DOCSLIB.ORG

Normal Histopath Anatomy

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Objectives • Present a introduction to histology of the skin Normal Skin Histology • Discuss the different cell types in the skin • Cover the reginal variation and artifacts that are seen in the skin Jason Stratton I have no conflicts of interest Duplicate Function Layers 1. Epidermis • Protectionor / mechanical barrier – UV, chemical, thermal insult – Dehydration 2. Dermis • Thermoregulation & electrolyte balance – Prevents & facilitates heat loss • Sensation – Receptors for pressure & pain • Immunologic organ • Sensuality & psychological well-being • Metabolic 3. Subcutaneous Adipose Tissue – Subcutaneous fat for energy – Vitamin D synthesis Distribute Epidermal Cell Function Dermal Cell Function • Immune organ • Supportive – Langerhan cells – antigen presenting cells – Fibroblasts – produce fibers & ground substance – Keratinocytes – produce interleukins, interferons, & growth • Collagen fibers – tensile strength factors • Elastic fibers – retractile properties • Protection UV • Immunologic function – Melanocytes – Dendritic cells, lymphocytes, mast cells, macrophages Not• Produce melanin from tyrosine via tyrosinase & store within • Provides nutrients melanosomes – Vascular networks • Transfer melanosomes to adjacent keratinocytes • Mechanical barrier • Thermoregulation – Keratinocytes – structural integrity via keratin filaments, – Vascular networks Do desmosomes, hemidesmosomes – Nerve supply 1 Epidermis Keratinocytes • Stratified keratinizing squamous epithelium – Continuously renewing itself • Stratified 4/5 layers – Maintains nl thickness via desquamation – Stratum corneum (cornified / horny layer) • Cells (4) • Cornified/keratin – Keratinocytes (80-90%) – Stratum lucidum • Keratin = intermediate filament (tonofilament) • Only palms & soles – Dendritic cells • Melanocytes – Stratum granulosum (granular layer) • Langerhan cells (3-5%) • Thickest on palms & soles – Stratum spinosum (squamous / prickle cell – Merkel cells (neuroendocrine cells) Stratum layer) Malpighi • Also contains – Stratum basalis / germinativum (basal – Opening eccrine ducts (acrosyringium) layer) – Opening hair follicles (acrotrichium) Duplicate Keratinocytes Basal layer (Stratum basalis, germinative layer) • Interface b/w epidermis • Single layeror of mitotically & dermis is irregular active cells above the – Dermal papillae basement membrane that • Upward projections of papillary dermis into give rise to other epidermis keratinocytes – Rete ridges • Basal cells contain melanin • Portion epidermis covering apical surface of separating the dermal papillae nucleus • Attach basement membrane via hemidesmosomes SquamousDistribute Layer Granular Layer (Stratum spinosum) (Stratum granulosum) • Flattened cells •5-10layers keratinocytes •2 to 3cell layers thick – Generally proportional to thickness horny • Maturation layer – Suprabasal cells are polyhedral • Filled with basophilic keratohyalin granules – Form 2 structures with abundant cytoplasm and a • Interfibrillary matrix / filaggrin vesicular nucleus w/ a prominent – Cements keratin filaments together • Marginal band nucleolus – Inner lining of horny cells – ↑ sulfur (cysteine disulfide bonds) → – SuperficialNot cells larger, flattened, strength & stability eosinophilic, oriented parallel • Tonofilaments ↓ sulfhydryl groups → soft & flexible → “soft” keratin • In contrast, hair & nails, which lack • Keratinocytes connected via keratohyaline granules, incorporate disulfide desmosomes (intercellular bonds themselves → “hard” keratin Dobridges) 2 Cornified Layer Basement Membrane Zone (Stratum corneum) • Specialized region at the interface between the • Flattened eosinophillic, anucleated epidermis & dermis • Dead • Homogeneous, • Basket-weave keratin eosinophilic band below pattern (orthokeratotic) Basement membrane (PAS) – Portion horny cytoplasm w/ “Basket-weave” the epidermis disulfide cystine bonds Stratum Corneum shrinks formalin fixation – 1.0 microns thick • Thinnest in eyelid and – Highlighted by periodic genitals acid-Schiff (PAS) stain • Thickest on palms and soles • Continuous around epidermal appendages Duplicate Melanocytes •Origin – Neural crest or • Function – Produce melanin, which protects against non-ionizing ultraviolet irradiation • Histology – Clear peripheral halo surrounding small deep purple ovoid nucleus along basal layer • Ratio of melanocytes to keratinocytes – Normally varies from 1:4 to 1:10 – Does not depend on race (type of melanosome does) • Immunohistochemistry – S-100 protein, Sox-10, Melan-A / MART-1 (Melanoma Antigens Recognized by T cells-1), HMB-45 Melanocytes Melanocytes •EM – Abundant pale cytoplasm – Scattered solitary melanosomes – No tonofibrils / desmosomes Distribute Melanosomes • Stages (4) – Round w/o melanin • I: seen in balloon