Integumentary System: Ch. 4 Integumentary System: The Skin and Its Parts

Applied Learning Outcomes 1. Use terminology associated with the Integumentary system 2. Learn about skin structure, function, appendages, glands, and care 3. Understand the aging and pathology of the Integumentary system

Case Study Investigation – Ch. 4 You are observing an elderly woman who is seeing a personal trainer as part of her rehabilitation therapy. The woman was hospitalized for problems associated with obesity & high blood sugar. She is now going through an exercise program to helpb bring her back to health. While working out, one of her socks rolled down exposing the lower part of her leg. A glance at the side of her left leg, revealed a large, shiny, deep red

sore. The sore had a dark margin, like tanned skin. Parts of it looked as if you could see right through to the muscle. The woman saw your face reacting to the sore and kindly said, “Don’t worry about that, it doesn’t cause me any pain.” Part of the personal’s trainer’s responsibility is to pay attention to the pathology that can be worsened by the patient’s rehab. By the end of this chapter you will be asked to determine the possible problems causing this skin condition.

Human Skin Trivia skin – largest organ in body (25sq.ft or 16% of your body weight) lose an avg. of 4 - 100 hairs/day stretchable & washable avg. scalp has 100,000 hairs shed 40lbs of skin/lifetime on avg. (1 layer every 24 hrs) body loses 30,000–40,000 dead cells/min. 45 miles of nerves in skin blondes have more hair than brunettes

Did You Know? Chaetophobia is the fear of hair. Tonsurphobia is the fear of haircuts.

Did You Know? Hair generally grows at a rate of approximately 3/16” per day, or approximately ½” per month.

Did You Know? Hair is naturally colored by pigment granules (melanin) in the cortex whereas dyed hair has melanin in the cuticle as well as the cortex.

Overview The skin is the largest organ is in the body and is composed of: Blood vessels Nerve Hair Nails Skin Glands Receptors

Overview Inherent: qualities an organism is born with ex. Genes for making nails only turn on in the upper tips of the fingers and toes Adaptive: ability of an organism’s genes to respond to environmental changes ex. calluses, suntan, skin stretches as the body grows and shrinks back after a woman gives birth

Functions of Integumentary System Protection - against environment (UV rays, microbes); and self-repairs cuts & burns Heat regulation – maintain homeostasis (blood vessels) Water resistant – prevents water from flushing out important nutrients Sensation – receiving stimuli from the environment (receptors) Absorption - can receive O2, N2, medicine Waste excretion – can excrete CO2, urea, sweat Synthesis of Vitamin D – Vit. D helps maintain normal blood calcium & phosphorus

3 Major Layers of the Skin Epidermis a. stratified squamous tissue (epithelial) b. strong & waterproof (keratin) Dermis a. dense connective tissue b. contains blood, sweat & oil glands 3. Hypodermis (subcutaneous) a. adipose tissue anchors skin (E & D) to underlying organs

Microscopic View Epidermis - get a new one every 25-45 days - melanocytes (melanin cells) - keratocytes (keratin cells) Dermis - functional layer Hypodermis / Subcutaneous - adipose tissue Microscopic View

5 Layers of the Epidermis OUTSIDE THE BODY***** 1. Stratum corneum (dead cells & melanin which gives skin color) 2-4. middle layers (protein keratin provides strength) 5. stratum germinativum (living & dividing cells) DERMIS*****

Why don’t we bleed when we shave?? The epidermis is AVASCULAR, meaning it has no blood supply of its own. You only bleed if you cut deep enough to reach the dermis.

Dermis functional layer contains blood vessels, sweat & oil glands, hair follicles, muscle fibers, nerve endings & elastic fibers dermal papillae  finger-like projections of the dermis that bind epidermis & dermis form ridges & grooves that create fingerprints

Dermal papillae

Hypodermis (subcutaneous) composed of adipose tissue & elastic (connective) fibers anchor skin to underlying fascia (tissue that covers muscles, skull & some organs) major blood vessels & nerves branch upward into the dermis absent/thin in eyelids, penis, scrotum, & nipples; responsible for increase in breasts & hips in females

Subcutaneous Injection ideal site for rapid & relatively pain free absorption of injected material (i.e. insulin/ flu shot) using a hypodermic needle

