DOCSLIB.ORG

Skin Swailes Module 3.1 Skin N. Swailes, Ph.D. Required Reading

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Skin Swailes Module 3.1 Skin N. Swailes, Ph.D. Required Reading Module 3.1 Skin N. Swailes, Ph.D. Required reading Mescher AL, Junqueira’s Basic Histology Text and Atlas, 12th Edition, Chapter 18: pp316-331 Learning objectives 1) Use your knowledge of the basic tissues to describe the histological organization of skin. 2) Identify the epidermis and discuss its embryological origin, organization and functions. 3) Identify the dermis and hypodermis and discuss their embryological origins, organization and functions. 4) Examine a variety of skin adnexa and determine their function. 5) Think about the histological organization of skin the next time you are making an incision during Gross Anatomy. A: General organization Skin is divided into 3 main regions, each providing a distinct role in the overall function of the skin. 1. Epidermis - is the most superficial layer of the skin - is derived from embryonic ectoderm and is a specialized stratified squamous epithelium - forms first physical and immunological barrier to invasion of foreign substances into the body. 2. Dermis - is connective tissue derived from embryonic mesoderm - provides mechanical support and elasticity of the skin - contains immune cells involved in defense against foreign invaders passing through the epidermis 3. Hypodermis - is connective tissue derived from embryonic mesoderm - also known as subcutaneous connective tissue - recognized as the superficial fascia in gross anatomy - stores adipose tissue for cushioning, insulation and energy. - 1 | Page: Skin Swailes PART B: Epidermis The epidermis consists of four main cell type: the main cell is the stratified squamous epithelial cells called (A) Keratinocytes, other cells are less abundant and include: (B) Melanocytes (pigment producing), (C) Langerhans cells (antigen presenting) and (D) Merkel cells (tactile cells). A. Keratinocytes From the dermis outwards the epidermis consists of four layers of keratinocytes (five in thick skin): 1. Stratum basale - layer of columnar ‘palisades’ on the basement membrane at dermal-epidermal junction - attached to the basal lamina by hemidesmosomes and to each other by desmosomes - undergo intense mitosis and are responsible for 5 1 the constant production of epidermal cells 2. Stratum spinosum 4* - the thickest part of the epidermis 3 - consists of slightly flattened cells that actively 1 synthesize keratin filaments - the filaments radiate outward and converge on the desmosomes that anchor the cells to each other 3. Stratum granulosum - 3-5 layers of flattened cells undergoing terminal keratinization 2 1 - granular appearance due to: i. Keratohyalin granules Contain the protein filaggrin that binds together keratin filaments in the cytoplasm. ii. Lamellar (Odland) bodies Contain lipid that when released by exocytosis surround the keratinocytes and 1 prevent water loss and serve a waterproofing 1 function. 4. Stratum lucidum* - an additional layer of pale staining keratinocytes only seen in thick skin (not illustrated here) 5. Stratum corneum - 15-20 stacked layers of flattened non-nucleated keratinized cells filled with filamentous keratin. Melanocyte Keratinocytes Merkel cell Langerhans cell - continuously shed at the surface of the corneum 2 | Page: Skin Swailes B. Melanocytes - neural crest derived cells that have migrated into the stratum basale of the epidermis - have characteristically long, irregular processes that branch into the epidermis between the keratinocytes of the stratum basale and spinosum - one melanocyte serves 5-6 basal keratinocytes forming a epidermal-melanin unit Pigmentation Melanin is: - primarily responsible for skin color - synthesized by melanocytes and accumulates in vesicles called melanosomes - transported within melansomes to the end of melanocyte processes. - phagocytosed when keratinocytes phagocytose the melansome containing processes - is released from melansomes around the keratinocyte nuclei. One melanocyte plus the keratinocytes that ingest its melanin make up a epidermal-melanin unit. - absorbs and scatters sunlight to protect nuclear DNA from UV radiation. Clinical Correlations Skin color Melanocytes of people with ancestral origins near the equator where the need for protection against UV light is greatest produce more melanosomes more rapidly and accumulate them in keratinocytes more abundantly resulting in dark skin. Tanning