Transcript (the skin).
The Integumentary System A review for test #2 in Anatomy and Physiology What are the major characteristics of the skin? Waterproof, stretchable,washable, and permanent-press, that automatically repairs small cuts, rips and burns and is guaranteed to last a lifetime. Surface area of up to 2.2 square meters 11 pounds 7% of total body weight Pliable yet tough What are the 2 + 1 major layers of the skin? (1)?? – Composed of epithelial tissue (stratified squamous) – Non-vascularized (2)?? – Tough leathery layer composed of fibrous connective tissue – Good supply of blood (3) (not considered skin) – Made of adipose and areolar tissue – Stores fat, anchors skin, protects against blows What are the 3 major layers of the skin? Epidermis (epi-upon) – Composed of epithelial tissue (stratified squamous) – Non-vascularized Dermis – underlies the epidermis – Tough leathery layer composed of fibrous connective tissue – Good supply of blood Hypodermis (not considered skin) – Made of adipose and areolar tissue – Stores fat, anchors skin, protects against blows Epidermis Dermis Basement membrane Epidermis Dermis Hypodermis What are the different types of cells in the epidermis? Name this cell type – Produce a fibrous protein – – – – called keratin Are formed in the lowest levels of the epidermis. Pushed upward by the production of new cells beneath them. Become dead and scale-like Millions rub off everyday What are the different types of cells in the epidermis? Keratinocytes – Produce a fibrous protein – – – – called keratin Are formed in the lowest levels of the epidermis. Pushed upward by the production of new cells beneath them. Become dead and scale-like Millions rub off everyday What are the different types of cells in the epidermis? Name this type of cell – Synthesizes the pigment melanin – Melan-black – Can transfer melanin to keratinocytes – Protects skin from ultraviolet light. What are the different types of cells in the epidermis? Melanocytes – Synthesizes the pigment melanin – Melan-black – Can transfer melanin to keratinocytes – Protects skin from ultraviolet light. melanocyte Melanin in keratinocytes What are the different types of cells in the epidermis? L????’ cells – Formed in bone marrow. – Move to the skin – Macrophages What are the different types of cells in the epidermis? Langerhans’ cells – Formed in bone marrow. – Move to the skin – Macrophages Langerhans’ cell What are the different types of cells in the epidermis? M?????? Cells – Has a spiked appearance – Connected to nerve cells from dermis – Function as sensory receptors for touch. What are the different types of cells in the epidermis? Merkel Cells – Has a spiked appearance – Connected to nerve cells from dermis – Function as sensory receptors for touch. What are the layers of the epidermis? Stratum basale: deepest layer of the epidermis, undergoes rapid ???????????????. Stratum spinosum: intermediate layer, contain ?????? shaped keratinocytes. Stratum corneum: outermost layer 20-30 cells thick of ?????????? cells. – Dandruff – Average person shed 40 pounds of these cells in their lifetime. – Everything you see on a human is dead! What are the layers of the epidermis? Stratum basale: deepest layer of the epidermis, undergoes rapid cell division. Stratum spinosum: intermediate layer, contain spiny shaped keratinocytes. Stratum corneum: outermost layer 20-30 cells thick of dead keratinized cells. – Dandruff – Average person shed 40 pounds of these cells in their lifetime. – Everything you see on a human is dead! 12- 3- 4- What are the characteristics of the dermis? Made up of ???????? tissue Richly supplied with ????? vessels and lymph vessels Has hair follicles, oil and sweat glands and sensory receptors Ridges formed from the papillary layer can form finger prints. What are the characteristics of the dermis? Made up of connective tissue Richly supplied with blood vessels and lymph vessels Has hair follicles, oil and sweat glands and sensory receptors Ridges formed from the papillary layer can form finger prints. 1- 2- 3- 1- 2- 3- Name this layer of the dermis Filled with dense irregular fibrous connective tissue Matrix is filled with thick bundles of collagen fibers (give the skin strength) Less dense regions are called lines of cleavage or tension lines; surgeons use these to make incisions because they heal quicker. Reticular layer of the dermis Filled with dense irregular fibrous connective tissue Matrix is filled with thick bundles of collagen fibers (give the skin strength) Less dense regions are called lines of cleavage or tension lines; surgeons use these to make incisions because they heal quicker. What causes the color of skin? 3 pigments contribute to skin color – (1)?? protein pigment (natural sunscreen) Can range in color from yellow to reddish-brown to black Everyone has the same number of melanocytes but make varying amounts and colors (differences in skin color) Increased ------ production can caused by sunlight. – (2)??-yellow to orange pigment found in carrots. Most commonly found in the palms or soles. Most intense when large amounts of carotenerich foods are eaten. – (3)???