Transcript THE INTEGUMENTARY SYSTEM

THE INTEGUMENTARY
SYSTEM
Skin and its Derivatives
Medical Terminology
Combining Forms
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Cutane/o, derm/o, dermat/o
skin
Hidr/o
sweat
Kerat/o
horny tissue, hard
Onych/o, ungu/o
nail
Seb/o
sebum (oil)
Trich/o
hair
Know anatomic locations and meanings! Diagrams!
Combining forms commonly used with
integumentary system terms
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Aut/o
Bi/o
Coni/o
Heter/o
Myc/o
Necr/o
Pachy/o
self
life
dust
other
fungus
death (cells, body)
thick
(combining forms continued)
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Rhytid/o
Staphyl/o
Strept/o
Xer/o
wrinkles
grapelike clusters
twisted chain
dry
Integumentary system prefixes
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epi intra para per sub -
on, upon, over
within
beside, beyond around
through
under, below
Integumentary system suffixes
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-a
noun suffix, no meaning
-coccus (pl. cocci) berry-shaped (bacterium)
-ectomy
excision or surgical removal
-ia
diseased or abnormal state,
condition of
• -itis
inflammation
• -malacia
softening
Integumentary system suffixes (cont.)
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-opsy
-phagia
-plasty
-rrhea
-tome
view of, viewing
eating or swallowing
surgical repair
flow, excessive discharge
instrument used to cut
Remember…
Four basic types of tissue
*Epithelium – epidermis
*Connective tissue - dermis
*Muscle tissue
*Nervous tissue
TYPES OF MEMBRANES
Epithelial + Connective Tissue (CT)
Serous
Cutaneous
Mucous
Connective Tissue (CT)
Synovial
Line body
cavities that
have no
openings to
outside.
Secrete watery
fluid.
Simple
squamous
epith + loose
CT
Serous Membranes
Serous membranes
• Types
– Parietal—line walls of body cavities
– Visceral—cover organs found in body
cavities
• Examples
Pleura—parietal and visceral layers line
walls of thoracic cavity and cover the lungs
(Disease) Pleurisy—inflammation of the serous
membranes that line the chest cavity and cover the
lungs
Serous membranes
Peritoneum—parietal and visceral layers
line walls of abdominal cavity and cover the organs in
that cavity
(Disease) Peritonitis—inflammation of the serous
membranes in the abdominal cavity that
line the walls and cover the abdominal
organs
Mucous Membranes
• Line cavities that lead to outside.
• Secrete mucus for protection.
• Epithelium + Loose CT
Serous, Mucous Membranes
Cutaneous Membrane –
THE SKIN!!!
Stratified squamous epithelium + CT + muscle + nervous tissue
(Composing about 16% of your body weight!!!! More info later!)
Synovial Membrane
Lines joint cavities at articulations.
Loose CT + elastic fibers + adipose tissue
Functions of Skin
• Protects from injuries
• Acts as barrier and regulates what
enters/leaves body.
• Regulates body temperature.
• Synthesizes, stores vitamins.
• Sensory functions
EPIDERMIS
Stratum corneum
Stratum lucidum**
Stratum granulosum
Stratum spinosum
Stratum basale (germinativum)
**Thick skin only (Where would this be???)
Epithelium: layers (on left) and cell types (on right)
Stratum Basale
• Lowest epidermal layer, single row of
DIVIDING cells attached to dermis
• Good nutrient supply
• Cuboidal, columnar in shape
• youngest cells; move to upper epidermis in
27 days.
• contains pigment cells called melanocytes,
which produce the brown pigment melanin
Melanocyte
Melanocyte
• Produces melanin
for protection from
UV radiation.
• Responsible for
skin color.
• Melanoma.
Melanoma
Stratum Basale
Stratum Spinosum
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Living cells
Dividing (lots of MITOSIS)
8-10 cells thick
Polygonal in appearance
Stratum Spinosum
Stratum Granulosum
• Poor nutrient supply.
• Layers of flattened keratinocytes producing
keratin (hair and nails made of it also).
• 3-5 cells thick.
• No cell division.
• Keratin accumulates.
Stratum Lucidum
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Found only in very thick skin.
Translucent.
Highly keratinized.
Dead cells
Stratum Corneum
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25-30 “dead” cells thick.
Cells are filled with keratin and hardened.
Sloughed off.
Outer most layer of epidermis.
Epidermis and dermis of (a) thick skin and (b) thin skin
(which one makes the difference?)
Layer
Stratum
Basale
Stratum
Spinosum
Stratum
Granulosum
Stratum
Lucidum
Stratum
Corneum
Superficial
or Deep
Layer?
Characteristics
Are cells Seen in
keratinized THIN
in this
skin
layer?
too?
