Mspa 2017 - Skin - Lecture 5 (Exam 2) - S&f Hg

Front 1

Components of the Integumentary System

Back 1

1) Epidermis and dermis

2) Hypodermis

3) Thick and thin skin

4) Skin color

5) Skin Marking

6) Hair and nails

7) Cutaneous glands

8) Skin disorders

Front 2

Skin is

Back 2

Largest organ (15% of body weight)

Thickness of various layers of skin varies

- Normally 1-2mm

- Dermis may thicken up to 6mm

- Stratum Corneum layer (dead cells) increased - calluses on hands and feet

Front 3

Epidermis

Back 3

Keratinized stratified squamous epithelium

Front 4

Hypodermis

Back 4

Subcutaneous fat and blood vessels

Front 5

Functions of the skin

Back 5

1) Resistance to trauma and infection

-- Acid mantle (ph 4-6)

2) Barrier to Ultraviolet light

3) Vitamin D synthesis

4) Sensory receptors

5) Thermoregulation

6) Excretion

7) Nonverbal communication

8) Appearance

Front 6

Cells of the epidermis

Back 6

1) Stem cells - Undifferentiated cell in basal layer

2) Keratinocytes - most of the skin cells

3) Melanocytes - synthesize pigment that shields from UV

4) Sensory (cutaneous) receptors

5) Dendritic (langerhans) cells - macrophages guard agains pathogens

Front 7

Keratin

Back 7

Fibrous, structural protein

- Beaks, baleen, claws, hooves, feathers, scales, silk, fingernails, hair

- White/Transparent

Front 8

Cutaneous Receptors - Mechanoreceptors

Back 8

1) Respond to deformation

2) Touch, proprioception, discrimination

3) Meissner's and Pacinian corpuscles

Front 9

Cutaneous Receptors - Thermoreceptors

Back 9

Hot or cold receptors

Front 10

Cutaneous Receptors - Nociceptors

Back 10

Pain receptors

Front 11

Cutaneous Receptors - Chemoreceptors

Back 11

Damage

Front 12

Stratum Basale

Back 12

Single layer of stem cells on basement membrane

- Basal Lamina

Front 13

Cell types in Stratum Basale

Back 13

1) Karatinocytes

- constant mitosis and subsequent apoptosis

2) Melanocytes

- distribute melanin through cell processes

- melanin picked up by keratinocytes

3) Merkel cells are touch receptors for somatosensory afferents

Front 14

Stratum Spinosum

Back 14

Several layers of living keratinocytes

- Inflated with keratin

Front 15

Stratum Spinosum contains

Back 15

Dendritic (langerhans) cells

- macrophages from bone marrow that migrate to the epidermis

- 800 cells/ millimeter

- helps protect body against pathogens by "presenting" them to the immune system

Front 16

Stratum Granulosum

Back 16

3 to 5 layers flat keratinocytes

- Cells undergo apoptosis and lose nuclei and organelles

Front 17

Stratum Granulosum produces

Back 17

Lipid filled vesicles - Lamellar Bodies - that release a glycolipid by exocytosis to waterproof the skin

- forms a barrier between surface cells and deeper layers of the epidermis

- cuts off surface strata from nutrient supply

Front 18

Stratum Lucidum

Back 18

Thin translucent zone seen only in thick skin (palms and soles)

