DOCSLIB.ORG

Practical Roadmap

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Practical Roadmap PRACTICAL ROADMAP GLANDS Mrs. A. Jovanović Unicellular Glands Multicellular Unicellular gland –Goblet cell Multicellular gland Simple tubular Simple Simple alveolar Simple tubulo‐alveolar Multicellular glands Compound tubular Compound Compound alveolar Compound tubulo‐alveolar MULTICELLULAR GLANDS Simple Simple tubular (Simple coiled tubular) Simple alveolar (Simple branched alveolar) Simple tubulo‐alveolar SIMPLE GLANDS • Slide 85 Jejunum Simple tubular gland Unicellular gland ‐ Goblet cell Plica circulares Lumen of jejunum Wall of jejunum Plica circulares Villus (singular) Villi (plural) Glands Simple tubular glands are labelled with a black arrow. Note how they open in between two adjacent villi. You can clearly see their one unbranched simple duct (D) and a tubular (tube shaped) secretory end piece (SE). Lumen The encircled structure is the secretory and piece of a gland cut in a cross section. The other glands have been cut longitudinally which is the reason you see both the ducts as well as secretory end pieces. The inset shows pale goblet cells labelled with a black arrow. SIMPLE GLANDS • Slide 91 Colon Simple tubular gland Unicellular gland –Goblet cell Wall of the colon Lumen Glands Mucosa Mucosa Simple tubular glands Simple tubular gland is encircled in black. The dominant goblet cells constitute the glandular epithelium. Simple columnar epithelial cells with a microvillus border are present but not often visible in between the goblet cells. The simple duct of the gland delivers mucous secretion (labelled with black arrows) onto the luminal surface. Lumen SIMPLE GLANDS • Slide 10 Uterus Simple tubular gland Lumen Simple tubular glands Stroma Lumen Blood vessels Simple tubular glands SIMPLE GLANDS • Slide 36 Thin skin Sebaceous gland ‐ Simple branched alveolar gland Eccrine sweat gland ‐ Simple coiled tubular gland Hair follicle Sebaceous gland Hypodermis Eccrine sweat gland Dermis Epidermis Sebaceous gland Note: This gland is only present in the thin skin since it is found associated with a hair follicle. The thick skin found on the soles of our feet and palms of our hands is hairless skin and thus has no sebaceous glands! Sebaceous gland Note: Sebaceous gland is associated with a hair follicle. This simple (one duct labelled with a black arrow) branched alveolar (secretory end pieces branched and sack like – encircled) gland delivers its waxy secretion called sebum into the hair follicle, coating the hair and providing lubrication. Note: Each cell of this gland undergoes programmed cell death after the sebum has been released into the hair follicle (holocrine mode of secretion). The cells of this gland are often confused with mucous cells, thus please note the shape of the cells in the sebaceous gland and position of the nucleus and compare those with the cells of the mucous secreting gland (goblet cell or submandibular gland)! Smooth muscle • Eccrine sweat gland This simple gland is present in both thick and thin skin (we sweat on our palms and soles as well as on our scalp!) Eccrine sweat gland Duct of the eccrine sweat gland leading to the skin surface Hair follicle The secretory end piece of the eccrine sweat gland is made out of the simple cuboidal epithelium or sometimes pseudostratified epithelium (encircled in black). Note the cuboidal cell shape and centrally placed round nucleus present in the encircled structure). The ducts of the eccrine sweat gland (encircled in red) are made out of the stratified cuboidal epithelial cells since they have more than one layer of epithelial cells. Note the presence of two layers of cells in the duct sections and the proximity of dark nuclei is the reason the ducts stain more basophilically. SIMPLE GLANDS • Slide 35 Thick skin Eccrine sweat gland Note: Eccrine sweat gland is present in both thin and thick skin. The duct of the eccrine sweat gland “traveling” through the epidermis of the thick skin Ducts Secretory end pieces The ducts with stratified cuboidal epithelium The secretory end piece with simple cuboidal or pseudostratified epithelial cells MALTICELLULAR GLANDS Compound Compound tubular Compound alveolar Compound tubulo‐alveolar MULTICELLULAR GLANDS • Slide 2 Submandibular gland Compound tubulo‐alveolar gland Connective tissue capsule Tissue parenchyma Connective tissue septa Interlobular duct Tissue parenchyma consists of both mucous (labelled with red arrows) and serous (labelled with black arrows) regions thus the gland is classified as mixed according to its nature of secretion Intralobular striated ducts Note the the presence of many intralobular ducts (black arrows) within connective tissue septae. These ducts are lined with stratified epithelial cells and surrounded with eosinophilically staining connective tissue Striated intralobular duct Intercalated intralobular ducts Striations Striated duct (intralobular duct Serous secretory end Mucous secretory piece end piece Note the difference between tubular mucous (blue tube) and pyramidal serous (black pyramid) secreting cells of the respective secretory end pieces. Also note the staining of the cell, position and shape of the nucleus. Note contractile myoepithelial cells (black arrow) located in between the basal plasma membrane of the secretory epithelial cells and the basement membrane. Their function is the move secretion towards the excretory duct.
