Integumentary System Flashcards
What are the parts of the Integumentary System?
skin & derivatives (nails, hair, sweat glands, & sebaceous/oil glands)
What’s Integument?
skin that covers the body
What is the scientific study of treatment for Integumentary system?
Dermatology
What are the 3 main layers in the Integumentary System?
1) epidermis
2) dermis
3) subcutaneous layer
Describe selective permeability
pass some materials, effectively block others
Define TEWL
Transepidermal Water Loss: interstitial fluids evaporate
Define: Insensible Perspiration
Release of water from sweat glands when NOT sweating.
Define: Sensible perspiration
Release of water through sweat glands when sweating
Describe: Epidermal dendritic cells
(Langerhans cells)
phagocytize pathogens that penetrated the epidermis & fights epidermal cancer cells
Describe: Tactile Cells
(Merkel Cells) large epithelial cells stimulate nerve endings that are distorted by fine pressure
Describe: Epidermis
- Keratinized stratified squamous epithelium
- avascular. nutrients diffusion from dermis
- Consist of 5 stratas
Define strata and what are the 5 categories in epithelium?
- Strata: Layers
- Stratum Basale, Stratum Spinosum, Stratum Granulosum, Stratum Lucidum, Stratum Corneum
- 1,2,3 stratas= living keratinocytes
- 4,5 startas=dead keratinocytes
Describe: Stratum Basale
- Basal Layer (Stratum Germinativum)
- attached to basement membrane. separates epidermis & CT
- Consists of living Keratinocytes & Melanocytes
Describe: Keratinocytes
cytokeratin; mitosis replace dead keratinocytes on top of epithelium.
-Makes epidermis tough & almost waterproof.
Describe: Melanocytes
(meleno=black)
-branching cytoplasmic processes transfer melanosomes (pigment granules) by phagocytosis and exocytosis into keratinocytes & around nucleus to protect DNA ultraviolet rays (tanning)
Describe: Stratum Spinosum
- “Spiny Layer”
- polygonal keratinocytes=nondividing. attach through desmosomes.
- Holds Epidermal dendritic (I.S. Cells)
Describe: Stratum Granulosum
- “Granular Layer”
- 3-4 layers of keratinocytes
- Keratinization Occurs: cells fill up w/ keratin (protein)
Describe: Stratum Lucidum
- clear layer; 2-3 cell layers
- only in thick skin
- eleidin: protein determine maturation of keratinocytes
- dead keratinocytes
Describe: Eleidin
- Present in Stratum Lucidum and changes to keratin in Stratum Corneum.
- clear intracellular protein, determines maturation of keratinocytes
Describe: Stratum Corneum
- (Corneus=horny/hornlike)
- dead keratin layer (SKIN)
- anucleate (without nucleus)
- protects against pathogens
Describe: Thick Skin
- tough & durable. sweat glands. NO hair or sebaceous glands
- ALL 5 STRATAS
- 400-600 um
- soles of feet, palms, fingertips
Describe: Thin Skin
- hair, sebaceous, sweat
- NO STRATUM LUCIDUM
- 75-150um
Define: Hemoglobin
- (haima=blood)
- oxygen binding protein in red blood cells
- gives red tint, especially in pale skin
Melanin
- TAN. yellow, brown, tan black tint.
- from amino acid tyrosine. eumelanin & pheomelanin.
- absorbs UV radiation.
Describe: Carotene
- yellow-orange tint.
- converted to Vitamin A, good for eyes
Describe: Nevus
- (naevus=mole/birthmark)
- Mole
- note changes for malignancy
Describe: Freckles
- excessive melanocyte activity
- Depends on sun exposure & heredity
Describe: Hemangioma
- (angio=vessel; oma=tumor)
- congenital, skin, red discolored tumor.
What are Friction Ridges?
- “fingerprints.”
- none identical.
- merocrine sweat keeps from slipping
What are the 2 parts of the dermis layer?
1) Papillary Layer
2) Reticular Layer
Describe the Papillary Layer
- adjacent to epidermis
- areolar CT. Dermal Papille interlock w/ Epidermal Ridges
- Brings nutrients to epidermis cells.
- sensory receptors touch tactile cells in epidermis
Describe the Reticular Layer of the Dermis
- “Network”
- Dense Irregular CT w/ large bundles of collagen fibers
- fibers connect into subcutaneous layer
What’s the medical term for stretch marks?
Stria
How are wrinkles formed?
- UV diminishes flexibility & thickness of dermis
- continuous use of facial muscles
What are Lines of Cleavage?
Tension lines identify predominant orientation of collagen fibers
Where are Blood vessels found in the dermis?
-At the barrier of the reticular layer & subcutaneous layer
Describe the Subcutaneous Layer
- (Hypodermis). (sub=beneath; cutis=skin)
- NOT Integument
- Areolar CT & Adipose CT
Describe: Subcutaneous Fat
- Predominates Subcutaneous layer
- protects, energy reservoir, thermal insulation
- Men: neck, upper arm, abdomen, along lower back, buttocks
- Women: breasts, buttocks, hips, thighs
Describe: Lanugo Hair
- un pigmented downy hair.
