Integumentary System Flashcards
The largest organ of the cell components:
Skin (Cutaneous membrane)
Nails
Hair
Cutaneous sense organs and glands
Skin has many percent in adult body
2sq.m (22sq.ft)
Weighs: 4.5-5 kg (20-11lb)
7% of total body weight
Skin has many percent in adult body
2sq.m (22sq.ft)
Weighs: 4.5-5 kg (20-11lb)
7% of total body weight
2 Major Tissue Layer of the Skin
Epidermis
Dermis
Superficial layer
Stratified squamous epithelium
Cornified or keratinized (hardened by keratin) to prevent water loss
Avascular (no blood supply)
Most cell are keratinocytes
Epidermis
A major tissue layer of skin which function is to prevent water loss and resist abrasion
Epidermis
Dense connective tissue
Vascular
10-30 thicker than the epidermis
Layer of dense connective tissue depending on the location (blood vessel, oil and sweat glands, nerves, hair follicles, etc)
Dermis
Major tissue layer of the skin which function is to
…
Skin rests on the subcutaneous tissue which is a layer of connective tissue (adipose, areolar)
It is not part of the skin but it connects the skin to underlying muscle or bone
Hypodermis
It function as padding and insulation
Hypodermis
Acceptable body fat for female and male
Female: 22-30%
Male: 23-25%
Layers of Epidermis (thick, hairless layer)
Stratum Corneum
Stratum Lucidum
Stratum Granulosum
Stratum Spinosum
Stratum Basale
Deepest layer of epidermis
Lies next to dermis
Wavy borderline with the dermis anchors the two together
Cells undergoing mitosis
Daughter cell are pushed upward to become more the superficial layer
Stratum Basale (Stratum Germinativum)
Several cell layer thick
Contain a weblike system of intermediate filaments
Stratum Spinosum (Pricky Layer)
4 to 6 Layers thick
Accumulates two type of granules
Stratum Granulosum (Granular Layer)
2 Types of Granules
Keratohyaline Granules
Lamellar Granules
Tyoe of granule that help to form keratin in the upper layer
Keratohyaline Granules
Type of granule that contain water-resistant glycolipid for slowing water loss across the epidermis
Lamellar Granules
Formed from dead cells of the deeper strata
Occurs only in thick, hairless skin of the palms of hands and sole of feet
Stratum Lucidum (Clear Layer)
Outermost layer of epidermis
Shingle-like dead cells are filled with keratin (protective protein prevent water loss from skin)
Stratum Corneum (Horny Layer)
Excessive sloughing of stratum corneum cells from the surface of the scalp
Dandruff
Skin subjected to friction, the number of layers in the stratum corneum greatly increases, producing a thickened area
Callus (Hard Skin)
Over a bony prominence, the stratum corneum can thicken to form a ccone-shaped structure
Corn
Why is the soles and palms have no hair?
Because it is very thick and highly keratinized
Location: Palms of hands, soles of feet
Thick Skin
Location: Rest of the body
Thin Skin
Structure: 5 epidermal layers, including stratum lucidum
Thick Skin
Structure: 4 epidermal layers without stratum lucidum
Thin Skin
Function: Protective, withstands friction and wear
Thick Skin
Function: Sensory Perception, Touch and Temperature Sensitivity
Thin Skin
Hair and Glands: No hair follicles or sebaceous (oil) glands
Thick Skin
Hair and Glands: Contain follicles, sebaceous glands and sweat glands
Thin Skin
Cells in Epidermis
Keratinocytes
Melanocytes
Dentritic (Langerhans) Cell / Intraepidermal Cells
Tactile (Merkel) Cells
Produces keratin, a fibrous protein that helps give the epidermis its protective properties
Arise in the deepest part of epidermis, stratum basale
Keratinocytes
Spider-shaped epithelial cell
Synthesize melanin pigment
Found in the deepest part of the epidermis
Melanocytes
Arise from bone marrow and migrate to the epidermis
Ingest foreign substances
Key activators of our immune system
Dendritic (Langerhans) Cell / Intraepidermal Cells
Present at the epidermal-dermal cell
Functions as sensory receptor for touch
Tactile (Merkel) Cell
2 Layers of Dermis
Papillary Layer (Upper Dermal Region)
Reticular Layer
Areolar Connective Tissue
Collagen and Elastic Fiber form a loosely woven mat
Projections called dermal
papillae
Some contain capillary
loops
Papillary region
Others house pain
receptors and touch
receptors called
tactile or
Meissner’s corpuscles
80% of the thickness of the dermis
Dense fibrous connective tissue
Reticular layer
Reticular layer has this that help or important to surgeon
Cleavage/Tension Line
It is in reticular layer that describe as a dermal folds that occur at or near joints
Flexure lines
Types of Flexure line
Normal palm creases
Simian Crease
Polymer made by tyrosine amino acid
Melanin
Melanin
Yellow to Red
Pheomelanin
Melanin
Brown to Black
Eumelanin
Precursor of vitamin A need for vison
Lipid soluble
Oranhe-yellow pigment from vegetable
Accumulates in the stratum corneum and in fatty tissue of the hypodermis
Carotene
Red coloring from blood cells in dermal capillaries
Oxygen content determines the extent of red coloring
Hemoglobin
It is produced by the golgi apparatus of the melanocyte
Melanosomes
Process of Keratinizaton
..