Layer
Stratum
Basale
Superficial
or Deep
Layer?
Deepest
Characteristics
A lot of mitosis here
Single row of cells
Youngest cells
Melanocytes
Stratum
Spinosum
Living, dividing cells
8-10 cells thick
Stratum
Granulosum
Poor nutrients, no cell
Division
Keratinocytes make keratin
Stratum
Lucidum
Stratum
Corneum
Only in thick skin
Highly keratinized,
dead cells
Most
Superficial
25-30 dead cells thick
Cells filled with keratin,
sloughed off
Are cells Seen in
keratinized THIN
in this
skin
layer?
too?
NO
NO
YES
YES
YES
NO
DERMIS
A. Strong, flexible connective tissue: your “hide”
B. Cells: fibroblasts, macrophages, mast cells, WBCs
C. Fiber types: collagen, elastic, reticular
D. Rich supply of nerves and vessels
E. Critical role in temperature regulation (the vessels)
F. Two layers (see next slides)
1. Papillary – areolar connective tissue; includes dermal papillae
2. Reticular – “reticulum” (network) of collagen and reticular
fibers
DERMIS
Irregular Dense Connective Tissue
Collagenous fibers
*Dermis layers
*Dermal pap
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Dermis
Dermis also contains
nerve endings,
muscle fibers,
hair follicles,
sweat and sebaceous
glands,
and many blood
vessels
Dermis (continued)
Birthmarks—malformation of dermal blood vessels
Strawberry hemangioma
Port-wine stain
Dermal-epidermal junction
*is specialized area between two
primary skin layers
* Blisters—caused by breakdown of
union between cells of primary layers
of skin
Fingerprints, palmprints, footprints
A. Dermal papillae lie atop dermal ridges and elevate
the overlying epidermis into epidermal ridges
B. Actually are “sweat films” because of sweat pores
C. Genetically determined
Flexion creases
• Deep in the dermis, from continual
folding
The dermis is the receptive
site for the pigment of tattoos
Fibers
A. Collagen: strength and resilience
B. Elastic fibers: stretch-recoil
– Striae: stretch marks
– Numbers decrease with age contributing to wrinkles
C. Tension lines (or lines of cleavage)
– The direction the bundles
of fibers are directed
Skin appendages
• Derived from epidermis but extend into dermis
• Include
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Nails
Hair and hair follicles
Skin glands
Sensory receptors
Nails
• Hard keratin
• Corresponds to hooves and claws
• Grows from nail matrix
Hair and hair follicles: complex
Derived from epidermis and dermis
Everywhere but palms, soles, nipples, parts of genitalia
*“arrector pili” is smooth muscle
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Hair papilla
is connective
tissue________________
Hair bulb: epithelial
cells surrounding
papilla
• Functions of hair
– Warmth – less in man than other mammals
– Sense light touch of the skin
– Protection - scalp
• Parts
– Root imbedded in skin
– Shaft projecting above skin surface
• Make up of hair – hard keratin
• Three concentric layers
– Medulla (core)
– Cortex (surrounds medulla)
– Cuticle (single layers, overlapping)
• Types of hair
– Vellus: fine, short hairs
– Intermediate hairs
– Terminal: longer, courser hair
• Hair growth: averages 2 mm/week
– Active: growing
– Resting phase then shed
• Hair loss
– Thinning – age related
– Male pattern baldness
• Hair color
– Amount of melanin for black or brown; distinct form of
melanin for red
– White: decreased melanin and air bubbles in the medulla
– Genetically determined, though influenced by hormones
and environment
Alopecia hair loss
Hair Follicle
Hair Follicles
Skin Glands
Types
• Sweat or sudoriferous
• Sebaceous
Types of Sweat Glands
(Sudoriferous Glands)
• Merocrine glands: release fluid by exocytosis
• Eccrine (respond to temperature)
– Most common
– Secretion is mostly water with solutes
– Cools body down; heat regulation
• Apocrine (respond to pain, emotions)
– Develops scent as bacteria metabolize secretion
– Stimulated when frightened, during pain, during
emotional upset
Sweat glands
• Entire skin surface
except nipples and
part of external
genitalia
• Prevent overheating
• 500 cc to 12 l/day! (is
mostly water)
• Humans most
efficient (only
mammals have)
• Produced in response
to stress as well as
heat
Sweat Gland
Sweat Gland Exiting the Skin
Eccrine Gland
Sebaceous Gland
» Secrete oil or sebum for hair and skin
» Levels and amounts of secretion
regulated by sex hormones; increases
during adolescence
» Sebum in sebaceous gland ducts may
darken to form a blackhead
» Acne vulgaris inflammation of
sebaceous gland ducts
Sebaceous Gland
Exocrine gland
Associated with follicle
Secretes oily substance
Holocrine gland
Sebaceous Gland
Sensory Structures of Dermis
• Deep touch/pressure: Pacinian
corpuscles
• Light touch/pressure: Meisner’s
corpuscles
• Warm temperature: Free nerve
endings
• Cold temperature: Free nerve endings
• Pain: Free nerve endings
Hypodermis
• “Hypodermis” (Gk) = below the skin
• “Subcutaneous” (Latin) = below the skin
• Also called “superficial fascia”
“fascia” (Latin) =band; in anatomy: sheet of connective tissue
• Fatty tissue which stores fat and anchors skin
(areolar tissue and adipose cells)
• Different patterns of accumulation
(male/female)
Hypodermis (Subcutaneous)
Recognized
by adipose
tissue.