- present on fetus during the last trimester.
- Replaced at birth by Vellus hair
What is a “single hair”?
Pilus
Describe: Vellus Hair
(veelu=fleece)
- un/lightly pigmented
- body covering
What hair is coarser, pigmented, long?
Terminal
Why does hair turn gray?
gradual reduction of melanin
How does hair turn white?
absence of melanin
What happens during the Anagen Phase?
- cells rapidly grow, divide, & transform to hair.
- 18months-7years.
- 80-95% follicles in this phase
What phase involves the shedding of hair?
Telogen Phase
What Phase involves the involution of hair cells?
Catagen Phase
*3-4 weeks
What process involves the thinning of hair?
Alopecia
What causes goose bumps?
Arrector Pilli Muscle pulling & tightening around hair follicles
What causes goose bumps?
Arrector Pilli Muscle pulling & tightening around hair follicles
What does the hair-root do?
Hair Sensory Reception
What does the hair-root do?
Hair Sensory Reception
What are the 2 sweat glands?
Merocrine & Apocrine
*coiled, tubular secretory portion in reticular layer or subcutaneous.
What are the 2 sweat glands?
Merocrine & Apocrine
*coiled, tubular secretory portion in reticular layer or subcutaneous.
Describe Myoepithelial Cells
-In secretory glands & basement membrane.
-respond sympathetic NS stimulation
squeeze duct
Describe Myoepithelial Cells
-In secretory glands & basement membrane.
-respond sympathetic NS stimulation
squeeze duct
Describe Merocrine Sweat Glads
- duct in epidermis sweat pore
- 3-4 million; mostly palms, soles, & forehead
- sensible & insensible; Clear Sweat: 99% water, 1% chemicals. electrolytes (primary sodium & chloride), metabolites (lactic acids), waste products (ammonia & urea)
- Thermoregulation, Secretion, Protection
Describe Merocrine Sweat Glads
- duct in epidermis sweat pore
- 3-4 million; mostly palms, soles, & forehead
- sensible & insensible; Clear Sweat: 99% water, 1% chemicals. electrolytes (primary sodium & chloride), metabolites (lactic acids), waste products (ammonia & urea)
- Thermoregulation, Secretion, Protection
Describe: Apocrine Sweat Glands
- duct in hair follicle
- axillae, areola, pubic region, anus
- sweat by exocytosis, larger lumen
- Sweat: Viscous, cloudy, & composed of proteins & lipids activated by bacteria, SMELL
- after puberty
Describe: Sebaceous Glands
- sebum into hair follicles
- lubricant for skin & lubricant
- bactericidal property
What is inflammation of a sebaceous gland called?
Folliculitis
What is a blocked duct of sebaceous gland called?
Furuncle (Boil)
What is cerumen made of?
earwax=○ secretion+sebum+exfoliated keratinocytes
Where are the Ceruminous Glands located?
external acoustic meatus.
What do Mammory Glads secrete?
Milk from Breasts
- modified apocrine sweat glands
- in Male & Female, functional in pregnant females
Describe Integument Regeneration:
replace/restore damaged w/ same cells. restores organ function
Describe Fibrosis
-Severe damage replaced w/ thickening scar tissue. -does not restore organ function.
Describe the Integument Repair Process. (4steps)
- Cut blood vessels bleed into wound.
- Blood clots form, leukocytes clean wound
- Blood vessels regrow, granulation tissue forms
(Granulation Tissue forms in wound, vascular CT) - Stratum Basal regenerates, CT fibrosis occurs
What can possibly be damaged during the Integument Repair process?
Hair follicles, exocrine glands, nerve cells, muscle fibers
What’s the difference between a hard and soft intercellular cements (extracellular matrix)?
Hard Matrix= strong hair
Soft Matrix=pliable & limp
Describe: Cuticle
Multiple cell layers around cortex
Describe: Hair Follicle
tube surrounds root hair
How does hair get it’s color?
- Synthesis of melanin in the matrix adjacent to the papillae
- Genetic & environment
What happens if there’s a decline of Vitamin D3?
Vitamin D3 decreases= decline in calcium & phosphorus= decline muscle activity & bone density
What is Basal Cell Carcinoma?
- First stage skin cancer.
- originates in stratum basale.
- Appears on face
What is Squamous Cell Carcinoma?
- 2nd stage skin cancer.
- keratinocytes of stratum spinosum. -Appears on scalp, ears, lower lip, back of hands.
- CAN TRAVEL
What is Malignant Melanoma?
- 3rd stage Amin cancer. Malignant!
- melanocytes,
- from a pre-existing mole.
- Melanoma Detection: Asymmetry, Border, Color, Diameter (+6mm)
When do nails start and finish forming?
10 weeks: finger & toe nails forming from nail fields, thickened ridges of epithelium
32 weeks: fingernails
36 weeks: toenails
What are the stages of hair growth?
lanugo hair (21st week)> vellus hairs (birth)> terminal hair (childhood)
What are the stages of mammary gland development?
- primary mammary bud: 6weeks
- secondary mammary bud: 16weeks
- mammary pit, Lactiferous Duct, Areola: 28 weeks
- female puberty fully developed
