Chapter 6 Flashcards
The integumentary system consist of…
Skin hair, nails, and associated glands
What is the body’s largest and heaviest Organ?
Skin (integument)
8% body weight
The skin consist of which two layers?
Epidermidis and dermis
Epidermidis
Stratified squamous epithelium
Dermis:
Deeper connected tissue
What is not part of the skin but usually studied with it? And below the dermis.
Hypodermis
If a paper cut does not hurt, it didn’t go through which layer?
Dermis layer
Thick skin covers…
Palms, soles and corresponding surfaces of fingers and toes
Thin skin covers….
The rest of the body, Has hair follicles, sweat glands, and sebaceous glands
One of the functions of the skin - is resistance to trauma and infection.
what provides physical protection?
Keratin
Functions of the skin-resistance to trauma and infection
What three things protect against bacteria?
Dermcidin, defensins, and acid mantle
Vitamin D synthesis with..
Cholesterol/steroids
Thermoregulation
Alter blood flow to release or retain heat
General features of the Epidermis
-Keratinized stratified squamous epithelium
-Avascular (lacks blood vessels)
-contain sparse nerve endings
Five Epidermal cell types:
Stem cells-
-Undifferentiated cells that give Rise to keratinocytes
-Deepest layer of epidermidis, Stratum basale
Five Epidermal cell types:
Keratinocytes-
-Great majority of epidermal cells
-Synthesize keratin
Five Epidermal cell types:
Melanocytes-
-Synthesize pigment melanin that shields DNA from ultraviolet radiation
-Occur only in stratum basale, but has branched processes that spread among keratinocytes and distribute melanin via melanosomes
Five Epidermal cell types:
Tactile cells-
-Touch, receptor cells associated with dermal nerve fibers
-Tactile disc—collective term for tactile cell and associated nerve fiber
-In basal layer of epidermidis
Five Epidermal cell types:
Dendritic cells-
-Phagocytic Immune cells that guard against toxins, microbes
-Capture, process and present antigens to lymphocytes, Initiates and regulates adaptive immune response
-Found in stratum spinosum and stratum granulosum
Tactile cells major types:
Merkel’s disc-
Unencapsulated, slow adaption
Tactile cells major types:
Meissners Corpuscle and Pacinian Corpuscle-
Encapsulated, rapid-adaption
Tactile cells major types:
Ruffini Corpuscles-
Encapsulated, slow- adaption
Layers of epidermis:
Stratum Basale (germinativum)-
Deepest, Single layer of stem cells and carrier tonight’s resting on the basement membrane.
Layers of epidermis:
Stratum Spinosum-
-Several layers of living keratinocytes, joined by desmosomes and tight junctions (flexibility and strength)
-“Spiny”
-also Contains dendritic cells
Layers of epidermis:
Stratum Granulosum
-3 to 5 layers of flat living keratinocytes.
-Prevention of fluid loss
-Cells contain dark staining keratonhyalin “granules”
Layers of epidermis:
Stratum Lucidum
-Thin, pale layer found only in !thick skin!
-!Friction reduction! between strat corn and Strat gran
Layers of epidermis:
Stratum corneum
-Up to 30 layers of dead, Scaly, keratinized cells
-! Resist, abrasion, penetration, water, loss!
-hydration
In 30 to 40 days a keratinocyte makes its way to the skin surface and …
Flakes off (exfoliates)
Filaggrin, A protein that binds keratin into tough bundles, keeps water in?
T/F
True
Epidermal water barrier
-Helps prevent dehydration
-Does not prevent the absorption of water by the stratum corneum- Prune fingers
The dermis
-Connective tissue layer .2 MM to 4 MM thick
-Composed of mainly collagen but also Contains elastic and reticular fibers
Well supplied blood vessels, sweat, glands, sebaceous, glands, and nerve endings
-Houses hair follicles and nail roots, muscles of facial expression.
