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    Integumentary System: Presented By: Patricia Adora G. Alcala

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    hendrix obciana
    The integumentary system consists of the skin, hair, nails, and glands. The skin is the largest organ of the body and has three main layers - the epidermis, dermis, and hypodermis. It acts as a protective barrier and plays roles in temperature regulation, sensation, excretion, and vitamin D synthesis. The skin contains glands that secrete oils, sweat, and wax to lubricate and cool the body. Hair, nails, and nerves endings in the skin help provide protection, sensation, and other functions. The integumentary system works together to protect the body from damage, regulate temperature, and detect stimuli.

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    Integumentary System: Presented By: Patricia Adora G. Alcala

    Uploaded by

    hendrix obciana
    68 views57 pages
    The integumentary system consists of the skin, hair, nails, and glands. The skin is the largest organ of the body and has three main layers - the epidermis, dermis, and hypodermis. It acts as a protective barrier and plays roles in temperature regulation, sensation, excretion, and vitamin D synthesis. The skin contains glands that secrete oils, sweat, and wax to lubricate and cool the body. Hair, nails, and nerves endings in the skin help provide protection, sensation, and other functions. The integumentary system works together to protect the body from damage, regulate temperature, and detect stimuli.

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    skin

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    Alcala - Skin

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    The integumentary system consists of the skin, hair, nails, and glands. The skin is the largest organ of the body and has three main layers - the epidermis, dermis, and hypodermis. It acts as a protective barrier and plays roles in temperature regulation, sensation, excretion, and vitamin D synthesis. The skin contains glands that secrete oils, sweat, and wax to lubricate and cool the body. Hair, nails, and nerves endings in the skin help provide protection, sensation, and other functions. The integumentary system works together to protect the body from damage, regulate temperature, and detect stimuli.

    Copyright:

    © All Rights Reserved
    Download as PPT, PDF, TXT or read online from Scribd
    Download as ppt, pdf, or txt
    68 views57 pages

    Integumentary System: Presented By: Patricia Adora G. Alcala

    Uploaded by

    hendrix obciana
    The integumentary system consists of the skin, hair, nails, and glands. The skin is the largest organ of the body and has three main layers - the epidermis, dermis, and hypodermis. It acts as a protective barrier and plays roles in temperature regulation, sensation, excretion, and vitamin D synthesis. The skin contains glands that secrete oils, sweat, and wax to lubricate and cool the body. Hair, nails, and nerves endings in the skin help provide protection, sensation, and other functions. The integumentary system works together to protect the body from damage, regulate temperature, and detect stimuli.

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    Integumentary

    System
    Presented by: PATRICIA ADORA G. ALCALA
    • This system is divided into:
    1- skin
    2- hair
    3- glands
    4- nails
    5- nerve endings
    I) Skin
    Skin is an organ because it consists of different tissues
    that are joined to perform a specific function.
    Largest organ of the body in surface area and weight.
    Dermatology is the medical specialty concerning the
    diagnosing and treatment of skin disorders.
    ANATOMY (STRUCTURE)
    Epidermis (thinner outer layer of skin)
    Dermis (thicker connective tissue layer)
    Hypodermis (subcutaneous layer or Sub-Q)
    Muscle and bone

    PHYSIOLOGY (FUNCTION)
    1- Protection
    - physical barrier that protects underlying tissues
    from injury, UV light and bacterial invasion.
    - mechanical barrier is part non specific immunity
    (skin, tears and saliva).
    2- Regulation of body temperature
    - high temperature or strenuous exercise; sweat is
    evaporated from the skin surface to cool it down.
    - vasodilation (increases blood flow) and
    vasoconstriction (decrease in blood flow) regulates body
    temp.

    3-Sensation
    - nerve endings and receptor cells that detect stimuli to
    temp., pain, pressure and touch.
    4- Excretion
    - sweat removes water and small amounts of salt, uric acid
    and ammonia from the body surface
    5- Blood reservoir
    - dermis houses an extensive network of blood vessels
    carrying 8-10% of total blood flow in a resting adult.
    6- Synthesis of Vitamin D (cholecalciferol)
    -UV rays in sunlight stimulate the production of Vit. D.
    Enzymes in the kidney and liver modify and convert to
    final form; calcitriol (most active form of Vit. D.) Calcitriol
    aids in absorption of calcium from foods and is considered
    a hormone.
    • Epidermis: keratinized stratified squamous epithelium
    with four distinct cell types and five distinct layers.
    Cells in the epidermis:
    - keratinoytes
    - melanocytes
    - Merkel cells
    - Langerhans’ cells

