follicle. Most hair follicles have an arrector pili muscle. When you get cold or nervous these muscles contract, causing good bumps to form. The shape of the follicle determines the shape of the hair. Gray hair occurs with aging, when we stop producing melanin. -a dark brown to black pigment occurring in the hair, skin, and iris of the eye in people and animals. It is responsible for tanning of skin exposed to sunlight. Dark-skinned people have more melanin in their skin than light-skinned people have. Melanin is produced by cells called melanocytes

Nails A nail grows from living cells in the nail root at the base of the nail. Nails are also made of keratin Nails protect the tips of your fingers and toes. And helps us grasp objects and allows us to scratch. The nail root forms your nail. As the cells grow out and over the nail bed they become keratinzed. The cells shrink and dry and are pushed to the surface and become filled with protein called keratin. The cuticle is a fold of tissue that covers the nail root. The portion we actually see is the nail body. The pink color comes from vascularization the process of becoming vascular- blood vessels and circulation of blood.

The nail root forms your nail The nail root forms your nail. As the cells grow out and over the nail bed they become keratinzed. The cells shrink and dry and are pushed to the surface and become filled with protein called keratin. The cuticle is a fold of tissue that covers the nail root. The portion we actually see is the nail body. The pink color comes from vascularization

Skin Injuries Skin is often damaged, but fortunately can repair itself. However, damage to the genetic material in skin cells can cause skin cancer.

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Diseases/Disorders Athletes Foot Fungal infection Causes scaling, flaking and itching of various areas of the skin Transmitted mostly in moist areas where people walk barefoot Usually affects the feet Treatment: creams or sprays to kill fungus

Diseases/Disorders Atopic Dermatitis or Eczema A red and itchy inflammation of the skin. Early stage areas on the skin may be red, swollen, and weeping. Later becomes red, scaly, and itchy. Treatments: Avoid allergens. Topical application and medicine.

Diseases/Disorders Warts Tiny, round, rough tumor Found typically on the hands and feet Caused by the human papilloma virus Can be contagious, and spreads from one person to another via contact Usually disappear after a few months Can also be removed

Dermatologist Trained to treat conditions and diseases of the skin, hair and nails. This may involve skin allergies, cancer, melanomas, moles, acne, etc. Complete college and medical school. Then one year of clinical training, 3-4 years as a resident specializing in dermatology