INTEGUMENTARYSYSTEM

Period 8

Regina

Jassiem

Winston

Jodi

Diane Torey

Wasiu

Fredericho

Semaya

Ybel

Diamond

Christina

Fatoumata

Janaisha

Damarian

Auyatta

Tamesha

Briana

Desmond

Shoudeline

Kamilla

Jada

Keniya

TV/Smart TV/board

Donald

DO NOW

1. Get notebooks

2. List the functions of the skin on the small paper at the door.

10 minutes

Marc

Selena Kimani Amanda Jamireus Malila

Adryene ArmoniWalid TrequanSumer Rhema

Victoria

Alexandria

Objectives

• Identify and describe the functions of the skin and its layers.

• Identify and describe the factors that determine skin color.

• Compare and contrast the structures of each layer of the skin.

• Recognize histological differences between the epidermis, dermis, hair follicles, and nail beds.

• Identify and explain the function of sudoriferous glands, sebaceous glands, and dermal nerves.

ESSENTIAL QUESTIONWhat are the structural and functional differences between the epidermis

and dermis?

Integumentary System

• The skin is the largest organ of the body

• It has a total area of about 20 square feet.

• The skin protects us from microbes and the elements.

• Helps regulate body temperature, and permits the sensations of touch, heat, and cold.

Skin Function• The main functions of the skin include:

• Protection of the human body.

• Sensation - transmitting to the brain information about surroundings.

• Temperature regulation

• Immunity - the role of the skin within the immune system

• Enables movement and growth without injury

• Excretion - from the body of certain types of waste materials

• Endocrine function - Vitamin D

Skin has three layers:

Epidermis

• The epidermis, the outermost layer of skin, provides a waterproof barrier and creates our skin tone. It is composed of stratified squamous epithelium.

• The skin’s color is created by special cells called melanocytes, which produce the pigment melanin. Melanocytes are located in the epidermis.

Dermis

• The dermis, beneath the epidermis, is thicker than the epidermis. It contains connective tissue (consisting of collagenous and elastic fibers), hair follicles, and sweat glands.

Hypodermis

• The deeper subcutaneous tissue (hypodermis) is made of fat and loose connective tissue. It is beneath the skin and not a true layer of skin.

What are the structural and functional differences between the epidermis and dermis?

• Epidermis –This is the top layer of skin made up of epithelial cells. It does not contain blood vessels. Its main function is protection, absorption of nutrients, and homeostasis. In structure, it consists of a keratinized stratified squamous epithelium comprising four types of cells: keratinocytes (main protector), melanocytes (skin color), Merkel cells (sensory perceptors), and Langerhans' cells (antigen presenting immune cells).

• A basement membrane anchors the epidermis to the dermis, and separates the two skin layers.

• Dermis – inner layer that houses hair, blood, nerves and glands.

Sudoriferous Glands• Sweat glands, also known as

sudoriferous or sudoriparousglands, from Latin sudor, meaning "sweat", are small tubular structures of the skin that produce sweat. Sweat glands are a type of exocrine gland, which are glands that produce and secrete substances onto an epithelial surface by way of a duct.

Sebaceous Glands

• Sebaceous glands are microscopic exocrine glands in the skin that secrete an oily or waxy matter, called sebum, to lubricate and waterproof the skin and hair of mammals.

Dermal Nerves

• The organization of sensory nerve fibers to the dorsal root ganglia found in the dermis

What determines skin color?

• Skin color is genetically determined, due to melanin.

• The amount of melanin that melanocytes produce and in the distribution and size of the pigment granules.

• If genes instruct melanocytes to produce abundant melanin, the skin is dark.

• External factors –

• Sunlight

• Blood oxygen concentration

• Diet high in various foods

• Biochemical imbalances

Epidermis Research - Skin Conditions

• Rash Dermatitis Eczema Psoriasis Dandruff

• Acne Cellulitis Skin abscess Rosacea Warts

• Melanoma Ringworm Shingles Scabies Hives

• Basal Cell Carcinoma Seborrheic Keratosis Actinic Keratosis

• Squamous Cell Carcinoma Tinea Versicolor Viral Exanthema

• Herpes

Hair Folicles• Hair is on all skin surfaces except the palms, soles, lips, nipples and part of the

external reproductive organs.

• It has a root.

• Sheath layer – covering that keritanizes

• Melanocytes for color

Nail

A protective covering on the ends of the fingers and toes.

*Nail Bed is made of epithelium cells.*Luna is the whitish half moon shape at the base of nail.*Nail plate is the keratinized nail plate or body

CHECK YOUR RECALLRead Pages 121-125

Complete 10-22

Healing of WoundsFibrin - is a fibrous, non-globular protein involved in the clotting of blood. It is formed by the action of the protease thrombin on fibrinogen which causes it to polymerize. The polymerized fibrin together with platelets forms a hemostatic plug or clot over a wound site.

Macrophage - a large phagocytic cell found in stationary form in the tissues or as a mobile white blood cell, especially at sites of infection.

PMN - . A polymorphonuclear leukocyte is a type of white blood cell. A type of immune cell that has granules (small particles) with enzymes that are released during infections, allergic reactions, and asthma. l

Collogen - plays a key role in each phase of wound healing.

Fibroblast - deposit ground substance into the wound bed, and later collagen, which they can adhere to for migration. ... Granulation tissue consists of new blood vessels, fibroblasts, inflammatory cells, endothelial cells, myofibroblasts, and the components of a new, provisional extracellular matrix (ECM).