Chapter 6
This presentation is the property of its rightful owner.
Sponsored Links
1 / 44

Skin and the Integumentary System PowerPoint PPT Presentation


  • 93 Views
  • Uploaded on
  • Presentation posted in: General

Chapter 6. Skin and the Integumentary System. Functions of the Skin. Maintain homeostasis Protective covering Contains immune cells Synthesizes vitamin D Excretes wastes Slows water loss Regulates body temp Houses sensory receptors. Cut-, skin Derm -, skin Epi -, upon Hypo -, below.

Download Presentation

Skin and the Integumentary System

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Chapter 6

Chapter 6

Skin and the Integumentary System


Functions of the skin

Functions of the Skin

  • Maintain homeostasis

  • Protective covering

  • Contains immune cells

  • Synthesizes vitamin D

  • Excretes wastes

  • Slows water loss

  • Regulates body temp

  • Houses sensory receptors


Layers of skin

Cut-, skin

Derm-, skin

Epi-, upon

Hypo-, below

Layers of Skin

  • 3 layers:

    • Epidermis

      • Outer layer

    • Dermis

      • Inner layer

    • Subcutaneous

      • Hypodermis layer


Epidermis

Epidermis

  • Thickest on palms and soles

    • 0.8-1.4mm

  • Accessory structures

    • Hair follicles

    • Nails

  • Melanocytes

    • Provide melanin


Epidermis1

Epidermis

  • Composed of stratified squamous epithelium

  • Keratinized

    • Cells synthesize keratin packed cells

  • Separated from dermis by basement membrane

  • Lacks blood supply


Layers of epidermis

Layers of Epidermis

  • Stratum corneum

    • corneum= horn (Latin)

    • Outer keratinized layer, dead

    • Desquamation

  • Stratum lucidum

    • lucid= clear (Latin)

    • Palms, soles

  • Stratum granulosum

    • granulose= granular (Latin)

    • Flat, granular (keratohyalin)


Layers of epidermis1

Layers of Epidermis

  • Stratum spinosum

    • Spiny, prickly

    • Dividing, melanocyte branches

  • Stratum basale (germinativum)

    • Basal = basement, bottom layer

    • Melanocytes, dividing, deepest layer


Dermis

Dermis

  • Bind epidermis to underlying tissue

  • Irregular dense CT

  • Muscle fibers

    • Smooth & skeletal

  • Dermal papillae

    • Increased surface area to nourish epidermis

    • Fingerprints

    • Friction for gripping

  • Average thickness

    • 1.0-2.0mm


Dermis1

Dermis

  • Accessory structures

    • Nerve cell processes

      • Pacinian (heavy touch/pressure)

      • Meissner’s (light touch/pressure)

      • Free nerve endings (temperature, pain)

    • Blood vessels

    • Sweat glands


Subcutaneous layer

Subcutaneous Layer

  • “Hypodermis”

  • Loose CT & adipose tissue

  • Major blood vessels

  • Insulation


Hair follicles

Hair Follicles

  • From epidermal cells

  • Extends into dermis

    • Contains hair root

  • Hair color

    • Melanin production

      • Albinism

  • Arrectorpili muscle

    • Smooth muscle

    • Attaches to each follicle

      • Autonomic innervation


Hair growth

Hair Growth

  • Cyclic growth

    • Formed by cells in follicle

    • Keratinize and die

    • Form hair shaft

  • Type of hair

    • Eyelash

      • Grow 30 days, 100 days rest

    • Scalp

      • Grow 3-6 years, rest few months

      • 0.3 mm/day


Sebaceous glands

Sebaceous Glands

Seb-, grease

  • Associate with hair follicles

    • Absent on palms and soles

  • Holocrineglands

    • Release entire cells

  • Secrete sebum

    • Mixture of fatty acids and cellular debris

    • Secreted into hair follicle

  • Excess sebum  acne


Clinical application

Clogged gland

Excess sebum, epithelial cells

Blackheads & whiteheads

Good environment for anaerobic bacteria

Clinical Application

  • Acne

    • Disorder of sebaceous glands

  • Hormonally influenced

    • At puberty

    • Adrenals  androgens

    • Stimulates sebum production


Clinical application1

Clinical Application

  • Immune system triggers inflammation

    • Pimple

  • Treatment options

    • Antibiotics

    • Estrogen

    • Retinoic acid (Vitamin A derivatives)

      • Accutane


Nails

Nails

  • Protective coverings on fingers, toes

  • Made of:

    • Nail plate

    • Nail bed (skin)

