Transcript Ch 5 BS and CH 12 MT

Chapter 12 Medical Terminology
and
Chapter 5 Body Structures:
THE INTEGUMENTARY SYSTEM
FUNCTIONS OF THE
INTEGUMENTARY SYSTEM – THE
OUTER COVERING OF THE BODY – THE SKIN
 Waterproofs body and prevents water loss
 Intact skin plays important role in immune
system
 Receptor for the sense of touch
 Screens out harmful UV rays from sun while
synthesizing Vitamin D
STRUCTURES OF THE
INTEGUMENTARY SYSTEM
 Skin (derma or cutaneous)
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Epidermis
Dermis
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Tissues within the dermis
Subcutaneous Layer
ASSOCIATED STRUCTURES OF
THE INTEGUMENTARY SYSTEM –
AND THEIR FUNCTIONS
 Sebaceous glands –
 secretes sebum to lubricate skin and discourage
bacteria growth
 Sweat glands –
 Help regulate body temp and H2O content by secreting
sweat – some metabolic waste secreted
 Hair –
 Helps control heat loss
 Nails –
 Protects dorsal surface of distal phalanges
ASSOCIATED STRUCTURES
THE EPIDERMIS –
MADE UP OF SEVERAL LAYERS OF EPITHELIAL CELLS
 Outer most layer of the skin – epidermis
 Does not contain any blood vessels or
connective tissue
 Dependent on lower layers for nourishment
 Cells are produced in lower (basal) layer and
push upwards – when they reach the surface,
they die and fill with keratin

Keratin: water-repellent protein
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Soft keratin: primary component of epidermis
Hard keratin: found in hair and nails
THE EPIDERMIS
www.aatb.org/aatbskinbank/ mission_statement.htm
coolshade.tamu.edu/ skin_2.html
Cells and Layers of the Epidermis
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Squamous (scalelike) epithelial tissue –
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upper layer, consists of flat, scaly cells that are
continuously sloughed off
Basal layer – Also contains melanocytes
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Melanocytes: cells that produce and contain dark
brown-black pigment (melanin) –
Type and amount of melanin determines color of
skin
Melanin also protects skin against harmful UV
rays of the sun
THE DERMIS –
THICK LAYER OF LIVING TISSUE DIRECTLY BELOW EPIDERMIS
 Contains:
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
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Connective tissue
Blood and lymph vessels
Nerve fibers: endings receive impulses enabling
body to recognize sensory stimuli like touch, temp,
pain, and pressure
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Hair follicles
Sebaceous and Sweat glands
TACTILE: pertaining to touch
PERCEPTION: the ability to recognize
sensory stimulus
www.bmb.psu.edu/.../tissues/ tissnote.htm
TISSUES WITHIN THE DERMIS –
Collagen: means glue, contains tough but flexible protein material
Also found in bone, cartilage, tendons, and ligaments
Mast Cells: respond to injury or infection by producing heparin and
histamine
 Heparin: released in response to injury, is an anticoagulant
 Histamine: released in response to allergens, causes itching and
increased mucous secretion
THE SUBCUTANEOUS LAYER –
CELLULITE = NONTECHNICAL TERM FOR SUBCUE FATTY DEPOSIT
 Just below dermis
 Connects skin to
surface muscles
 Made up of loose
connective tissue and
adipose (fatty) tissue
 Lipocytes: fat cells,
predominant in the
subcutaneous layer
where they
manufacture and store
large quantities of fat
THE SEBACEOUS GLANDS –
CLOSELY ASSOCIATED WITH HAIR FOLLICLES, LOCATED IN DERMIS
 Secrete sebum which is released through
ducts opening into the hair follicles
 Sebum lubricates skin and discourages the
growth of bacteria on the skin = slightly acidic
 What glands are considered part of the
Integumentary system as modified
sebaceous glands but are also part of the
Reproductive system??
 MAMMARY GLANDS
THE SWEAT GLANDS –
TINY GLANDS FOUND ON ALMOST ALL BODY SURFACES
 Most numerous in palms of hands and soles
of the feet, forehead, and armpits (axilla)
 Pores: openings on the surface of the skin
through which sweat gland ducts open
 Sweat: perspiration – secreted by sweat
glands
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Made up of 99% water + salt + metabolic waste
Perspiration: excretion of excess H2O – cools
body as sweat evaporates into air
 What causes body odor associated with sweat?
 INTERACTION SWEAT + BACTERIA ON SKIN
THE HAIR – FIBERS OF TIGHTLY FUSED, DEAD
PROTEIN CELLS FILLED WITH HARD KERATIN
 What factors determine hair color??
 Amount of melanin produced by the
melanocytes that surround core of the hair
shaft
 Hair follicles: sacs that hold root of hair fibers