- Keratinocytes are packed with eleidin - a precursor to keratin

- It does not stain well

- Cells have no nucleus or organelles

Front 19

Stratum Corneum

Back 19

15 to 20 layers of dead keratinized cells

Caluses: Increase in thickness of stratum corner due to chronic friction

Desquamation: Shedding of dead cells from surface

Front 20

Superficial and deep skin layers

Back 20

Superficial layers

1) Stratum Corneum

2) Stratum Lucidum

3) Stratum Granulosum

Deep layers

1) Stratum Spinosum

2) Straum Basale

Front 21

Life history of keratinocytes

Back 21

1) Produced by stem cells in stratum basal

- Daughter cells through mitosis

2) New cells push others toward surface

- cells grow flat and fill with vesicles and pigment

3) Cells filled with keratin and melanin

- forms water barrier

4) Cells die and exfoliate

5) 28 to 30 days timeline

Front 22

Skin thickness

Back 22

Varies by location

- Eyelids thinest

- Palmar and plantar surfaces thickest

Primarily dependent on thickness of stratum corner

Front 23

Genetic Factors

Back 23

1) Melanin production: 16 genes for skin

- default setting from conception

2) Thickness

- By location

- Changes after grafting

Front 24

Environmental factors

Back 24

1) Melanin production: UV light for skin

- Immediate increase in production

- Quick return to default

- Tan lost in 2 to 4 weeks

2) Thickness: > fraction - > Stratified layer

- Decreased speed of transit through layers

Front 25

Friction Blisters

Back 25

1) Separation of epidermis layers

2) Usually at stratum spinosum

3) Fill with tissue fluid and cell plasma

4) Blood blisters indicate damage to dermis

Front 26

Dermis - Connective tissue layer

Back 26

1) Thickness = 0.6mm to 3mm

2) Composition - Collagen, elastic and reticular fibroblasts

- Conservative: Low turnover rate

3) Dermal papillae - extensions of the dermis into the epidermis

- forms the ridges of the fingerprints

4) Layers

- Papillary layer

- Reticular layer is deeper part of dermis

Front 27

Dermis is impregnated with

Back 27

1) Sensory neuron receptors

2) Fibroblasts

3) Blood vessels

4) Hair follicles

5) Sweat glands

6) Arrector pili muscles

7) Immune cells and mast cells

***Tattoos: Ink injected into upper layers

Front 28

Aging Skin

Back 28

1) Thinner, less collagen, elastin and GAGs

2) Stretch marks: Torn dermis

3) Wrinkles: Collagen and elastin damage

4) Age spots: sun damage, excess melanin production

Front 29

Hypodermis

Back 29

1) Subcutaneous tissue/ superficial fascia

2) Mostly adipose

Hypodermis injection (SubQ)

- Highly vascular

Front 30

Hypodermic functions

Back 30

1) Energy reservoir

2) Thermal insulation

3) Appearance

4) Protection from shearing

Front 31

Wound Healing

Back 31

1) Hemostasis: Clotting, vasoconstriction

2) Inflammation: Cytokines, immune cells, macrophage cleanup

3) Proliferation (granulation): Angiogenesis, Fibroplasia, Granulation tissue, Epithelial regenration

4) Remodeling: Wolff's law

- Bony tissue adapts to the forces exerted on them

Front 32

Abnormal skin colors

Back 32

1) Cyanosis

2) Erythema

3) Jaundice

4) Bronzing

5) Pallor

6) Albinism

7) Hematoma

Front 33

Cyanosis

Back 33

Blueness from deficiency of oxygen in the circulating blood (cold weather)

e.g. Blue lips

Front 34

Erythema

Back 34

Redness due to dilated cutaneous vessels (anger, sunburn, embarrassment)

Front 35

Jaundice

Back 35

Yellowing of skin and sclera due to excess bilirubin in blood (liver disease)

Front 36

Bronzing

Back 36

Golden-brown color of Addison Ds

- (deficiency of glucocorticoid hormone - Adrenal glands)

Front 37

Pallor

Back 37

Pale color from lack of blood flow (shock, rage)

Front 38

Albinism

Back 38

A genetic lack of melanin

Front 39

Hematoma

Back 39

A bruise (visible clotted blood)

Front 40

Skin Markings - Hemangiomas (Birthmarks)

Back 40

Discolored skin caused by benign tumors of dermal blood capillaries

- strawberry birthmarks disappear in childhood

- port wine birthmarks lasts for life

Front 41

Skin markings - Freckles

Back 41

Piebald suntan from irregular distribution of melanocyte (genetic)

