Integumentary-System power point presentation of one of the systems

A full explanation of integumentary system

1. Integumentary System Gene Karlo D. Abag, RN, MAN(c)

2. Skin and Body Membranes Cover surfaces, line body cavities, and form protective sheets around organs epithelial membranes: include the cutaneous, mucous, and serous membranes ( covering and lining membranes) connective tissue membranes: represented by synovial membranes ( no epithelial cells) The cutaneous membrane, generally called the skin or integumentary system, is the outer covering that we all rely on for protection. Skin is absolutely essential because it keeps water and other precious molecules in the body. It also keeps excess water (and other things) out.

3. Introduction The integumentary system, also called the integument , which simply means “covering,” performs a variety of functions; most, but not all, of which are protective. - insulates and cushions the deeper body organ - protects the entire body from mechanical, chemical, and thermal damage - protects the body from ultraviolet radiation and microbes

4. capillary network and sweat glands regulates heat loss from the body surface capillary network and sweat glands; urea, salts, and water are lost when we sweat manufactures several proteins important to immunity and synthesizes vitamin D. produces acidic secretions, called the acid mantle , that protect against bacterial invasion

5. 2 Kinds of Skin Tissue Epidermis - made up of stratified squamous epithelium that can become hard and tough. Dermis - made up mostly of dense connective tissue. The epidermis and dermis are firmly connected, and the dermis is fairly tear resistant Subcutaneous Tissue or Hypodermis - adipose (fat) tissue. It is not considered part of the skin , but it does anchor the skin to underlying organs and provides a site for nutrient storage. Subcutaneous tissue serves as a shock absorber and insulates the deeper tissues from extreme temperature changes occurring outside the body. It is also responsible for the curves that are more a part of a woman’s anatomy than a man’s.

6. Epidermis Cells are Keratinocytes (keratin producing) Keratinization = the process of producing keratin Desmosomes connects keratinocytes throughout the epidermis Avascular = no blood vessels 5 layers or strata Stratum basale Stratum spinosum Stratum granulosum Stratum lucidum Stratum corneum

7. Stratum Basale closest to the dermis contains the most adequately nourished of the epidermal cells also called “ stratum geminativum ” – germinating new cells daily Of the new cells produced, some become epidermal cells, and others maintain the population of stem cells by continuing to divide. Epidermal cells continue moving upward becoming part of the stratum spinosum and then the stratum granulosum , they become flatter and increasingly keratinized. As these cells leave the stratum granulosum, they die, forming the clear stratum lucidum.

8. Stratum spinosum Cells contain thick bundles of intermediate filaments made of pre-keratin. Stratum granulosum Cells are flattened, organelles are deteriorating; cytoplasm full of granules. Stratum corneum Cells are dead, flat membranous sacs filled with keratin. Glycolipids in extracellular space make skin water resistant. Stratum corneum Cells are dead, flat membranous sacs filled with keratin. Glycolipids in extracellular space make skin water resistant.

9. Stratum corneum 20 to 30 cell layers thick, but it accounts for about three-quarters of the epidermal thickness. The shinglelike dead cell remnants, filled with keratin, are referred to as cornified, or horny, cells ( cornu = horn). Stratum lucidum This layer is not present in all skin regions. It occurs only where the skin is hairless and extra thick, that is, on the palms of the hands and soles of the feet.

10. Epidermal Dendritic cells (DCs) - specialized antigen presenting cells abundant in peripheral tissues such as skin where they function as immune sentinels . Skin DCs migrate to draining lymph node where they interact with naïve T cells to induce immune responses to microorganisms, vaccines, tumors and self-antigens. Melanocyte is  a highly differentiated cell that produces a pigment melanin inside melanosomes . This cell is dark and dendritic in shape. Melanin production is the basic function of melanocyte. Melanin is  a substance in your body that produces hair, eye and skin pigmentation . The more melanin you produce, the darker your eyes, hair and skin will be. The amount of melanin in your body depends on a few different factors, including genetics and how much sun exposure your ancestral population had. Merkel cells - associated with sensory nerve endings and serve as touch receptors called Merkel discs.

11. Dermis “hide” strong, stretchy envelope that helps to bind the body together (leather belts, bag, shoes are treated dermis of animals) Two Major Regions of Dermis Papillary – areolar connective tissue Reticular – dense irregular connective tissue

12. Papillary Layer superficial dermal region uneven and has peg-like projections from its superior surface, called dermal papillae many of the dermal papillae contain capillary loops, which furnish nutrients to the epidermis house pain receptors ( free nerve endings ) and touch receptors. On the palms of the hands and soles of the feet, the papillae are arranged in definite patterns that form looped and whorled ridges on the epidermal surface that increase friction and enhance the gripping ability of the fingers and feet. Papillary patterns are genetically determined . The ridges of the fingertips are well provided with sweat pores and leave unique, identifying films of sweat called fingerprints on almost anything they touch.