- Red blood gives a pinkish hue to fair skin What causes the color of skin? 3 pigments contribute to skin color – Melanin- protein pigment (natural sunscreen) Can range in color from yellow to reddish-brown to black Everyone has the same number of melanocytes but make varying amounts and colors (differences in skin color) Increased melanin production can caused by sunlight. – Carotene-yellow to orange pigment found in carrots. Most commonly found in the palms or soles. Most intense when large amounts of carotene-rich foods are eaten. – Hemoglobin- Red blood gives a pinkish hue to fair skin What are the major appendages of the skin? ??? glands ??? glands ???? ???? What are the major appendages of the skin? Sudoriferous-Sweat glands Sebaceous glands Hairs Nails What are the types of glands found in the skin? Sweat glands-sudoriferous – Merocrine- common sweat glands Hot sweats vs. Cold sweats – A??????- produce sweat plus a milky or yellowish substance composed of fat and protein. Found in the arm pits and genitalia Thought to be scent glands. – C???- produce cerumen (ear wax) – Mammary glands- produce milk Sebaceous glands- ??? glands (sebum) – Softens and lubricates hair and skin – Slows water loss and kills ??????? What are the types of glands found in the skin? Sweat glands-sudoriferous – Merocrine- common sweat glands Hot sweats vs. Cold sweats – Apocrine- produce sweat plus a milky or yellowish substance composed of fat and protein. Found in the arm pits and genitalia Thought to be scent glands. – Ceruminous- produce cerumen (ear wax) – Mammary glands- produce milk Sebaceous glands- oil glands (sebum) – Softens and lubricates hair and skin – Slows water loss and kills bacteria 1= 2= Why is hair useful? Name 2 … Why is hair useful? Senses insects that land on the skin. Hair on the head protects the head from a blow, sunlight and heat loss. Eyelashes shield the eye Nose hairs filter the air What are hairs? Made from hair follicles Made of dead keratinized skin cells Two parts shaft and root Shaft has 3 layers of cells – Medulla(central core) – Cortex (bulky layer) – Cuticle (heavily keratinized; protects hair) 1= Why do humans have arrector pili muscles? 2= 3= Why do humans have arrector pili muscles? 1= 2= 3= What are the parts of nails? A nail is a scalelike modification of the epidermis Made of tightly compressed keratinized cells Useful tools to pick up small objects or scratch an itch. Nail matrix is the region responsible for nail growth. 1= 2= 1= 2= What are the primary functions of the Integumentary System? Protection: provides 3 types of barriers C???? barriers: low pH of skin secretions slows bacterial growth. Human defensin is an antibiotic that destroys bacteria (produced by human skin) What are the primary functions of the Integumentary System? Protection: provides 3 types of barriers – Chemical barriers: low pH of skin secretions slows bacterial growth. Human defensin is an antibiotic that destroys bacteria (produced by human skin) P?? barriers – barriers: very few substance are able to enter the skin. Substances able to pass. Lipid-soluble substances: oxygen, carbon dioxide, some vitamins Oleoresins- poisons (poison ivy) Organic solvents- dry-cleaning fluid, paint thinner Salts of heavy metals- lead, mercury, nickel Penetration enhancers- drug agents that help substances into the body. Physical barriers – Physical barriers: very few substance are able to enter the skin. Substances able to pass. Lipid-soluble substances: oxygen, carbon dioxide, some vitamins Oleoresins- poisons (poison ivy) Organic solvents- dry-cleaning fluid, paint thinner Salts of heavy metals- lead, mercury, nickel Penetration enhancers- drug agents that help substances into the body. B???? barriers Langerhans’ cellsact as macrophages police the epidermis for viruses and bacteria. Biological barriers Langerhans’ cellsact as macrophages police the epidermis for viruses and bacteria. Functions cont. (1)??- skin contains sweat glands that secrete watery fluid, that when evaporated, cools the body. (2)??- Skin contains sensory receptors that detect cold, touch, and pain. (3)??- cholesterol in the skin is bombarded by sunlight and converted to vitamin D (calcium cannot be absorbed from digestive tract) Functions cont. Thermoregulation- skin contains sweat glands that secrete watery fluid, that when evaporated, cools the body. Sensation- Skin contains sensory receptors that detect cold, touch, and pain. Vitamin D synthesis- cholesterol in the skin is bombarded by sunlight and converted to vitamin D (calcium cannot be absorbed from digestive tract) Functions cont. (4)- blood will be moved from skin to muscles during strenuous activity. (5)- Sweating is an important outlet for wastes such as salt and nitrogen containing compounds. (urine) Functions cont. Blood reservoir- blood will be moved from skin to muscles during strenuous activity. Excretion- Sweating is an important outlet for wastes such as salt and nitrogen containing compounds. (urine) Skin Cancer B????tumors such as warts and moles are not serious. M??? tumors can start on the skin and invade other body areas. Crucial risk factor- overexposure to UV radiation Skin Cancer Benign tumors such as warts and moles are not serious. Malignant tumors can start on the skin and invade other body areas. Crucial risk factor- overexposure to UV radiation Types of Skin Cancer (1) carcinoma- most common, 30% of all white skin people get it. – Arises from the stratum basale layer of the skin – 99% curable if caught early – Dome shaped nodules that form an ulcer in the center. Squamous Cell carcinoma– Arise from stratum spinosum – Grows rapidly and metastasizes if not removed – Small red rounded elevation on the skin Types of Skin Cancer Basal cell