Integumentary System PDF

The Integumentary System Lessons:  1. Anatomy and Physiology  2. Pathophysiology This module presents the knowledge of the anatomy and physiology of the integumentary s...

The Integumentary System Lessons:  1. Anatomy and Physiology  2. Pathophysiology This module presents the knowledge of the anatomy and physiology of the integumentary system. The skin’s physiology is explained in the context of going out for a morning, how the skin responds to injury, burns and others concepts correlated with this system  Pre-test This pretest shall aim to test your initial knowledge on The Basics of the Anatomy and Physiology with Pathophysiology. It shall seek to know what is the current knowledge or perception you know regarding on the course Instructions: Answer the following questions based on your own understanding. Choose from the provided choices and please put your answers on the space provided before each number. _______1. What do you use to measure acidity and alkalinity? a. Blood Pressure b. Temperature c. pH scale d. Blood sugar _______2. What molecule contains the usable form of energy for the cell? a. ATP b. ACP c. SGPT d. Nucleus _______3. What is the four major types of organic molecules? a.Zinc, Iron, Vit. C and Vit. E b. Lipids, Carbohydrates, Proteins, Nucleic Acids c. Nucleus, Golgi Complex, RER, Mitochondria _______4. What organelles assemble proteins? a. Lysosomes b. Ribosomes c. Nucleolus d. Rough ER _______5. What is programmed cell death? a. Neoplasia b. Apoptosis c. Necrosis How do you rate yourself?  If you got a perfect score, you have appropriate knowledge of the human body and its processes.  If you got a score of 3-4, it means you have a basic knowledge of the human body.  If you got a score of 0-2, it means that you need to have additional readings in anatomy and physiology with pathophysiology. HUMAN ANATOMY AND PHYSIOLOGY WITH THE INTEGUMENTARY SYSTEM PATHOPHYSIOLOGY Lesson 1: Anatomy Introduction: As the body’s largest organ, the skin makes up approximately 15% of the body’s total weight. It consists of two layers, the epidermis and the dermis. EPIDERMIS skin’s most superficial layer, composed of stratified squamous epithelial tissue. The epidermis is subdivided into four or five general layers called the strata. Stratum basale- is the only stratum of the epidermis with cells that actively grow and divide to produce new epidermis. Stratum lucidum-is found only on thick skin. It is not found on thin skin. Stratum corneum- composed of tough, waterproof dead cells that eventually flake off (exfoliate). CELLS OF THE EPIDERMIS KERATINOCYTES- begin in the stratum basale and make up the majority of epidermal cells. Their purpose is to grow and divide. As they divide, they push the older cells up towards the surface. The keratinocytes fill themselves with keratin (a hard, waterproof protein) as they move towards the surface. By the time they reach the stratum corneum, the keratinocytes have completely filled with keratin and died. This process is called cornification. MELANOCYTES produce skin pigments called melanin. These cells stay in the stratum basale, but they have projections to more superficial layers. The keratinocytes take in the melanin produced by pinching off bits of the melanocyte extension that contain melanin-filled vesicles called melanosomes. TACTILE CELLS serve as receptors for fine touch only. DENDRITIC CELLS are immune system cells found in the stratum spinosum and the stratum granulosum. They alert the body’s immune system to the invasion of pathogens that could make it through the stratum corneum. DERMIS  found deeper to the epidermis. It is composed of loose or areolar connective tissue over dense irregular connective tissue. Cutaneous glands, hair follicles, and most of the skin’s nerve endings can be found in the dermis.  sometime called the true skin. Blood vessels, fibers, nerve ending, hair follicles and cutaneous glands are found in the dermis. PAPPILAE HUMAN ANATOMY AND PHYSIOLOGY WITH THE INTEGUMENTARY SYSTEM PATHOPHYSIOLOGY  are the bumps on the superficial edge of the dermis. They are arranged in a random pattern over most of the body, form individual-specific patterns of ridges on the palmar and plantar surfaces. FIBERS the dermis changes from loose tissue to dense connective tissue. The cells (fibroblasts) of both tissues produce two types of protein fibers; collagen and elastin. Collagen give the skin strength. Elastin provide elasticity, which allows the skin to come back to shape when stretched. NERVE ENDINGS nerve cells have endings in the dermis that serves as receptors (receiving devices). These include warm receptor, cold, pain and pressure receptor. CUTANEOUS GLANDS considered exocrine glands, are located throughout the dermis. Exocrine glands produce and secrete products that