What is the cofactor for collagen?
Vitamin C
The dermis/2 zones:
Papillary layer
Thin zone of areolar tissue In and near the dermal papillae, Allows for mobility of Leukocytes and other defense cells, Rich in small blood vessels.
The dermis/ 2 zones
-Reticular layer
Deeper thicker layer of the dermis, composed of !dense irregular connective tissue! , stretch marks, damage dermal blood vessels
Hypodermis (subcutaneous tissue)-
Layer of connective tissue beneath the skin that contains more areolar and adipose tissue than the dermis.
! Common site of drug injection due to many Blood vessels!
Subcutaneous Fat refers to
Refers to tissue that is comprised predominantly of Adipose tissue.
-!Thinner in infants, elderly!
Autograft-
Tissue from another location on the same persons body
Allograft-
Tissue from unrelated person, usually deceased donors
Cyanosis-
blueness due to oxygen deficiency
Erythema-
Redness due to increased blood flow to skin
Pallor-
Paleness due to decreased blood flow to skin
Hematoma-
Bruising/clotted blood under skin
Hemangioma
Birthmark
Downy hair (lanugo)-
Fine, unpigmented (fetus)
Vellus hair
Fine, pale hair
-2/3 of the hair of women
-1/10 of the hair of men
-All children’s hair except eyebrows lashes, and scalp hair
Terminal hair
-Longer courser pigmented
-after puberty
-Male facial hair
Arrector muscle
Bundle of smooth, muscle attaching follicle to dermis; contracts to make hair stand on end (piloerection)
Sensory nerve fibers
-Entwine each follicle and respond to
!hair movements!
Gray and white hair have a little or no melanin. T/F
True. Air is also present in medulla
Hirsutism
Excessive hairiness in areas not usually hairy.
Guard hairs
Guard nostrils and ear canals
Fingernails and toenails derivatives of stratum ______
Corneum
Clubbed fingertips
-Can be a sign of low oxygen, cancer, liver disease, or from family
-in rare cases, celiac or Crohn’s
-Low oxygen will affect the lungs, brain and heart
Apocrine sweat glands
-Groin, anal region, axilla, areola, beard area in men-after puberty
-Bromhidrosis
-Sluggish lymph system?? Apocrine is effected
Eccrine sweat glands
Most numerous 3-4 million, dense in palms, soles, forehead
Myoepithelial cells
Found in both Apocrine and eccrine glands
How many gallons of sweat do you lose her year while sleeping?
36 gal
Insensible perspiration
Not notice does not produce visible witnesses skin 500ml/day
Diaphoresis
Sweating with a wetness of the skin in response to heat, exercise or shock.
1L or more per hour
Sebaceous glands produce…
Oily secretion called sebum
No part of the cell is lost with secretion e.g. salivary glands
Merocrine
The top of the cell is lost with the secretion e.g. mammory glands
Apocrine
The whole cell detaches with secretion e.g. sebaceous gland
Holocrine
Ceruminous glands
Modified apocrine glands found only in external ear canal
Produces wax
Mammary glands
Milk producing
Modified apocrine sweat gland
What is the most common easily treated cancer?
Skin cancer
What is the most common type of skin cancer?
Basal cell carcinoma
Which skin cancer forms from the cells in Stratum basale (deepest layer)
Basal cell carcinoma
Which cancer arises from keratinocytes of stratum spinosum?
Squamous cell carcinoma
Squamous cell carcinoma Tends to metastasized to lymph nodes, and may become lethal. T/F
True
Melanoma
Arises from melanocytes
Less common
Family history risk
ABCDs of melanoma
Asymmetry, border, color, diameter
Blister burn-several weeks to heal- possible scarring
Second degree
Burn may require skin graft, fluid replacement, infection control and supplemental nutrition
Third degree
Burn required surgery, grafts, possibly amputation. Nerves destroyed. Also chemical burns
Fourth degree
