Chapter 05 Lecture Outline - Anatomy & Physiology

Chapter 05 Lecture Outline See separate PowerPoint slides for all figures and tables pre- inserted into PowerPoint without notes. Copyright © McGraw-Hill Education. Permission required for reproduction or display. 1 ...

Chapter 05 Lecture Outline See separate PowerPoint slides for all figures and tables pre- inserted into PowerPoint without notes. Copyright © McGraw-Hill Education. Permission required for reproduction or display. 1  2 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Chapter 5-Integumentary System What does integument mean? Copyright © McGraw-Hill Education. Permission required for reproduction or display. covering Hairs Components: Epidermis Sebaceous – Skin skin gland – hair Arrector pili (smooth muscle) Dermis Hair follicle – nails Nerve Vein – Artery Subcutaneous tissue glands Sweat gland Adipose tissue (hypodermis) Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Functions 1. Protection: water loss, microbes, UV light 2. Sensation: hot, cold, pain, pressure 3. Temperature regulation: helps maintain homeostasis 4 Copyright © McGraw-Hill Education. Permission required for reproduction or display. 4. Excretion: removes waste 5. Vitamin D production: UV light stimulates production 5 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Skin Facts Weighs 9 lbs. Used to determine body fat 2 main regions: epidermis and dermis 6 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Epidermis 1st major skin region (outside) Composed of stratified squamous epithelium Keratinization: - process in which new cells (with keratin) push old cells to surface - 40-56 days for new cells to reach surface 8 Copyright © McGraw-Hill Education. Permission required for reproduction or display. 1..Stratum basale(basal layer) - deepest layer of epidermis - single layer of cells - firmly attached to dermis -undergo cell division to produce millions of new cells daily 9 Copyright © McGraw-Hill Education. Permission required for reproduction or display. 2. Stratum spinosum (spiny layer) Superficial to the basal layer It appear spiky(cell shrink but their desmosomes hold tight) Cell division occur in this layer Copyright © McGraw-Hill Education. Permission required for reproduction or display. 10  3.Stratum granulosum(granular layer) It is named for abundant granules in its cells Some of these contain a waterproofing glycolipid that is secreted into the extracellular space Contain the subunits of keratin The upper border,the cells are beginning to die 11 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  4. Stratum lucidum(clear layer) It is thin translucent band of flattened dead keratinocytes It is thick skin -palm of the hands -soles of the feet 12 Copyright © McGraw-Hill Education. Permission required for reproduction or display. 5. Stratum corneum (horny layer) - outermost layer of epidermis - 20-30 layers of dead squamous cells filled with keratin - accounts for 75% of epidermal thickness - dandruff is this layer flaking off scalp 13 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Cont. Melanocytes- spidery,brown to black pigment-producing cells – Add color to the skin – It provide protection from UV radiation – Production increases when the skin exposed to sunlight – (Melanin is the pigment or color produced by melanocytes) 14 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Epidermal dendritic cells - they alert and activate immune cells to a threat such as bacterial or viral invasion 15 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Dermis 2nd major skin region Dense fibrous connective tissue Contains collagen and elastic fibers Contains fibroblasts, nerve endings, smooth muscle, glands, blood vessels, sensory receptors and hair follicles 16 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  2 principal region 1.Papillary layer – Dermal papillae-Produce fingerprints – It is unique patterns of loops and ridges in the epidermis that remain unchanged throughout life – Furnish nutrients for the epidermis – Allow heat to radiate to the skin surface – Meissner’s corpuscles-pain & temperature receptors 17 Copyright © McGraw-Hill Education. Permission required for reproduction or display. 2. Reticular layer -it is deepest skin layer -accounts for 80% of dermis -it contain blood vessels,sweat & sebaceous glands -Pacinian receptors-pressure receptors 18 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Hypodermis/subcutaneous tissue It is not part of skin Located,Below dermis Foundation of skin Attaches skin to underlying muscle and bone Contains loose and adipose tissue Contains ½ of body’s fat/adipose tissue Shock absorber and insulate deeper tissue Body fat for females 20-23%, males 13-25% 19 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Skin Color and Variations Determined by: - pigments - genetics - blood circulation - thickness of stratum corneum Melanocytes of darker skinned people produce more and darker melanin than fairer skinned people All races have same number of melanocytes 20 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Skin Pigments Melanin: - produced by melanocytes - ranges from yellow to reddish-brown to black - responsible for hair and eye color - provides protection against UV light - amt. produced determined by genetics, UV light, hormones - freckles are accumulation of melanin - albinism is absence of melanin 21 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Carotene: - yellow-orange pigment found in plants - accumulates in stratum corneum