13. Reticular Layer deepest skin layer contains dense irregular connective tissue, as well as blood vessels, sweat and oil glands, and deep pressure receptors called lamellar corpuscles contains other cutaneous sensory receptors tiny receptors that includes touch, pressure, temperature, and pain receptors

14. Phagocytes are found here acting to prevent microbes that have managed to get through the epidermis from penetrating any deeper into the body. collagen and elastic fibers are found throughout the dermis. Collagen fibers are responsible for the toughness of the dermis ; they also attract and bind water and thus help to keep the skin hydrated . Elastic fibers give the skin its elasticity when we are young. As we age, the number of collagen and elastic fibers decreases, and the subcutaneous tissue loses fat . As a result, the skin loses its elasticity and begins to sag and wrinkle.

15. Three pigments contribute to skin color: melanin, carotene , and hemoglobin . Skin exposure to sunlight stimulates melanocytes to produce more melanin pigment, resulting in tanning of the skin. Melanin forms a pigment umbrella over the superficial, or “sunny,” side of their nuclei and shields their genetic material (DNA) from the damaging effects of UV radiation in sunlight Carotene is an orange-yellow pigment plentiful in carrots and other orange, deep yellow, or leafy green vegetables.

16. Homeostatic Imbalances Cyanosis – Bluish Discoloration of the skin due to lack of Oxygen in the blood Redness or Erythema – may indicate embarrassment (blushing), fever, hypertension, inflammation, or allergy. Pallor or Blanching – emotional stress (fear, anger, and others), some people become pale. Pale skin may also signify anemia, low blood pressure, or impaired blood flow into the area. Jaundice or yellow cast . An abnormal yellow skin tone usually signifies a liver disorder in which excess bile pigments accumulate in the blood, circulate throughout the body, and become deposited in body tissues. Rubor – reddening or dark discoloration  that occurs when a limb has poor arterial flow Bruises – black-and-blue marks of bruising reveal sites where blood has escaped from the circulation and has clotted in the tissue spaces. Such clotted blood masses are called hematomas . An unusual tendency to bruise may signify a deficiency of vitamin C in the diet or hemophilia (bleeder’s disease).

17. Appendages of the Skin Cutaneous glands Hair and hair follicles Nails Each of these appendages arises from the epidermis and plays a unique role in maintaining body homeostasis.

18. Cutaneous Glands exocrine glands that release their secretions to the skin surface via ducts. Two groups of Cutaneous Glands are sebaceous glands and sweat glands . As these glands are formed by the cells of the stratum basale , they push into the deeper skin regions and ultimately reside almost entirely in the dermis. Two groups of Cutaneous Glands are sebaceous glands and sweat glands .

19. Sebaceous Glands/Oil Glands found all over the skin, except on the palms of the hands and the soles of the feet ducts usually empty into a hair follicle, but some open directly onto the skin surface. Sebum = product of sebaceous glands, mixture of oily substances and fragmented cells lubricant that keeps the skin soft and moist and prevents the hair from becoming brittle. contains chemicals that kill bacteria, so it is important in preventing bacterial infection of the skin The sebaceous glands become very active when androgens (male sex hormones) are produced in increased amounts (in both sexes) during adolescence. Thus, the skin tends to become oilier during this period of life.

20. Sweat Glands are widely distributed in the skin more than 2.5 million per person Two types of sweat glands Eccrine - far more numerous and are found all over the body. They produce sweat, a clear secretion that is primarily water plus some salts (sodium chloride), vitamin C, that cause them to secrete sweat when the external temperature or body temperature is too high. Apocrine - are largely confined to the axillary (armpit) and genital areas of the body. They are usually larger than eccrine glands, and their ducts empty into hair follicles. Their secretion contains fatty acids and proteins, as well as all the substances present in eccrine sweat; consequently, it may have a milky or yellowish color. The secretion is odorless, but when bacteria that live on the skin use its proteins and fats as a source of nutrients for their growth, it can take on a musky, sometimes unpleasant odor.

21. Hair and Hair Follicles Hair is produced by Hair Follices Among the fastest growing tissue in the body Hair protects the head against bumps, shields the eye, helps keep foreign bodies out of the respiratory tract

22. Hair part of the hair enclosed in the hair follicle is called the root, and the part projecting from the surface of the scalp or skin is called the shaft forms by division of the well-nourished stratum basale epithelial cells in the matrix (growth zone) of the hair bulb at the deep end of the follicle. daughter cells are pushed farther away from the growing region, they become keratinized and die. Thus the bulk of the hair shaft, like the bulk of the epidermis, is dead material and almost entirely protein.

23. Hair Follicles compound structures Epithelial root sheath – inner, composed of epithelial tissue and forms the hair. Fibrous sheath – outer, dermal connective tissue, supplies blood vessels to the epidermal portion and reinforces it. Hair papilla supplies blood to the hair bulb. Arrector pili connect each side of the hair follicle to the dermal tissue. Responsible for “ goose bumps ”

24. Nail scalelike modification of the epidermis has a free edge , a body (visible attached portion), and a root (embedded in the skin) borders of the nail are over-lapped by folds of skin called nail folds The edge of the thick proximal nail fold is commonly called the cuticle stratum basale of the epidermis extends beneath the nail as the nail bed Its thickened proximal area, called the nail matrix thickened nail matrix that appears as a white crescent and is called the lunule