Load more

Recommended publications
  • Skates and Rays Diversity, Exploration and Conservation – Case-Study of the Thornback Ray, Raja Clavata
    UNIVERSIDADE DE LISBOA FACULDADE DE CIÊNCIAS DEPARTAMENTO DE BIOLOGIA ANIMAL SKATES AND RAYS DIVERSITY, EXPLORATION AND CONSERVATION – CASE-STUDY OF THE THORNBACK RAY, RAJA CLAVATA Bárbara Marques Serra Pereira Doutoramento em Ciências do Mar 2010 UNIVERSIDADE DE LISBOA FACULDADE DE CIÊNCIAS DEPARTAMENTO DE BIOLOGIA ANIMAL SKATES AND RAYS DIVERSITY, EXPLORATION AND CONSERVATION – CASE-STUDY OF THE THORNBACK RAY, RAJA CLAVATA Bárbara Marques Serra Pereira Tese orientada por Professor Auxiliar com Agregação Leonel Serrano Gordo e Investigadora Auxiliar Ivone Figueiredo Doutoramento em Ciências do Mar 2010 The research reported in this thesis was carried out at the Instituto de Investigação das Pescas e do Mar (IPIMAR - INRB), Unidade de Recursos Marinhos e Sustentabilidade. This research was funded by Fundação para a Ciência e a Tecnologia (FCT) through a PhD grant (SFRH/BD/23777/2005) and the research project EU Data Collection/DCR (PNAB). Skates and rays diversity, exploration and conservation | Table of Contents Table of Contents List of Figures ............................................................................................................................. i List of Tables ............................................................................................................................. v List of Abbreviations ............................................................................................................. viii Agradecimentos ........................................................................................................................
    [Show full text]
  • Vocabulario De Morfoloxía, Anatomía E Citoloxía Veterinaria
    Vocabulario de Morfoloxía, anatomía e citoloxía veterinaria (galego-español-inglés) Servizo de Normalización Lingüística Universidade de Santiago de Compostela COLECCIÓN VOCABULARIOS TEMÁTICOS N.º 4 SERVIZO DE NORMALIZACIÓN LINGÜÍSTICA Vocabulario de Morfoloxía, anatomía e citoloxía veterinaria (galego-español-inglés) 2008 UNIVERSIDADE DE SANTIAGO DE COMPOSTELA VOCABULARIO de morfoloxía, anatomía e citoloxía veterinaria : (galego-español- inglés) / coordinador Xusto A. Rodríguez Río, Servizo de Normalización Lingüística ; autores Matilde Lombardero Fernández ... [et al.]. – Santiago de Compostela : Universidade de Santiago de Compostela, Servizo de Publicacións e Intercambio Científico, 2008. – 369 p. ; 21 cm. – (Vocabularios temáticos ; 4). - D.L. C 2458-2008. – ISBN 978-84-9887-018-3 1.Medicina �������������������������������������������������������������������������veterinaria-Diccionarios�������������������������������������������������. 2.Galego (Lingua)-Glosarios, vocabularios, etc. políglotas. I.Lombardero Fernández, Matilde. II.Rodríguez Rio, Xusto A. coord. III. Universidade de Santiago de Compostela. Servizo de Normalización Lingüística, coord. IV.Universidade de Santiago de Compostela. Servizo de Publicacións e Intercambio Científico, ed. V.Serie. 591.4(038)=699=60=20 Coordinador Xusto A. Rodríguez Río (Área de Terminoloxía. Servizo de Normalización Lingüística. Universidade de Santiago de Compostela) Autoras/res Matilde Lombardero Fernández (doutora en Veterinaria e profesora do Departamento de Anatomía e Produción Animal.