Arrector pili: (erector muscles) tiny muscle
fibers attached to hair follicles that, upon
contraction, cause the hair to stand up (i.e.
cold or fright = goose bumps) reducing heat
loss through skin
THE NAILS – UNGUIS, KERATIN PLATE COVERING
DORSAL SURFACE OF DISTAL PHALANGES
 Each nail consists of the following:
 Nail body – translucent, made up
of hard keratinized plates of
epidermal cells
 Nail bed – joins nail body to
underlying connective tissue,
nourishes the nail
 Blood vessels give nail bed it’s
pink color
 Free edge – the portion not
attached to the nail bed, extends
beyond the tip of the phalanx
MEDICAL SPECIALTIES
 Dermatologist

Diagnosing and treating disorders of the skin
 Cosmetic surgeon – Plastic Surgeon
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Restoration and repair
PATHOLOGY OF THE
INTEGUMENTARY SYSTEM
 Acne vulgaris: inflammatory disease with
pustular eruptions of the skin in or near the
sebaceous glands
 Comedo: aka blackhead - sebum plug
exposed to air = oxidizes
 Seborrheic Dermatitis: aka dandruff – scaling
of the scalp due to inflammation of upper
layers of the skin
Acne vulgaris
anhidrosis
Comedo or
blackheads
Seborrheic
dermatitis
Sebaceous cyst
SWEAT GLAND DISORDERS
 Anhidrosis: lacking sweat
 Hyperhidrosis: excessive sweat
 Diaphoresis: profuse, but not necessarily
excessive sweating
 Miliaria: heat rash/prickly heat – inflammation
caused by trapped sweat
HAIR”Y “DISORDERS
 Excessive Hairiness
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Hirsutism: appearance of male body or facial
hair patterns in the female
 Abnormal hair loss
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Alopecia: baldness, partial or complete
Female pattern baldness: thinning in front and
on sides, sometimes on crown
Male pattern baldness: receding hairline from
front to the back until only a horseshoe
shaped area remains in back and temples
hirsutism
folliculitis
alopecia
PIGMENTATION
 Albinism: deficiency or absence of pigment in
skin, hair, eyes due to abnormality in
production of melanin
 Chloasma: mask of pregnancy – brownish
colored spots on face
chloasma
melanosis
SURFACE LESIONS –
PATHOLOGIC CHANGE OF TISSUES DUE TO DISEASE OR INJURY
 Described by appearance, location, color, and
size (cm)
 Contusion: does not break skin, swelling,
discoloration, and pain
 Ecchymosis: bruise – purple discoloration
caused by hemorrhaging within the skin
 Nodule: solid bump, may be felt within skin or
may be raised as if it had formed below the
surface and pushed upward (i.e. cyst)
 Papule: solid raised skin lesion < 0.5 cm in
diameter (i.e. warts, insect bites, and skin
tags)
SURFACE LESIONS OF THE SKIN
FLUID-FILLED LESIONS
LESIONS THROUGH THE SKIN
WARNING!!
 THE FOLLOWING PICTURES MAY BE
DIFFICULT FOR VIEWING
 VIEW AT YOUR DESCRETION
ecchymosis
petechia
bruise
purpura
contusion
dermatitis
Birthmark
vascular
Port-wine stain
Nodular skin lesions
Open lesions
coccidioidomycosis
Ulcers
Skin ulcer post spider bite