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3/28/20141 Chapter 6 (Integument). 3/28/20142 Introduction to the Integumentary System Integument = skin Integumentary system = skin and its appendages.

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Presentation on theme: "3/28/20141 Chapter 6 (Integument). 3/28/20142 Introduction to the Integumentary System Integument = skin Integumentary system = skin and its appendages."— Presentation transcript:

1 3/28/20141 Chapter 6 (Integument)

2 3/28/20142 Introduction to the Integumentary System Integument = skin Integumentary system = skin and its appendages –Appendages Hair Nails skin glands –(sweat and sebaceous) PRIMARY FUNCTION: Protection

3 3/28/20143 Cutaneous Membrane Structure The skin is called the cutaneous membrane Two primary layers –Epidermis –Dermis

4 3/28/20144 EPIDERMIS FEATURES –Outer, Thinner Layer of Skin –Tissue Type Membranous Epithelium –(Stratified Squamous Epithelium Keratinized)

5 3/28/ CELL TYPES: KERATINOCYTES Most Numerous and Important Cells in the Epidermis Filled with (or in the Process of Becoming Filled with) Keratin (Keratinization) –Keratin Strong Protein Protects and Waterproofs the Skin –Keratinization Process by Which Cells in the Epidermis Become Filled with Keratin and Moved to the Skin's Surface (Cells Die in the Process)

6 3/28/ CELL TYPES: MELANOCYTES MELANOCYTES - Produce Melanin Functions of Melanin –Responsible for Color of Skin, Hair, and Eyes –Filters UV Light

7 3/28/20147

8 8 3 CELL TYPES: LANGERHANS LANGERHAN'S CELLS –Provide Defense against Foreign Invaders (Work with the Immune System)

9 3/28/20149 EPIDERMAL CELL LAYERS 5 Layers

10 3/28/ CELL LAYERS STRATUM CORNEUM 1 st layer STRATUM CORNEUM –"Hardened Layer": Cells in this Layer are Totally Filled with Keratin (Replaces the Cytoplasm) –Known as the Barrier Area –Cells at the Surface of this Layer are Dead

11 3/28/ CELL LAYERS STRATUM LUCIDUM STRATUM LUCIDUM –"Clear Layer": Cells in this Layer have a Clear Appearance (Keratin Precursor) –Only Present in Thick Skin (palms of hands and soles of feet)

12 3/28/ CELL LAYERS STRATUM GRANULOSUM STRATUM GRANULOSUM –"Granular Layer": Cells in this Layer are Filled with Granules (Keratin Precursor) –Keratinization Begins in this Layer

13 3/28/ CELL LAYERS STRATUM SPINOSUM STRATUM SPINOSUM –"Spiny Layer": Cells in this Layer Have an Irregular Shape (Plasma Membranes Modified To Hold Tightly Together) –Rich in RNA (Preparation for Keratinization)

14 3/28/ CELL LAYERS STRATUM BASALE STRATUM BASALE –"Base Layer": The Innermost Layer of Epidermis –Mitosis Occurs in this Layer


16 3/28/ EPIDERMAL GROWTH AND REPAIR TURNOVER (REGENERATION) TIME –Time Required for Epithelial Cells to Form in the Stratum Basale and Migrate to the Skin's Surface –Average Turnover Time = 35 Days (Maintains a Constant Skin Thickness –Application: Shortened Turnover Time Results in Formation of Callus

17 3/28/ EPIDERMAL GROWTH AND REPAIR EPIDERMAL PROLIFERATING UNIT (EPU) –Each Group of 8 10 Basal Cells Along with the Vertical Columns of Cells Above (Up to the Skin's Surface) –Epidermis Grows in Units Not as a Whole

18 3/28/ DERMAL EPIDERMAL JUNCTION The Union Between the Epidermis and the Dermis A Basement Membrane Functions: –Tightly "Glues" the Epidermis to the Dermis –Provides Support for the Epidermis –Serves as a Partial Barrier Between the Epidermis and the Dermis

19 3/28/ DERMIS FEATURES –Inner, Thicker Layer of Skin –Tissue Type: Connective Tissue –Called "True Skin" (Thicker and Gives Strength to Skin)

20 3/28/ STRUCTURES PRESENT IN THE DERMIS SENSORY RECEPTORS ( Skin Functions as a Sense Organ) –Specialized Nerve Endings for Hot Cold Pressure Pain Touch

21 3/28/201421

22 3/28/ STRUCTURES PRESENT IN THE DERMIS MUSCLE FIBERS 2 Types –SKELETAL Located Only in the Dermis of the Face and Scalp Function: Voluntary Movement of the Face and Scalp –SMOOTH ARRECTOR PILI MUSCLES Involuntary The Most Abundant of the 2 Types of Muscle Fibers Form Arrector Pili Muscles Produces "Goose Bumps"

23 3/28/ STRUCTURES PRESENT IN THE DERMIS HAIR FOLLICLES –Tubes That Hold Hairs (More Detail with Hair) SWEAT, SEBACEOUS GLANDS –Skin Glands (More Detail with Skin Glands)