are delivered to the appropriate locations through ducts. See table 1.1 Two basic types of cutaneous glands; sebaceous glands and sweat glands. SEBACEOUS GLANDS-are associated with hair follicle. Sebum- a very oily, lipid-rich substance is produce by the sebaceous gland to moisturize the skin and hair. Table 1.1 Types of Glands GLAND LOCATION PRODUCT FUNCTION MEROCRINE Deliver sweat Watery sweat composed Helps cool the body through SWEAT through pore. They of 99% of water, lactic evaporation. GLAND are located all over acid, nitrogenous waste the body. called urea and some salt. APOCRINE Deliver sweat Lipid-rich sweat that Serves as scent to influence SWEAT through hair follicle. bacteria feed on. the behavior of others. GLAND They are associated with axillary hair, pubic hair and the beard. CERUMINOUS Found only in the ear Cerumen (earwax) Keeps the ear drum flexible, GLAND canal waterproofs the ear canal, kills bacteria and protects ear canal from foreign debris. HUMAN ANATOMY AND PHYSIOLOGY WITH THE INTEGUMENTARY SYSTEM PATHOPHYSIOLOGY  MAMMARY Found in the breast Breast milk Nourishes an infant. GLAND Hair  Under normal circumstances, hair is present wherever there is thin skin on the body.  It is present wherever there is a thin skin on the body. It serves as guard of the head against bumps, shielding the eyes (via eyashes), and helping to keep foreign particles out of the respiratory system (via nose hairs), provides insulation in cold weather. HAIR FOLLICLES (See figure 1.1) Each hair follicle is positioned at an angle in the dermis with a dermal papilla at its base. The dermal papilla has a blood vessel, which feeds the keratinocytes and melanocytes contained in the hair follicle. The keratinocytes produce the hair, melanocytes produce the color. Active keratinocytes produce the hair matrix just above the dermal papilla (the hair’s growth center and contains important nerves and blood vessels that provide amino acids for keratin production). ARRECTOR PILI MUSCLE- this muscle attaches the hair follicle’s base to the epidermis at an angle. When this muscle contracts, it pulls on the hair follicle’s base, making the hair stand in an upright position to the skin’s surface (goose bumps). SECTIONS OF HAIR  BULB – thickening of the hair at the end of the hair follicle.  ROOT – extends from the bulb to the skin surface.  SHAFT – is the section of the hair extending out from the skin surface. Matrix- growth zone of the hair bulb at the inferior end of the follicle. Medulla- central core of each hair Cortex- surrounds the medulla Cuticle- formed by a single layer of celles that overlap one another like shingles on a roof. It is the most keratinized region; it provides strength and helps the inner hair layers tightly compacted.  Hair pigment is made by melanocytes in the hair bulb, and varying amounts of different types of melanin (yellow, rust, brown and black) combine to produce all varieties of hair color from pale blond to pitch black.  Hair comes i a variety of sizes and shapes. i. When the hair shaft is oval, hair is smooth and silky and the peson has a wavy hair. ii. when the shaft is flat and ribbonlike, the hair is curly or kinky. iii. if it is perfectly round, the hair is straight and tends to be coarse. Epidermal Sheath- composed of epithelial tissue and forms the hair. HUMAN ANATOMY AND PHYSIOLOGY WITH THE INTEGUMENTARY SYSTEM PATHOPHYSIOLOGY Dermal Sheath- is dermal connective tissue that supplies blood vessels to the epidermal portion and reinforces it. TYPES OF HAIR:  LANUGO HAIR- is very fine and colorless, forms on a fetus during the last three months of its development. This hair is usually replaced by birth.  VELLUS HAIR – also colorless and very fine, replaces lanugo hair around the time of birth.  TERMINAL HAIR – thick, coarse, and heavily pigmented, forms the eyebrows, eyelashes and hair on the scalp. Sections of Hair:  Bulb is a thickening of the hair at the end of the hair follicle.  Root extends from the bulb to the skin’s surface.  Shaft is the section of the hair extending out from the skin’s surface. Cross-Sectional Layers of Skin:  INNER MEDULLA – the central core, composed of soft keratin  MIDDLE CORTEX – surrounds the medulla, composed of hard keratin  OUTER CUTICLE – encloses the cortex, appears as interlocking scaly plates like shingles of the roof. It is the most heavily keratinized region. It provides strength and helps keep the inner hair layers tightly compacted. Split ends – a phenomenon which the keratin fibrils in the inner hair regions frizz out Hair Textures (accdg. to shaft’s cross-sectional shape):  Straight – round shaft  Wavy – oval shaft  Curly – flatter shaft  The hair bulb on the hair follicle contains active growing cells made up of a protein.  