Shared Flashcard Set

Details

2 Integumentary System
SALADIN - CHAPTER 6 - THE UNITY OF FORM AND FUNCTION
31
Medical
Undergraduate 1
10/18/2013

Additional Medical Flashcards

 


 

Cards

Term
Two layers of skin
Definition
Epidermis: stratified squamous epithelium
Dermis: connective tissue layer
Term
Thick skin
Definition
—on palms and sole, and corresponding surfaces on fingers and toes
Has sweat glands, but no hair follicles or oil glands
Epidermis 0.5 mm thick
Term
Thin skin
Definition
covers rest of the body
Epidermis about 0.1 mm thick
Possesses hair follicles, sebaceous glands, and sweat glands
Term
Functions of the skin
Definition
Resistance to trauma and infection
Keratin
Acid mantle

Other barrier functions
Waterproofing
UV radiation
Harmful chemicals

Vitamin D synthesis
Skin first step
Liver and kidneys complete process
Term
Epidermis
Definition
—keratinized stratified squamous epithelium

Dead cells at the surface packed with tough protein called keratin
Lacks blood vessels
Depends on the diffusion of nutrients from underlying connective tissue
Sparse nerve endings for touch and pain
Term
Five types of cells of the epidermis
Definition
Keratinocytes – 90%
Synthesize keratin
Stem cells
Undifferentiated cells that give rise to keratinocytes
Melanocytes – 8%
Tactile (Merkel) cells
Touch receptor cells associated with dermal nerve fibers
Dendritic (Langerhans) cells
Macrophages; originate in bone marrow
Stand guard against toxins, microbes, and other pathogens that penetrate skin
Term
Stratum basale / germinativum
Definition
A single layer of cuboidal to low columnar stem cells and keratinocytes resting on the basement membrane

Melanocytes and tactile cells are scattered among the stem cells and keratinocytes

Cells attached to each other / basement membrane by desmosomes and hemidesmosomes
Term
Stratum spinosum
Definition
Produce more and more keratin filaments which causes cell to flatten; the higher up in this stratum, the flatter the cells appear
Dendritic cells found throughout this stratum
Named for artificial appearance created in histological section
Numerous desmosomes and cell shrinkage produces spiny appearance
Consists of several layers of keratinocytes
Term
Stratum granulosum
Definition
Consists of three to five layers of flat keratinocytes

Contains coarse dark-staining keratohyalin granules

Contain lamellar granules that release lipid that repels water
Term
Stratum lucidum
Definition
Seen only in thick skin on palms and soles of feet
Keratinocytes are densely packed with eleidin
Cells have no nucleus or other organelles
Zone has a pale, featureless appearance with indistinct boundaries
Term
Stratum corneum
Definition
Up to 30 layers of dead, scaly, keratinized cells
Form durable surface layer

Surface cells flake off (exfoliate)

Resistant to abrasion, penetration, light, heat, chemicals, bacteria, and water loss
Term
where are keratinocytes produced
Definition
produced deep in the epidermis by stem cells in stratum basale
Term
Calluses or corns
Definition
—thick accumulations of dead keratinocytes on the hands or feet
Term
two layers of dermis
Definition
Papillary layer
Reticular layer
Term
Papillary layer
Definition
—superficial zone of dermis
Thin zone of areolar tissue in and near the dermal papilla
Allows for mobility of leukocytes and other defense cells should epidermis become broken
Rich in small blood vessels
Term
Dermal papillae
Definition
—upward fingerlike extensions of the dermis
Friction ridges on fingertips that leave fingerprints
Term
Reticular layer
Definition
—deeper and much thicker layer of dermis
Consists of dense, irregular connective tissue
Stretch marks (striae): tears in the collagen fibers caused by stretching of the skin due to pregnancy or obesity
Term
function of hypodermis
Definition
Subcutaneous tissue:
More areolar and adipose than dermis

Pads body:
Binds skin to underlying tissues
Drugs introduced by injection
Highly vascular and absorbs them quickly

Subcutaneous fat:
Energy reservoir
Thermal insulation
8% thicker in women
Term
what is melanin and what 2 kinds are there?
Definition
most significant factor in skin color
Produced by melanocytes by converting tyrosine to melanin
Accumulate in the keratinocytes of stratum basale and stratum spinosum
Eumelanin—brownish black
Pheomelanin—a reddish yellow sulfur-containing pigment
Term
Explain and describe how the skin heals itself from minor trauma.
Definition
1)injury occurs, mast cells release histamine to dialate + increase blood flow, blood plasma seeps in w/ platelets and clotting proteins,
2)blood clot forms, scab formation, macrophages begin to digest tissue debris
3)fibroblastic (reconstructive) phase starts 3-4 days into injury, granulation tissue forms, blood clot gets removed + replaced by collagen
4)epithelial cells on surface infiltrate area of scab until that falls off, epthelium regenerates but connective tissue scars (fibrosis), last phase is called remodeling or maturation phase, can take up to 2 years
Term
People of different skin colors have the same number of melanocytes, but why different skin color then?
Definition
Dark-skinned people
Produce greater quantities of melanin

Light-skinned people
Melanin clumped near keratinocyte nucleus
Melanin breaks down more rapidly
Term
describe the normal and pathological colors that the skin can have, and explain their causes
Definition
Term
Cyanosis
Definition
—blueness of the skin from deficiency of oxygen in the circulating blood
Airway obstruction (drowning or choking)
Lung diseases (emphysema or respiratory arrest)
Cold weather or cardiac arrest
Term
Erythema
Definition
—abnormal redness of the skin due to dilated cutaneous vessels
Exercise, hot weather, sunburn, anger, or embarrassment
Term
[image]
Definition
[image]
Term
[image]
Definition
[image]
Term
[image]
Definition
[image]
Term
[image]
Definition
[image]
Term
[image]
Definition
[image]
Supporting users have an ad free experience!