cell melanoma – Ellipsoidal w/ numerous longitudinal filaments • II: melanin deposits start Not • III: melanin deposits are prominent • IV: fully-packed w/ melanin obscuring internal structures Melanocyte – Transferred to keratinocytes » Epidermal melanin unit = 1 melanocyte : 36 keratinocytes DoMelanocyte 3 Melanosomes Langerhan Cells Lightly Darkly •Origin Pigmented Pigmented – Dendritic cells derived from bone marrow Skin Skin • Function – Antigen presenting cells Melanization Stages II, III Stage IV>III • Important role in cutaneous immunity – Allergic contact dermatitis, allograft rejection & immune tolerance and immune surveillance • Depleted by chronic UVL, steroid application, HIV/AIDS Size 0.3-0.5 0.5-0.8 • Histology microns microns – Clear cells (appear to lie w/i lacunae) in the suprabasal epidermis w/ reniform nucleus Number per <20 >200 • Immunohistochemistry cell – POS: HLA-DR antigen, CD4, S-100 protein, CD1a, langerin – Also positive: Fc & C3 receptors, CD1c (M241), LCA, actin-like & Distribution Groups of 2- Singly vimentin filaments, ATPase, & aminopeptidase – PNA (peanut agglutinin) – stains w/ characteristic halo and/or dot 10 dispersed pattern •EM Degradation Fast Slow – Cerebriform nucleus with Birbeck granules = tennis racquet shaped membrane bound vesicle w/ a dilated end and laminated elongated handle Duplicate or Langerhans Cells Langerhans Cells Langerhan Cells (CD1a) Langerhan Cells (CD1a) Distribute Merkel Cells (Neuroendocrine cells) • Location – Scattered irregularly throughout basal layer – May group together above enlarged terminal sensory nerve fibers • Function – Mediate tactile sensation Not • Histology – Not recognized • Immunohistochemistry – Express a synaptophysin, neuron specific enolase, cytokeratin 20 (and other non-specific low molecular weight cytokeratins such as CK 8, CK 18, & CK 19) Langerhans Cell •EM – Possess membrane-bound electron-dense (neurosecretory) Do granules that vary in size between 80 and 200 nm 4 Merkel Cell Merkel Cells (CK20) Merkel Cells (CK20) Duplicate Dermis • Composition • Layers or – Glycoprotein matrix – Papillary • Ground substance largely • Thin, superficial •c/o finely woven collagen nonsulfated acid fibers mucopolysaccharides such • Periadnexal dermis of as hyaluronic acid similar quality (adventitial – Stains w/ colloidal iron & dermis) digests w/ hyaluronase • Predominantly type III – Type I collagen (90%) collagen • Fine elastic fibers • Eosinophilic fibers in orientated perpendicular birefringent bundles – Reticular – Elastic fibers • Wider, deeper • Wavy, eosinophilic fibers • Coarse thick collagen • Verhoeff Van Gieson bundles elastic staining • Predominantly type I • Orcein / resorcin-fuchsin collagen Dermis stains • Elastic fibers thicker & parallel to the surface epithelium Dermis Distribute Oxytalan Elaunin Not DoElastic Fibers Elastic Fibers Collagen & Fibroblasts 5 Dermal Vessels •Two plexi – Superficial plexus • Located at the papillary & reticular dermal junction – Deep plexus • Located at the dermal & subcutaneous junction • Connected by vertically oriented communicating vessels • Endothelial cells –POS: CD34, CD31, Ulex europaeus lectin, factor VIII-related antigen (vWF) – Contain HLA class I (HLA-A, B, C) & HLA II (HLA-DR) antigens Duplicate Dermal Lymphatics Glomus Body • Specializedor arteriovenous (AV) shunts (Sucquet-Hoyer canal-arterial segment) • Location • Location – Collapsed in normal dermis – Pads & nail beds of fingers & toes, central • May be difficult to distinguish from blood face and ears vessels, unless valve represented • Function – Form a complex network and follow the distribution of the blood vessels – Modified smooth muscle cells that regulate • Histology blood flow and temperature – Lined by a single layer of flattened cells • Histology – Have a thin wall without pericytes – Large cells with uniform, round to oval nuclei – Surrounded by a discontinuous basement and abundant cytoplasm membrane – Surround endothelial lined lumen • Immunohistochemistry • Immunohistochemistry – POS: CD31, D2-40 – NEG: FVIII-related antigen, CD34 – POS: Smooth muscle actin (SMA) Nerves ofDistribute Dermis Pacinian Corpuscle (Vater-Pacini Corpuscle) • Sensory & autonomic nerves • Location – Permeate entire dermis – Travel along course along superficial – Weight-bearing surfaces of & deep plexi deep dermis & subcutis • Sensory (fingers & toes) – Mediate pain, touch, itch, • Function temperature,Not pressure & vibration – Mediates sense of pressure & • Autonomic vibration – Derived from the sympathetic nervous • Histology system – Innervate blood vessels, arrector pili, – Concentrically arranged eccrine and apocrine glands Schwann cells with an axon Do (Onion skin) 6 Meissner Corpsuscle Subcutaneous Tissue • Location (Subcutis, hypodermis)
Recommended publications
  • Anatomy and Physiology of Hair