carcinoma- most common, 30% of all white skin people get it. – Arises from the stratum basale layer of the skin – 99% curable if caught early – Dome shaped nodules that form an ulcer in the center. Squamous Cell carcinoma– Arise from stratum spinosum – Grows rapidly and metastasizes if not removed – Small red rounded elevation on the skin Skin Cancer Types cont. Name this cancer – Cancer of melanocytes (very dangerous) – 5% of skin cancers but rising fast – Can arise from preexisting moles – Appears as a spreading brown or black patch – Chance of survival is poor if the lesion is greater than 4 mm thick Skin Cancer Types cont. Melanoma – Cancer of melanocytes (very dangerous) – 5% of skin cancers but rising fast – Can arise from preexisting moles – Appears as a spreading brown or black patch – Chance of survival is poor if the lesion is greater than 4 mm thick Basal Cell Carcinoma Lesion removed from patient Basal Cell Carcinoma Squamous cell carcinoma Melanoma What is the ABCD rule? Used for recognizing melanoma A-???: two sides of the pigmented mole do not match B-????? irregularity: borders are not smooth C- ????: lesion has a multiple of colors D- ????? the spot is larger than 6 mm in diameter (size of a pencil eraser) What is the ABCD rule? Used for recognizing melanoma A-Asymmetry: two sides of the pigmented mole do not match B-Border irregularity: borders are not smooth C- Color: lesion has a multiple of colors D- Diameter the spot is larger than 6 mm in diameter (size of a pencil eraser) New Notes: What are the 3 types of burns? First-degree burns: only the epidermis is damaged. Redness, swelling and pain are common. (sunburn) 2-3 days to heal Second-degree burns: epidermis and upper layers of dermis. Blistering can occur. 3-4 weeks to heal. Third-degree burns: involves the entire thickness of the skin. (pg. 164-165) Second-degree burns Third-degree burn Skin (Integument) – Test Review for Ch. 6 Consists of two major regions + an insulating layer Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Skin (Integument) – Test Review for Ch. 6 Consists of three major regions Epidermis – outermost superficial region Dermis – middle region (=true skin) Hypodermis (superficial fascia or subcutaneous layer) – deepest region Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Skin (Integument) Figure 5.1 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Skin (Integument) Figure 5.1 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epidermis Composed of k s s epithelium, consisting of four distinct cell types and four or five layers Cell types include ______________________, Merkel cells, and Langerhans’ cells Outer portion of the skin is exposed to the external environment and functions in protection Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Epidermis Composed of keratinized stratified squamous epithelium, consisting of four distinct cell types and four or five layers Cell types include keratinocytes, melanocytes, Merkel cells, and Langerhans’ cells Outer portion of the skin is exposed to the external environment and functions in protection Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cells of the Epidermis Keratinocytes – produce the fibrous protein keratin Melanocytes – produce the brown pigment melanin Langerhans’ cells – epidermal macrophages that help activate the ____________system Merkel cells – function as _________receptors in association with sensory nerve endings Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cells of the Epidermis Keratinocytes – produce the fibrous protein keratin Melanocytes – produce the brown pigment melanin Langerhans’ cells – epidermal macrophages that help activate the immune system Merkel cells – function as touch receptors in association with sensory nerve endings Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Layers of the Epidermis: Stratum Basale (Basal Layer) Deepest epidermal layer firmly attached to the dermis Consists of a single row of the youngest keratinocytes Cells undergo rapid division, hence its alternate name, stratum _____________________ Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Layers of the Epidermis: Stratum Basale (Basal Layer) Deepest epidermal layer firmly attached to the dermis Consists of a single row of the youngest keratinocytes Cells undergo rapid division, hence its alternate name, stratum germinativum Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Layers of the Epidermis: Stratum Basale (Basal Layer) Figure 5.2b Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Layers of the Epidermis: Stratum Spinosum (Prickly Layer) Cells contain a weblike system of intermediate filaments attached to __________________ Melanin granules and Langerhans’ cells are abundant in this layer Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Layers of the Epidermis: Stratum Spinosum (Prickly Layer) Cells contain a weblike system of intermediate filaments attached to desmosomes Melanin granules and Langerhans’ cells are abundant in this layer Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Layers of the Epidermis: Stratum Granulosum (Granular Layer) Thin; three to five cell layers in which drastic changes in keratinocyte appearance occurs Keratohyaline and __________________accumulate in the cells of this layer Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Layers of the Epidermis: Stratum Granulosum (Granular Layer) Thin; three to five cell layers in which drastic changes