Tanning is the result of a darkening of pre-existing melanin and an increase in melanin synthesis and its transfer to surrounding keratinocytes in response to exposure to solar radiation C. Merkel cells Merkel cells are mechano-receptors derived from neural crest cells and located in the stratum basale. They are present in greatest numbers in areas of high tactile sensitivity. Their basolateral surfaces contact sensory nerve fibers that penetrate the basal lamina. D. Langerhans cells Langerhans cells are antigen-presenting cells. They are found in the stratum spinosum but send out long processes between the keratinocytes of all layers. Due to this extensive coverage of the skin, they can can present any antigens that may invade the epidermis to surrounding T-lymphocytes triggering an immune response. 3 | Page: Skin Swailes PART C: Dermis and Hypodermis A. Dermis The dermis is the connective tissue component of the skin. It supports the epidermis and binds it to the hypodermis and contains the numerous blood vessels that supply the avascular epidermis with nutrients and are responsible for thermoregulation. If you examine the dermis carefully you will observe a number of features: 1. Dermal papillae - a series of dermal projections into the epidermis - more pronounced in regions of skin that regularly receive pressure (soles, hands etc). 2. Papillary dermis - a thin layer of loose irregular connective tissue below the basement membrane - it forms the dermal papillase - anchoring fibrils (Type VII collagen) in this layer insert into the basal lamina to hold the epidermis and dermis together. 3. Reticular dermis - a thick layer of dense irregular connective tissue immediately below the papillary dermis. - contains Type I collagen bundles which gives skin its strength against tensile forces - contains elastin fibers (seen only with special stains) that provide skin with its elasticity. - contains glands and hair follicles (see adnexa). 4. Vascular network - a deep vascular plexus lies between the reticular dermis and hypodermis - deep plexus supplies a superficial plexus that lies between papillary and reticular dermis - capillary loops extend from the superficial plexus into the dermal papillae - the plexuses, particularly the superficial plexus, vasoconstrict and vasodilate under cold and hot environment conditions to assist in thermoregulation 5. Meissner’s (tactile) corpuscles - elliptical structures located in the dermal papillae of the fingertips, palms and soles - they are encapsulated mechanoreceptors for light touch B. Hypodermis The hypodermis or subcutaneous tissue layer is composed of loose irregular connective tissue and adipocytes (fat cells). It is highly vascular and is therefore a prime site for administration of drugs (like insulin). If you examine the hypodermis carefully you may observe the following feature: 1. Pacinian (lamellated) corpuscles - large, oval structures deep in the reticular dermis or hypodermis - have concentric lamellae of flat Schwaan-type cells that surround an axon - are speicalized in the sensation of coarse touch, pressure (sustained touch) and vibrations 4 | Page: Skin Swailes PART D: Adnexa A. Glands 1. Sebaceous glands Location - widely distributed except palms and soles of feet - often associated with hair follcles Structure - acinar Secretion - sebaceous glands are holocrine glands - sebum is a lipid secretion released by decomposition of secretory cells Function - sebum helps maintain the stratum corneum and hair, it also has Sebaceous gands are antibacterial and antifungal properties branched acinar glands - a disturbance in the flow of sebum from these glands is one of the reasons for developing acne - a chronic inflammation of the sebaceous gland that obstructs sebum flow 2. Eccrine (merocrine) sweat glands Location - widely distributed in the skin - most abundant on the soles of the feet - ~3 million sweat glands in the body - produce around 1.8 liters of sweat per hour Structure - coiled, tubular gland - pale staining secretory cells located in hypodermis - dark staining duct portion difficult to locate but opens at skin surface Secretion - sweat is produced by secretory cells that form the deep portion of the gland in the hypodermis. - myoepithelial cells contract in response to cholinergic stimulation by Eccrine sweat glands are sympathetic nerves to increase flow of secretion into the duct. coiled tubular glands. Function - sweat is an effective means of temperature regulation, removing excess heat from the body by evaporation. 