24 3/28/ STRUCTURES PRESENT IN THE DERMIS BLOOD VESSELS –The Dermis Contains an Extensive Network of Blood Vessels That Play an Important Role in Regulation of Body Temperature

25 3/28/ Dermis is composed of 2 layers Papillary layers –dermal papillae show through making fingerprints

26 3/28/ Dermis is composed of 2 layers Reticular layer –Inner, thicker layer –dense network of collagenous and elastic fibers –Contains muscle fibers hair follicles sweat and sebaceous glands blood vessels sense receptors

27 3/28/ Dermal Growth and Repair: Scars Dermis does not continually shed and regenerate itself. –In the healing of a wound, fibroblasts reproduce and begin forming a dense mass of connective tissue fibers. –If this fiber is not replaced by normal tissue, it remains a scar.

28 3/28/ Dermal Growth and Repair-Reticular Layer Collagenous fibers form Langers Lines –the collagenous fibers that characterize the dermal layer line themselves up in lines (sometime called cleavage lines). –If surgical incisions are made along these cleavage lines, there will be a less noticeable scar and healing will be much quicker.

29 3/28/ Dermal Growth and Repair-Reticular Layer Elastic Fibers: –If overstretched and torn, forms stretch marks.

30 3/28/ Tattoo pigment is usually black and is inert and non- polarizable; however, red tattoo pigment often contains cinnabar (which has mercury in it). Epidermis Dermis Tattoo Pigment

31 3/28/ Subcutaneous Layer –Hypodermis –superficial fascia) –Tissue type: connective loose areolar adipose

32 3/28/ SKIN LAYERS-Review Primary Layers Epidermis Stratum corneum Stratum lucidum Stratum granulosum Stratum spinosum Stratum basale Dermal-Epidermal Junction (not a primary layer) Dermis Papillary Reticular Subcutaneous Layer (hypodermis; superficial fascia) Tissue type: connective (loose areolar and adipose)

33 3/28/ Skin Color Skin color is essentially determined by the quantity of melanin produced by melanocytes in the stratum basale. Determining Factors –Number of melanocytes – all races have approximately the same number of melanocytes. –Amount of melanin produced by melanocytes is determined by: Heredity – the primary factor Sunlight – sunlight increase melanin production Hormones – Adrenocorticotropic hormones (ACTH) and MSH (Melanocyte stimulating hormone) Age – Increase in age may also influence melanocyte activity (age spots, graying hair) –Temporary Changes Amount of blood flow to skin, more = pinker Amount of oxygen in blood, less oxygen = blue (cyanosis)

34 3/28/ THE SKINS FUNCTIONS: Protection Protection From: –Microbe infection (by layers of nonvascular keratinocytes) –Harmful chemicals (by layers of nonvascular keratinocytes) –Dehydration (by keratin) –UV light (by melanin) –Mechanical injury (by thick, strong dermis)

35 3/28/ THE SKINS FUNCTIONS: Protection SURFACE FILM –A Thin Film of Materials That Covers the Skins Surface Consists of Secretions From Sweat and Sebaceous Glands As Well As Dead Epithelial Cells –FUNCTIONS Barrier Antibacterial/Antifungal (D/T Chemical Components) Lubricates (D/T Oil) Hydrates (D/T Sweat) Buffers (D/T Chemical Components)

36 3/28/ THE SKINS FUNCTIONS: Sensations SENSATION –Skin Functions as a Sense Organ for the Sensations of Hot, Cold, Pressure, Pain, and Touch -D/T Sensory Receptors in the Dermis

37 3/28/ THE SKINS FUNCTIONS: Movement –Skin Allows Body Growth and Movement of the Body Without Injury to Underlying Tissues and Organs D/T Elasticity of the Dermis and SQ Layer Watch: Ehlers Danlos syndrome Characterized by stretchy skin and loose joints MOVEMENT WITHOUT INJURY

38 Collagen 3/28/ Mutations in amino acid sequence causes defects in collagen that can cause problems in these areas:

39 Collagen & Aging 3/28/ Collagen Theory of Aging with age, collagen gets older old collagen gets stiff and not as flexible causing problems such as: Hypertension- (vessels cant expand enough) organs malfunction (stiffness) hinders metabolic functions Wrinkles Due to changes in reduced collagen decreased protein synthesis affect collagen type 1 & 3 in dermis reduced elastin general atrophy in extracellular matrix due to reduced fibroblasts

40 3/28/ THE SKINS FUNCTIONS: Excretion EXCRETION –Skin Functions as an Excretory Organ D/T Sweat Glands Located in the Dermis

41 3/28/ THE SKINS FUNCTIONS: Vitamin D VITAMIN D PRODUCTION (ENDOCRINE FUNCTION) –Mechanism: Precursor Compound in Skin Cells Activated By UV Light Transported By Blood to Liver, Kidney Converted to Vitamin D (Needed for Calcium Absorption) –Vitamin D Classifies Loosely as a Hormone)

