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77 Cards in this Set
- Front
- Back
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Skin weight and surface area:
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Weight: 16% of body weight (heaviest organ in the body)
Surface area: 1,2- 2,3 square meters |
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Main layers of skin:
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Epidermis
Dermis Tela subcutanea (hypodermis - does not belong to skin as an organ |
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Skin derivatives:
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Hair, nails and glands
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Functions of skin: (7)
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1. Protection
2. Thermoregulation - sweat gland - blood flow changes 3. (respiration)- perspiratio insensibilis 4. Excretion 5. Immunity 6. Metabolism (ergosterole--> vit. D) 7. Emotions and psychics |
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Skin- relief: (6)
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1.skin sulci- rhombic skin areas between them
2. dermal/papillary ridges (cristae cutis)- 9 types after Purkyne-- dactyloskopy 3. Tactile elevations (toruli tactiles)- 10 in hand (e.g.g thenar) 4. tension/cleavage lines (linea distractiones 5. skin ligaments (retinacula cutis) 6. striae (striae cutaneae)- growth, gravidity, obesity |
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Grooves:
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1. sulci at joints, wrinkles
2. sulcus mentolabialis, nasolabialis 3. suprapalpebralis, infrapalpebralis 4. sulcus gluteus, crena ani 5. hand- "Purkyne"- chiromancy/palmistry |
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Grooves on hands- Purkyne- chiromancy palmistry: (5)
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1. linea oppositionsis pollicis (vitalis)
2. linea manus clausae (cephalica, naturalis) 3. linea occlusionis dig. trium ulnarium (mensalis) 4. sulcus cutaneus intercarpalis (linea rasecta)- most proximal of wrist 5. linea restricta- middle of wrist |
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Risks with tension/ cleavage lines:
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Thorax: keloid formation
Groin: secondary infection Palms and feets: poor cosmetic healing Calf: stasis changes may obscure biopsy |
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Tension/ cleavage lines (Langer´s skin lines):
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Run in the same direction as fibril bundles in dermis (stratum reticulare).
Wrinkles on skin surface is perpendicular to the direction of the heaviest tension, important in plastic surgery. |
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Epidermis develop from:
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Ectoderm
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Dermis develop from:
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Mesoderm (mesenchyme)
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Melanocytes and Merkel`s cells develop from:
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Neural crest
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Development of epidermis:
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Primordum: only one layer of epidermal cells.
Then proliferation of superficial ectoderm---> PERIDERM and BASAL GERMINAL LAYER (=future startum basale). Epidermal ridges are formed (dermatoglyphes). Migration of neural crest cells--> melanoblasts. Keratinization and desquamation= VERNIC CASEOSA: - protect from exposition to amnial fluid - facilitates delivery |
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Development of dermis:
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From somatopleura of lateral mesoderm and partly from dermatomes.
Production of fibers starts at 11th week (collagen and elastine). Continous capillarization and innervation. Epidermis and dermis invaginates mutually |
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Thick skin type characteristics:
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Locatded on palma and planta.
Is smooth and bald 400-800 micrometer thick epidermis |
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Thin skin characteristics:
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Located on the rest of the body
Haired 75-150 micrometer thick epidermis |
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Total thickness of skin depends on region, e.g.:
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Back= 4mm thick
Haired part of head= 1,5 mm |
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Epidermis- 5 (6) layers of keratinization:
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1. stratum basale
2. stratum spinosum 3. stratum granulosum 4. stratum lucidum 5. stratum corneum 6. (stratum disjunctum) |
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Cells of epidermis:
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Keratinocytes
Melanocytes Lanherhan`s cells Merkel`s cells |
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Stratum basale:
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1 layer of cylindric/ cuboidal cells
Basophilic Desmosomes, hemidesmosomes Mitotic activity - whole epidermis regenerates in 15-30 days 10nm, middle filaments (cytokeratines) - number is increasing towards skin surface |
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Stratum spinosum:
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Spiny cells with desmosomes in their angles
Cytokeratines (tonofilaments) converge into desmosomes Multiplied in palm and sole Numerous mitoses |
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Stratum germinativum malpighi:
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Stratum basale+ stratum spinosum
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Stratum granulosum:
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3-5 cell layers
Polygonal cells with centrally located nucleus Contain 2 types of granules: - basophilic granules: keratohyaline - multilamellar granula= Odland`s bodies (their content is secreted into intercellular space and serves as cement against foreign material penetration) |
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Stratum lucidum:
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Thin layer
Flat eosinophilic cells Nucleus and organelles not obvious Mainly filaments in electrodense matrix Visible desmosomes ELEIDIN |
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Stratum corneum:
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15-20 layers of flatened cells= cells of horny layer
Nucleus and organels is absent (lysosomal enzymes effect) Cytoplasm filled with keratine (composed scleroproteine stuck by basal substance from keratohyaline granules) |
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(Stratum disjunctum):
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Unbinding cells
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Skin color is due to:
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Melanine
Carotene Number of blood capillaries within dermis Blood color in dermis vessels |
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Melanocytes:
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Located in stratum basale, and in hair follicles
Round bodies with processes to epidermis Produce melanine (eumelanine): - dark brown pigment - pheomelanine in red hair Tyrosinase synthesis, storage in melanosomes injected in keratinoctes (melanophores) |
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Where is melanin stored:
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In melanosomes within keratinocytes
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Melanine production:
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1. Tyrosinase converts:
- tyrosine into 3,4-dihydroxyphenylalanine (DOPA) - DOPA into dopachinone 2. Dopachinone is converted into melanin (microscopically 4 stages in melanosome) |
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Mature melanin granules=
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Melanosomes
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How is melanosomes secreted into keratinocytes:
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By cytokrinne secretion
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Melanin secretion:
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Cytokrinne secretion through processes.
