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Presentation on theme: "ANATOMY AND PHYSIOLOGY"— Presentation transcript:


2 INTRODUCTION All living things are made of cells
Cells join together to make tissues Tissues join together to form organs

3 Skin Skin is the principal organ of the integumentary system
Skin is one of a group of anatomically simple but functionally important sheetlike structures called membranes

4 Membranes

5 Membranes A membrane is a thin, sheetlike structure with many important functions in the body Membranes cover and protect the body surface, line body cavities, and cover the inner surfaces of the hollow organs.

6 Two major categories of membranes
Epithelial – composed of epithelial tissue and an underlying layer of specialized connective tissue Connective tissue membranes – composed exclusively of various types of connective tissue

7 Three types of epithelial membranes
Cutaneous Serous Mucous

8 Cutaneous Membrane

9 Cutaneous Membrane Commonly called the skin
One of the largest and more versatile organs of the body

10 Functions of Cutaneous Membrane
Protective covering Regulates body temperature Prevents water loss Houses sensory receptors Synthesizes various biochemical Excretes small qualities of waste

11 Serous Membranes

12 Serous Membranes Found only on surfaces within closed cavities
Composed of 2 layers of tissue – the epithelial sheet and a thin layer of connective tissue Secrete serous fluid- watery fluid which lubricates the membranes surface

13 Serous Membranes Two types:
Parietal – lines the walls of a body cavity Visceral – covers the surface of organs found in the body cavities

14 Serous Membranes Pleura Peritoneum
Serous membranes that line the thoracic cavity Peritoneum Serous membranes that line the abdominal cavity

15 Mucous Membranes

16 Mucous Membranes Lines cavities and tubes that are open to the outside
Consist of epithelial overlying a layer of loose connective tissue Specialized cells within a mucous membrane secrete mucus

17 Mucous Membrane Examples – linings of: Respiratory Digestive
Urinary, and Reproductive tracts

18 Mucocutanous Junction

19 Mucocutanous Junction
The transitional area that serves as a point of “fusion” where the skin and mucous membranes meet

20 Connective Tissue Membranes
Also called synovial membranes Line the spaces between bones and joints that move Slick, smooth membranes that secrete synovial fluid, which lubricates the ends of bones within the joint Reduce friction between bones

21 Cutaneous Membrane (Skin)
Composed of the following layers: Epidermis-outer layer of skin Dermis- middle layer of skin Subcutaneous-innermost layer of skin – thick layer of loose connective tissue and fat

22 Epidermis Tightly packed epithelial cells arranged in layers
Inner – stratum germinativum Outer – stratum corneum

23 Epidermis Inner layer – stratum germinativum – cells specialize to increase their ability to protect the tissues below them. This enables the skin to repair itself if it is injured. As the cells approach the surface, the cytoplasm is replaced by keratin, a protein which is tough and waterproof and protects the body Sometimes called the pigment layer because it is responsible for melanin production

24 Epidermis Outer layer – stratum corneum
Keratin-filled cells are constantly pushed to the surface and “flake off” Millions of epithelial cells reproduce daily to replace the millions shed

25 Melanin Melanocytes are the cells within the pigment layer that produce melanin Melanin is a dark pigment that provides skin color

26 Melanin Melanin absorbs light energy and protects deeper cells from the ill effects of UV light. Skin color is due largely to melanin Color is mostly genetically determined but can also be modified by sunlight exposure

27 Skin Color Abnormalities
Cyanosis - bluish discoloration of the skin Jaundice - yellowish discoloration of the skin Erythemia - reddish discoloration

28 Skin Color Abnormalities
Vitiligo – patchy areas of light skin resulting from the acquired loss of epidermal melanocytes. Most cases are genetic in origin. Albinism – hereditary condition, characterized by a partial or total lack of melanin. Affected individuals are prone to eye damage and sunburn

29 Dermis Binds the epidermis to the subcutaneous layer
Contains blood vessels, hair follicles, nerve endings, sweat glands and nerve fibers

30 Dermis Upper region has parallel rows of peg like projections called dermal papillae Form the dermal-epidermal junction Form groves and ridges that make fingerprints The pattern of these are unique in every person

31 Dermis, cont. Deeper area of dermis is collagen that gives toughness to skin. Elastic fibers are present Makes skin stretchable and elastic Wrinkles form as skin loses elasticity

32 Appendages Hair Receptors Nails Skin glands

33 Appendages-Hair Millions of small hairs cover the body
Follicles - present at birth, required for hair growth Newborns are covered with soft, fine hair called lanugo Areas of body that are hairless are lips, palms of hands and soles of feet Most visible on scalp, eyelids and eyebrows

34 Appendages-Hair Growth begins from a small cluster of cells called the papilla. Cells grow down into the dermis forming a small tube called the hair follicle The root is the part of the hair that we can’t see (under the skin) The shaft is the part of the hair we can see

35 Appendages-Hair Alopecia is hair loss
Arrector pili – involuntary muscle that contracts when we are frightened or cold, producing raised places called “goose bumps” or “goose pimples.”