42 3/28/ THE SKINS FUNCTIONS: Immunity IMMUNITY –Skin Works With the Immune System to Defend Against Microorganisms D/T Langerhans Cells in the Epidermis and Phagocytes

43 3/28/ THE SKINS FUNCTIONS: Homeostasis HOMEOSTASIS OF BODY TEMPERATURE –Skin Helps to Maintain Constant Body Temperature (Sweat Glands and Blood Vessels) –BASIC PRINCIPLE To Maintain a Constant Body Temperature: Heat Production Must Equal Heat Loss HEAT PRODUCTION: FROM FOOD CATABOLISM –Nutrient Catabolism Energy »1) Chemical (ATP) »2) Heat (Released) RELATES TO ACTIVITY –Increased Activity Increased Catabolism Increased Heat Production – Cells That Are the Most Active and Produce the Most Heat: Liver, Skeletal Muscle

44 3/28/ THE SKINS FUNCTIONS: Temperature Control-Heat Loss –HEAT LOSS – 80% Occurs Through the Skin FROM EVAPORATION AND RADIATION Evaporation –Vaporization of Liquid (Requires Heat Energy) –Example: Evaporation of Sweat – Most Impt. Way Heat Loss Occurs in Hot Temps.

45 3/28/ THE SKINS FUNCTIONS: Temperature Control-Heat Loss –HEAT LOSS – 80% Occurs Through the Skin FROM EVAPORATION AND RADIATION Radiation –Heat Transfer (Warmer Cooler) Without Direct Contact Between 2 Objects –Example: Dilation of Blood Vessels in the Dermis (Text) –Most Impt. Way Heat Loss Occurs in Cool Temps.



48 3/28/ Burns Burns are classified based on depth –1 st is just epidermal (top layer) –2 nd is deeper, involves both dermal and epidermal layers. –3 rd is deepest, involves epidermis, dermis, and sometimes deeper levels.

49 3/28/ Burns-1 st degree 1 st degree –causes minor discomfort –some reddening –typical sunburn –Peeling –no blistering.

50 3/28/ Burns-2 nd degree 2 nd degree –involves the deep epidermal layers –and some dermal layers –may damage sweat glands, etc –blistering –swelling –scarring.

51 3/28/ Burns-3 rd degree 3 rd degree burns –full-thickness burns –complete destruction of dermis and epidermis –no pain due to destruction of nerve endings

52 3/28/ Rule of 9s Estimation of body surface area is accomplished by the rule of 9s. Victims palm size is roughly 1% Of body surface.

53 3/28/ Rule of Nines

54 3/28/ Appendages: Hair-Follicle HAIR FOLLICLE & GERMINAL MATRIX –Hair Follicle Tubelike, Holds Hair Root Formation: Cells from the Epidermis Push Down into the Dermis Follicle Wall: 2 Layers –1) Outer: Dermal Root Sheath –2) Inner: Epithelial Root Sheath

55 3/28/ Appendages: Hair-Germinal Matrix –Germinal Matrix Cap-shaped Cluster of Cell at Bottom of Hair Follicle Formed from stratum germinativum Forms the Hair (Mitosis and Keratinzation) Papillas (from dermis) capillaries nourish g. matrix-next slide.

56 3/28/ Appendages: Hair-Papilla, Root, Shaft HAIR PAPILLA – Dermis that Protrudes into the Germinal Matrix –Contains Blood Vessels HAIR ROOT –Hidden Portion of the Hair (Lies in Hair Follicle) HAIR SHAFT –Visible Portion of the Hair

57 3/28/ Appendages: Hair-Cortex & Medulla CORTEX AND MEDULLA OF HAIR –Medulla: Inner Core of the Hair –Cortex: Outer Portion of the Hair (Cells Contain Melanin and Keratin) –Cuticle: Covers Cortex

58 3/28/ Appendages: Hair-Sebaceous Glands SEBACEOUS GLANDS –Oil Glands; Part of Hair Follicle –Secrete Sebum Directly into Follicle –Functions of Sebum: 1) Lubricates Skin, Hair 2) Antifungal –Located in Dermis in All Areas Except Palms and Soles

59 3/28/ Appendages: Nails Nail body – visible part of the nail –Heavily keratinized cells. Root – invisible part found behind cuticle Cuticle – fold of skin Lunula – moon shape, –Cells beneath are stratus germinativum that produce nail cells by mitosis. Nail bed – cells supporting the nail

60 3/28/ Appendages: Skin Glands Sweat Glands –most numerous skin glands –produces watery liquid in which waste materials such as ammonia and urea and salts are excreted –bacterial growth causes it to stink –Two types: Eccrine –most common type Apocrine –deep in the subcutaneous layer; armpit, areola, around anus

61 3/28/ Appendages: Skin Glands Sebaceous glands – Oil glands; sebum (oil) has antifungal and antibacterial properties

62 3/28/ Appendages: Skin Glands Ceruminous glands – specially modified sweat glands; found in external ear canals; produce cerumen (wax)

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