5 | Page: Skin Swailes 3. Apocrine sweat glands Location - axillae, genital region, external auditory meatus, eyelids and areola of the nipple. Structure - coiled tubular glands - wider lumen than eccrine sweat glands - empty sweat into hair follicles not onto the skin surface - myoepithelial cells contract when stimulated by adrenergic sympathetic nerves to increase flow of secretion Secretion - despite the gland name, this is a holocrine secretion - sweat produced is an odorless, milky secretion - when broken down by bacteria it causes body odor Function - function in humans is unknown - in other mammals they function as scent glands Apocrine glands are coiled tubular glands. B. Nails
Load more

Recommended publications
  • Development and Maintenance of Epidermal Stem Cells in Skin Adnexa
    International Journal of Molecular Sciences Review Development and Maintenance of Epidermal Stem Cells in Skin Adnexa Jaroslav Mokry * and Rishikaysh Pisal Medical Faculty, Charles University, 500 03 Hradec Kralove, Czech Republic; [email protected] * Correspondence: [email protected] Received: 30 October 2020; Accepted: 18 December 2020; Published: 20 December 2020 Abstract: The skin surface is modified by numerous appendages. These structures arise from epithelial stem cells (SCs) through the induction of epidermal placodes as a result of local signalling interplay with mesenchymal cells based on the Wnt–(Dkk4)–Eda–Shh cascade. Slight modifications of the cascade, with the participation of antagonistic signalling, decide whether multipotent epidermal SCs develop in interfollicular epidermis, scales, hair/feather follicles, nails or skin glands. This review describes the roles of epidermal SCs in the development of skin adnexa and interfollicular epidermis, as well as their maintenance. Each skin structure arises from distinct pools of epidermal SCs that are harboured in specific but different niches that control SC behaviour. Such relationships explain differences in marker and gene expression patterns between particular SC subsets. The activity of well-compartmentalized epidermal SCs is orchestrated with that of other skin cells not only along the hair cycle but also in the course of skin regeneration following injury. This review highlights several membrane markers, cytoplasmic proteins and transcription factors associated with epidermal SCs. Keywords: stem cell; epidermal placode; skin adnexa; signalling; hair pigmentation; markers; keratins 1. Epidermal Stem Cells as Units of Development 1.1. Development of the Epidermis and Placode Formation The embryonic skin at very early stages of development is covered by a surface ectoderm that is a precursor to the epidermis and its multiple derivatives.
    [Show full text]
  • Pathologic Patterns of the Sebaceous Gland* John S
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector PATHOLOGIC PATTERNS OF THE SEBACEOUS GLAND* JOHN S. STRAUSS, M.D.t AND ALBERT M. KLIGMAN, M.D. By studying the way in which a structurecells which subsequently rupture in the fundus reacts to an imposed experimental stress, oneof the gland. Fragments of the thin eosinophilie can often better understand the changes ex-cell wall, which morphologically resemble kera- hibited in spontaneous dlsease. Much has beentin, persist in the sebum; occasionally the entire learned about the potentialities of the eccrinecell walls survive as ghosts. Furthermore, the in- and apocrine sweat units in this fashion (1—12).dividual oil droplets are separated by keratin- Previous study of the response to injury in thelike trabeculae. A dual potentiality is exhibited sebaceous gland has been restricted mainly to theby sebaceous cells in their capacity to produce changes that occur in the sebaceous duct per sefat predominantly and keratin to a minor de- (13). In this study we have followed the reac-gree. Epidermal cells have this bipotentiality tion of the sebaceous gland itself to a variety ofwith keratin as the major product. cutaneous insults and have correlated the findings with those which occur in disease states. MA.TERIALS AND METRODS The scalp and cheek of post-puberal individuals MOBPOLOGY AND FUNCTION OF were selected for study because the glands here TRN SEACEOUS GLAND are among the largest and most numerous. Biopsy 1.Morphology: The glands of the glabrous skinspecimens were obtained before the experimental are not free but are associated with hair follicles,stresses as well as at varying intervals afterwards.