Front 42

Skin markings - Nevi (moles)

Back 42

1) Clusters of Melanocytes

2) Benign Neoplasms

3) Monitor for change

Front 43

Keratoses

Back 43

1) Actinic: Precancer

- Sun damage

- Crusty

2) Seborrheic: Benign

- Age related

- " Liver spots"

Front 44

Psoriasis

Back 44

1) Chronic inflammation of skin

2) Autoimmune

3) Genetic component

4) Overproduction of keratinocytes

Front 45

Scarring

Back 45

1) Collagen plug formed by Fibroblasts

2) Replaces normal dermis and epidermis

3) Subsequent remodeling

4) No hair, sweat glands, basal layer

5) Keloid: Hypertrophic collagen in scarring

- Raised thickened tissue

Front 46

Characteristics of human hair

Back 46

1) Hair - composed of hard keratin

- disulfide bridges between molecules

2) Hair found almost everywhere

- differences between sexes, or individuals is difference in texture, color and shape of hair

Front 47

Body hair types

Back 47

1) Lanugo - fine, unpigmented fetal hair

2) Vellus - fine, unpigmented hair of children and women

3) Terminal hair - coarse, long, pigmented hair or scalp and skin

Front 48

Structure of hair

Back 48

Hair shaft is filament of keratinized cells

- shaft = above skin

- root = within follicle

- in cross section: medulla, cortex and cuticle

Front 49

Hair follicle

Back 49

Follicle is oblique tube within the skin

- bulb is where hair originates

- vascular tissue (papilla) in bulb provides nutrients

- continuous with epidermal layer

Front 50

Structure of Hair follicle

Back 50

1) Epithelial root sheath

2) Connective tissue root sheath

3) Hair receptors entwine each follicle

4) Piloerector muscle

- goose bumps

Front 51

Hair texture

Back 51

Cross-sectional shape determines body

1) Round = straight

2) Oval = wavy

3) Flat = kinky

Denaturable: set and perm

Front 52

Hair Color

Back 52

1) Eumelanin: Black and Brown

2) Pheomelanin: Orange and Yellow

3) Gray/White: Decreased Melanin

- Age

- Stress

- Illness

Front 53

Hair Cycle

Back 53

3 repeating cycles

1) Anagen is growth stage (90% scalp follicles)

- Lasts 6 to 8 years in young adults

2) Catagen is shrinking follicle

- Lasts 2 to 3 weeks

3) Telogen is resting stage

- Lasts 1 to 3 months

New Anagen phase: Old hair pushed out

Front 54

Thinning or Baldness

Back 54

Alopecia

Front 55

Pattern Baldness

Back 55

Genetic

1) Sex influenced trait. Dominant in males and recessive in females

Hormonal

2) Testosterone sensitivity

Front 56

Hirsutism

Back 56

Excessive hair growth

- hormone imbalance (ovary or adrenal cortex problem)

Front 57

Functions of hair

Back 57

1) Body hair - too thin to provide warmth

- alerts us to parasites crawling on skin

2) Scalp hair - heat retention and sunburn cover

3) Beard, pubic and axillary hair - indicates sexual maturity and help distribute sexual scents

4) Guard hairs and eyelashes - prevent FB from getting into nostrils, ear canals or eyes

5) Expression of emotions with eyebrows

Front 58

Nails

Back 58

Derivative of stratum corneum

- Densely packed cells filled with hard keratin

Front 59

Nail growth

Back 59

1) New cells added by mitosis in the germinal matrix

2) Nail plate is visible part of nail

Damage to Germinal matrix: Loss of nail and regrowth

Front 60

Nail growth rate

Back 60

1) Fingernails = 1 mm per week

2) Toenails = 1 mm per month

Front 61

Nail Pathologies

Back 61

1) Vitamin A, D, B or Mineral Fe, Ca deficiency: Dry, brittle, misshapen, discolored nails

2) Fungus: Thick, crumbly, irregular, discolored

- Tx: topical (ineffective) or systemic (liver toxicity)

