Integumentary System

Integumentary System ST110

Concorde Career College, Portland

Objectives

Define the term integument Describe the functions of the

integumentary system List and identify the structures of the

integumentary system and describe the function of each

Identify the layers of the skin

Objectives

List the appendages of the integumentary system and describe the function of each

Describe the mechanism by which the integumentary system helps to maintain homeostasis

Objectives

Describe common diseases, disorders, and conditions of the integumentary system including signs and symptoms, diagnosis, and available treatment options

Demonstrate knowledge of medical terminology related to the integumentary system verbally and in the written form

General Information

The term integument means covering The integumentary system consists of

the skin and its appendages The skin is a membrane because it is a

thin layer of tissue that covers the entire body

General Information Largest organ First line of defense Protects against the

invasion of microbes Barrier for ultraviolet

rays Covers and protect

external surface & internal structures

Aids in control of body temperature

Sense of touch- organ activity

Self-repairing/Regenerating

Waterproof barrier Manufacturing of Vitamin

D Drug absorption

Interesting Facts

Contents of one square centimeter

of skin!

Three Main Functions of the Skin

1. Protection

2. Regulation

3. Receptors

Function - Protection First line of defense from microbes,

chemicals, UV rays…

Melanin protects us to a degree, however repeated & long exposure to the sun w/o protection can lead to skin cancer

Function - Regulation Body Temperature

› Radiation › Conduction › Convection › Hypothermia › Hyperthermia

Function - Regulation Vitamin D

› UV rays from the sun stimulate the production of Vitamin D progenitor molecules by the skin

› These molecules travel to the liver and kidneys where they mature into Vitamin D

› Essential for metabolism of calcium

Function - Receptors Sensation

› Touch/pressure› Pain› Warmth› Cold

Nerve endings act as receptors for sensation› Thermoreceptors: Temperature › Nociceptors: Pain› Mechanoreceptors: Touch/pressure/stretch

Receptors send messages to the cerebral cortex for interpretation

Functions - Receptors› Merkel Discs (Cells): touch impulses

› Pacinian Corpuscles: sense pressure & vibrations

› Meissner’s Corpuscles: sense changes in texture & slow vibrations

› Ruffini Corpuscles: senses slipping and stretching

› Krause end Bulbs aka mucocutaneous Corpuscles: detect temperature

Structures of the Integumentary System

Epidermis Dermis

› Subcutaneous Layer Appendages of the skin

› Sweat glands› Sebaceous glands› Hair› Nails

Skin Layers

Epidermis

squamous epithelium (scale like) “tightly packed together”

Epidermis Outer most layer of the skin and is

avascular Composed of Stratified Squamous

Keratinized Epithelium › Keratinocytes –epidermal cells

Does not contain blood vessels

Layers of the Epidermis

1. Stratum corneum2. Stratum lucidum3. Stratum

granulosum4. Stratum

spinosum5. Stratum basale

Integumentary SystemStratum Germinativum

Deepest layer Contains the only cells that perform

mitosis Also called the stratum basale

› The layer that rests on the superficial fascia Contains melanocytes - melanin is

produced in this layer

Integumentary SystemStratum Spinosum

Many layers Spiny-shaped cells

Integumentary SystemStratum Granulosum

Two or three layers thick Flattened cells Granules accumulate here

Integumentary SystemStratum Lucidum

Just below the stratum corneum Cells are transparent and flat One or two layers thick

Integumentary SystemStratum Corneum

Outermost layer of the epidermis Consists of dead cells converted to protein Surrounded by lipids Constantly being sloughed off

› Dandruff The thickness of the layer is determined by

the amount of stimulation or pressure› Callus-area exposed to much abrasion and friction› Corn-abrasions on bony prominences of the foot

Dust Mites

Dermis Deeper of the two layers of skin Aka corium Located below the epidermis Contains capillary vessels, nerves, hair follicles,

and glands Composed of loose fibrous connective

tissue Divided into 2 layers:

› Papillary layer Dermal papillae

› Reticular layer

Integumentary SystemDivisions of the

Dermis

1. Papillary layer

2. Reticular layer

Dermis

Cells loosely packed together (mostly connective tissue)

Subcutaneous Tissue Layer Aka Hypodermis Connects dermis to underlying

structures Consists of areolar and adipose

tissue› Adipocytes: cells that store fat

Insulates from cold Acts as a cushion for internal organs

Hair Characteristic of all mammals Amount of hair is related to genetic factors Growth

› The deepest layer of cells is responsible for mitosis and continuously is pushed up from the basement membrane

› Hair growth begins in the hair bulb› Scalp Hair typically grows for 3 years and rests

for 1 to 2 years› The presence of the hair follicles allows for new

growth

Hair Hair areas:

› Cuticle-outermost portion› Cortex-underneath the cuticle› Medulla-central portion› Shaft-visible portion› Hair root-inside hair follicle in the stratum

germinativum› Arrector Pili Muscle-attached to hair follicle

Hair Texture

› Genetics control if the hair is curly, straight, kinky

Color› Determined by heredity and some

environmental factors› Gray hair starts to occur when pigment is

absent in the cortex

Hair

Hair Alopecia (al-uh-pee-shee-uh)= The

partial or complete absence of hair from areas of the body where it normally grows; baldness