    [Show full text]
  • Basic Histology (23 Questions): Oral Histology (16 Questions
    Board Question Breakdown (Anatomic Sciences section) The Anatomic Sciences portion of part I of the Dental Board exams consists of 100 test items. They are broken up into the following distribution: Gross Anatomy (50 questions): Head - 28 questions broken down in this fashion: - Oral cavity - 6 questions - Extraoral structures - 12 questions - Osteology - 6 questions - TMJ and muscles of mastication - 4 questions Neck - 5 questions Upper Limb - 3 questions Thoracic cavity - 5 questions Abdominopelvic cavity - 2 questions Neuroanatomy (CNS, ANS +) - 7 questions Basic Histology (23 questions): Ultrastructure (cell organelles) - 4 questions Basic tissues - 4 questions Bone, cartilage & joints - 3 questions Lymphatic & circulatory systems - 3 questions Endocrine system - 2 questions Respiratory system - 1 question Gastrointestinal system - 3 questions Genitouirinary systems - (reproductive & urinary) 2 questions Integument - 1 question Oral Histology (16 questions): Tooth & supporting structures - 9 questions Soft oral tissues (including dentin) - 5 questions Temporomandibular joint - 2 questions Developmental Biology (11 questions): Osteogenesis (bone formation) - 2 questions Tooth development, eruption & movement - 4 questions General embryology - 2 questions 2 National Board Part 1: Review questions for histology/oral histology (Answers follow at the end) 1. Normally most of the circulating white blood cells are a. basophilic leukocytes b. monocytes c. lymphocytes d. eosinophilic leukocytes e. neutrophilic leukocytes 2. Blood platelets are products of a. osteoclasts b. basophils c. red blood cells d. plasma cells e. megakaryocytes 3. Bacteria are frequently ingested by a. neutrophilic leukocytes b. basophilic leukocytes c. mast cells d. small lymphocytes e. fibrocytes 4. It is believed that worn out red cells are normally destroyed in the spleen by a. neutrophils b.
    [Show full text]
  • Exocrine Glands  Ccasslassified Da Acco Rd Ing to
    Glandular tissues Danil Hammoudi.MD A gland is an organ that synthesizes a substance for relfbthlease of substances such •as hormones • breast milk, •often into the bloodstream (endocrine gland) • into cavities inside the body or its outer surface (exocrine gland). Myoepithelial Cells • These are contractile cells that lie within the basal lamina in the secretory ppgortion of glands and intercalated ducts, which form the initial portion of the duct system. • They are instrumental in moving the secretions toward the excretory duct. Histologically, glands are described using some standard vocabulary, with which you should be familiar. exocrine / endocrine Destination of product: Nature of product: serous / mucous / mixed Location of gland: mucosal / submucosal Arrangement of secretory cells: acinus / tubule / cord Number of interconnected units: simple / compound intercalated / striated Duct function: secret/tory / excre tory Duct location: intralobular / interlobular / interlobar Tissue composition: parenchyma / stroma The endocrine system of humans Pineal gland Hypothalamus Posterior pituitary Anterior pituitary Thyroid Parathyroid Thymus Heart Liver Stomach and small intestine Pancreas Adrenal cortex Adrenal medulla Kidney Skin Silverthorn, Human Gonads Physiology, 3rd edition Figure 7-2 Duussgadsapoduoosctless glands that produce hormones Secretions include amino acids, proteins, glycoproteins, and steroids Endocrine Glands More numerous than endocrine glands Secrete their products onto body surfaces (skin) or into body cavities
    [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]
  • Histogenesis of the Proventricular Submucosal Gland of the Chick As Revealed by Light and Electron Microscopy Dale S
    HISTOGENESIS OF THE PROVENTRICULAR SUBMUCOSAL GLAND OF THE CHICK AS REVEALED BY LIGHT AND ELECTRON MICROSCOPY DALE S. THOMSON Malone College, Canton, Ohio ABSTRACT The development of the submucosal tubuloalveolar glands of the proventriculus was studied with both light and electron microscopes, with special reference given to the 13-18-day period. Beginning as an invagination in the stratified columnar epithelium lining the lumen of the proventriculus, the simple tubular gland, by repeated bifurcation of the invaginated portion, by sloughing of the superficial cells, and by remodeling of the residual basal cells from columnar to cuboidal, becomes a compound tubuloalveolar gland composed of numerous secretory units. Concomitant with the gross cellular changes, ultra- structural changes in the intercellular membranes are