Skin, hair, mammary gland group 8.pdf

Histology and embryology 2 • • • • indoor shoes !!! PRACTICAL NOTEBOOK - PROTOCOL pen, colour pencils any notebook for your notes • the same place in the practical room • the same light microscope • the same box with slides LITERATURE GENERAL MEDICINE: Histology and Embryology 1, 2 Compulsory li...

Histology and embryology 2 • • • • indoor shoes !!! PRACTICAL NOTEBOOK - PROTOCOL pen, colour pencils any notebook for your notes • the same place in the practical room • the same light microscope • the same box with slides LITERATURE GENERAL MEDICINE: Histology and Embryology 1, 2 Compulsory literature: 1. Adamkov M. et al.: Introduction to FUNCTIONAL HISTOLOGY, Textbook, 2016, 3rd Edition (compulsory; Library – UPJŠ) 2. Mechírová E. and Domoráková I.: HISTOLOGY, Practical lessons (compulsory; available in the Book shop, SNP 1, Košice) 3. Study material of Histology and Embryology – Supplement: http://www.lf.upjs.sk/uhe/histology_topics/ 4. Moore K. L. and Persaud T. V. N.: Before We Are Born, Essentials of Embryology and Birth Deffects (compulsory; Library – UPJŠ) 5. http://www.histologyguide.com/slidebox/slidebox.html 6. Junqueira L. C. et al.: Basic Histology (compulsory; Library – UPJŠ) 7. Ovalle W. K. and Nahirnay P. C.: Netter´s ESSENTIAL HISTOLOGY, Ilustrations, colour atlas (recommended; Library – UPJŠ) 8. Ross M.H. and Pawlina W.: Histology: A Text and Atlas: With Correlated Cell and Molecular Biology, 2015. 9. Notes from practical lessons and lectures!!! REQUIREMENTS FOR COMPLETION OF SUBJECT Practical lessons 1. Student has to attend all practical lessons (100%). 2. In the case of excused absence on practical lessons (maximally 3), student has to study missing slides and draw them to the practical textbook individually (the latest in 2 weeks after the absence). Student has to study theory as well and be prepared for examination (oral or written). 3. Student has to pass at least 5 control tests (oral or written) during the semester and gain the average of results minimally 60 %. 4. In the event of failure to attain these limits, final exam is not permitted and the student is graded Fx (failed) at the end of semester 5. In the 14th week of semester – student has to pass final slide test, which consists of description of 3 histological slides from the winter and summer semester, and gain minimally 60% → register to the final exam. One retake term for final slide test during the first or second week of the examination period. REQUIREMENTS FOR COMPLETION OF SUBJECT Final exam consists of 2 parts: A. Final written test – The student must gain minimally 60% from the test, to continue to the final oral exam. B. Final oral exam – three questions: a) cytology and tissues b) microscopic anatomy c) embryology Student must pass each of three questions minimally for 60% (E). The total evaluation of the final exam includes outcomes of the final slide test and written test and final oral exam (graded A-E) Skin – Cutis Skin appendages – Adnexae cutis Skin - function The largest organ, 16% of body weight (4-5kg) ? Skin - function The largest organ, 16% of body weight (4-5kg) 1. Regulation of body temperature 2. Protection against invasion of microorganisms, external various injuries and desiccation 3. Sensation – the largest sensory organ, it contains a variety of receptors (temperature, touch, pressure and pain) 4. Metabolic functions – absorption of UV radiation → synthesis of vitamin D, store of energy (in subcutaneous adipose tissue) 5. Excretion from sweat glands ? ? ? SKIN (CUTIS) 1. 