    • Lunula

      • White region

      • Half-moon shape

      • Active in growth

  • Reflection of health status

    • Blue = cyanosis; white = anemia; pigment = injury or melanoma; depressions/furrows = anemia, malnourishment; red streaks = ulcers, hypertension, RA

  • Growth rate

    • 0.5-1.2 mm/day


Sweat glands

Sweat Glands

  • Sudoriferous glands

    • Widespread in skin

      • Deep dermis or subcutaneous layer

  • Eccrine glands

    • Most numerous

  • Apocrine glands

    • Active in puberty

  • Modified sweat glands

    • Ceruminous

    • Mammary


Sweat glands1

Sweat Glands

  • Eccrine glands

    • Most numerous

    • Response to

      • High temp

      • Exercise

      • Stress (on hands)

    • Open as pore

      • Forehead, neck, back


Sweat glands2

Sweat Glands

  • Apocrine glands

    • Onset @ puberty

    • Response to

      • Fear

      • Pain

      • Distress

    • Open into hair follicle

      • Armpit

      • Groin

    • Odor

      • Bacterial metabolism of secretions

Sympathetic response


Sweat

Sweat

  • Water

  • Salts

    • Sodium

    • Chloride

    • Potassium

    • Magnesium

  • Wastes

    • Urea

    • Lactate


Regulation of body temp

Regulation of Body Temp

  • Heat

    • Product of cellular metabolism

  • Active cells are major heat producers

    • Skeletal muscle

  • As body temp , body releases heat

  • Homeostasis

    • Maintain body temp at 37C or 98.6F


Releasing body heat

Releasing Body Heat

  • Radiation (2)*

    • Most of heat loss

    • Infrared heat rays escape from warmer to cooler surroundings

  • Evaporation (5)*

    • At high temp, eccrine sweat glands release sweat onto skin

    • Heat carried away as skin cools

  • Conduction

    • Heat transferred from body directly to cooler object

    • Ex. Cold car seats

  • Convection (4)

    • Warm air circulates away from body


Conserving body heat

Conserving Body Heat

  • Dermal blood vessels

    • Reduce heat-carrying blood thru skin

  • Muscle activity

    • Increased cell respiration

      • Heat production

    • Shivering

      • Small groups of muscles contract

      • Produce heat


Problems in body temp regulation

Problems in Body Temp Regulation

  • Hyperthermia

    • Abnormally high

    • Humid air prevents evaporation of sweat

      • No cooling

    • High air temp reduces radiation cooling

  • Hypothermia

    • Abnormally low

    • Shivering  mental confusion, lethargy, loss of reflexes, shut down of major organs

      • Some surgeries (heart, brain) require body to be cooled  less oxygen is required


Skin color

Skin Color

  • Genetic Factors

    • Melanocytes

      • Same # in all people

    • Melanin production

      • Varies by person

    • Melanin production

      • High  darker skin

      • Low  fairer skin

    • Albinism

      • No melanin

  • Environmental factors

    • Darken existing melanin

    • Stimulate production

      • Sunlight

      • UV light from

        • Sunlamps

      • X rays

    • Tans fade

      • Pigmented epidermal cells keratinize

      • Wear away


Skin color1

Skin Color

  • Physiological Factors

    • Blood vessels in dermis adds color

      • Content of vessels

        • High oxygen  hemoglobin is bright red

          • Pinkish hue to skin

        • Low oxygen  hemoglobin is dark red

          • Bluish hue to skin (cyanosis)

      • State of vessels

        • Dilation  skin reddens

        • Constriction  skin pales

  • Dietary influences

    • Carotene  yellow/orange skin tone

  • Health influences

    • Jaundice  yellowish skin (liver)


Healing of wounds and burns

Healing of Wounds and Burns

  • Inflammation

    • Response to injury or stress

    • Healing events depend on nature of injury

  • Cuts

    • Shallow

      • Epithelial cells divide  fill in gap

    • Deep cut

      • Blood vessels break  blood clot


Healing of wounds and burns1

Healing of Wounds and Burns

  • Clot

    • Scab formation

      • Fibrin, blood cells, platelets, fluids

  • Fibroblasts

    • Secrete collagen

      • Binds wound together

  • Scar

    • Extensive wound

    • Connective tissue on skin surface


Burns

Burns

  • First degree

    • Superficial partial thickness

      • Injuring epidermis only

      • Healing in 2-3 days

    • Common examples

      • Sunburn

      • Scalding water

      • Chemicals

    • Treatment

      • Flush with cool water (no ice)

      • Aloe (no oil)