evident. By day 4 after hatching, the cells forming the secretory units appear to be functional. INTRODUCTION The avian stomach is peculiar in that it consists of two morphologically and physiologically distinct parts: the glandular portion, or proventriculus, and the muscular portion, or gizzard. The proventriculus is a relatively thick-walled structure located at the distal end of the oesophagus and containing both simple mucous-secreting glands and compound submucosal tubuloalveolar glands. The gizzard is a thick muscular bulb, the mucosa of which contains simple glandular cells which secrete a tough, horny layer. The proventriculus has been described by Cazin (1886, 1887), Zietschmann (1908), Calhoun (1933, 1954), Batt (1924), and Bradley and Graham (1950). Aitken (1958) and Toner (1963) further amplified the literature with specific reference to the compound submucosal glands. Sjogren (1941) and Hibbard (1942) described the embryonic development of the submucosal glands.
    [Show full text]
  • Histology -2Nd Stage Dr. Abeer.C.Yousif
    Dr. Abeer.c.Yousif Histology -2nd stage What is histology? Histology is the science of microscopic anatomy of cells and tissues, in Greek language Histo= tissue and logos = study and it's tightly bounded to molecular biology, physiology, immunology and other basic sciences. Tissue: A group of cells similar in structure, function and origin. In tissue cells may be dissimilar in structure and functions but they are always similar in origin. Classification of tissues: despite the variations in the body the tissues are classified into four basic types: 1. Epithelium (epithelial tissue) covers body surfaces, line body cavities, and forms glands. 2. Connective tissue underlies or supports the other three basic tissues, both structurally and functionally. 3. Muscle tissue is made up of contractile cells and is responsible for movement. 4. Nerve tissue receives, transmits, and integrates information from outside and inside the body to control the activities of the body. Epithelium General Characterizes of epithelial tissues: 1. Cells are closed to each other and tend to form junctions 2. Little or non-intracellular material between intracellular space. 3. Cell shape and number of layers correlate with the function of the epithelium. 4. Form the boundary between external environment and body tissues. 5. Cell showed polarity 6. Does not contain blood vesicle (vascularity). 7. Mitotically active. 8. Rest on basement membrane (basal lamina). 9. Regeneration: because epithelial tissue is continually damage or lost. 10. Free surface: epithelial tissue always has apical surface or a free adage. Dr. Abeer.c.Yousif Histology -2nd stage Method of Classification epithelial tissue 1- Can be classified according to number of layer to two types: A.
    [Show full text]
  • Histology Lecture II
    Histology lecture II Epithelial tissue (Epithelium) Prepared by Dr. Mohamed Abdalla Eltayeb College of medicine Taibah University 1 1. Stratified squamous epithelium The surface layer consists of squamous cells. It is a protective epithelium. There are two types of stratified squamous epithelium:- 2. Stratified squamous keratinized epithelium : the cells of the surface layer are dead cells consisting of keratin which is a type of protein e.g. skin 1. Stratified squamous non-keratinized epithelium: the cells of the surface layer are nucleated living cells and do not form keratin e.g. oesophagus 2 Dr. Mohamed Abdalla Eltayeb Surface layer of keratin without nucleated cells Stratified squamous keratinized epithelium Location:- Basement membrane Skin Connective tissue 3 Dr. Mohamed Abdalla Eltayeb Surface cells are nucleated living squamous cells without keratin Stratified squamous nonkeratinized epithelium Location:- Oral cavity and oesophagus Basement membrane 4 Connective tissue Dr. Mohamed Abdalla Eltayeb 2. Stratified columnar epithelium In stratified columnar epithelium the cells of the surface layer of the epithelium are columnar. This type of epithelium is found in few locations in the body e.g. ducts of salivary glands . Dr. Mohamed Abdalla Eltayeb 5 Stratified columnar epithelium Surface layer of columnar cells Connective tissue 6 Dr. Mohamed Abdalla Eltayeb 3. Transitional epithelium This type of epithelium is found in the urinary system (ureter and urinary bladder). It is protective and impermeable. The cells of the surface layer may be squamous or large dome-shaped. The cells of the surface layer are large with a rounded free border in the contracted urinary bladder The surface cells change to squamous (flat) in a stretched or distended bladder.