    1- Keratinocytes: most abundant


    - produce keratin (fibrous protein)
    - protective; waterproofing the skin
    - continuous mitosis
    - form in the deepest layer called the stratum basale
    - cells push their way up to the surface where they are
    dead cells filled with keratin; will slough off.
    Regenerates every 25-45 days.
    2- Melanocytes:
    - cells produce brownish/black pigment
    called melanin. (8% of epidermal cells)
    - stratum basale
    - branching processes (dendrites)
    - melanin accumulates in melanosomes
    and transported along dendrites of the
    melanocytes to keratinocytes.
    - melanin accumulates on the superficial aspect of
    the keratinocyte shielding its nucleus from
    harmful UV light.
    - lack of melanin: albino
    3- Merkel cells:
    - stratum basale
    - epidermis of hairless skin
    - attach to keratinocytes by desmosomes
    - make contact with a sensory neuron ending called a
    Merkel disc (touch).

    4- Langerhans’ cells:
    - star-shaped cells arising from bone marrow that
    migrate to epidermis.
    - epidermal dendritic cells (macrophages)
    - interact with a WBC called a T- helper cell
    - easily damaged by UV light.
    Stratum corneum

    Stratum lucidum

    Stratum
    Stratum
    granulosum
    spinosum

    Stratum
    basale
    5 layers of the epidermis:
    1- Stratum corneum (horny layer)
    - layer has many rows of dead cells filled with keratin
    - continuously shed and replaced (desquamation)
    - effective barrier against light, heat and bacteria
    - 20-30 cell layers thick
    - dandruff and flakes
    - 40 lbs. of skin flakes in a lifetime (dust mites!)
    2- Stratum lucidum
    - seen in thick skin of the palms and soles of feet.
    - 3-5 rows of clear flat dead cells
    - keratohyalin (precursor) to keratin

    3- Stratum granulosum
    - 3-5 rows of flattened cells
    - nuclei of cells flatten out
    - organelles disintegrate cells eventually die
    - keratohyalin granules (darkly stained)
    accumulate
    - lamellated granules secrete glycolipids into
    extracellular spaces to slow water loss in the epidermis
    4- Stratum spinosum: “spiny layer”
    - 8-10 rows of polyhedral (many sided) cells
    - appearance of prickly spines
    - shrink when prepared for slide
    - melanin granules and Langerhans’ cell predominate
    5- Stratum basale: deepest epidermal layer
    - attached to dermis
    - single row of cells
    - mostly columnar keratinocytes
    - with rapid mitotic division
    - stratum germinativum
    - contain merkel cells and melanocytes
    - 10-25%
    • Dermis:
    - flexible and strong connective tissue
    - elastic, reticular and collagen fibers
    - cells: fibroblasts, macrophages (WBC),
    mast cells (histamine).
    - nerves, blood and lymphatic vessels
    - oil and sweat glands originate
    - two layers: papillary and reticular
    1- Papillary layer:
    - loose connective tissue with nipple like surface
    projection called dermal papilla.
    - capillaries
    - contain pain receptors
    - contain touch receptors (Meissner’s corpuscles
    - dermal ridges- epidermal ridges- pattern called
    fingerprints
    2- Reticular layer:
    - dense irregular c.t.
    - collagen fibers offer strength
    - holds water
    - dermal tearing causes stretch marks.
    - striae

    Skin color: attributed to melanin, hemoglobin and carotene.


    Race is determined by amount of melanin not # of
    melanocytes.
    Local accumulation of melanin will result in
    freckles and pigmented moles.
    Melanin is made through interaction with tyrosinase
    present in melanocytes

    UV light stimulates melanin production. Excessive


    UV light can damage DNA and cause solar elastosis
    (elastin fibers clump)