Small blood vessels in the skin give the root nutrients to help with cell growth allowing the hair to grow  As the hair begins to grow; it pushes up from the root and out of the follicle and eventually breaks through the surface of the skin. You can see the visible part of the hair known as shaft.  Once the hair is on the skin surface the cells within the strand of the hair, they become keratinized and die, and are now called dead cells. This is why it doesn’t hurt when we get a haircut. If the cells in hair are still alive, then the haircut would be unpleasant. Hair Cycle: HUMAN ANATOMY AND PHYSIOLOGY WITH THE INTEGUMENTARY SYSTEM PATHOPHYSIOLOGY   ANAGEN (growing)– the state which hair grows (0.5 inch in a month). This phase can last for approximately 3 yrs. It can be shorten through factors including stress and diet.  CATAGEN (detaching)– period of time which hair detaches from the blood vessels and dermal papilla.  TELOGEN (resting)– hair detached and resting in skin. Catagen and Telogen lasts for about 1 to 2 years.  EXOGEN (Shedding)– extension of telogen phase characterized by the shedding of telogen hair. The old hair sheds, new hair grows simultaneously and new anagen phase begins.  Hair pigment – is made by melanocytes in the hair bulb, and varying amounts of different melanin (yellow, rust, brown and black) combine to produce all varieties of hair color from pale blond to black.  Grey to white color – lack of melanin in the hair’s cortex and from the possible presence of air in the medulla.  It is perfectly normal to lose 50-100 hairs from your scalp every day. NOT ALL of the hairs undergo cycle on the same schedule. Figure 1.1 Structures of hair NAIL  protects the ends of the fingers and toes, aids in grasping objects and are used for scratching. See figure 1.2  scalelike modification of the epidermis that corresponds to the hoof or claw of other animals. Functions: HUMAN ANATOMY AND PHYSIOLOGY WITH THE INTEGUMENTARY SYSTEM PATHOPHYSIOLOGY   Protects our fingertip  Good indicator of health; conditions of the nails can be used by doctors to get clues for overall health Anatomy of a nail:  Nail root – found under the skin  Nail plate – visible part of the nail  Free edge – nail plate that extends out of the skin  Nail body – nail plate on the surface of the skin  Nail bed – where the nail plate lies  Nail fold – rise or bump of the skin over the nail’s lateral edge  Nail groove – where the nail fits into  Cuticle or eponychium – at the proximal edge of the nail body, is composed of stratum corneum cells extending onto the nail bed.  Nail matrix – responsible for nail growth. It is composed of active keratinocytes in the stratum basale.  Lunula or lunule – (white crescent) this is where the nail matrix is thick enough to hide the blood vessels of the dermis deep to it. Figure 1.2 Anatomy of Nail HUMAN ANATOMY AND PHYSIOLOGY WITH THE INTEGUMENTARY SYSTEM PATHOPHYSIOLOGY HYPODERMIS (SUBCUTANEOUS LAYER/TISSUE) it is found deeper to the dermis and it is not technically part of the skin. But it attaches the skin to the rest of the body. Mainly composed of adipose connective tissue. It serves as an insulating layer, a cushioning layer and an energy source. Physiology Now find a pen and draw four dots on the posterior surface if your hand to represent the corners of a square inch. This 1 square of skin you have on your own hand is typically composed of:  20 blood vessels  65 hairs and arrector pili muscles  78 nerve endings for heat  13 nerve endings for cold  160 to 165 sensors for pressure  100 sebaceous gland  650 sweat glands  19,500,000 cells FUNCTIONS OF THE SKIN 1. PROTECTION Skin is the body’s first line of defense against the foreign pathogens, The skin’s surface is dry with an acidic pH, making it unfriendly for bacteria to grow. Dendritic cells of the epidermis stand guard if any pathogens try to make it past the stratum corneum. 2. VITAMIN D PRODUCTION UV light encourages skin to produce vitamin D, as it activates a precursor molecule in the skin. The liver and kidney then modify this molecule to become active vitamin D. It is also important for the absorption of calcium from the diet into the blood-stream. Calcium is needed for bone development and maintenance. 3. TEMPERATURE REGULATION The body becomes too warm, so blood vessels dilate and sweat glands produce sweat to cool the body down to a normal temperature, in freezing conditions, you may see the skin first redden as blood vessels dilate in the dermis to warm the skin and prevent it from freezing. If however, this process draws too much heat from the body’s core, the dermal blood vessels will constrict to preserve the heat for the core and thus preserve life. Frostbite of the skin may then occur. 