2. Epidermis – epithelial layer: stratified squamous keratinized epithelium, THICK or THIN type of skin Dermis (corium) – papillary layer – reticular layer 3. (Subcutaneous tissue – hypodermis) – loose connective tissue beneath – adipocytes – mimic muscles – smooth muscle cells – nipple – dense connective tissue - ear Skin appendages: • hairs • nails • sweat and sebaceous glands Subpapillary plexus, deep plexus – capillary network EPIDERMIS Stratified squamous keratinized epithelium (keratinocytes): LAYERS ? EPIDERMIS Stratified squamous keratinized epithelium (keratinocytes): 1. Stratum basale 2. Stratum spinosum 3. Stratum granulosum 4. Stratum lucidum – thick skin 5. Stratum corneum 6. Stratum disjunctum NON-KERATINOCYTES • Melanocytes • Langerhans cells • Merkel cells 1. Stratum basale ? 1. Stratum basale • cuboidal/low columnar cells attached to the BM • basophilic cytoplasm (↑ ribosomes, GA, mitochondria) • hemidesmosomes, desmosomes • intense mitotic activity – proliferation • keratins-intermediate filaments • melanocytes • Merkel cells 2. Stratum spinosum ? 2. Stratum spinosum • thickest layer of epidermis • polyhedral prickle cells numerous short cytoplasmic projections • cytokeratin → tonofibrils – eosinophilic cytoplasm • desmosomes Str. basale + Str. spinosum = STRATUM GERMINATIVUM MALPIGHI 3. Stratum granulosum ? 3. Stratum granulosum • 1-3 layers of flattened cells (thick vs. thin skin) • keratohyaline granules: basophilic, non-membrane bounded, included in process of keratinization (associated with tonofibrils) • lamellar granules: small, ovoid, membranous, glykolipids+fosfolipids – makes epidermis waterproof 4. Stratum lucidum ? 4. Stratum lucidum • • • • only in thick type of the skin thin 2-3 layers of dead keratinocytes translucent layer (due to eleidin) keratinocytes: flattened eosinophilic, without nucleus and organelles • cells contain coarse keratin filaments 5. Stratum corneum ? 5. Stratum corneum • most superficial layer • 15-20 layers of cells • keratinocytes: dead, squamous, keratinized, desiccated, without nucleus and organelles • desmosomes only between cells in deeper layers • continuous desquamation of dead cells NONKERATINOCYTES: Melanocytes (pigment cells) • • • • • Black/brown pigments – eumelanins stratum basale, hair follicle neural crest derivates irregular long cytoplasmic processes melanosomes – form supranuclear cap in keratinocytes People with dark skin People with pale skin Melanocytes in dark↓ and pale↑ type of skin NONKERATINOCYTES: Merkel cells • • • • • scattered only in the basal layer of epidermis morphologically resemble melanocytes epithelial tactile cells sensitive mechanoreceptors form synaptic junction with unmyelinated sensory peripheral nerve endings NONKERATINOCYTES: Langerhans cells • • • • • • APCs, part of monocytomacrophage system star shaped cells with many processes, pale cytoplasm provide immune reaction of skin mobile – migrate to regional lymf node, interact with T-Ly Birbeck bodies – rod-like granules decrease in number after exposure to UV light !!! (skin cancer) DERMIS – papillary layer (loose connective tissue) ? DERMIS - papillary layer (loose connective tissue) • dermal papillae interconnected with evaginations of epidermis • below epithelium • lot of fibrocytes, fibroblasts, macrophages, mast cells, plasma cells • more amorphous ground substance • fine collagen fibers, elastic and reticular fibers • ANCHORING FIBRILS – type VII collagen • well-vascularised – termoregulation, nourishment of epidermis DERMIS – reticular layer (dense connective tissue irregular) ? DERMIS – reticular layer (dense irregular connective tissue) • stress resistance and protection • less of cells • thick bundles of collagen fibers (all directions) • blood vessels • small amount of amorphous ground substance (proteoglycans – dermatan sulfate) SKIN APPENDAGES – Adnexae cutis • Hair - pilus • Nail - unguis • Skin glands - glandulae cutis: Merocrine sweat gland - gl. sudorifera merocrina Apocrine sweat gland - gl. sudorifera apocrina Holocrine sebaceous gland - gl. sebacea holocrina HAIR • Hair are produced by deep epithelial ingrowths – form hair follicles Hair root Hair shaft - part extending beyond the skin Hair follicle • terminal dilatation - hair bulb • dermal papilla - capillary network • Internal root sheath - completely surrounds the initial part (3 layers) • External root sheath - continuous with epidermis (stratum basale and spinosum) • Connective tissue root sheath - dermis + Arrector pili muscle - small bundle of the smooth muscle c. Cellular part: K - cortex - heavily keratinized, densely packed D - medulla - large vacuolised cells Internal root sheat(A) *k – inner root sheat cuticle and hair cuticle H – Huxley layer (eosinophilic trichohyalin granules) He – Henle layer External root sheath (B) str. basale a str. spinosum glassy membrane - thickened basement membrane Connective tissue root sheath Hair follicle: bulbus pili (B) papilla pili (P) External root sheath (E) Keratinized hair (V) GLANDULAE CUTIS Holocrine sebaceous glands Sweat glands Eccrine sweat glands Apocrine sweat glands Holocrine sebaceous gland/glandulae sebaceae • • • • • • • not present in thick skin of palmes and soles alveolar glands stratified epithelium holocrine secretion short duct empties into upper part of a hair follicle sebocytes the product of glands – oily substance – sebum Sebaceous glands Adipocytes Sweat glands Eccrine sweat glands = glandula sudorifera eccrina • • • • simple, tubular, coiled merocrine secretion tubulus: simple columnar epithelium duct: stratified epithelium, darker cells Apocrine sweat glands = glandula sudorifera apocrina • • • • • aromatic sweat glands axillary and perineal region merocrine secretion branched tubular glands tubulus: simple columnar epithelium A B C 1. Epidermis 1.a. basement membrane 1.b. stratum basale 1.c. stratum spinosum 1.d. stratum granulosum 1.e. stratum corneum 2. Dermis 2.a. papillary layer 2.b. reticular layer 3. Merocrine sweat glands 4. Apocrine sweat glands 5. Hair follicle 5.a. papilla pili (dermal papilla) 5.b. bulbus pili (hair bulb) 5.c. medulla pili 5.d. cortex pili 5.e. internal root sheath 5.f. external root sheath 5.g. connective tissue root sheath 5.h. hair shaft – keratinized 6. Sebaceous gland MAMMARY GLAND GLANDULA MAMMAE, GLANDULA LACTIFERA • breasts are compound tuboalveolar glands composed of 15-20 distinct lobes • lobes are separated from each other by adipose tissue and dense connective tissue septa (INTERLOBAR DENSE CONNECTIVE TISSUE) • until the menopause, it undergoes cyclical changes in activity (controlled by hormones of the ovarian cycle) • after menopause - progressive atrophy and involution FUNCTION: • secrete milk providing high-quality nourishment for newborn Milk contains: • 1,5 % proteins (albumine, caseins, Ig A) – merocrine secretion • 7 % lactose • 4% lipids – apocrine secretion • minerals, vitamins Development of mammary gland (A) Newborn Epithelial cords converge to the nipple. (B) Before puberty Gland is composed of lactiferous sinuses and several branches of the lactiferous ducts. (C) Puberty Increased in the amount of estrogens: 1. Accumulation of adipose and collagenous CT. 2. Increased growth and branching of lactiferous ducts, prominent nipple develops . (D) Adult female gland Mamma non lactans: Secretory lobules are not well developed. Adipose and dense CT interlobular predominate. Pregnant woman - mamma lactans: Secretory lobules are fully differentiated, epithelial cells of alveoli produce milk. Interlobular CT is reduced. Senil mammary gland: Involution of glandular tissue, atrophic changes also occur in the interlobular CT. Resting mammary gland – gl. lactifera non-lactans Lobes • Interlobar dense connective tissue+adipocytes PREDOMINANT Lobules: • separated by dense connective tissue • intralobular ducts - intralobular loose connective tissue • interlobular ducts • lactiferous duct – lobar duct • lactiferous sinus • porus lactiferi - areola mammae Mammary gland during lactation – gl. lactifera lactans • Proliferation in secretory alveoli and duct system • Lumens are opened, filled with milk • Realtive reduction of interlobar and interlobular CT • Intralobular connective tissue: infiltrated by Ly and plasma cells