in keratinocyte appearance occurs Keratohyaline and lamellated granules accumulate in the cells of this layer Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Layers of the Epidermis: Stratum ?????? (Clear Layer) Thin, transparent band superficial to the stratum granulosum Consists of a few rows of flat, dead keratinocytes Present only in thick skin Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Layers of the Epidermis: Stratum Lucidum (Clear Layer) Thin, transparent band superficial to the stratum granulosum Consists of a few rows of flat, dead keratinocytes Present only in thick skin Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Layers of the Epidermis: Stratum Corneum (Horny Layer) Outermost layer of keratinized cells Accounts for three quarters of the epidermal thickness Functions include: __________________ Protection from abrasion and penetration Rendering the body relatively insensitive to biological, chemical, and physical assaults Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Layers of the Epidermis: Stratum Corneum (Horny Layer) Outermost layer of keratinized cells Accounts for three quarters of the epidermal thickness Functions include: Waterproofing Protection from abrasion and penetration Rendering the body relatively insensitive to biological, chemical, and physical assaults Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Dermis Second major skin region containing strong, flexible _____________ tissue Cell types include ______________, macrophages, and occasionally mast cells and white blood cells Composed of two layers – ____________________ Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Dermis Second major skin region containing strong, flexible connective tissue Cell types include fibroblasts, macrophages, and occasionally mast cells and white blood cells Composed of two layers – papillary and reticular Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Layers of the Dermis: Papillary Layer Papillary layer __________________ connective tissue with _c_____________ and _e_______ fibers Its superior surface contains peglike projections called dermal papillae Dermal papillae contain capillary loops, Meissner’s corpuscles, and free nerve endings Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Layers of the Dermis: Papillary Layer Papillary layer Areolar connective tissue with collagen and elastic fibers Its superior surface contains peglike projections called dermal papillae Dermal papillae contain capillary loops, Meissner’s corpuscles, and free nerve endings Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Layers of the Dermis: Reticular Layer Reticular layer Accounts for approximately 80% of the thickness of the skin Collagen fibers in this layer add__________ and resiliency to the skin _________ fibers provide stretch-recoil properties Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Layers of the Dermis: Reticular Layer Reticular layer Accounts for approximately 80% of the thickness of the skin Collagen fibers in this layer add strength and resiliency to the skin Elastin fibers provide stretch-recoil properties Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hypodermis Subcutaneous layer deep to the skin Composed of adipose and areolar connective tissue Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Skin Color Three pigments contribute to skin color _______ – yellow to reddish-brown to black pigment, responsible for dark skin colors Freckles and pigmented moles – result from local accumulations of melanin ________ – yellow to orange pigment, most obvious in the palms and soles of the feet __________ – reddish pigment responsible for the pinkish hue of the skin Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Skin Color Three pigments contribute to skin color Melanin – yellow to reddish-brown to black pigment, responsible for dark skin colors Freckles and pigmented moles – result from local accumulations of melanin Carotene – yellow to orange pigment, most obvious in the palms and soles of the feet Hemoglobin – reddish pigment responsible for the pinkish hue of the skin Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Sweat Glands Different types prevent overheating of the body; secrete cerumen and milk _______ sweat glands – found in palms, soles of the feet, and forehead ________ sweat glands – found in axillary and anogenital areas __________ glands – modified apocrine glands in external ear canal that secrete cerumen Mammary glands – specialized sweat glands that secrete milk Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Sweat Glands Different types prevent overheating of the body; secrete cerumen and milk Eccrine sweat glands – found in palms, soles of the feet, and forehead Apocrine sweat glands – found in axillary and anogenital areas Ceruminous glands – modified apocrine glands in external ear canal that secrete cerumen Mammary glands – specialized sweat glands that secrete milk Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Sebaceous Glands Simple alveolar glands found all over the body Soften skin when stimulated by hormones Secrete an oily secretion called sebum Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Structure of a Nail Scalelike modification of the epidermis on the distal, dorsal surface of fingers and toes Figure 5.4 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Structure of a Nail Scalelike modification of the epidermis on the distal, dorsal surface of fingers