4. SENSATION During a morning run, the nerve endings in the stratum basale and dermis of the skin constantly send the brain message. The body will sense the cool temperature from the cold receptors in the dermis. They will feel the sun on their faces from the heat receptors and feel the presence of their clothing and shoes from the pressure sensors. The body will even detect the ant crawling on his legs as it disturbs his leg hair, activating the sensors wrapped around his hair follicles. If the person stumbles and falls, pain receptors will alert the person to any skin injury 5. NON VERBAL COMMUNICATION HUMAN ANATOMY AND PHYSIOLOGY WITH THE INTEGUMENTARY SYSTEM PATHOPHYSIOLOGY  It is crucial to note that the condition of their skin in their hair sends nonverbal messages to anyone seeing them, A person may blush if he is embarrassed by something he/she has done, Or a person’s face may become pale if he/she if frightened and even the color, texture, silkiness and other qualities of the skin and hair can all be indicative of overall health. 6. WATER RETENTION The skin’s epidermis waterproofs the body by keeping water from the environment out and body fluids in, when a person stays in a bath for too long abrasions in the skin may be present, abrasion allow some water to pass through the epidermis causing swelling in the underlying tissues. The wrinkling seen while bathing is the swelling of these underlying cells going through osmosis. HUMAN ANATOMY AND PHYSIOLOGY WITH THE INTEGUMENTARY SYSTEM PATHOPHYSIOLOGY Lesson 1: Pathophysiology Skin can be damaged by all sorts of injuries, including cuts, punctures, and burns. These injuries can happen in everyday life and are not necessarily from a disease process. REGENERATION VS. FIBROSIS REGENERATION- The wound is healed with the same tissue that was damaged and normal function is returned. FIBROSIS- The wound is healed with scar tissue and normal function is not returned. WOUND CONTRACTURE – a scab forms and pulls the edges of the wound closer together as it dries. What happens to heal the wound? 1. Cutting into the dermis means severing blood vessels, so the wound bleeds and the clots. 2. A scab forms and pulls the edges of the wound closer together as it dries which is called wound contracture. 3. A race begins between the dermis’ fibroblasts and the stratum basale’s keratinocytes. 4. It depends on whether the keratinocytes reach contact inhibition before the fibroblasts can fill the wound with collagen that prevents keratinocytes from meeting. BURNS – common skin injury  First degree burns – most common burns. Symptoms are redness, pain and swelling.  Second degree burns – sometimes called partial-thickness burns. Symptoms are redness, pain, swelling and blisters.  Third degree burns – sometimes called full-thickness burns, most serious burns. Symptoms are charring and no pain. EFFECTS OF AGING ON THE INTEGUMENTARY SYSTEM  The epidermis becomes drier, with uneven tanning and age spots.  The dermis thins and produces less collagen and elastic fibers; this along with gravity, causes sagging andwrinkling of the skin.  The hypodermis thins, providing less cushioning and less insulation.  Nail becomes thinner and more susceptible to fracture.  Hair thins and turns gray. HUMAN ANATOMY AND PHYSIOLOGY WITH THE INTEGUMENTARY SYSTEM PATHOPHYSIOLOGY  Diagnostic Test Description Skin Biopsy The removal of a piece of tissue or a sample of cells from a body so that it can be analyzed in a laboratory Skin Scraping The taking of skin cell scrapings so that the cells can be viewed under a microscope Wood’s light The use of a black light to view pigment changes in the skin Table 1.2 Types of Diagnostic test for Integumentary system. INTEGUMENTARY SYSTEM DISORDERS SKIN CANCER – usually associated with sun exposure and it is more common in older, light skinned people. Basal cell carcinoma – starts in stratum basale cells and first appears as a small, shiny bump on the face, hands, ears, and neck. Squamous cell carcinoma – starts from keratinocytes in the stratum spinosum. First appearing as red, scaly patch that develops a central crust, it commonly forms on the face, hands, ears and neck. Malignant melanoma – the rarest but deadliest form of skin cancer. It starts with melanocytes, usually in a pre-existing mole. It can be seen as a dark spot under a nail or as a mole that is asymmetrical and has uneven color and scalloped HUMAN ANATOMY AND PHYSIOLOGY WITH THE INTEGUMENTARY SYSTEM PATHOPHYSIOLOGY SKIN INFECTIONS can stem from an assortment of bacterial, viral and fungal infection. BACTERIAL SKIN INFECTIONS Impetigo – is an infectious skin disease caused by the bacterium staphylococcus or streptococcus. Appear as a cluster of vesicles, which are fluid filled blisters that burst and crust over. Risk factors include a possible break in the skin, moist environment of the skin, poor hygiene, and the existence of staphylococcus bacterium in the nose. Cellulitis – commonly occurs on the face and