    [Show full text]
  • Study Guide Medical Terminology by Thea Liza Batan About the Author
    Study Guide Medical Terminology By Thea Liza Batan About the Author Thea Liza Batan earned a Master of Science in Nursing Administration in 2007 from Xavier University in Cincinnati, Ohio. She has worked as a staff nurse, nurse instructor, and level department head. She currently works as a simulation coordinator and a free- lance writer specializing in nursing and healthcare. All terms mentioned in this text that are known to be trademarks or service marks have been appropriately capitalized. Use of a term in this text shouldn’t be regarded as affecting the validity of any trademark or service mark. Copyright © 2017 by Penn Foster, Inc. All rights reserved. No part of the material protected by this copyright may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the copyright owner. Requests for permission to make copies of any part of the work should be mailed to Copyright Permissions, Penn Foster, 925 Oak Street, Scranton, Pennsylvania 18515. Printed in the United States of America CONTENTS INSTRUCTIONS 1 READING ASSIGNMENTS 3 LESSON 1: THE FUNDAMENTALS OF MEDICAL TERMINOLOGY 5 LESSON 2: DIAGNOSIS, INTERVENTION, AND HUMAN BODY TERMS 28 LESSON 3: MUSCULOSKELETAL, CIRCULATORY, AND RESPIRATORY SYSTEM TERMS 44 LESSON 4: DIGESTIVE, URINARY, AND REPRODUCTIVE SYSTEM TERMS 69 LESSON 5: INTEGUMENTARY, NERVOUS, AND ENDOCRINE S YSTEM TERMS 96 SELF-CHECK ANSWERS 134 © PENN FOSTER, INC. 2017 MEDICAL TERMINOLOGY PAGE III Contents INSTRUCTIONS INTRODUCTION Welcome to your course on medical terminology. You’re taking this course because you’re most likely interested in pursuing a health and science career, which entails ­proficiency­in­communicating­with­healthcare­professionals­such­as­physicians,­nurses,­ or dentists.
    [Show full text]
  • CHAPTER 4 the Integumentary System
    CHAPTER 4 The Integumentary System LEARNING OBJECTIVES Upon completion of this chapter, you should be able to: • Name the two layers of the skin. • Name the accessory structures of the integumentary system. • Build and pronounce medical terms of the integumentary system. • Name the disorders and treatments relating to the integumentary system. • Name the major classifi cations of pharmacologic agents used to treat skin disorders. • Analyze and defi ne the new terms introduced in this chapter. • Interpret abbreviations associated with the integumentary system. 53 54 PART TWO • BODY SYSTEMS Introduction The largest organ of the body is the skin. The skin covers the entire body—more than 20 square feet on average—and weighs about 24 pounds. It is part of the integumentary system, which also includes the accessory structures: hair, nails, and sebaceous (oil) and sudoriferous (sweat) glands. Integumentum is Latin for “covering” or “shelter.” The physician who specializes in the diag- nosis and treatment of skin disorders is called a dermatologist (dermat/o being one of the com- bining forms for skin). Coupling the root dermat/o with the previously learned suffi x -logy gives us the term dermatology , which is the term for the specialty practice that deals with the skin. Word Elements The major word elements that relate to the integumentary system consist of various anatomical components, accessory structures, colors of the skin, and abnormal conditions. The Word Ele- ments table lists many of the roots, their meanings, and examples associated
    [Show full text]
  • The Integumentary System
    CHAPTER 5: THE INTEGUMENTARY SYSTEM Copyright © 2010 Pearson Education, Inc. OVERALL SKIN STRUCTURE 3 LAYERS Copyright © 2010 Pearson Education, Inc. Figure 5.1 Skin structure. Hair shaft Dermal papillae Epidermis Subpapillary vascular plexus Papillary layer Pore Appendages of skin Dermis Reticular • Eccrine sweat layer gland • Arrector pili muscle Hypodermis • Sebaceous (oil) gland (superficial fascia) • Hair follicle Nervous structures • Hair root • Sensory nerve fiber Cutaneous vascular • Pacinian corpuscle plexus • Hair follicle receptor Adipose tissue (root hair plexus) Copyright © 2010 Pearson Education, Inc. EPIDERMIS 4 (or 5) LAYERS Copyright © 2010 Pearson Education, Inc. Figure 5.2 The main structural features of the skin epidermis. Keratinocytes Stratum corneum Stratum granulosum Epidermal Stratum spinosum dendritic cell Tactile (Merkel) Stratum basale Dermis cell Sensory nerve ending (a) Dermis Desmosomes Melanocyte (b) Melanin granule Copyright © 2010 Pearson Education, Inc. DERMIS 2 LAYERS Copyright © 2010 Pearson Education, Inc. Figure 5.3 The two regions of the dermis. Dermis (b) Papillary layer of dermis, SEM (22,700x) (a) Light micrograph of thick skin identifying the extent of the dermis, (50x) (c) Reticular layer of dermis, SEM (38,500x) Copyright © 2010 Pearson Education, Inc. Figure 5.3a The two regions of the dermis. Dermis (a) Light micrograph of thick skin identifying the extent of the dermis, (50x) Copyright © 2010 Pearson Education, Inc. Q1: The type of gland which secretes its products onto a surface is an _______ gland. 1) Endocrine 2) Exocrine 3) Merocrine 4) Holocrine Copyright © 2010 Pearson Education, Inc. Q2: The embryonic tissue which gives rise to muscle and most connective tissue is… 1) Ectoderm 2) Endoderm 3) Mesoderm Copyright © 2010 Pearson Education, Inc.