and toes Figure 5.4 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hair Filamentous strands of dead keratinized cells produced by hair follicles Contains hard keratin which is tougher and more durable than soft keratin of the skin Made up of the shaft projecting from the skin, and the root embedded in the skin Consists of a core called the_________, a ______, and an outermost ____________ Pigmented by melanocytes at the base of the hair Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hair Filamentous strands of dead keratinized cells produced by hair follicles Contains hard keratin which is tougher and more durable than soft keratin of the skin Made up of the shaft projecting from the skin, and the root embedded in the skin Consists of a core called the medulla, a cortex, and an outermost cuticle Pigmented by melanocytes at the base of the hair Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hair Function and Distribution Functions of hair include: Helping to maintain ______ Alerting the body to _______ Guarding the scalp against physical trauma, heat ____, and _______________ Hair is distributed over the entire skin surface except Palms, soles, and lips Nipples and portions of the external genitalia Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hair Function and Distribution Functions of hair include: Helping to maintain warmth Alerting the body to presence of insects on the skin Guarding the scalp against physical trauma, heat loss, and sunlight Hair is distributed over the entire skin surface except Palms, soles, and lips Nipples and portions of the external genitalia Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hair Follicle Root sheath extending from the epidermal surface into the dermis Deep end is expanded forming a hair bulb A knot of sensory nerve endings (a root hair plexus) wraps around each hair bulb Bending a hair stimulates these endings, hence our hairs act as sensitive touch receptors Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hair Follicle Figure 5.6a Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hair Follicle Figure 5.6a Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hair Follicle Figure 5.6c Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hair Follicle Figure 5.6c Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Types of Hair ______ – pale, fine body hair found in children and the adult female _________ – coarse, long hair of eyebrows, scalp, axillary, and pubic regions Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Types of Hair Vellus – pale, fine body hair found in children and the adult female Terminal – coarse, long hair of eyebrows, scalp, axillary, and pubic regions Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hair Thinning and Baldness Alopecia – hair thinning in both sexes True, or frank, baldness Genetically determined and sex-influenced condition Male pattern baldness – caused by follicular response to DHT Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Functions of the Integumentary System Protection – chemical, physical, and mechanical barrier Body temperature regulation is accomplished by: Dilation (cooling) and constriction (warming) of dermal vessels Increasing sweat gland secretions to cool the body Cutaneous sensation – exoreceptors sense touch and pain Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Functions of the Integumentary System Metabolic functions – synthesis of vitamin D in dermal blood vessels Blood reservoir – skin blood vessels store up to 5% of the body’s blood volume Excretion – limited amounts of nitrogenous wastes are eliminated from the body in sweat Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Skin Cancer Most skin tumors are benign and do not metastasize A crucial risk factor for nonmelanoma skin cancers is the disabling of the p53 gene Newly developed skin lotions can fix damaged DNA Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Skin Cancer The three major types of skin cancer are: … … … Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Skin Cancer The three major types of skin cancer are: Basal cell carcinoma Squamous cell carcinoma Melanoma Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Basal Cell Carcinoma Least malignant and most common skin cancer Stratum basale cells proliferate and invade the dermis and hypodermis Slow growing and do not often metastasize Can be cured by surgical excision in 99% of the cases Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Squamous Cell Carcinoma Arises from keratinocytes of stratum spinosum Arise most often on scalp, ears, and lower lip Grows rapidly and metastasizes if not removed Prognosis is good if treated by radiation therapy or removed surgically Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Melanoma Cancer of melanocytes is the most dangerous type of skin cancer because it is: Highly metastatic Resistant to chemotherapy Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Melanoma Melanomas have the following characteristics (ABCD rule) A: B: C: D: Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Melanoma Melanomas have the following characteristics (ABCD rule) A: Asymmetry; the two sides of the pigmented area do not match B: Border is irregular and exhibits indentations C: Color (pigmented area) is black, brown, tan, and sometimes red or blue D: Diameter is larger than 6 mm (size of a pencil eraser) Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Melanoma