Concept Check Questions 1-3 1. List 5 major components of the Integumentary system? blood vessels, receptors, glands, nails, nerves, & hair 2. Distinguish between inherent and adaptive characteristics. Give an example of each. Adaptive – cause changes in skin that adjust the structure of skin to environmental conditions (tanning) Inherent – structures that appear at birth (nails) 3. List 5 main functions of the Integumentary system? protection (melanin), heat regulation (adipose tissue, blood vessels, sweat), absorption (blood vessels, pores), water-resistant (keratin,oil), sensation (receptors), waste excretion (pores, sweat), makes Vit. D (melanin)

Concept Check Questions 4-6 4. What are the 3 layers of skin from superficial to deep? epidermis, dermis, hypodermis/subcutaneous 5. What kind of tissues can be found within each layer of skin? epidermis  stratified squamous (epithelial) dermis  connective tissue hypodermis  adipose & connective tissue 6. How do the 5 layers of the epidermis differ? Be specific. stratum corneum  dead cells and melanin for color middle layers  keratin for strength stratum germinativum  living and dividing cells

Concept Check Questions 7-9 7. Why don’t we bleed when we shave usually? When would you see blood? The epidermis is avascular – doesn’t contain any blood vessels; only bleed if you reach dermis 8. Why is the dermis considered the “functional” layer? contains blood vessels, receptors, glands, muscle, nerve endings 9. Where are dermal papillae found AND what 2 functions are they responsible for? Found in dermis; 1) connects the dermis to the epidermis 2) create fingerprints

Skin Appendages assist skin with its functions glands nerves nails http://www.youtube.com/watch?v=IAAt_MfIJ-Y assist skin with its functions glands nerves nails hair

Blood Vessels expand/contract according to internal body temperature of body 1. warm body blood flow increases heat leaves 2. cold body blood flow decreases heat stays 3. sweat evaporation  lowers body temperature

Glands 3 types of glands commonly found in skin Cerumenous glands (wax) Sebaceous glands (oil) 3. sweat a. apocrine sweat glands b. eccrine sweat glands

Ceruminous Glands produce cerumen or ear wax that line ear canal surrounded by small hairs collects dirt & dust and carries it out of the ear

Sebaceous Glands attached to hair follicle produces sebum, an oily secretion sebum lubricates hair and surface of skin to prevent them from drying out

Sweat Glands produces sweat through pores 2 types a) Apocrine: made of protein, fat, etc. responsible for body odor found in armpits, naval, groin & areolae (secrete fat Into milk ducts)

Apocrine Sweat Glands inactive till puberty & taper off in activity in elders secretions contain pheromones (play a role in courtship & social behavior); dogs are notorious for sniffing these secretions secretions are thicker, stickier and produce more odorous sweat  bacteria break sweat down into acids found deep in dermis and secrete fluid into tiny canals of hair follicles

b) Eccrine: found everywhere; concentrated in armpits, forehead, palms & soles of feet composed of salt & H20  activity, amount & distribution is genetically determined not as deep in dermis and secrete into pores

Eccrine Sweat Glands allow chemicals causing food odors leak out of the body bacteria feed off nutrients in sweat  causing odors antiperspirants reduce amont of sweat produced by glands  reduce dampness & odors (-) charged ingredients repel (-) charged sweat molecules

Nerves Sensory receptors: communicate information from the environment to the body found in all skin layers; concentrated in dermis & fascia

Types of Sensory Receptors Free nerve endings: detect pain in the epidermis

Types of Sensory Receptors Meissner’s corpuscles: in dermis detect touch dermal papillae --------------- Also  Krause end bulbs (cold temp.)