    [Show full text]
  • Índice De Denominacións Españolas
    VOCABULARIO Índice de denominacións españolas 255 VOCABULARIO 256 VOCABULARIO agente tensioactivo pulmonar, 2441 A agranulocito, 32 abaxial, 3 agujero aórtico, 1317 abertura pupilar, 6 agujero de la vena cava, 1178 abierto de atrás, 4 agujero dental inferior, 1179 abierto de delante, 5 agujero magno, 1182 ablación, 1717 agujero mandibular, 1179 abomaso, 7 agujero mentoniano, 1180 acetábulo, 10 agujero obturado, 1181 ácido biliar, 11 agujero occipital, 1182 ácido desoxirribonucleico, 12 agujero oval, 1183 ácido desoxirribonucleico agujero sacro, 1184 nucleosómico, 28 agujero vertebral, 1185 ácido nucleico, 13 aire, 1560 ácido ribonucleico, 14 ala, 1 ácido ribonucleico mensajero, 167 ala de la nariz, 2 ácido ribonucleico ribosómico, 168 alantoamnios, 33 acino hepático, 15 alantoides, 34 acorne, 16 albardado, 35 acostarse, 850 albugínea, 2574 acromático, 17 aldosterona, 36 acromatina, 18 almohadilla, 38 acromion, 19 almohadilla carpiana, 39 acrosoma, 20 almohadilla córnea, 40 ACTH, 1335 almohadilla dental, 41 actina, 21 almohadilla dentaria, 41 actina F, 22 almohadilla digital, 42 actina G, 23 almohadilla metacarpiana, 43 actitud, 24 almohadilla metatarsiana, 44 acueducto cerebral, 25 almohadilla tarsiana, 45 acueducto de Silvio, 25 alocórtex, 46 acueducto mesencefálico, 25 alto de cola, 2260 adamantoblasto, 59 altura a la punta de la espalda, 56 adenohipófisis, 26 altura anterior de la espalda, 56 ADH, 1336 altura del esternón, 47 adipocito, 27 altura del pecho, 48 ADN, 12 altura del tórax, 48 ADN nucleosómico, 28 alunarado, 49 ADNn, 28
    [Show full text]
  • Squamous Epithelium Are Thin, Which Allows for the Rapid Passage of Substances Through Them
    Chapter 2 1st Prof. Anatomy Arsalan (Lecturer Department of Pharmacy University of Peshawar) Tissue is an aggregation of similar cells and their products that perform same function. There are four principal types of tissues in the body: ❑ epithelial tissue: covers body surfaces, lines body cavities and ducts and forms glands ❑ connective tissue: binds, supports, and protects body parts ❑ muscle tissue: produce body and organ movements ❑ nervous tissue: initiates and transmits nerve impulses from one body part to another • Epithelial tissues cover body and organ surfaces, line body cavities and lumina and forms various glands • Derived from endoderm ,ectoderm, and mesoderm • composed of one or more layers of closely packed cells • Perform diverse functions of protection, absorption, excretion and secretion. Highly cellular with low extracellular matrix Polar – has an apical surface exposed to external environment or body cavity, basal layer attached to underlying connective tissue by basement membrane and lateral surfaces attached to each other by intercellular junctions Innervated Avascular – almost all epithelia are devoid of blood vessels, obtain nutrients by diffusion High regeneration capacity Protection: Selective permeability: in GIT facilitate absorption, in kidney facilitate filtration, in lungs facilitate diffusion. Secretions: glandular epithelium form linings of various glands, involved in secretions. Sensations: contain some nerve endings to detect changes in the external environment at their surface Epithelium rests on connective tissue. Between the epithelium and connective tissue is present the basement membrane which is extracellular matrix made up of protein fibers and carbohydrates. Basement membrane attach epithelium to connective tissue and also regulate movement of material between epithelium and connective tissue Epithelial cells are bound together by specialized connections in the plasma membranes called intercellular junctions .