Treated by wide surgical excision accompanied by immunotherapy Chance of survival is poor if the lesion is over 4 mm thick Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Burns First-degree – only the __________is damaged Symptoms include localized redness, swelling, and pain Second-degree – epidermis and upper regions of ______ are damaged Symptoms mimic first degree burns, but ________ also appear Third-degree – entire thickness of the skin is damaged Burned area appears gray-white, cherry red, or black; there is no initial edema or ____ (since nerve endings are destroyed) Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Burns First-degree – only the epidermis is damaged Symptoms include localized redness, swelling, and pain Second-degree – epidermis and upper regions of dermis are damaged Symptoms mimic first degree burns, but blisters also appear Third-degree – entire thickness of the skin is damaged Burned area appears gray-white, cherry red, or black; there is no initial edema or pain (since nerve endings are destroyed) Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Rule of Nines Estimates the severity of burns Burns considered critical if: Over 25% of the body has second-degree burns Over 10% of the body has third-degree burns There are third-degree burns on face, hands, or feet Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Rule of Nines Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 5.8a Developmental Aspects of the Integument: Fetal Epidermis develops from ectoderm Dermis and hypodermis develop from mesoderm Lanugo – downy coat of delicate hairs covering the fetus Vernix caseosa – substance produced by sebaceous glands that protects the skin of the fetus in the amnion Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Developmental Aspects of the Integument: Adolescent to Adult Skin and hair become oilier and acne may appear Skin shows the effects of cumulative environmental assaults around age 30 Scaling and dermatitis become more common Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Developmental Aspects of the Integument: Old Age Epidermal replacement of cells slows and skin becomes thinner Skin becomes dry and itchy Subcutaneous fat layer diminishes, leading to intolerance of cold Decreased elasticity and loss of subcutaneous tissue leads to wrinkles Decreased numbers of melanocytes and Langerhans’ cells increase the risk of skin cancer Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Skin consists of three layers: Layers of Skin Epidermis - upper, thin layer consists of stratified squamous ET Dermis - lower, thicker layer consists of dense irregular CT Hypodermis - the layer below the skin consists of adipose tissue and areolar CT. Hints: The border between the dermis and epidermis is rippled. The epidermis (all cells) stains darker than the dermis (mostly fibers). The epidermis is thin relative to the dermis. The hypodermis is the lower layer of skin and has the light color of adipose CT. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Question 1 Which is thicker, the dermis or epidermis? ANSWER #1 Hypodermis not considered part of the skin Question 2 What part of the integumentary system is composed of stratified squamous epithelium? ANSWER Question 3 Know where smooth muscles, nerves, hair follicles, and glands are located in the skin: be prepared for matching type questions and diagram labeling of these structures (use study guides for review) Answer: Reticullar Layer Question 4 What layer contains smooth muscle and nerves? Reticullar Layer Question 5 Put the following in the correct order: subcutaneous, epidermis, and dermis. 1-epidermis 2-dermis 3-hypodermis Question 6 Which layer of the epidermis is most superficial? Question 7 • Which layer of the epidermis is the only one that can undergo mitosis? Question 8 • What happens to cells as they are pushed from the deep epidermis? Epidermal Growth-Repair • EPU- epidermal proliferating unit • Cells moving upward- starting at the stratum basale where mitosis occurs • Cell Differentiate (die, keratinization, and desquamate/fall way) 35 days • Callus form- turnover time is shortened Question 9 • What kind of tissue is the dermis mostly composed of? Question 10 • What happens when a circular muscle contracts? Question 11 • What happens to body heat when the smooth muscles in the walls of the dermal blood vessels contract (vasoconstriction)? Dilate (vasodilation)? Figure 22-19: Thermoregulatory reflexes Question 12 • What type of vitamin is produced by the skin? Question 13 • What is the job of the nerve fibers throughout the dermis? Types of Sensors in the Dermis • Free nerve endingsbranching, unsheathed sensors of temperature, light touch, pressure, and pain; found all over the body and in all types of connective tissue Types of Sensors in the Dermis Meissner’s corpuscle- encapsulated nerve ending in the skin’s upper dermis, especially on the palms, soles, lips, eyelids, external genitals, and nipples; respond to light pressure. Types of Sensors in the Dermis Ruffini corpuscleencapsulated receptor in the skin and deeper tissue that reacts to continuous touch and pressure Types of Sensors in the Dermis Pacinian corpuscle- large, covered receptor located deep in dermis; senses stronger, more sustained pressure Question 14 What type of cells produce the shaft of the hair? Question 14 What type of cells produce the shaft of the hair? Hair growth begins when cells of the epidermis