    Carotene is formed from Vit. A and deposits in


    stratum corneum and imparts an orange tone to skin
    Freckles
    Hemoglobin (blood) will impart pinkish tones to skin.
    Blushing
    1- Redness (erythema) - reddened skin, embarrassment, fever,
    hypertension, inflammation, or allergy
    2- Pallor/blanching - pale skin, emotional distress or anemia,
    low blood pressure
    3- Jaundice - liver disease, bile deposited in tissue
    4- Bronzing - bronze coloration (Addison's disease)
    hypofunction of adrenal cortex
    5- Black & blue - bruises, escaped blood clots in tissue spaces
    (clotted blood masses = hematomas)
    Hair color:
    Dark hair: mostly melanin
    Blond and red hair: melanin with Fe and S.
    Gray hair: loss of pigment (decr. tyrosinase)
    White hair: air bubbles in the medullary hair shaft.
    • Hair (pili)
    - main function is
    protection
    - hair root nerve plexus
    for touch
    - normal hair loss in adult
    70-100 hairs/day
    Hair anatomy:
    - composed of dead columns of keratinized cells.
    - shaft: is the superficial portion of hair
    - root: below the surface in the dermis
    Shaft and root are composed of three layers: inner medulla,
    middle cortex and outer cuticle.
    Inner medulla has 2-3 rows of polyhedral cells where pigment
    is located
    Cortex is major portion of shaft
    Cuticle is scaly and heavily keratinized (shingles)
    Vellus hair: fine hair
    Terminal hair : coarser hair; axillary and pubic
    region. Grow in response to sex hormones
    Hirsutism: excessive hairiness: incr. androgens
    Hair follicle surrounds the root.
    Bulb is the enlargement at the end of the follicle.
    - Also houses the germinal layer
    Papilla (nipple like) is located in the bulb and is where
    the blood supply nourishes the hair.
    Arrector pili (pl. pilorum) is smooth muscle located in
    the dermis and is attached to the side of the hair
    shaft.
    - fright, cold and emotions will contract muscle and
    pull hair in vertical position. “Goose bumps”.
    Glands:
    Two types of glands exist in the integument.
    - Sebaceous glands (oil glands)
    - Sudoriferous glands (sweat glands)

    Sebaceous glands: (holocrine glands)


    - connected to hair follicle
    - not found on palms and soles of feet
    - secretes sebum (fats, cholesterol and proteins
    - keep hair from drying out, keeps skin moist
    - whiteheads, blackheads and acne
    Whitehead: When the trapped sebum and bacteria stay below the skin surface, a
    whitehead is formed.
    Blackhead: A blackhead occurs when the trapped sebum and bacteria partially open to
    the surface and turn black due to melanin, the skin's pigment. Blackheads can last for a
    long time because the contents very slowly drain to the surface.
    Sudoriferous glands: exocrine glands
    - millions located throughout the skin
    - two types:
    - eccrine: more common (merocrine)
    - originate in subQ layer
    - duct empties on skin surface
    - palms and soles of feet
    - sweat is watery (99% H20)
    - sweating regulated by
    sympathetic nervous system
    - apocrine: axillary and pubic region
    - duct empties onto hair follicle
    - viscous fluid
    - causes body odor (“b-o “) when bacteria break it
    down
    Ceruminous glands: located in ear only
    - modified apocrine glands
    - originate in Sub Q layer
    - ducts open onto EAM.
    - produces cerumen (ear wax) : brown
    sticky substance that prevents foreign
    material from entering.
    Nails:
    - Produced by cells in the epidermis
    - Nail plate (body): visible portion
    - Nail root: located under cuticle
    - Lunula: half moon crescent shaped
    white portion under cuticle
    - Nail bed: located under nail plate
    - Hypoxia: decr. oxygen in blood, nail bed will turn blue-
    cyanosis
    Nerve endings:
    - Exteroceptors (stimulus outside of body)
    - Pacinian (lamellated) corpuscles: deep
    pressure and stretch
    - Meissner’s (tactile) corpuscles: light touch, vibration
    and discriminative touch.
    - hair root plexus
    - free (naked) nerve endings: nociceptors (pain) and
    thermoreceptors ( hot – deep and cold- surface)
    - Ruffini’s corpuscles: deep pressure
    Pacinian corpuscle
    • Hypodermis
    - called subcutaneous, Sub-Q or superficial fascia
    - anchors skin to underlying structures
    - contains adipose tissue and blood vessels
    - common site for injection
    THANK YOU!
    Dermatopathological terms
    • Macule – flat spot on skin with color (freckle)
    • Wheal – round and temp. elevation of skin (hives)
    • Papule - solid elevated area, epidermal and papillary
    (insect bite)
    • Nodule - large papules extending into subcutaneous
    layer (cyst)
    • Vesicle - papule with fluid core (varicella zoster virus)
    • Pustule - papule with pus core (acne)
    • Erosion - ruptured vesicle (ulcer)
    • Xeroderma - "dry skin"
    • Hemangiomas - benign tumor in the dermis (capillary
    and cavernous)
    • Sebaceous hyperplasia - enlargement of the sebaceous
    gland
    • Pruritis - irritating itching sensation of the skin
    • Seborrheic dermatitis - inflammation around
    abnormally active sebaceous glands
    • Basal cell carcinoma - malignant cancer originating in
    the germinative layer
    • Squamous cell carcinoma - malignant cancer originating
    in the top layer of the skin
    • Malignant melanomas - metastasizing melanocytes

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