    [Show full text]
  • Histology of Male Reproductive System
    Histology of Male Reproductive System Dr. Rajesh Ranjan Assistant Professor Deptt. of Veterinary Anatomy C.V.Sc, Rewa 1 Male Reproductive System A-Testis B-Epididymis C-Ductus Deferens D-Urethra 1-Pelvic part 2-Penile part E-Penis G-Accessory Glands 1. Seminal vesicles 2-Prostate gland 3-Bulbouretheral gland/ Cowper’s gland Testis The testis remains covered by: Tunica vaginalis- The outermost covering (peritoneal covering of the testis and epididymis). It has a parietal and visceral layer. The parietal layer remains adhered to the scrotum while the visceral layer adheres to the capsule of the testis. The space between the these two layers is called the vaginal cavity. The layers consists of mesothelium lining and connective tissue that blends with the underlying connective tissue of the scrotum. Tunica albuginea: Capsule of the testis Consists of dense irregular connective tissue, predominantly collagen fibers, few elastic fibers and myofibroblast. It has vascular layer (Tunica vasculosa) that contains anatomizing branches of testicular artery and veins. The tunica albuginea gives connective tissue trabeculae called septula testis which converge towards the mediastinum testis. The septula testis divides the testicular parenchyma into number of testicular lobules. Each lobule contains 1-4 seminiferous tubules. Mediastinum testis is a connective tissue area containing the channels of rete testis, large blood and lymph vessels. In bull it occupies the central position along the longitudinal axis of the gonad. Interstitial cells (Leydig cells) The inter-tubular spaces of the testis contain loose C.T., blood and lymph vessels, fibrocytes, free mononuclear cells and interstitial cells called Leydig cells.
    [Show full text]
  • Frequency Vs. Interval
    Frequency vs. Interval • Milking Frequency – 2 times/day (2X) or 3 times/day (3X) • Milking Interval – 12 hours, 8 hours, etc. • How often do cows want to be milked? Frequency vs. Interval What are the advantages and disadvantages of more frequent milkings? Chemotactic agents: attract PMN into tissues & milk! • Alveoli • Basic milk-producing unit • Lined with epithelial cells • Phagocyte • Cell that engulfs and absorbs bacteria • PMN • Polymorphonuclear neutrophil • First line of defense against invading pathogens during mastitis • Majority cell type accounting for SCC • Macrophages, lymphocytes • Chemotaxis • Movement of an organism in response to a chemical stimulus • Somatic cells and bacteria move according to chemicals in their environment • Where and why would they be moving? • What is a common example of chemotaxis unrelated to milk secretion? Altered Composition During Mastitis Somatic cell counts (SCC) Na, Cl, whey protein (e.g., serum albumin, Ig) lactose, casein, K, α-lactalbumin Altered Composition During Mastitis • Lactose • Synthesis is decreased • Casein • Proteolysis • Proteolytic enzymes from leukocytes and bacteria • Milk fat • Susceptibility of milk fat globule membranes to the action of lipases, resulting in breakdown of triglycerides. Altered Composition During Mastitis • Na+, Cl-, K+ • Electrical potential across apical membrane disrupted • This is the basis of the electrical conductivity methods of detecting mastitis • https://www.youtube.com/watch?v=P-imDC1txWw • Polymorphonuclear neutrophils (PMNs) • Mastitis causes chemotaxis of the cells into the tissue and disruption of epithelial tight junctions • This is the basis of many mastitis detection methods • Albumin, immunoglobulins • Enter the milk via disrupted tight junctional complexes PHYLOGENY & ONTOGENY Phylogeny – the evolutionary development of any animal species (related to mammary gland development) Class Mammalia: Monotremes I.
    [Show full text]