spread down into the dermis (forming a small tube = follicle) Cells of the germinal matrix (stratum germinativum =stratum basale) form hairs Question 14 • In what layer are hair follicles found? Question 15 • Where is the subcutaneous layer located and what is the function? Question 15 • What is the function of the subcutaneous layer? Question 15 The main function of the subcutaneous layer is to provide a cushion for the delicate organs lying beneath the skin. It also functions to insulate the body to maintain body temperature. Question 16 • What are the other names for the subcutaneous layer? Question 16 • What are the other names for the subcutaneous layer? hypodermis or superficial fascia Question 17 • What is the main function of eccrine sweat glands? Where are eccrine glands located? Question 18 What is the main function of melanocytes? Question 18 What is the main function of melanocytes? Melanocytes are cells located in the epidermis that are responsible for producing melanin, a brown pigment that helps screen against the harmful effects of UVlight. Question 19 • How are epidermal cells supplied with nutrients? Question 19 • How are epidermal cells supplied with nutrients? BY diffusion from the dermis Question 20 • What layer of the epidermis are nails produced? Note: Mitosis for the creation of new cells for nails- happens in the stratum germantivum =stratum basale Question 21 • What causes a thickened stratum corneum? Question 21 • What causes a thickened stratum corneum? 1- abrasion continues over a prolonged period of time 2-leading to an increase in mitotic activity 3- shortened turnover time = Development of a callus Question 22 • What layer of skin leads to fingerprints? Question 22 • What layer of skin leads to fingerprints? Papillary layer of the dermis- thin superficial layer called the dermal papillae Question 23 • What causes goose bumps? Question 23 • What causes goose bumps? • Arrector pili muscle contracts in response to cold (smooth muscleinvoluntary) Question 24 • What is the cause of a pressure ulcer (otherwise known as decubitus ulcer)? WARNING: next picture is a severe case (please look away if you are prone to squeamishness or would rather not have to see the image of the condition) Question 24 • What is the cause of a pressure ulcer (otherwise known as decubitus ulcer)? This was induced because the person was lying in one position for too long, and this compromised blood supply to the skin. Pressured area dies • Stage I: A reddened area on the skin that, when pressed, is "non-blanchable" (does not turn white). This indicates that a pressure ulcer is starting to develop. • Stage II: The skin blisters or forms an open sore. The area around the sore may be red and irritated. • Stage III: The skin breakdown now looks like a crater where there is damage to the tissue below the skin. • Stage IV: The pressure ulcer has become so deep that there is damage to the muscle and bone, and sometimes tendons and joints Question 25 Changes in moles associated with which type of skin cancer? • Changes in moles associated with which type of skin cancer? ABCD rule Melanoma Question 25 Melanoma • Cancer of melanocytes is the most dangerous type of skin cancer because it is: – Highly metastatic – Resistant to chemotherapy Melanoma • Melanomas have the following characteristics (ABCD rule) – A: – B: – C: – D: Melanoma • Melanomas have the following characteristics (ABCD rule) – A: Asymmetry; the two sides of the pigmented area do not match – B: Border is irregular and exhibits indentations – C: Color (pigmented area) is black, brown, tan, and sometimes red or blue – D: Diameter is larger than 6 mm (size of a pencil eraser) Melanoma • Treated by wide surgical excision accompanied by immunotherapy • Chance of survival is poor if the lesion is over 4 mm thick What skin condition? Melanoma What skin condition? Basal Cell Carcinoma Untreated….. Actinic Keratosis Caused by sun damage. Can lead to squamous cell carcinoma. What skin condition? PSORIASIS Question 26 • What is the most common kind of skin cancer? Basal cell carcinoma -80 percent of all skin cancers A slow growing cancer that does not tend to spread, it can badly damage the skin. If left untreated, moreover, basal cell cancer may spread to nearby cartilage or bone. Basal cell carcinoma typically begins as a pink or pearly white area, which may later form an ulcer or bleed. Question 27 • How do melanocytes respond to overexposure to sunlight? . Question 27 • How do melanocytes respond to overexposure to sunlight? Melanin granules close to the surface of the skin are oxidized by UVA radiation and become darker. Melanocytes deeper in the epidermis are stimulated to produce new melanin granules. These new granules are transferred to keratinocytes in the upper cell layers of the skin. These granules become positioned in the outer portions of the cells above the cell nuclei, thus providing additional protection. Question 28 • What area is “true skin”? The dermis, or true skin, lies below the epidermis and gradually blends into the deeper tissues. It is a wide area of connective tissue that contains blood vessels, nerve fibers, smooth muscles, and skin appendages. Question 29 • How does the dermis differ from the epidermis in terms of cell loss and regeneration? Dermal Growth and Repair • Cleavage Lines/Langer Lines Bundles of white collagenous fibers in reticular layer in dense bundles Rapid Regeneration only in healing