This document summarizes the histology of epithelium and connective tissue. It describes the four basic types of tissues as epithelial, connective, muscle and nervous tissues. It focuses on epithelium and connective tissue. Epithelial tissue is composed of closely packed cells that line surfaces and form glands. Connective tissue contains extracellular matrix and fibers. The document classifies epithelia based on cell layers and cell shape. It describes the structure and functions of simple, stratified, pseudostratified and transitional epithelia. It also discusses the extracellular matrix, basement membrane and cells of connective tissue.
11.03.08(c): Histology of the Cardiovascular SystemOpen.Michigan
Slideshow is from the University of Michigan Medical School's M1 Cardiovascular / Respiratory sequence
View additional course materials on Open.Michigan:
openmi.ch/med-M1Cardio
11.03.08(c): Histology of the Cardiovascular SystemOpen.Michigan
Slideshow is from the University of Michigan Medical School's M1 Cardiovascular / Respiratory sequence
View additional course materials on Open.Michigan:
openmi.ch/med-M1Cardio
This is the presentation that I gave in 3rd semester in English.
This presentation is about histology of different animals with focus on equine, bovine, canine, and feline.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
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A presentation with a view on how infection spreads through the focus of dental caries into a full cellulitis. Since dentists have to deal often with large space infections, this presentation helps to review your knowledge in this subject. - Dr. Abhishek John Samuel, MDS, Endodontics
Tissues are a group of similar cells of the same origin that carry out a specific function together. Humans have four different types of basic tissues. Connective tissues such as bone tissue are made up of fibrous cells and give shape and structure to organs. Muscle tissue is made up of cells that can contract together and allow animals to move. Epithelial tissues make up the outer layers of organs, such as the skin or the outer layer of the stomach. Nervous tissue is made of specialized cells that transmit information through electrochemical impulses, such as the tissue of nerves, the spinal cord, and the brain.
Epithelial tissue, also known as the epithelium, is one of the four tissues found in the human body. It exists in various parts of the body, such as our digestive system, outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs.
Histology
Junqueira’s Basic Histology Text and Atlas, 15th Ed
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
2. Human body is composed of 4 basic types of tissue : Epithelial Tissues Composed of closely aggregated polyhedral cells with very little extracellular substance. Connective Tissues Characterized by the abundance of extracellular material produced by its cells. Muscle Tissues Composed of elongated cells that have the specialized function of contraction. Nervous Tissues Composed of cells with elongated processes extending from the cell body that have the specialized function of receiving, generating, transmitting nerve impulses. BBC 1 2
3. EPITHELIUM Derive from ectoderm, mesoderm, endoderm. Epithelium : Covers and lines body surfaces (except articular cartilage, enamel of the tooth, anterior surface of iris) Forms the functional units of secretory glands salivary glands, liver BBC 1 3
4. Basic function : Protection (skin) Absorption (small and large intestine) Transport of material (by cilia) Secretion (gland) Excretion (tubulus of the kidney) Gas exchange (lung alveolus) Gliding between surface (mesothelium) Epithelia anchored to a basal lamina. Basal lamina + connective tissue component basement membrant BBC 1 4
5. Classified into 3 major categories : Simple epithelia : 1 layer of cells simple squamous epithelium Simple cuboidal epithelium Simple columnar epithelium Endothelium : simple epithelium lining the blood and lympatic vessel. Mesothelium : simple epithelium lining all body cavities. Stratified epithelia : 2 or more cell layers Stratified squamous epithelium : Non keratinized Keratininized : (nuclei absent in the outer layer) Stratified cuboidal epithelium Sratified columnar epithelium Pseudostratified epithelium : basal and columnar cells Pseudostratified columnar ciliated epithelium trachea Pseudostratified columnar epithelium with stereocilia epididymis Transitional epithelium urinary passage (urothelium) BBC 1 5
9. BBC 1 9 Figure 4—13. Section of a vein containing red blood cells. All blood vessels are lined with a simple squamous epithelium called endothelium (arrowheads). Pararosaniline–toluidine blue (PT) stain. Medium magnification.
10. Simple cuboidal epithelium BBC 1 10 Figure 4—15. Simple cuboidal epithelium from kidney collecting tubules. Cells of these tubules are responsive to the antidiuretic hormone and control the resorption of water from the glomerular filtrate, thus affecting urine density and helping retain the water content of the body. PT stain. Low magnification.
11. Simple columnar epithelium BBC 1 11 Figure 4—16. Simple columnar epithelium formed by long cells with elliptical nuclei. The epithelium rests on the loose connective tissue of the lamina propria. A basal lamina (not visible) is interposed between the epithelial cells and the connective tissue. The round nuclei within the epithelial layer belong to lymphocytes that are migrating through the epithelium (arrows). H&E stain. Medium magnification. (Courtesy of PA Abrahamsohn.)