Types of Sensory Receptors Pacinian corpuscles: deep in dermis & hypodermis detect strong pressure (vibrations) -------------------- also  Ruffini receptors

Nails nail root lies beneath cuticle (skin fold) keratocytes in nail root move up, die & flatten  forms nail body lunula- moon shaped whitish area nails grow 1/8 in/mo. faster than toenails

Hair each strand of hair grows from a hair follicle (inward protrussion of epidermis) hair papilla (base of follicle) has its own blood & nerve supply hair shaft - dead, hardened, keratinized stratum corneum-like cells

Layers of Hair 3 layers  cuticle, cortex & medulla cuticle  thin, colorless, protects cortex & scales point toward tip; large in humans cortex  strength, color & texture medulla  only present in thick hair; small or non-exsitent in humans

Hair Structure Cuticle – outer coating composed of overlapping scales Cortex – protein-rich structure around the medulla that contains pigment Medulla – central core (may be absent) The structure of hair has been compared to that of a pencil with the medulla being the lead, the cortex being the wood and the cuticle being the paint on the outside.

http://www.videojug.com/interview/csi-and-trace-evidence-2

Hair color determined by melanin amount & location determines color  genetically controlled arrector pili muscle (smooth muscle) attachs to hair follicle  causes goosebumps (traps heat)

Drugs & Hair capture many chemicals (drug/poison) that pass through blood advantages: 1) goes back months not days 2) non-invasive, 3) holds up in court disadvantages: 1) expensive, 2) takes time to get results

Stages of Hair Development: Root must be present in order to test hair evidence for DNA Anagen: growing Catagen: at rest Telogen: dying

Habits & Hair Loss hair loss is a slowing down of hair growth and replacement physical stress is a major cause of hair loss (childbirth, illness, injury, pregnancy, and too much exercise when body has to use its energy to cope with stress to places hair growth as a lower priority malnutrition and under-nutrition (diets low in amino acids) increase in male hormones tight braids or ponytails might also pull off hair faster than it can be replaced excessive hair combing emotional stress seems to accelerate growth

Concept Check Questions 10-12 10. What are skin appendages? Provide 4 examples. - assist skin perform functions; hair, nails, glands, muscles, nerves 11. The dermis has the ability to regulate heat. Describe 2 ways the dermis does this. When hot  BV expand to release heat; releases sweat When cold  BV contract to retain heat. 12. What do ceruminous & sebaceous glands produce and how do these secretions differ in function. - ceruminous glands  cerumen (wax)  clean ear - sebaceous glands  oil (fats)  lubricate skin & hair

Concept Check Questions 13-15 13. Describe how appocrine & eccrine glands differ in location and what they secrete. - appocrine – secrete odorous sweat-like material; armpits, genitals (can contain pheromones) - eccrine – secrete H2O, salts, ammonia; all over the body 14. What is the general function of nerves/receptors in the skin? Name 3 & state what each detects. communicate info from environment to body - free nerve endings  pain Meisners corpuscletouch - Pacinian corpuscle  pressure 15. Describe the differences btwn the 3 layers of hair. - cuticle – outer layer; protects cortex & medulla - cortex – middle layer; contains pigments; provides strength - medulla – inner layer; usually only present in thick hair

Concept Check Questions 16-18 16. Why doesn’t a hair cut hurt, but pulling a hair out of the head does? - visible hair is made out of dead cells; hair root is living 17. What does the arrector pili muscle attach to and what’s its function? hair; allows hair to stand erect and trap in hot hair 18. What are the advantages & disadvantages of the testing hair samples for drugs? Advantages – 1) detects up to months not days, 2) holds up in court, 3) non-invasive Disadvantages – 1) expensive, 2) takes a long time to get results

causes skin to lose ability to maintain homeostasis majority of Burns causes skin to lose ability to maintain homeostasis majority of burnssun exposure & cooking accidents other causes chemicals, electricity, fires & steam

1st Degree  superficial damage; reddening and swelling Types of Burns 1st Degree  superficial damage; reddening and swelling chemicals, steam, flame heat & mild sun exposure http://videos.howstuffworks.com/howstuffworks/131-how-sunburns-work-video.htm

Types of Burns 2nd Degree  stratum germinativum & dermal papillae damaged; blisters, fluid buildup, painful, long healing time;  longer exposure to previous factors

Types of Burns 3rd Degree  stratum germinativum not available for healing; dermis, adipose, muscle, nerve & bone damage;  excessive exposure to previous factors