of wounds (unlike the epidermis) Question 30 • Where is thin skin found? Thick skin? Question 31 • Where on the body are apocrine glands found? Sweat Glands • Eccrine- numerous; watery liquid • Apocrine- armpit, areola of breast, around anus Question 32 • What type of gland is involved with blackheads? Question 32 • What type of gland is involved with blackheads? Common causes of Blackheads : • • • • Overactivity of the sebaceous Testosterone. Propionibacterium. Cysts. glands. Question 33 What causes body odor? Sweat is odorless—until bacteria on the skin's surface act upon the dead skin cells…creating what we call BO. Usually from sections produced by the apocrine glands Question 34 • What is the role of basement membrane? Where is it located? BONUS Point on test Question 35 • What is the major difference between a second degree and a third degree burn? Question 36 Be able to name at least six functions of the integumentary system. Question 36 • Be able to name at least 6 functions of the integumentary system Protection Sensation Excretion Vitamin D production Immunity Homeostasis of Body Temperature Movement without Injury Question 37 • Understand the importance of Langer cleavage lines for surgery Dermal Growth and Repair • Cleavage Lines/Langer Lines Bundles of white collagenous fibers in reticular layer in dense bundles Rapid Regeneration only in healing of wounds (unlike the epidermis) Question 37 • Understand the importance of Langer cleavage lines for surgery • Langer's lines, or cleavage lines are lines in the skin that are characteristic for each part of the body. The lines are formed by collagen fibers running parallel to each other. Cleavage lines correspond to the crease lines on the surface of the skin in most parts of the body. • These lines are of particular interest to surgeons because an incision made parallel to the lines heals with a fine linear scar, while an incision across the lines may set up irregular tensions that result in an unsightly scar. In some areas of the body Langer's lines are visible or can easily be seen by compressing the skin. Question 38 • What protein is found in fingernails? Question 38 • What protein is found in fingernails? Keratin Question 39 • What is the cutaneous membrane? Question 39 • What is the cutaneous membrane? cutaneous membrane - the membrane which covers the outer surface of the body (the skin). Question 40 • Why is the subcutaneous (hypodermis) layer an ideal site for the injection of liquid medications like insulin? Question 40 • Why is the subcutaneous (hypodermis) layer an ideal site for the injection of liquid medications like insulin? • Closest to blood vessels • Loose tissue Question 41 • What does it mean to say the skin looks “cyanotic” Question 41 • What does it mean to say the skin looks “cyanotic” • poor oxygen binding and decreased oxygen release--can rapidly lead to tissue hypoxia Question 42 • What is the name of the waxy secretion in the external ear canal? Question 42 • What is the name of the waxy secretion in the external ear canal? Cerumen or ear wax Question 43 • Know the parts of the hair Skin Appendages Continued… Hair Follicle Figure 5.6c Hair Follicle Figure 5.6c Question 44 Name the skin condition that results in a yellowish discoloration of the skin. Question 44 • Name the skin condition that results in a yellowish discoloration of the skin. • Jaundice is a yellow color in the skin, the mucous membranes, or the eyes. The yellow pigment is from bilirubin, a byproduct of old red blood cells. Question 45 • What is the function of the surface film found on the skin? Question 45 • What is the function of the surface film found on the skin? • Antimicrobial (protection) • Body Temperature regulation (evaporation; dehydration) Question 46 • Name the skin condition that results from a lack of the enzyme tyrosinase Skin Color- 3 pigments – Melanin (yellow – black) synthesized in melanocytes from tyrosine by tyrosinase Dispersed to keratinocytes in epidermis – protects nucleus from UV radiation – Number of melanocytes similar in all people, amount of pigment produced differs – Sunlight stimulates melanocytes – Carotene (orange) Present in epidermis, dermis&subcutaneous layer – Hemoglobin (red) • Present in skin blood vessels Skin Color-little to no melanin Albinism – Albinos unable to synthesis tyrosinase enzyme From: http://www.albinism.org/ Question 47 How much time does it take a cell to move from the stratum basale (where mitosis occurs- and stem cells exist) to the stratum corneum (at the surface where dead cells fall off? type of tissue Question 48 What is the “rule of nines”? The rule of palms? RULE OF PALMS Using the rule of palms, the surface of the patient's palm represents approximately 1% of body surface area and is helpful in estimating the area of small burns. Question 49 What are fingerprints? Papillary layer: Consists of areolar connective tissue made up of loose collagen and elastic fibers, projections called papillae - form epidermal ridges found on the surfaces of palms, fingers and feet. On the palm and fingers they form the fingerprints (genetic markers of individualilty). Wound Healing video clips http://www.youtube.com/watch?v=IYL6vg89uds http://www.youtube.com/watch?v=zZpMQ_7qiRg http://www.youtube.com/watch?v=ijz3591BXyA http://www.youtube.com/watch?v=jUSEreOzFpg (intrinsic vs. extrinsic factors) http://www.youtube.com/watch?v=kS0tzhDAAFo (Body Atlas- sun's impact on skin)