16. BBC 1 16 Epithelial membranes are classified according to the number of cell layers between the basal lamina and the free surface and by the morphology of the epithelial cells (Table 5–1). If the membrane is composed of a single layer of cells, it is called simple epithelium; if it is composed of more than one cell layer, it is called stratified epithelium (Fig. 5–1). The morphology of the cells may be squamous (flat), cuboidal, or columnar when viewed in sections taken perpendicular to the basement membrane. Stratified epithelia are classified by the morphology of the cells in their superficial layer only. In addition to these two major classes of epithelia, which are further identified by cellular morphology, there are two other distinct types: pseudostratified and transitional. For more information see the Epithelium section of Chapter 5: Gartner and Hiatt: Color Textbook of Histology, 3rd ed. Philadelphia, W.B. Saunders, 2007.
19. EPITHELIAL CELL POLARITY On apical polarity : Cilia trachea For protection Motile cell projection originating from basal bodies Microvilli intestine For absorption Finger like projections of the apical epithelial cell surface Stereocilia epididymis Long and branching finger like projections of the apical epithelial cell surface Basolateral domain : Cell adhesion molecules Junctional complexes BBC 1 19
22. Cell adhesion molecules : Ca2+ dependent : chaderin and selectin Ca2+ independent : cell adhesion of the imunoglobulinsuperfamily (CAMs) and integrins Junctional complexes : BBC 1 22
23. Tight junction (zonulaoccludens) Function impermeable, as barrier Determine epithelial cell polarity and preventing the free diffusion of lipids and proteins between them Prevent of free passage of substance across an epithelial cell layer (paracellular pathway barrier) Transmembrane proteins are found : occludin, claudins and junctional adhesion molecule (JAM) Anchoring junction below the tight junction Zonulaadherens or belt desmosome a beltlike junction associated with actin microfilament mediated by interaction of cadherin with catenins = E - cadherin – catenin complex BBC 1 23
24. Macula adherens or spot desmosome : a spot like junction Associated with keratin intermediate filament (tonofilament) Provide strength and rigidity to an epithelial cell layer Hemidesmosome asymmetrical structure Link the basal domain of an epithelial cell to the basal lamina Increase the overall stability of epithelial tissues by linking intermediate filament of cytoskeleton with component of the basal lamina Gap Junction Permit the direct passage of signaling molecules from one cell to another heart muscle Form by integral membrane protein called connexins 6 connexin monomer a connexon End to end ligament of connexons in adjacent cells provides a direct channel of communication between cytoplasm of two adjacent cells BBC 1 24
27. LAMININ, FIBRONECTIN AND THE BASEMENT MEMBRANE Laminin + Fibronectin : Distinct protein of ECM Associated with collagens, proteoglycans and other protein organize a basement membrane Basement membrane consists of 2 components : Basal lamina : result from lamina molecules with type IV collagen, entactin and proteoglycans Reticular lamina : formed by collagen fibers Basal and reticular lamina can be distinguished by electron microscopy Basement membrane can be recognized by the Periodic Acid-Schiff (PAS) stain light microscopy BBC 1 27
33. ENDOCRINE Lack an excretory duct Their product released into the blood circulation Surrounded by fenestrated capillaries Synthesize and release after stimulation by chemical or electrical signals Types of endocrine glands : The agglomerated cells form anastomosis cords interspersed between dilated blood capillaries (adrenal gland, parathyroid, anterior lobe of pituitary) The cell line a vesicle or follicle filled with noncellular material (thyroid gland) BBC 1 33
34. EXOCRINE Connected to the surface of the epithelium by an excretory duct A secretory portion : Contains the cells responsible for the secretory process One cell type (unicellular) goblet cell Many cells (multicellular) Shape : tubular (large intestine), coiled (sweat glands of the skin), alveolar (sebaceous gland) Classified : Simple gland : have only one unbranched duct Compound gland : have ducts that branch repeatedly Excretory duct : Transport the secretion to the exterior of the gland BBC 1 34
35. LIVER One cell type may function both ways : endocrine + exocrine Cells that secrete bile into the duct system and also secrete some of their products into the bloodstream PANCREAS Endocrine secretion : the islet cells secrete insulin and glucagon into the bloodstream Exocrine secretion : the acinar cells secrete digestive enzymes into the intestinal lumen BBC 1 35
36. Types of secretion : Mucous glands : glycoprotein + water Serous glands : protein + water Mixed glands : mucous + serous cells Mechanism of secretion : Merocrine : the secretorygranul leave the cell by exocytosis with no loss of other cellular material skin Apocrine : the secretory products is discharge together with parts of the apical cytoplasm axilla Holocrine : the secretory product constitute the entire cell and its product sebaceous gland BBC 1 36
37. CONNECTIVE TISSUE Provides the supportive ang connecting framework (or stroma) for all the other tissues of the body. Connective tissue is formed by : Cells Extracellular matrix (ECM) : fiber and ground sbstance BBC 1 37
49. MACROPHAGE When trypan blue or India ink is injected into an animal, macrophage engulf and accumulate the dye in their cytoplasm in the form of granules or vacuoles visible in the light microscope Have phagocytic properties and derive from monocytes, cells formed in the bone marrow Macrophage in the liver : Kupffer cells, in bone : Osteoclast, in the central nervous system : microglial cells Constitute the mononuclear phagocyte system BBC 1 44
52. BBC 1 47 Figure 5—6. Section of pancreas from a rat injected with the vital dye trypan blue. Note that 3 macrophages (arrows) have engulfed and accumulated the dye in the form of granules. H&E stain. Low magnification.