Concentration is highest in supranuclear area of keratinocytes |
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Function of melanin secretion:
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Protection of mitotic active cells from UV radiation
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2 phases of epidermis color change:
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1. Darkening performed by melanin
2. Formation of new melanosomes |
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Langerhan`s cells (Dendrocytes):
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Are macrophages
2-8 % of epidermals cells Mainly within stratum spinosum |
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Merkel`s cells (tactile cells):
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In thick type of skin
Dark granules of uncertain content Have free nerve endings at base Mechanoreceptors (conplexus epithelialis tactus) Derived from neural crest |
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Structure of dermis:
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1.Collagen layer under basal membrane of epidermis.
2. Up to 4 mm thick (back). 3. Have processes (dermal papillae/ridges- correlate to epidermal ones) 4. Have 2 not clearly separated layers: - stratum papillare - stratum reticulare 5. Rich capillary network 6. Skin derivatives present |
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Stratum papillare of dermis:
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Forms majority of dermal ridges/papillae
Have loose connective tissue Usual components "Anchoring fibers" insert into basal membrane of epidermis |
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Stratum reticulare of dermis:
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Consist of dense connective tissue.
Many fibers, mainly collagen type I. Dermatan- sulphate. Elastic net inserted into basal membrane of epidermis |
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Function of dermis:
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1. Fixation of epidermis:
- ridges= papillae - anchoring structures 2. Blood supply 3. Thermoregulation and regulation of blood pressure 4. Sensory organ: - free nerve endings (terminationes neurales liberae) - sensory corpcules |
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Arterial supply of skin:
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Deep and superficial plexus:
- constant pedicle for certain areas--> skin flaps for replantation - capillaries- a-v anastomoses (Veins corresponds to aa.) |
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Lymph drainage of skin:
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Capillaries--> subcapillary network--> collectors
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Nervous innervation of skin:
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(NO PARASYMPATHETIC INNERVATION!!)
1. Nerve endings (free x corpuscules) 2. 5th sense= touch- somatosensory fibers 3. Sympathetic postganglionic vasomotor fibers- adrenergic 4. Visceromotor fibers 5. Sympathetic fibers for sweat glands- cholinergic |
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Skin derivatives:
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Piles
Nails Hair Skin glands |
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Hairs (pili):
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1. Everywhere except: palms, soles, lips, glans and labia minora.
2. Distribution, density and color depend on: - sex, age, race and region of body - hormones influence (androgenes, T3, T4, corticoids) 3. Growth periods (anagene) 4. Quite periods (catogene, telogene) |
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Hair growth:
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Anagene: 3years/ 1000 days
Catagene: 3 weeks/ 10 days Telogene 3 months/ 100 days Bulbus disappearance and its recovery |
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How many mm growth/ day:
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0,4mm/day
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How many hairs are lost each day:
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100 (if more= effluvium)
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Bald sites:
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Alopecia
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Influences of hair growth:
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Hormones
Nutrition Toxins Infection Chemotherapy Autoimmune diseases |
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Structure of hairs:
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1. Hair follicle (invaginations of epidermis)
2. Hair bulb (corresponds to startum germinativum) 3. Dermal papilla (at hair bulb base, with capillary network) 4. Cells around papilla (hair root): - medulla: large vacuolized elements - cortex: keratinized spindle elements - cuticle |
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Hair follicle layers:
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Medulla
Cortex Cuticula Internal+ external root sheat (vagina radicularis epithelialis int+ ext.) Glassy membrane (membrana vitrea) Fibrous sheath (vagina radicularis dermalis)- derived from mesoderm |
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Nails (ungis):
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Plates of keratinized epithelial cells on dorsal surface of distal phalanges
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Nail structure:
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Matrix, nail fold (vallum), nail body
Hidden lateral free border Root (radix)- in nail groove Eponychium (cuticle) Hyponychium- epidermal base (mirror of blood oxygenation) Lunula Nail bed (lectulus) |
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Nail develeopment:
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Nails originates as thickening of epidermis on the finger tips
(nails overreaching fingertips are one of the marks of the fetus maturation (full term baby) |
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Skin glands:
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Sebaceous
Sweat Apocrine |
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Sebaceous glands:
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Holocrine
In dermis all over the body (100/ cm2) Missing in palmes and soles Abundant in face (400-900/ cm2) Alveolar with duct usually into hair follicle Produce SEBUM (mixture of TAG, waxes, squalene, cholesterol and its esters) |
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Sweat glands:
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Merocrine secretion (vesicles):
- eccrine - apocrine |
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Eccrine glands:
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= Sweat glands
Simple, contorted, tubulus Empty outside hair follicles All over the body, densest in palm, sole and forehead Missing in glans and inner surface of preputium (dark cells- mucoid, light cells- transport of ions) Produces non-viscous fluid Water, NaCl, urea ammonia, uric acid (ultrafiltrate of blood plasma) Thermoregulation Cholinergic innervation |
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Apocrine glands:
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"Odour glands"
3-5mm in diameter Located in hypodermis Empty into hair follicles Viscous secretion without smell Aromatic smell= bacterial effect Adrenergic innervation |
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Pemphigus vulgaris:
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Autoimmune disease
Circulation IgG antibodies against surface antigens of squamous epithelium are associated with desmosomes ---> antibody binding triggers activation of proteases==> epidermis disintegrates and forms blisters (intraepidermal blisters located suprabasally) |
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Bulous pemphigoid:
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Autoimmune disease
Circulating IgG antibodies bind to antigens BP1 and BP2 in area of basal membrane. Antibody binding triggers activation of complement, tissue damage and formation of blisters. Subepidermal blisters are covered with rather normal epidermis. |
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Mammary glands, general facts:
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Largest skin gland (apocrine) holocrine??