    Anatomy and Physiology of Hair

    Chapter 2 Provisional chapter Anatomy and Physiology of Hair Anatomy and Physiology of Hair Bilgen Erdoğan ğ AdditionalBilgen Erdo informationan is available at the end of the chapter Additional information is available at the end of the chapter http://dx.doi.org/10.5772/67269 Abstract Hair is one of the characteristic features of mammals and has various functions such as protection against external factors; producing sebum, apocrine sweat and pheromones; impact on social and sexual interactions; thermoregulation and being a resource for stem cells. Hair is a derivative of the epidermis and consists of two distinct parts: the follicle and the hair shaft. The follicle is the essential unit for the generation of hair. The hair shaft consists of a cortex and cuticle cells, and a medulla for some types of hairs. Hair follicle has a continuous growth and rest sequence named hair cycle. The duration of growth and rest cycles is coordinated by many endocrine, vascular and neural stimuli and depends not only on localization of the hair but also on various factors, like age and nutritional habits. Distinctive anatomy and physiology of hair follicle are presented in this chapter. Extensive knowledge on anatomical and physiological aspects of hair can contribute to understand and heal different hair disorders. Keywords: hair, follicle, anatomy, physiology, shaft 1. Introduction The hair follicle is one of the characteristic features of mammals serves as a unique miniorgan (Figure 1). In humans, hair has various functions such as protection against external factors, sebum, apocrine sweat and pheromones production and thermoregulation. The hair also plays important roles for the individual’s social and sexual interaction [1, 2].
  • Diapositiva 1

    Diapositiva 1

    Ingegneria delle tecnologie per la salute Fondamenti di anatomia e istologia Apparato tegumentario aa. 2017-18 INTEGUMENTARY SYSTEM integumentary system = refers to skin and its accessory structures responsible for much more than simply human outward appearance: about 16% of body weight, covering an area of 1.5 to 2 m2 (= largest organ system in human body). • skin protects inner organs INTEGUMENTARY SYSTEM • skin = even not typical, but an organ, made of tissues that work together as a single structure to perform unique and critical functions • integumentary system = skin + its accessory structures, providing body with overall protection. • made of multiple layers of cells and tissues, which are held to underlying structures by connective tissue: deeper layer of skin is well vascularized (has numerous blood vessels) and also has numerous sensory, and autonomic and sympathetic nerve fibers ensuring communication to and from brain. INTEGUMENTARY SYSTEM Overview • Largest organ (15% of body weight) • Epidermis – keratinized stratified squamous epithelium • Dermis – connective tissue layer • Hypodermis • Thickness variable, normally 1-2 mm – dermis may thicken, up to 6 mm – stratum corneum layer increased • calluses on hands and feet Structure of the Skin 2 layers: epidermis + dermis SKIN: histology SKIN: histology SKIN: histology Cells of the Epidermis • Stem cells – undifferentiated cells in deepest layers • Keratinocytes – most of the skin cells • Melanocytes – synthesize pigment that shield UV • Tactile (merkel) cells – receptor cells associated with nerve fibers • Dendritic (langerhans) cells – macrophages guard against pathogens Cell and Layers of the Epidermis Epidermis: histology = composed of keratinized, stratified squamous epithelium, made of 4 or 5 layers of epithelial cells, depending on its location in body.
  • Enabling Sweat-Based Biosensors: Solving the Problem of Low