55. mucosal mast cell intestinal mucosaPLASMA CELLS large, ovoid, basophilic cytoplasma due to their richness in RER, nucleus spherical and eccentrically placed. BBC 1 49
60. ADIPOSE CELL colour : white to dark yellow, polyhedral, eccentric and flattened nuclei 54 Figure 6—1. Photomicrograph of unilocular adipose tissue of a young mammal. Arrows show nuclei of adipocytes (fat cells) compressed against the cell membrane. Note that, although most cells are unilocular, there are several cells (asterisks) with small lipid droplets in their cytoplasm, an indication that their differentiation is not yet complete. Pararosaniline—toluidine blue (PT) stain. Medium magnification. Figure 6—5. Photomicrograph of multilocular adipose tissue (lower portion) with its characteristic cells containing central spherical nuclei and multiple lipid droplets. For comparison, the upper part of the photomicrograph shows unilocular tissue. PT stain. Medium magnification.
61. LEUCOCYTE migrate through the walls of capillaries and post capillary venules from the blood to connective tissue by a process called diapedesis this process increases greatly during inflammation FIBERS 2 system of fibers : Collagen system : collagen, reticular fibers Elastic system : oxytalan, elaunin, elastic fibers 55
62. COLLAGEN FIBERS a famili of proteins the most abundant protein in the human body classified in the following groups : 1. form long fibril : type I,II,III,V,XI collagen type I collagen fibers 2. fibril associated collagens : type IX,XII,XIV 3. form networks : type IV 4. form anchoring fibrils : type VII fresh collagen are colorless strands,in great numbers (eg.tendons) are white in the light microscope : collagen fibers are acidophilic, they stain pink with eosin, blue with Mallory’s trichrome stain, green with Masson’s trichrome stain, red with sinus red 56
64. RETICULAR FIBERS consist mainly of collagen type III thin, not visible in HE preparations stain black by impregnation with silver salts, are called argyrophilic abundant in smooth muscle, endoneurium, hematopoetic organs 58 Figure 5—48. Reticular connective tissue showing only the attached cells and the fibers (free cells are not represented). Reticular fibers are enveloped by the cytoplasm of reticular cells; the fibers, however, are extracellular, being separated from the cytoplasm by the cell membrane. Within the sinuslike spaces, cells and tissue fluids of the organ are freely mobile.
77. 65 Figure 5—41. Section of rat skin in the process of repair of a lesion. The subepithelial connective tissue (dermis) is loose connective tissue formed soon after the lesion occurs. In this area, the cells, most of which are fibroblasts, are abundant. The deepest part of the dermis consists of dense irregular connective tissue, which contains many randomly oriented thick collagen fibers, scarce ground substance, and few cells. H&E stain. Medium magnification. LOOSE CONNECTIVE TISSUE
78.
79. Collagen fibers are arranged in bundles without a definite orientation, such arreas as the dermis
83. 67 Figure 5—41. Section of rat skin in the process of repair of a lesion. The subepithelial connective tissue (dermis) is loose connective tissue formed soon after the lesion occurs. In this area, the cells, most of which are fibroblasts, are abundant. The deepest part of the dermis consists of dense irregular connective tissue, which contains many randomly oriented thick collagen fibers, scarce ground substance, and few cells. H&E stain. Medium magnification. DENSE IRREGULER CONNECTIVE TISSUE
84. 68 Figure 5—46. Longitudinal section of dense regular connective tissue from a tendon. A: Thick bundles of parallel collagen fibers fill the intercellular spaces between fibroblasts. Low magnification. B: Higher magnification view of a tendon of a young animal. Note active fibroblasts with prominent Golgi regions and dark cytoplasm rich in RNA. PT stain. DENSE REGULER CONNECTIVE TISSUE