Hemoglobin: - gives pinkish-red color - found in red blood cells 23 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Tanning and Sunburns Exposure to UV light stimulates melanocytes to increase production of melanin Melanin builds up to help protect skin against UV radiation (tan) A sunburn is the skin reacting to UV exposure UV light causes elastic fibers to clump and become leathery UV light can alter DNA in cells causing them to mutate (cancer) 24 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Skin Color and Disease Redness/ erythema: fever, hypertension, inflammation, allergies, blushing Pallor/ blanching:anemia or low blood pressure, feeling of fear and anger Jaundice: liver disorder (yellow) Bronzing: Addison’s disease (kidney disease) Bruising: broken blood vessels Cyanosis: Bluish or purple color skin 25 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Appendages of the skin 1.cutaneous glands 2.hair 3.Hair follicles 4. nails 26 Copyright © McGraw-Hill Education. Permission required for reproduction or display. 1. Cutaneous glands Exocrine glands – It releases secretion to the skin surface via ducts – 2 groups Sebaceous/oil glands Sweat gland 27 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Sebaceous/oil glands -found all over the skin except on the palms of the hands and the soles of the feet No hair follicle sebum-/grease-product- is a mixture of oily substances and fragmented cells Sebum Lubricate skin that keep the skin soft and moist 28 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  -prevent hair to becoming brittle -contain chemicals that kills bacteria -it become very active when androgens(male sex hormones) -are produced in increase amounts in both sexes during adolescence 29 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  -when sebaceous gland ducts blocked by the sebum ACNE appears on the skin. – Acne-an active infection of the sebaceous glands – blackhead-accumulated material oxidizes and dries,it darken – Whitehead-if the material doed not dry – Seborrhea-fast flowing sebum known as “cradle cap in infants 30 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  2. Sweat glands/sudoriferous gland - Are widely distributed in the skin-2.5 million/person - 2 types 1.Eccrine glands-produce sweat-a clear secretion primarily water plus salts(NaCl),vit.c,traces of metabolic waste(ammonia,urea,uric acid),lactic acid 4-6pH- sweat is acidic- inhibits the growth of certain bacteria 7liters on hot day,possible lose up -Respond primarily to elevated body temperature 31 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  2.Appocrine glands – -widely confined to the axillary(armpit) &in genital areas of the body – Secretion contains fatty acids and proteins – It may have a milky or yellowish color – Secretion is odorless but when bacteria that live on the skin use its proteins and fats as a source of nutrients,it can take a musky or unpleasant odor 32 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  HAIR -it is an important part of our body image -it found all over the body except on the palms of the hands,soles of the feet,nipples and lips function: 1. protection-guarding head,shielding the eyes,helping to keep foreign particles out of the respiratory(nose hair) 33 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  2. help to attract sexual partners -hair follicle-enclosed the hair,also an epithelial structure 2 parts of hair – Root-enclosed within the follicle – Shaft-portion projecting from the skin 34 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Hair bulb-it is formed by mitosis of the germinal epithelial cells at the base of the follicle. -deepest part of the follicle 35 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Hair region 1. medulla –consist of central region,surrounded first by the cotex & then by a protected cuticle 2.cortex-composed of several layers of flattened cell,bulky layer 3.cuticle-it encloses cortex,formed by a single layer of cells 36 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Dermal sheath-it enclosed inner epithelial sheath Arrector pili-small bands of smooth muscle cells,connect each hair follicle to the dermis. – When muscle contract(during cold,fright)the hair follicle is pulled upright,dimpling the skin surface with goose” bumps” 37 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Hair Facts Testosterone and good nutrition promote hair growth Growth occurs in cycles: active and resting Scalp hair grows for 3 years and rests for 1 year Eyelashes grow for 30 days and rest for 105 days We lose about 90 scalp hairs/day Grey hair is the loss or fading of melanin Male pattern baldness is from the loss of the hair follicle 39 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Copyright © McGraw-Hill Education. Permission required for reproduction or display. Sweat pores Duct of eccrine sweat gland Duct of Arrector pili apocrine (smooth muscle) sweat gland Hair follicle Sebaceous gland Eccrine sweat gland Hair bulb Apocrine sweat gland 40 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Nails What are they? thin plate with layers of dead stratum corneum cells with hard keratin It is a scalelike modification of the epidermis that corresponds to the hoof or claw of other animals Nail are transparent and nearly colorless but they look pink because of the rich blood supply in the underlying dermis. Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Nail Structure Nail body: visual part,free edge Nail root: covered by skin Nail folds- the border of the nail,overlapped folds of skin Nail beds- the stratum basale of the epidermis extends beneath the nail Nail matrix-its thickened proximal area,responsible for nail growth,it produces nail cells,heavily keratinized and die. Cuticle:stratum corneum that extends into nail body Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Lunule(crescent)- thickened nail matrix that appears as a white crescent 43 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Vitamin D Production 1. UV light causes skin to produce a precursor molecule of vitamin D 2. Precursor is carried by blood to liver where it is modified 3. Next to kidneys where it is modified again to form active vitamin D Vitamin D can also be ingested through fish oils, fortified milk, eggs, and butter. Vitamin D stimulates intestine to absorb calcium and phosphate (bone growth and muscle function) Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Temperature Regulation Body temp. should be 98.6oC Rate of chemical reactions (metabolism) is altered by changes in temp. To cool body: blood vessels in dermis dilate and heat is transferred from deep in tissues to skin and sweat is produced To heat body: blood vessels constrict to reduce blood flow to skin and heat is retained Copyright © McGraw-Hill Education. Permission required for reproduction or display. Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Aging and the Integument Blood flow decreases and skin becomes thinner due to decreased amounts of collagen Decreased activity of sebaceous and sweat glands make temperature regulation more difficult Loss of elastic fibers cause skin to sag and wrinkle 48 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  49 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Classification of Burns 1st degree: - damages only epidermis - redness, slight swelling, pain - heals within 2-3 days (usually no scar) - includes sunburns or exposure to cold 2nd degree: - damages epidermis and upper dermis - redness, swelling, pain, blisters - heals in 2 weeks with some scarring 50 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  3rd degree: - destroys epidermis and dermis - burned areas are cherry red to black - nerve endings are destroyed, thus burned area is not painful. - skin graft might be necessary because regeneration is not possible. 51 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  4th degree: -full thickness burns , but they extend into deeper tissues such as muscles, bones and tendons. -appears dry and leathery. - in sever cases, amputation is required. 52 Copyright © McGraw-Hill Education. Permission required for reproduction or display. BURNS are CRITICAL if: 1.Over 30% of the body has 2nd degree burns 2.Over 10% of the body has 3rd or 4th degree burn 3.There are third or 4th degree burns of the face, hands, feet or genitals 4.Burns affect the airways 5.Circumferential burns have occurred. 53 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Copyright © McGraw-Hill Education. Permission required for reproduction or display. Partial- Full- thickness thickness First- Second- Third- degree degree degree Epidermis Dermis Subcutaneous tissue 54 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Skin infection/allergies 1.Athlete’s foot/tinea pedis- an itchy,red,peeling condition of the skin between the toesresulting from an infection with the fungus 2.Boils(furuncles)- are caused by inflammation of hair follicles and surrounding tissues commonly on the dorsal neck. 55 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  3.carbuncles- are cluster of boils often caused by the bacterium staphlylococcus aureus 4. cold sores(fever blisters)- small fluid-filled blisters that itch and sting,it is caused by human herpesvirus 1 infection 5. contact dermatitis-itching,redness and swelling of the skin,it is caused by exposure of the skin to chemicals 56 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  6. impetigo(impet-an attact)-pink,fluid,raised lesions commonly around the mouth and nose that develop yellolw crust and eventually rupture,common in elementary school aged children 7. psoriasis-is reddened epidermal lesion covered with dry,silvery scales yhat itch,burn,crack and sometimes bleed,chronic condition. 57 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Skin Cancer Most common cancer Mainly caused by UV light exposure Fair-skinned people more prone, aging and male contribute as risk factors. Prevented by limiting sun exposure and using sunscreens UVA rays cause tan and is associated with malignant melanomas UVB rays cause sunburns Sunscreens should block UVA and UVB rays 58 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Types of Skin Cancer Basal cell carcinoma: - cells in stratum basale affected - cancer removed by surgery Squamous cell carcinoma: - cells above stratum basale affected - can cause death Malignant melanoma: - arises from melanocytes in a mole - rare type - can cause death 59 Copyright © McGraw-Hill Education. Permission required for reproduction or display.  Malignant melanoma: ABCDE rule Asymmetry Border irregularity Color Diameter Evolution 60 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Lanugo- downy type of hair covering a fetus Vernix caseosa- oily coating when baby is born, white cheesy looking substance; it protects the baby skin while it is floating in its mom’s water filled sac. 61 Copyright © McGraw-Hill Education. Permission required for reproduction or display. Copyright © McGraw-Hill Education. Permission required for reproduction or display.