    [Show full text]
  • 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.
    [Show full text]
  • 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
    [Show full text]
  • Curling Cuticles of the Great Toenails: a Case Report of Eponychogryphosis
    Open Access Case Report DOI: 10.7759/cureus.3959 Curling Cuticles of the Great Toenails: A Case Report of Eponychogryphosis Philip R. Cohen 1 1. Dermatology, San Diego Family Dermatology, San Diego, USA Corresponding author: Philip R. Cohen, [email protected] Abstract The cuticle, also referred to as the eponychium, creates a seal between the proximal nail fold and the nail plate. It is derived from both the ventral and dorsal portions of the proximal nail fold. In addition to its principle function as a barrier preventing allergens, irritants and pathogens from entering the nail cul-de- sac, the cuticle can play a role as a model for evaluating the etiology and management of diseases that affect capillary microcirculation, provide a source of solid tissue for genetic disorder studies, and aid in the evaluation of patients in whom the diagnoses of either systemic scleroderma or dermatomyositis is being entertained. Curling cuticle is a distinctive and unique occurrence. The clinical features of a man with curling cuticles on the lateral portion of both great toes is described. Although a deficiency in personal hygiene may partially account for the clinical finding, the pathogenesis of this observation remains to be established. The term ‘eponychogryphosis’ is proposed to describe the alteration of the patient’s cuticles. Categories: Dermatology, Internal Medicine, Rheumatology Keywords: curl, curling, cuticle, eponychium, eponychogryphosis, fold, great, onychogryphosis, nail, toe Introduction The cuticle, also known as the eponychium, is an extension of the stratum corneum from the proximal nail fold [1-3]. It forms a seal that prevents allergens, irritants, and pathogens from entering the potential space between the distal skin of the digit and the nail plate [4-5].
    [Show full text]
  • The Integumentary System
    5 The Integumentary System PowerPoint® Lecture Presentations prepared by Jason LaPres Lone Star College—North Harris © 2012 Pearson Education, Inc. An Introduction to the Integumentary System • Learning Outcomes • 5-1 Describe the main structural features of the epidermis, and explain the functional significance of each. • 5-2 Explain what accounts for individual differences in skin color, and discuss the response of melanocytes to sunlight exposure. • 5-3 Describe the interaction between sunlight and vitamin D3 production. • 5-4 Describe the roles of epidermal growth factor. © 2012 Pearson Education, Inc. An Introduction to the Integumentary System • Learning Outcomes • 5-5 Describe the structure and functions of the dermis. • 5-6 Describe the structure and functions of the hypodermis. • 5-7 Describe the mechanisms that produce hair, and explain the structural basis for hair texture and color. © 2012 Pearson Education, Inc. An Introduction to the Integumentary System • Learning Outcomes • 5-8 Discuss the various kinds of glands in the skin, and list the secretions of those glands. • 5-9 Describe the anatomical structure of nails, and explain how they are formed. • 5-10 Explain how the skin responds to injury and repairs itself. • 5-11 Summarize the effects of aging on the skin. © 2012 Pearson Education, Inc. An Introduction to the Integumentary System • The Integument • Is the largest system of the body • 16% of body weight • 1.5 to 2 m2 in area • The integument is made up of two parts 1. Cutaneous membrane (skin) 2. Accessory structures © 2012 Pearson Education, Inc. An Introduction to the Integumentary System • Two Components of the Cutaneous Membrane 1.