Functions of the Skin (Review)
• Protection—first line of defense
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Against infection by microbes
Against ultraviolet rays from sun
Against harmful chemicals
Against cuts and tears
Skin grafts
Functions of the Skin (Review)
• Temperature regulation
– Skin can release almost 3000 calories of
body heat per day
• Mechanisms of temperature regulation
– Regulation of sweat secretion
– Regulation of flow of blood close to the
body surface
Functions of the Skin (Review)
• Sense organ activity
– Skin functions as an enormous sense
organ
– Receptors serve as receivers for the body, keeping it
informed of changes in its environment
—disorders of the skin (dermatoses)
Disorders of the integumentary system
• Burns
– Threat to life
• Catastrophic loss of body fluids
• Dehydration and fatal circulatory shock
• Infection
– Types
• First degree – epidermis: redness (e.g. sunburn)
• Second degree – epidermis and upper dermis: blister
• Third degree - full thickness
• Skin cancer
• Lesions
• Infections
Burns
First-degree
(epidermis only; redness)
Second-degree
(epidermis and dermis,
with blistering)
Thirddegree
(full thickness, destroying
epidermis, dermis, often part of
hypodermis)
Estimate by “rule of 9’s”
Critical burns
• Over 10% of the
body has thirddegree burns
• 25 % of the body
has second-degree
burns
• Third-degree burns
on face, hands, or
feet
Burns
• Estimating body surface area using the “rule of
nines” in adults
– Body divided into 11 areas of 9% each
– Additional 1% of body surface area around
genitals
Tumors of the skin
• Benign, e.g. warts
• Cancer – associated with UV exposure (also
skin aging)
• Three common types of cancer
– Basal cell - cells of stratum basale, rarely
spreads
– Squamous cell – keratinocytes; the most
common type, characterized by hard,
raised tumors
Skin Cancer
– Melanoma—malignancy in a nevus (mole);
involves melanocytes; most dangerous;
recognition:
• A - Asymmetry
• B - Border irregularity
• C - Colors
• D - Diameter larger than 6 mm
Skin Cancer
Sqaumous cell carc
Basal cell carcinoma
Melanoma
Basal Cell Carcinoma
Untreated…..
Actinic Keratosis
Caused by sun damage. Premalignant; can lead to
squamous cell carcinoma.
Skin Lesions
• Elevated lesions—cast a shadow
outside their edges
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Papule—small, firm raised lesion
Plaque—large raised lesion
Vesicle—blister
Pustule—pus-filled lesion
Crust—scab
Wheal (hive)—raised, firm lesion with a
light center
Skin Lesions
• Flat lesions—do not cast a shadow
– Macule—flat, discolored region
• Depressed lesions cast a shadow within their
edges
– Excoriation—missing epidermis, as in a scratch
wound
– Ulcer—craterlike lesion
– Fissure—deep crack or break
Skin Infections
• Impetigo—highly contagious
staphylococcal infection
– Tinea—fungal infection (mycosis) of the
skin; several forms occur
– Boils—furuncles; staphylococcal infection
in hair follicles
– Scabies—parasitic infection
Vascular and
Inflammatory Skin Disorders
• Decubitus ulcers (bedsores) develop when pressure
slows down blood flow to local
areas of the skin
• Urticaria or hives—red lesions caused by
fluid loss from blood vessels
• Scleroderma—disorder of vessels and connective
tissue characterized by hardening
of the skin; two types: localized and systemic
Vascular and
Inflammatory Skin Disorders
• Psoriasis—chronic inflammatory
condition accompanied by scaly
plaques
• Eczema—common inflammatory
condition characterized by papules, vesicles,
and crusts; not a disease
itself but a symptom of an underlying
condition
PSORIASIS
MAP SHOWING SKIN COLOR
DISTRIBUTION
EVOLUTION OF SKIN COLOR
• Balance between
– Need for protection against UV radiation which
Causes skin cancer
Destroys folate (vitamin B)
– Need for UV to produce vitamin D for calcium
absorption