Normal skin color determinants
Melanin
Carotene
Hemoglobin
Alteration in skin color
Cyanotic
Redness (Erythema)
Pallor (Blanching)
Jaundice (Yellowing)
Depigmentation
Bronzing (Hyperpigmentation)
Albinism
Bruises
Skin appear bluish
Cyanotic
Due to embarrassment, inflammation, hypertension, fever or allergy
Redness (Erythema)
Due to emotional stress such as fear, anemia, low blood pressure, impaired blood flow to an area
Pallor (Blanching)
Liver disorder, gallbladder or pancreas; occurs when too much bilirubin builds up in the body
Jaundice (Yellowing)
Vitiligo (Skin condition)
Happens when the skin entirely loses pigment and turns white
Depigmentation
Addison’s Disease
Primary adrenal insufficiency
Bronzing (Hyperpigmentation)
Genetic Disorder
inherited condition that leads to someone having very light skin, hair, and eyes
Albinism
Hematomas
Bruises
Skin Appendages
Cutaneous glands
-all exocrine glands
-sebaceous (oil) glands
-sweat (sudoriferous) glands
Hair
Hairl Follicles
Nail
Homeostatic Imbalance of Skin
Whitehead
Blackhead
Acne
Seborrhea
Produce oil (sebum), accumulated lipids and cell fragments
Most have ducts that empty into hair follicles; others open directly onto skin surface
Glands are activated at puberty
Oil (sebaceous) gland
Function of oil (sebaceous) glands
•Lubricant for skin
•Prevents brittle hair
•Kills bacteria
Sebum is released by
Holocrine secretion
accumulated sebum blocks a
sebaceous gland duct
whitehead
material oxidizes and dries
blackhead
an active inflammation of sebaceous glands
accompanied by “pimples” – caused by bacterial
infection (Staphylococcus)
Acne
overactive sebaceous gland, in infants
it is known as
Seborrhea “Cradle Cap”
Produce sweat
Widely distributed in skin except nipples and parts of external genitalia
Sweat (Sudoriferous) glands
2 Types of Sweat (Sudoriferous) glands
Eccrine
Apocrine
Numerous and abundant in the palms, soles of the feet and forehead
Open via duct to pore on skin surface
Produce sweat (clear) – water & few salts
Eccrine (Merocrine) Sweat Glands
Aprox. 2,000 are largely confined to the axillary and anogenital areas
Ducts empty into hair follicles
Begin to function at puberty
Release sweat that also contains fatty acids and
proteins (milky/yellowish color)
Apocrine sweat glands
Sweat Composition
•Mostly water
•Salts and vitamin C
•Some metabolic waste
•Fatty acids and proteins (apocrine only)
Sweat Function
•Helps dissipate excess heat
•Excretes waste products
•Acidic nature inhibits bacteria growth
Associated with bacteria
sweat
Modified apocrine sweat glands
Ciliary glands
Ceruminous glands
Mammary glands
Found in the eyelids
Ciliary glands
Modified apocrine glands found in the lining of the external ear canal
Secretion mixes with sebum to produce cerumen or ear wax
Ceruminous glands
Secretes milk
Mammary glands
Produced by hair follicle
Consists of hard keratinized epithelial cells
Melanocytes provide pigment for hair color
Hair grows in the matrix of the hair bulb in stratum basale
Hair / Pili
Dermal and epidermal sheath surround hair root
Hair follicle
Smooth muscle cells
Pulls hairs upright when cold or frightened
Important role: contractions force sebum out of hair
follicles to the skin surface where it acts as skin lubricant.
Arrector Pili Muscle
Types of Hair growth
Lanugo
Vellus Hair
Terminal (Androgenic) Hair
very thin, soft, usually unpigmented, downy hair that is sometimes found on the body of a fetus or newborn
Lanugo
thin, fine hair that grows on most of your body
vellus hair
coarse, thick hair that is found on the scalp, underarms, and pubic area and in men found in face
Terminal (androgenic) hair
homeostatic imbalance in hair
Hirsutism
Alopecia
True or Frank Baldness
excessive hairiness
may result from an adrenal gland or ovarian tumor
Hirsutism
hair thinning and some degree of baldness
Alopecia
Most common, male pattern baldness
true or frank baldness
Scale-like modifications of the epidermis
Heavily keratinized
Stratum basale extends beneath the nail bed
Responsible for growth
Lack of pigment makes them colorless
Nail