    Enabling Sweat-Based Biosensors: Solving the Problem of Low

    Enabling sweat-based biosensors: Solving the problem of low biomarker concentration in sweat A dissertation submitted to the Graduate School of the University of Cincinnati in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Biomedical Engineering of the College of Engineering & Applied Science by Andrew J. Jajack B.S., Biology, Wittenberg University, 2014 Committee Chairs: Jason C. Heikenfeld, Ph.D. and Chia-Ying Lin, Ph.D. Abstract Non-invasive, sweat biosensing will enable the development of an entirely new class of wearable devices capable of assessing health on a minute-to-minute basis. Every aspect of healthcare stands to benefit: prevention (activity tracking, stress-level monitoring, over-exertion alerting, dehydration warning), diagnosis (early-detection, new diagnostic techniques), and management (glucose tracking, drug-dose monitoring). Currently, blood is the gold standard for measuring the level of most biomarkers in the body. Unlike blood, sweat can be measured outside of the body with little inconvenience. While some biomarkers are produced in the sweat gland itself, most are produced elsewhere and must diffuse into sweat. These biomarkers come directly from blood or interstitial fluid which surrounds the sweat gland. However, a two-cell thick epithelium acts as barrier and dilutes most biomarkers in sweat. As a result, many biomarkers that would be useful to monitor are diluted in sweat to concentrations below what can be detected by current biosensors. This is a core challenge that must be overcome before the advantages of sweat biosensing can be fully realized. The objective of this dissertation is to develop methods of concentrating biomarkers in sweat to bring them into range of available biosensors.
  • Nomina Histologica Veterinaria, First Edition

    Nomina Histologica Veterinaria, First Edition

    NOMINA HISTOLOGICA VETERINARIA Submitted by the International Committee on Veterinary Histological Nomenclature (ICVHN) to the World Association of Veterinary Anatomists Published on the website of the World Association of Veterinary Anatomists www.wava-amav.org 2017 CONTENTS Introduction i Principles of term construction in N.H.V. iii Cytologia – Cytology 1 Textus epithelialis – Epithelial tissue 10 Textus connectivus – Connective tissue 13 Sanguis et Lympha – Blood and Lymph 17 Textus muscularis – Muscle tissue 19 Textus nervosus – Nerve tissue 20 Splanchnologia – Viscera 23 Systema digestorium – Digestive system 24 Systema respiratorium – Respiratory system 32 Systema urinarium – Urinary system 35 Organa genitalia masculina – Male genital system 38 Organa genitalia feminina – Female genital system 42 Systema endocrinum – Endocrine system 45 Systema cardiovasculare et lymphaticum [Angiologia] – Cardiovascular and lymphatic system 47 Systema nervosum – Nervous system 52 Receptores sensorii et Organa sensuum – Sensory receptors and Sense organs 58 Integumentum – Integument 64 INTRODUCTION The preparations leading to the publication of the present first edition of the Nomina Histologica Veterinaria has a long history spanning more than 50 years. Under the auspices of the World Association of Veterinary Anatomists (W.A.V.A.), the International Committee on Veterinary Anatomical Nomenclature (I.C.V.A.N.) appointed in Giessen, 1965, a Subcommittee on Histology and Embryology which started a working relation with the Subcommittee on Histology of the former International Anatomical Nomenclature Committee. In Mexico City, 1971, this Subcommittee presented a document entitled Nomina Histologica Veterinaria: A Working Draft as a basis for the continued work of the newly-appointed Subcommittee on Histological Nomenclature. This resulted in the editing of the Nomina Histologica Veterinaria: A Working Draft II (Toulouse, 1974), followed by preparations for publication of a Nomina Histologica Veterinaria.
  • Sweat Glands • Oil Glands • Mammary Glands