Secretes milk Paired gland, sulcus internmammarius 3th- 6th intercostal space, fat pad (pre- and retromammary) Parasternal--> ant. axillary line 11 cm x 12 cm 150g, 300- 800g in lactation |
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Mammary gland structure:
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1. Body of brest- axillar process
2. Lobes--> lobules--> glandular alveoli (glandular epithelium, myoepithelial cells) 3. 15-20 composed tuboalveolar glands 4. Each has it own secretory dicy (lactiferous duct)--> sinus lactifer (in lactation only)--> nipple 5. Separated with dense connective tissue and adipose tissue 6. Supersensory ligament of breast (retinaculum cutis mammae) |
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Areola mammae:
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Glandulae areolares Montgomery
Tubercula areolae Smooth mm. cells (radially) Pigmentation |
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Nipple (papilla mammaria):
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Area cribiformis papillae:
- lactiferous ducts Sebaceous glands Smooth muscle cells (spirally)- m.sphincter papillae) |
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Development of mammary gland:
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6th week:
Mammary ridge/milk line (=thickened epidermis) from axilla under naval 2nd trimester: 15-20 epithelial buds- future lactiferous ducts Newborns of both sexes: Average: 3,5-9 Ducts swollen with heaped secret Secret excretion (under influence of maternal hormones= "Witch milk" |
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Mammary gland in puberty:
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1. Enlargement of girls breasts du to:
- collection of adipose and connective tissue - proliferation and ramification of lactiferous ducts - both under influence of ovarian estrogens 2. In boys the breasts are without changes |
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Mammary gland in pregnancy and lactation:
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1. Proliferation of alveols in lobules
2. Cells with secretory vacuoles and adipose droplets 3. 4-6 myoepithelial cells around alveolus 4. Synergic action of hormones--> growth of secretory part 5. Secretion into alveolar lumen 6. Water, lipids, proteins (kaseines), lactosis, IgA 7. Colostrum, sucking, oxytocine |
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Arterial supply of mammary gland:
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1. rr. perforantes from aa. intercostales anteriores
2. r.pectoralis, a.thoracoacromialis, a.thoracica lat, a. subscapularis from a. thoracica superios 3. aa. intercostales posteriores--> rr. perforantes |
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Venous drainage from mammary gland:
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Plexus venosus Halleri- under areola
v.axillaris v.thoracica interna vv.intercostales posteriores |
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Carcinoma of mammary gland:
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Most frequent tumor in females, affects 9% of women.
Clinical symptoms: - swelling - impact of skin/papilla - ulceration Examination: - palpation - ultrasound - mammography Treatment: - extirpation - mastectomy (partial/ total) |
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Lymph drainage of mammary gland:
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4 quadrants:
1. nodi.l.axillares: - Sorgius- most cranial group of nodi.l.pectorales, at 2nd/3rd tooth of m.serratus ant 2. nodi.l.parasternales: - nodi.mediastinales ant. - nodi epigastrici sup.+ inf. 3. nodi.l.supraclaviculares 4. contralaterally to the other gland and axilla (plexus subareolaris Sappeyi) |
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Innervation of mammary gland:
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nn. intercostales IV- VI (rami ant- + lat.)
Sensory plexus around papilla (T4) |
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Anogenital adnexal glands:
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van der Putte 1991
Structure similar to glandula mammaria Transition between eccrine and apocrine gland Hormonal receptors--> cyclic changes Located in sulcus interlabialis and perianal region Function not known, possible sexual function |
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Subcutaneous tissue (tela subcutanea/ hypodermis):
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Retinacula cutis
Panniculus adiposus: - stratum musculorum - stratum fibrosum Stratum membranosum Textus connectivus laxus Bursae synoviales subcutaneae |