36 Appendages-Receptors
Act as sense organs Relay messages such as touch, pain, temperature and pressure Free nerve endings - respond to pain Meissner’s corpuscles - located near the surface and detects light touch Ruffini’s corpuscles – located in dermal layer and subcutaneous tissues of fingers, detect touch and pressure Pacinian corpuscle- deep in dermis and capable of detecting pressure Krause’s end bulb-responds to cold

37 Appendages-Nails Produced by cells in the epidermis
Form when epidermal cells fill with keratin and become hard and platelike

38 Appendages-Nails Nail body-visible part of the nail
Root-lies in a groove Cuticle-groove and is hidden by a fold of skin Lunula-”little moon”, near the root Nail bed- area beneath nail Color pink due to abundant supply of blood vessels seen through translucent nail bodies

39 Appendages-Skin Glands
Sweat or Sudoriferous Most numerous of skin glands Two types: Eccrine and Apocrine Sebaceous Oil-secreting glands

40 Appendages-Skin Glands
Eccrine Sweat Glands Numerous and widespread throughout the body Secrete watery liquid called perspiration (sweat) Sweat assists in the elimination of waste products such as ammonia and uric acid

41 Appendages-Skin Glands
Apocrine Sweat Glands Found in axilla and in pigmented areas of genitals Large, secrete milky secretions Produces odor that is caused by mixing with skin bacteria Enlarge and begin functioning at puberty

42 Appendages-Skin Glands
Sebaceous Glands Secrete oil for the hair and skin Grow where hair grows Tiny ducts open into hair follicles so that their secretion, called sebum, can lubricate hair and skin. Sebum darkens to form blackheads Acne vulgaris is the over secretion of sebum

43 Disorders of Skin Dermatosis-any disorder of the skin
Dermatitis-inflammation of the skin Lesion-measurable variation from the normal structure of a tissue Distinguished by abnormal density, or coloration Discoloration usually occurs

44 Skin Lesions ELEVATED Papule Plaque Vesicle Pustule Crust Wheal FLAT
Macule DEPRESSED Excoriation Ulcer Fissure

45 Skin Lesions ELEVATED Papule - warts
Plaque – can be caused by friction Vesicle – non-genital herpes Pustule – acne Crust - scab Wheal - hives

46 Skin Lesions FLAT Macule - freckles Patch - vitiligo DEPRESSED
Excoriation – scratches Atrophy – stretch marks Ulcer - bedsore Fissure – athlete’s foot

47 Classification of Burns
First-degree burns Second-degree burns Third-degree burns Fourth-degree burns Third- and fourth-degree burns are both called full-thickness burns

48 Burns-Classifications
First-degree burns-causes minor discomfort Example-sunburn Reddening of the skin No blistering Tissue damage is minimal

49 Burns-Classifications
Second-Degree Burns Involves deep epidermal layers Causes injury to upper layers of dermis Damages sweat glands, hair follicles and sebaceous glands Blisters, severe pain, generalized swelling Scarring is common

50 Burns-Classifications
Third-Degree Burns Complete destruction of the epidermis and dermis Tissue death extends to subcutaneous layer Insensitive to pain due to destruction of nerve endings Increased fluid loss

51 Burns-Classifications
Fourth-Degree Burns Full thickness burn that extends below the subcutaneous layer to reach muscle or bone Often result from electrical burns or exposure to intense heat over time Insensitive to pain due to destruction of nerve endings Increased fluid loss

52 Burns-Classifications
Serious burns result in over 50,000 hospital admissions each year. Circulatory shock, fluid loss, respiratory injury, and infections are common complications. May require skin grafting or amputation of limbs

53 Estimating Body Surface Area
“Rule of Nines”-body is divided into 11 areas of 9% Each arm is 9% for total of 18% Head is 9% Each leg is 18% for total of 36% Torso is 18% Back is 18% Perineal area is 1%

54 Bacterial infections (streptococcal or staphylococcal)
Skin Infections Bacterial infections (streptococcal or staphylococcal) Impetigo Boils

55 Skin Infections Viral infections Warts

56 Skin Infections Fungal infections
Tinea – ringworm, jock itch, athlete’s foot

57 Skin Infections Arthropod infestations
Scabies – caused by the itch mite

58 Skin Infections Other skin disorders Decubitus ulcers – bedsores
Urticaria – hives (often caused by allergic reaction) Scleroderma – autoimmune disease affecting blood vessels and connective tissues Psoriasis – plaques that remain on the skin for a long time Eczema – inflammation, caused by an underlying disease

59 Skin Cancers Squamous Cell Carcinoma Basal Cell Carcinoma Melanoma
Kaposi’s Sarcoma


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