    Sweat Glands • Oil Glands • Mammary Glands

    Chapter 4 The Integumentary System Lecture Presentation by Steven Bassett Southeast Community College © 2015 Pearson Education, Inc. Introduction • The integumentary system is composed of: • Skin • Hair • Nails • Sweat glands • Oil glands • Mammary glands © 2015 Pearson Education, Inc. Introduction • The skin is the most visible organ of the body • Clinicians can tell a lot about the overall health of the body by examining the skin • Skin helps protect from the environment • Skin helps to regulate body temperature © 2015 Pearson Education, Inc. Integumentary Structure and Function • Cutaneous Membrane • Epidermis • Dermis • Accessory Structures • Hair follicles • Exocrine glands • Nails © 2015 Pearson Education, Inc. Figure 4.1 Functional Organization of the Integumentary System Integumentary System FUNCTIONS • Physical protection from • Synthesis and storage • Coordination of immune • Sensory information • Excretion environmental hazards of lipid reserves response to pathogens • Synthesis of vitamin D3 • Thermoregulation and cancers in skin Cutaneous Membrane Accessory Structures Epidermis Dermis Hair Follicles Exocrine Glands Nails • Protects dermis from Papillary Layer Reticular Layer • Produce hairs that • Assist in • Protect and trauma, chemicals protect skull thermoregulation support tips • Nourishes and • Restricts spread of • Controls skin permeability, • Produce hairs that • Excrete wastes of fingers and supports pathogens prevents water loss provide delicate • Lubricate toes epidermis penetrating epidermis • Prevents entry of
  • Histochemical Studies on the Skin

    Histochemical Studies on the Skin

    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector HISTOCHEMICAL STUDIES ON THE SKIN II. THE ACTIVITY OF THE SUccINIC, MALIC AND LACTIC DEHYDROGENASE SYSTEMS DURING THE EMBRYONIC DEVELOPMENT OF THE SKIN IN THE RAT* KEN HASHIMOTO, M.D., KAZUO OGAWA, M.D., Ph.D. AND WALTER F. LEVER, M.D. As a continuation of our histochemical studies After an incubation for 3 to 12 hours at 37° C. on the skin (1), the changes in the succinic, maliethe sections were removed from the incubation medium, rinsed briefly in 0.1 M Sorensen's phos- and lactic dehydrogenase systems during thephate buffer, pH 7.6, and fixed in neutral formalin embryonic development of the skin have beenfor 2 to 3 hours at room temperature. investigated. Practically no work has been done In some instances, quinone compounds, such as as yet on the activity of any of these dehydroge-menadione (8, 9), phenanthraquinone (9) or Co- enzyme Q7 (8, 10), were added to act as a mediator nase systems during the embryonic developmentin the electron transfer between the succinic of the skin; and only the succinie dehydrogenasedehydrogenase and the tetrazolium salts. The activity has been investigated in adult skin byfinal concentration of menadione as well as of several authors (2—6). phenanthraquinone was 0.1 mg. per ml. of in- cubation medium. MATERIALS AND METHODS For controls were used a substrate-free medium and also the incubation medium containing, in Animal Material. Twenty-five rats of theaddition to sodium succinate, sodium malonate as Wistar strain were used.
  • Basic Biology of the Skin 3

    Basic Biology of the Skin 3

    © Jones and Bartlett Publishers, LLC. NOT FOR SALE OR DISTRIBUTION CHAPTER Basic Biology of the Skin 3 The skin is often underestimated for its impor- Layers of the skin: tance in health and disease. As a consequence, it’s frequently understudied by chiropractic students 1. Epidermis—the outer most layer of the skin (and perhaps, under-taught by chiropractic that is divided into the following fi ve layers school faculty). It is not our intention to present a from top to bottom. These layers can be mi- comprehensive review of anatomy and physiol- croscopically identifi ed: ogy of the skin, but rather a review of the basic Stratum corneum—also known as the biology of the skin as a prerequisite to the study horny cell layer, consisting mainly of kera- of pathophysiology of skin disease and the study tinocytes (fl at squamous cells) containing of diagnosis and treatment of skin disorders and a protein known as keratin. The thick layer diseases. The following material is presented in prevents water loss and prevents the entry an easy-to-read point format, which, though brief of bacteria. The thickness can vary region- in content, is suffi cient to provide a refresher ally. For example, the stratum corneum of course to mid-level or upper-level chiropractic the hands and feet are thick as they are students and chiropractors. more prone to injury. This layer is continu- Please refer to Figure 3-1, a cross-sectional ously shed but is replaced by new cells from drawing of the skin. This represents a typical the stratum basale (basal cell layer).
  • Chapter 5 Lecture Outline