Rule of Nines: method to determine extent of a burn injury

Wellness and Illness over the Life Span Skin pathology can be categorized as: degenerative (diseases that progressively deteriorate skin) genetic (inherited; mutations) infectious (contagious, microorganisms) Intrinsic: aging caused by the natural decline of cells Extrinsic: aging caused by environmental factors (disease, pollution, sun exposure) Degenerative: refers to diseases that progressively deteriorate tissues -examples include skin cancer, moles, skin tags Genetic disorders include acne, psoriasis, spider veins Infectious diseases include impetigo, ringworm, warts

Degenerative Skin Disorders freckles or solar lentigene (age spots)  sun exposure dermatitis (eczema) skin inflammation caused by allergic rxn or irritant

Degenerative Skin Disorders skin cancer  has an underlying genetic component moles  flat squamous- cell tumors; heavily pigmented by melanocytes http://videos.howstuffworks.com/sciencentral/4149-how-not-getting-enough-sun-can-be-harmful-video.htm

Degenerative Skin Disorders skin tags  soft, colored, knob-shaped tumors that grow out of skin (neck, armpits, body); surgery can easily remove

Genetic Skin Disorders acne, cysts, boils  hormonal changes causes overproduction of sebum around hair follicles psoriasis  inflammation of skin and increased skin cell production; dry, itchy; environmentally trigged??

Genetic Skin Disorders port wine stains & spider veins  common birthmarks vitiligo  white spots on skin; decrease in melanin production (immune attack on melanocytes ???)

Infectious Skin Disorders MRSA  caused by Staphylococcus aureus bacteria; produces destructive secretions that erode and inflame skin

Infectious Skin Disorders Ringworm (tinea)  skin fungus that eats keratin rich materials human papilloma virus (HPV) group of viruses that cause various types of warts in humans

Aging of the Integumentary System Aging is due to: intrinsic factors (natural decline; genetic, maturation, stress) extrinsic factors (environmental factors, contracting disease, pollution) lifestyle can accelerate aging loss of head hair graying/whitening of hair, decrease in sweating excessive growth of hair, loss of fat wrinkles; drying out of skin = decrease in oil

Concept Check Questions 19 - 21 19. Explain how the 3 categories of skin burns differ? - 1st degree – superficial damage – reddening, swelling -2nd degree – stratum germinativum damage - blisters -3rd degree – dermis is damaged – nerve damage 20. According to the rules of nines, what % of my body would be burned if the anterior part of 1 leg, both sides of my right arm, and my head were burnt? 27% 21. How do the 3 categories of skin disorders differ? -degenerative – progressive deterioration of skin - genetic – inherited / mutations in DNA - infectious - microorganisms

Concept Check Questions 22-24 22. Describe 2 types of degenerative skin conditions. freckles & solar lentigene (age spots)  too much sun dermatitis –> dry irritation of the skin skin cancer –> abnormal, malignant growths of skin 23. Describe 2 types of genetic skin conditions. Acne  infected sebaceous glands Psoriasis  inflammation of skin Port wine / vitiligo  birthmarks, reduced melanin 24. How do the 2 major categories of skin aging differ? Extrinsic environmentally triggered Intrinsic  natural / genetic causes

continous high blood-sugar levels cause smaller blood CSI Investigation Name at least 3 symptoms your patient is suffering from. elderly, obesity, high blood pressure & open sore 2. Based on these symptoms, what might your patient be suffering from? decline of blood vessels associated with prolonged / untreated diabetes 3. Explain why/how the dermis became exposed in her sore? continous high blood-sugar levels cause smaller blood vessels in the skin to break down; skin can’t produce epidermis (and make S.Corneum layer that sheds with physical damage)

CSI Investigation Why would such an “ugly” sore not cause any pain sensation? As her personal trainer, why would you recommend an exercise program for this patient? What would her program entail? Sore is deep in the skin; all nerves and receptors have been damaged. Routine should include exercise that reduces weight and increases blood flow. Inflexible skin may cause restriction movements. Increase the amount of protein  build immune system and provide S.germinativum with amino acids required for normal rate of mitosis.

sores in elders are common  natural decrease in blood flow CSI Investigation exercise program  increase weight loss & increase blood flow  inflexibility of skin may cause movement restrictions?? sores in elders are common  natural decrease in blood flow increase protein  provides stratum germinativum with amino acids to divide avoid stress on body  reduces immune response and will slow healing