Hirsutism (hur-soo-tiz-uhm) = Excessive hairiness, especially in women

Hair Root and Sheaths

Nails

Medical Term onxy/onych = nail

Nails Very hard keratinized cells Nail areas

› Lunula-white half-moon shaped area at nail base

› Nail body-visible area› Nail root-inside the nail bed› Cuticle-a layer of stratum corneum extending

over the nail body› Free edge

Nails

Sebaceous Glands Along the walls of hair follicles Produce sebum-oily substance that

lubricates skin Vernix caseosa Acne

Sebaceous Glands Located throughout the body

› Largest # in face Very active in puberty (due to androgen)

› Excess of sebum within the glands› Glands become clogged (blackhead)› Easily infected (pimple)

Meibomian Glands:› Largest sebaceous glands › Located in the eyelids

Sudoriferous GlandsSweat Glands (Sudoriferous Glands) Two main types

› Merocrine› Apocrine

Found in most body regions except margins of lips and head of penis

Consist of a secretory portion and an excretory duct

Body Odor Modified glands

› Ceruminous, ciliary, mammary

Trivia The odor associated with apocrine

gland secretion is not caused by the secretion itself… it is caused by the contamination and decomposition of the secretion by skin bacteria!!!

Ceruminous Glands Located in the dermis of the auditory

canal Secrete yellow substance called

Cerumen (ear wax)› Prevents auditory canal and tympanic

membrane from drying out

Cerumen

Blood Supply Arterioles supplying the skin

help maintain body temperature Vasodilate: increasing blood flow

to the dermis, transferring heat to the skin surface to escape from the body

Skin Pigmentation Melanin concentrations determine the

variations in skin color of individuals and races as well as Suntans and Freckles

Melanin protects keratinocytes from the carcinogenic ultraviolet rays of the sun

Albinism – recessive gene or mutation that prevents the production of melanin. Therefore the individual has no skin color

Cyanosis - Caused by a lack of blood oxygen or decreased blood flow; turns skin a bluish-gray color

Immune Response of the Skin

Langerhans cells › phagocytize bacteria that enter

through breaks in the skin › Attack cancerous cells › Attract T-cells important in allergic

reactions Allergic contact dermatitis

Common Disorders and Diseases

Ringworm› Fungus

Athlete’s foot Jock itch


Psoriasis

› Unknown cause› Red patches covered

with thick, dry scales› Overproduction of

epithelial cells


Warts› Human papillomavirus

Uncontrolled growth of epidermal tissue Direct contact

Cold Sores› Herpes simplex virus› Can by active or inactive


Herpes Simplex Virus I


Impetigo› Staphylococcus aureus› Blisters erupt with pus› Direct contact, highly contagious

Shingles› Herpes zoster› Remains inactive until triggered› Vesicular skin eruptions


Impetigo


Vitiligo› Irregular patches of non-pigmented skin

Skin Cancer› UV radiation› Types

Basal cell carcinoma-topical, easily treated Squamous cell carcinoma-giant tumor that contains

much keratin, can spread Malignant Melanoma-most dangerous, starts with a

mole, as a dark nodule, or spreading flat lesion

Basal Cell Carcinoma

Squamous Cell Carcinoma

Malignant Melanoma

Skin Cancer

Skin Cancer Kaposi sarcoma is a rare form of skin

cancer that is usually associated with AIDS

Kaposi Sarcoma


Folliculitis


Contact dermatitis(poison oak)


Jaundice


Ecchymosis


Venous Star


Varicose Vein

Burns One of the most serious and frequent

problems to affect the skin Heat or cold Chemicals, gases, electricity, &

radiation Classified by degree indicating depth of

burn

Burns

Burn Severity

First Degree Burns Partial thickness burn 1st degree affects only the epidermis Usually heals in 1 week No scaring or blisters Symptoms

› Slight swelling › Erythema › Pain

First Degree Burns

Second Degree Burns 2nd degree involves the epidermis and the dermis

› Superficial: heal In about 2 weeks No scar

› Deep Longer heal time Scar May require debridement May require skin grafting Prone to infection (strict aseptic technique)

Symptoms › Extreme pain › Blisters › Swelling

Second Degree Burns

Third Degree Burns 3rd degree burns involve all the skin

layers (+) subcutaneous tissue layer Symptoms

› Shock› Dehydration› Possibly pain

Third Degree Burns

Eschar

Fourth Degree Burns Called Char Burns Involve: muscle, tendon, possibly

damage to bone Treatment: Emergency debridement,

irrigation, and dressings

Fourth Degree Burns

Burn Treatment Treatment and recovery depend on the

total area involved and the severity of the burn

“Rule of Nines”

Determines the Extent of a Burn Injury

Skin Grafting

Skin Grafting

Burn Contracture

Burn Contracture

Aging of the Skin Aging Thickness of dermis decreases Skin becomes less elastic Fat loss from hypodermis Sagging wrinkling of the skin Decreased melanin production Decreased blood flow to skin Decreased Vitamin D production Result Sagging and wrinkling of the skin Become more sensitive to cold Hair becomes gray Skin becomes thinner and translucent Bones become brittle

Pressure Sore

Decubitis ulcer (dih-kyoo-bi-tuhs)= Pressure sore, bed sore

Documents

Integumentary System