    Chapter 5 Lecture Outline

    Anatomy Lecture Notes Chapter 5 I. functions • protection • prevents water loss • body temperature control • synthesizes vitamin D • sensory reception II. basic structure the skin is an epithelial membrane (cutaneous) epithelial layer = epidermis (stratified squamous keratinized e.) c.t. layer = dermis (areolar c.t. and dense irregular c.t.) A. epidermis 1. cells a. keratinocytes are found in all layers and produce keratin b. melanocytes are found in the stratum basale • they make the pigment melanin and transfer it to keratinocytes • melanin protects keratinocytes from ultraviolet (UV) radiation • the lighter an individual's skin, the more of the melanin is degraded as cells move towards the surface • the amount of melanin in the skin increases with exposure to UV radiation c. Merkel cells are found in the stratum basale • they are associated with dermal nerve endings • they may be used for the sense of touch d. dendritic (Langerhans) cells are found in the stratum spinosum • they migrate to the skin from bone marrow and function as part of the immune system • they are sensitive to UV radiation Strong/Fall 2008 page 1 Anatomy Lecture Notes Chapter 5 2. layers a. stratum basale/stratum germinativum - single layer of cuboidal or columnar keratinocyte stem cells • attached to c.t. of dermis • cells undergo mitosis • one daughter cell migrates to the next layer and one stays in the stratum basale to be the new stem cell b. stratum spinosum - 8 to 10 layers of keratinocytes • gradually change shape from cuboidal to squamous as they migrate towards the surface c. stratum granulosum - 3 to 5 layers of keratinocytes with degrading nuclei • cells contain keratin precursor molecules (keratohyalin) and granules of glycolipids • the glycolipids are secreted into the extracellular space d.
  • The Integumentary System the Integumentary System

    The Integumentary System the Integumentary System

    Essentials of Anatomy & Physiology, 4th Edition Martini / Bartholomew The Integumentary System PowerPoint® Lecture Outlines prepared by Alan Magid, Duke University Slides 1 to 51 Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Integumentary Structure/Function Integumentary System Components • Cutaneous membrane • Epidermis • Dermis • Accessory structures • Subcutaneous layer (hypodermis) Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Integumentary Structure/Function Main Functions of the Integument • Protection • Temperature maintenance • Synthesis and storage of nutrients • Sensory reception • Excretion and secretion Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Integumentary Structure/Function Components of the Integumentary System Figure 5-1 Integumentary Structure/Function The Epidermis • Stratified squamous epithelium • Several distinct cell layers • Thick skin—five layers • On palms and soles • Thin skin—four layers • On rest of body Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Integumentary Structure/Function Cell Layers of The Epidermis • Stratum germinativum • Stratum spinosum • Stratum granulosum • Stratum lucidum (in thick skin) • Stratum corneum • Dying superficial layer • Keratin accumulation Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings Integumentary Structure/Function The Structure of the Epidermis Figure 5-2 Integumentary Structure/Function Cell Layers of The Epidermis • Stratum germinativum
  • The Integumentary System the Integumentary System

    The Integumentary System the Integumentary System

    The Integumentary System The Integumentary System Integument is skin Skin and its appendages make up the integumentary system A fatty layer (hypodermis) lies deep to it Two distinct regions Epidermis Dermis Epidermis Keratinized stratified squamous epithelium Four types of cells Keratinocytes – deepest, produce keratin (tough fibrous protein) Melanocytes - make dark skin pigment melanin Merkel cells – associated with sensory nerve endings Langerhans cells – macrophage-like dendritic cells Layers (from deep to superficial) Stratum basale or germinativum – single row of cells attached to dermis; youngest cells Stratum spinosum – spinyness is artifactual; tonofilaments (bundles of protein) resist tension Stratum granulosum – layers of flattened keratinocytes producing keratin (hair and nails made of it also) Stratum lucidum (only on palms and soles) Stratum corneum – horny layer (cells dead, many layers thick) (see figure on next slide) Epithelium: layers (on left) and cell types (on right) Dermis Strong, flexible connective tissue: your “hide” Cells: fibroblasts, macrophages, mast cells, WBCs Fiber types: collagen, elastic, reticular Rich supply of nerves and vessels Critical role in temperature regulation (the vessels) Two layers (see next slides) Papillary – areolar connective tissue; includes dermal papillae Reticular – “reticulum” (network) of collagen and reticular fibers *Dermis layers *Dermal papillae * * Epidermis and dermis of (a) thick skin and (b) thin skin (which one makes the difference?) Fingerprints,
  • The Distribution of Nerves, Monoamine Oxidase and Cholinesterase in the Skin of Cattle by D