      • Clean, dry bandage


Burns1

Burns

  • Second degree

    • Deep partial thickness

      • Injures epidermis and dermis

      • Fluid escapes capillaries  blisters

      • Healing time 1-2 weeks

    • Common examples

      • Prolonged sunburn or scalding water

      • Brief exposure to flame

    • Treatment

      • Flush with water, bandage

      • Do NOT break blisters

      • > 2-3 inches, see physician

        • Hydration

        • Antibiotics

        • Grafting


Burns2

Burns

  • Third degree

    • Full-thickness

      • Epidermis, dermis, accessory organs

      • Healing time: weeks to months

    • Common examples

      • Contact with flame

      • Corrosive chemicals

      • Immersion in hot liquids

    • Treatment

      • Burn center

      • Debridement

      • Grafting


Grafting

Grafting

  • Autograft

    • “Auto”  self

      • Remove skin from unburned part of body and “transplant” it to injured site

  • Homograft

    • “Homo”  like

      • Cadaveric skin used if can’t do autograft

  • Skin substitutes

    • Amniotic membrane

    • Artificial membrane

    • Cultured epithelial cells

  • Scarring


Healing of burns

Healing of Burns

  • Treatment of patient:

    • Requires estimate of body surface injury

      • Replace body fluids and electrolytes

      • Determine amount of skin needed for graft

    • Use “rule of nines”

      • Divide skin surface into regions

      • Each region = 9% (or multiple of 9%)


Life span changes aging skin shows many signs

Life Span ChangesAging skin shows many signs…

  • Cell cycle slows

  • Age (liver) spots

  • Dermis reduced

    • Connective tissue growth slows

      • Slower wound healing

    • Loss of fat

      • Wrinkles & sagging skin

  • Melanin production slows

    • Hair grays/whites

  • Less vitamin D production

    • Needed for calcium uptake in bones


Life span changes aging skin shows many signs1

Life Span ChangesAging skin shows many signs…

  • Hair growth slow

    • Thins and # follicles decreases

  • Lowered blood supply to nail beds

    • Dulls/hardens nails

  • Sensory receptors decline

    • Less sensitive to pain/pressure

  • Inability to control body temperature

    • # sweat glands drop & dermis blood vessel numbers


Common skin disorders

Common Skin Disorders

  • Athlete’s foot

    • Skin fungus infection (Tineapedis)

  • Boil

    • Bacterial infection, bacteria enter skin via follicle

  • Chickenpox

    • Varicella-zoster infection; blistery lesions that scab


Common skin disorders1

Common Skin Disorders

  • Eczema

    • Dry, itchy, scaly skin (genetic)

  • Mole

    • Benign skin tumor (nevus) usually pigmented brown black

  • Psoriasis

    • Red skin w/ silvery scale


Rashes

Rashes

  • Infectious

    • Roseola

    • Measles

    • Rubella

    • 5th disease

    • Shingles

    • Impetigo

    • Lyme disease

    • RMSF

    • Meningitis

    • Candidiasis

  • Allergic

    • Hives

    • Penicillin

    • Food allergies

    • Poison ivy

    • Cosmetics

  • Autoimmune

    • Lupus

    • Psoriasis


Skin cancer types

Skin CancerTypes

  • Basal cell carcinoma

    • Most common

    • Basal layer of epidermis

    • Nodule, shiny bump, scar-like lesion

  • Squamous cell carcinoma

    • 2nd most common

    • Upper layers of skin (squamous)

    • Begin as scaly red patches, open sores, elevated with centralized depression

    • Typically superficial


Skin cancer types1

Skin CancerTypes

  • Malignant melanoma

    • Most deadly

    • Brown/black patches, nodules

    • Look like or arise from moles


Skin cancer risks

Skin CancerRisks

  • Fair skin, hair, eye color

  • Family history

  • Personal history

  • Chronic sun exposure

  • History of sunburns early in life

  • Certain types of moles, # moles

  • Freckles

    • Sun sensitivity, sun damage


Skin cancer detection

Skin CancerDetection

  • A

    • Asymmetry

  • B

    • Border irregularity (scalloped, notched)

  • C

    • Color variation

  • D

    • Diameter > ¼ inch

  • E

    • Evolution


Skin cancer treatment

Skin CancerTreatment

  • Excision

    • Virtually all types of skin cancer are 100% curable if caught early

  • Invasive

    • Lymph node testing

    • Chemotherapy

    • Immunotherapy


Suggested homework problems

Suggested Homework Problems

  • Chapter assessments

    • 3-6, 9, 11-14, 17, 19-25, 27, 28

  • Integrative Assessments/Critical Thinking

    • 1-7


  • Login