lower legs, characterized by redness and swelling of an area of a skin that increases in size rapidly. The infected area has a tight, glossy appearance and is tender or painful. VIRAL SKIN INFECTIONS Warts – are growth caused by an infection of the skin produced by the human papillomavirus(HPV). Types of warts include common warts, plantar warts, genital warts and flat warts (found on frequently shaved surfaces). HUMAN ANATOMY AND PHYSIOLOGY WITH THE INTEGUMENTARY SYSTEM PATHOPHYSIOLOGY  Herpes Simplex Virus (HSV) – this virus is characterized by small painful blisters that appear on the skin and on the mucus membranes of the mouth genitals. This type of infection is extremely contagious and can be spread through direct contact of the infected area, even when there is no active infection present. 2 forms: a) HSV-1 - causes viral herpes infections seen on the lips or mouth b) HSV-2 - causes viral herpes infections on the genitals  Herpes Varicella-Zoster – another type of herpes infection causes chicken pox in children and shingles in adults:  Chicken Pox – is a common childhood disorder characterized by red, itchy, fluid-filled vesicles or pox that appear on the skin. The rash is also accompanied by fever, headache, and malaise. Chicken pox is contagious and can be contracted through direct or indirect contact.  Shingles – occurs in adult and is similar in appearance to chicken pox. It is characterized by small, painful vesicles that usually follow a path along an area of skin supplied by a spinal nerve. It usually occurs in the elderly or in immunocompromised patients. It also occurs in adults who have had chicken pox in the past. HUMAN ANATOMY AND PHYSIOLOGY WITH THE INTEGUMENTARY SYSTEM PATHOPHYSIOLOGY Fungal Skin Infections  Tinea infections – caused by a fungus. Contact with an infected person, damp surfaces like shower floors or pool decks, or even pets can transmit the fungus.  Ringworms – circular rash that clears from the center, giving it a ringlike appearance.  Athlete’s foot – causes burning, itching, and cracking of the skin between the toes.  Jock itch – causes an itchy, burning rash in the groin region. Parasitic Skin Infections  Scabies – a parasitic infection of the skin caused by the infestation of mites. It causes small red bumps on the skin that itch severely. HUMAN ANATOMY AND PHYSIOLOGY WITH THE INTEGUMENTARY SYSTEM PATHOPHYSIOLOGY Other Common Disease Disorders  Psoriasis – a common skin disease characterized by the overgrowth of skin cells and improper keratinization of the epidermis and nails. It is a hereditary autoimmune disorder.  Dermatitis- is characterized by inflammation of the skin and may also show symptoms of redness, swelling, oozing, crusting, scaling, pimples or vesicles and itching. a. Contact dermatitis-inflammation of the skin caused by direct contact with a substance like skin irritant or something that causes an allergic reaction. b. Atopic dermatitis (atopic eczema)- allergic reaction that causes an infection  Decubitus ulcers- also known as pressure ulcers or bedsores. They are areas of nerotic or ulcerated tissue caused by the pressure of a bony prominence in the body and another surface.  Hives- also known as urticaria, is an skin reaction that can be caused by insect bites. HUMAN ANATOMY AND PHYSIOLOGY WITH THE INTEGUMENTARY SYSTEM PATHOPHYSIOLOGY   Scledorma- involves the accumulation of excess connective tissue in the skin and various organs. Disease/ Disorder Description Acne Inflammation of sebaceous glands caused by oil, excess cells, and bacteria found on the skin. Alopecia Baldness or excessive loss of hair Burns Damage to tissues caused by heat, chemicals, sunlight, radiation or electricity Cellulitis An infection of the skin’s dermis or hypodermis, which is frequently caused by Streptococcus or Staphylococcus bacteria Decubitus ulcers Inflammation of the skin Herpes Viral infections of the skin, including the oral and genital areas Hives A reaction of the skin that can be caused by insect bites or by contact with substances that cause an allergic reaction, such as certain foods or drugs Impetigo An infectious disease of the skin caused by the Staphylococcus or Streptococcus bacteria Onychomycosis A fungal infection of the nails Psoriasis Skin condition of the nails an epidermis characterized by an overgrowth of skin cells and improper keratinization Scabies An infection of the skin caused by an infestation of mites Scleroderma Increased collagen production in the skin an organs HUMAN ANATOMY AND PHYSIOLOGY WITH THE INTEGUMENTARY SYSTEM PATHOPHYSIOLOGY  Tinea infections Fungal infections of the skin Warts Growths caused by an infection of the skin produced by the human papillomavirus (HPV) Table 1.3 Disorders of Integumentary system HUMAN ANATOMY AND PHYSIOLOGY WITH THE INTEGUMENTARY SYSTEM PATHOPHYSIOLOGY