    The Distribution of Nerves, Monoamine Oxidase and Cholinesterase in the Skin of Cattle by D

    J. Anat. (1966), 100, 3, pp. 593-613 593 With 21 figures Printed in Great Britain The distribution of nerves, monoamine oxidase and cholinesterase in the skin of cattle By D. McEWAN JENKINSON, B. P. SENGUPTA* AND P. S. BLACKBURN Departments of Physiology and Veterinary Pathology, Hannah Dairy Research Institute, Ayr The sweat glands in cattle are active organs (McDowell, McDaniel, Barrada & Lee, 1961; McLean, 1963). Taneja (1959) suggested on indirect evidence that they were supplied by adrenergic nerves and Findlay & Robertshaw (1964) showed that thermal sweating in the bovine requires an intact sympathetic nerve supply. There appear to be no histological studies of the innervation of the skin of cattle apart from investigations on the nerve endings in the muzzle (Nisbet, 1956) and in the hoof (Wagai & Tohara, 1962). The present work was therefore undertaken to investi- gate histologically the innervation of the skin of cattle and the distribution of mono- amine oxidase and cholinesterase within it with particular reference to the sweat glands. MATERIALS AND METHODS Specimens of skin (15 x 15 mm) were taken from the neck or dewlap immediately after slaughter from a total of seventy-five adult cattle (bulls, bullocks and cows) of varying ages (2-12 years) and breeds (Aberdeen-Angus, Ayrshire, Dairy Shorthorn, Friesian, Galloway and Hereford). Skin samples were also obtained by biopsy, using the technique of Findlay & Jenkinson (1960), from ten Ayrshire bull calves (aged 6-12 months) and from areas of skin on four Ayrshire bullocks (aged 5-11 months) 6-10 weeks after they had been sympathectomized as described by Findlay & Robertshaw (1965).
  • Integumentary System

    Integumentary System

    Integumentary System Chapter 5 Integumentary System Integumentary system consists of: 1) Skin….the cutaneous membrane-Composed of epidermis and dermis 2) Accessary structures- hair, nails, glands. Dermatology: branch of medicine that deals with the diagnosis and treatment of skin disorders. Epidermis Papillary layer Dermis Reticular layer Hypodermis Fat Hypodermis/subcutaneous layer- NOT a part of the skin: - attaches skin to the muscle underneath. - contains blood vessels and nerves and large amount of adipose tissue - permits independent movement of deeper structures Functions of Skin 1) Protection: Stratified squamous epithelium….protects from abrasions. Sweat and oils….protects from bacterial infections. Keratin….water-proofing protein….prevents dehydration. Melanin….brown pigment….protects from UV exposure. 2) Thermoregulation: Sweat glands….evaporation of sweat cooling. Blood vessels vasoconstrict/vasodilate control blood flow in the skin heat loss/conservation. 3) Sensation: Nerve endings…sense temperature, touch, pressure, pain. Abundant in skin of the face, fingers, nipples, genitals. Fewer in skin of the back, knees, elbows. 4) Excretion: sweat…water, salt, organic substances. 5) Fat storage: adipose tissue in skin and subcutaneous layers. 6) Immunity: WBCs in skin….protect from infections. 7) Blood reservoir: blood vessels in skin hold 5% blood can be diverted to other organs. 8) Synthesis of vitamin D: skin, kidneys, liver together help make vitamin D used to absorb Ca bone development and maintenance. 9) Communication: facial expression, reflection of age, emotions. Structure of Skin Epidermis Papillary layer Dermis Reticular layer Hypodermis Skin is composed of two layers: 1) Epidermis – top layer of the skin. Skin is defined as thin or thick based on the epidermis: Thinner in thin skin (most of the body) and thicker in thick skin (palm, soles).