    [Show full text]
  • 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
    [Show full text]
  • •Nail Structure •Nail Growth •Nail Diseases, Disorders, and Conditions
    •Nail Structure Nail Theory •Nail Growth •Nail Diseases, Disorders, and Conditions Onychology The study of nails. Nail Structure 1. Free Edge – Extends past the skin. 2. Nail Body – Visible nail area. 3. Nail Wall – Skin on both sides of nail. 4. Lunula – Whitened half-moon 5. Eponychium – Lies at the base of the nail, live skin. 6. Mantle – Holds root and matrix. Nail Structure 7. Nail Matrix – Generates cells that make the nail. 8. Nail Root – Attached to matrix 9. Cuticle – Overlapping skin around the nail 10. Nail Bed – Skin that nail sits on 11. Nail Grooves – Tracks that nail slides on 12. Perionychium – Skin around nail 13. Hyponychium – Underneath the free edge Hyponychium Nail Body Nail Groove Nail Bed Lunula Eponychium Matrix Nail Root Free Edge Nail Bed Eponychium Matrix Nail Root Nail Growth • Keratin – Glue-like protein that hardens to make the nail. • Rate of Growth – 4 to 6 month to grow new nail – Approx. 1/8” per month • Faster in summer • Toenails grow faster Injuries • Result: shape distortions or discoloration – Nail lost due to trauma. – Nail lost through disease. Types of Nail Implements Nippers Nail Clippers Cuticle Pusher Emery Board or orangewood stick Nail Diseases, Disorders and Conditions • Onychosis – Any nail disease • Etiology – Cause of nail disease, disorder or condition. • Hand and Nail Examination – Check for problems • Six signs of infection – Pain, swelling, redness, local fever, throbbing and pus Symptoms • Coldness – Lack of circulation • Heat – Infection • Dry Texture – Lack of moisture • Redness
    [Show full text]
  • 26 April 2010 TE Prepublication Page 1 Nomina Generalia General Terms
    26 April 2010 TE PrePublication Page 1 Nomina generalia General terms E1.0.0.0.0.0.1 Modus reproductionis Reproductive mode E1.0.0.0.0.0.2 Reproductio sexualis Sexual reproduction E1.0.0.0.0.0.3 Viviparitas Viviparity E1.0.0.0.0.0.4 Heterogamia Heterogamy E1.0.0.0.0.0.5 Endogamia Endogamy E1.0.0.0.0.0.6 Sequentia reproductionis Reproductive sequence E1.0.0.0.0.0.7 Ovulatio Ovulation E1.0.0.0.0.0.8 Erectio Erection E1.0.0.0.0.0.9 Coitus Coitus; Sexual intercourse E1.0.0.0.0.0.10 Ejaculatio1 Ejaculation E1.0.0.0.0.0.11 Emissio Emission E1.0.0.0.0.0.12 Ejaculatio vera Ejaculation proper E1.0.0.0.0.0.13 Semen Semen; Ejaculate E1.0.0.0.0.0.14 Inseminatio Insemination E1.0.0.0.0.0.15 Fertilisatio Fertilization E1.0.0.0.0.0.16 Fecundatio Fecundation; Impregnation E1.0.0.0.0.0.17 Superfecundatio Superfecundation E1.0.0.0.0.0.18 Superimpregnatio Superimpregnation E1.0.0.0.0.0.19 Superfetatio Superfetation E1.0.0.0.0.0.20 Ontogenesis Ontogeny E1.0.0.0.0.0.21 Ontogenesis praenatalis Prenatal ontogeny E1.0.0.0.0.0.22 Tempus praenatale; Tempus gestationis Prenatal period; Gestation period E1.0.0.0.0.0.23 Vita praenatalis Prenatal life E1.0.0.0.0.0.24 Vita intrauterina Intra-uterine life E1.0.0.0.0.0.25 Embryogenesis2 Embryogenesis; Embryogeny E1.0.0.0.0.0.26 Fetogenesis3 Fetogenesis E1.0.0.0.0.0.27 Tempus natale Birth period E1.0.0.0.0.0.28 Ontogenesis postnatalis Postnatal ontogeny E1.0.0.0.0.0.29 Vita postnatalis Postnatal life E1.0.1.0.0.0.1 Mensurae embryonicae et fetales4 Embryonic and fetal measurements E1.0.1.0.0.0.2 Aetas a fecundatione5 Fertilization
    [Show full text]