Front 62

Sweat Glands

Back 62

Eccrine glands

Density varies:

1) Palms - 370/sq cm

2) Forehead - 170/sq cm

3) Back - 60/sq cm

Front 63

Sweat gland functions

Back 63

1) Thermoregulation

2) Excretion

3) Protection

Front 64

Sweat glands containts

Back 64

1) Primarily water and salt

2) Urea

3) Lactic acid

pH = 4-6 - Hostile environment for bacterias, viruses

Front 65

Sebaceous glands (exocrine gland)

Back 65

1) Highest concentration in face and scalp

2) Absent in palms and soles

Front 66

Sebaceous glands function

Back 66

1) Produces oily secretion

2) Lubricant for skin and hair

3) Bacteria Fodder

4) Bloakage associated with acne

Front 67

Apocrine glands

Back 67

1) Type of sweat gland associated with certain hair follicles

2) Located in axillary, pubic, nasal, nipples, ears

Front 68

Apocrine glands functions

Back 68

1) Bacterial digestion of exudate produces scent

2) Produces secretion in response to emotions, stress, sex

3) Contributes to body odor

4) Pheromones

Front 69

Ceruminous Glands

Back 69

1) Found only in external ear canal

2) Their secretion combines with sebum to produce ear wax

3) Waterproofing - keeps the eardrum flexible

4) Bitterness repels mites and other pests

Front 70

Mammary glands

Back 70

1) Subcutaneous structures in both males and females

2) Secondary sex characteristics

3) Estrogen induces glandular (Apocrine) development

4) Testosterone inhibits development

5) Oxytocin induces expression of milk

Front 71

Oxytocin

Back 71

1) Neurohypophyseal (Pituitary) Hormone

2) Released into bloodstream

Front 72

Oxytocin roles

Back 72

1) Sex

2) Lactation

3) Childbirth

4) Wound healing

5) Social interactions

Front 73

Skin Cancer

Back 73

Induced by UV rays of the sun

Front 74

Skin cancer types

Back 74

1) Basal cell carcinoma (least dangerous)

2) Squamous cell carcinoma

3) Malignant melanoma (most deadly)

Front 75

Basal cell carcinoma

Back 75

1) Least dangerous

2) Arises from stratum basal and invades dermis

Front 76

Squamous cell carcinoma

Back 76

1) Arises from keratinocytes in stratum spinosum

2) Metastasis to the lymph nodes can be lethal

Front 77

Malignant melanoma

Back 77

1) Most deadly

2) Arises from melanocytes of a preexisting mole

3) ABCD - Asymmetry, irregular Border, Color mixed and Diameter over 6mm

Front 78

First Degree burn

Back 78

1) Epidermis only, Basal lamina intact

2) Sunburn

Front 79

Second Degree burn

Back 79

1) Extends into Dermis

2) Blistering, dermal damage, repair

Front 80

Third Degree burn

Back 80

1) Entire Dermis

2) Scarring, contraction, infection, grading & Dermal destruction

Front 81

Fourth Degree burn

Back 81

1) Subcutaneous, muscle, bone

2) Surrounding tissue and vascular loss, amputation

Front 82

Third-degree burns require

Back 82

Skin grafts

Front 83

Graft options

Back 83

1) Autograft - Tissue from patient

2) Isograft - Tissue from identical twin

3) Culdtured keratinocyte patches

Front 84

Temporary grafts

Back 84

1) Immune response

2) Homograft (allograft) - from unrelated person

3) Heterograft (xenograft) - from another species

4) Amnion from after birth

5) Artificial skin from silicone and collagen

Front 85

Pressure ulcers (Decubitus)

Back 85

1) Stage 1 - redness after pressure removed

2) Stage 2 - damage to, but not thru dermis

3) Stage 3 - damage thru dermis into SubQ fat

4) Stage 4 - damage beyond fascia into underlying muscle, bone, ligament, tendon