1_Epithelial Tissues.pdf

Epithelial Tissue Eroschenko, VP. (2017). Atlas of Histology with Functional Correlations. 13th edition. pp. 122-145. Click here to access photomicrographs.  Learning Objectives Identify the common characteristics of epithelial tissues Describe the basement m...

Epithelial Tissue Eroschenko, VP. (2017). Atlas of Histology with Functional Correlations. 13th edition. pp. 122-145. Click here to access photomicrographs.  Learning Objectives Identify the common characteristics of epithelial tissues Describe the basement membrane, and the epithelial modifications found in the apical, lateral and basal surfaces of epithelia Classify epithelial tissues based on stratification and morphology Justify the type of epithelia in specific locations of the body through form-function relationships  Epithelial Tissue Sheets of cells that cover ______________ and line __________ Classified based on _____________ and _______________ Separated from underlying connective tissues via the ______________ consisting of the upper ________ directly connected to epithelial cells, and the underlying collagen- rich ___________ Except for the epithelium of the _______________, which has the capillary-rich _______________, almost all epithelia are non-vascular; hence delivery of nutrients and removal of metabolic wastes occur via ___________________ Exhibits a high __________ for continuous replacement of worn-out cells  Special Surface Modifications Motile _________ that arise from the ____________ are found in the ___________, ___________ and ______________ Non-motile apical modifications include the ____________ that function in nutrient and fluid absorption in the ___________ and the ___________ of the kidney; and the longer ____________ found in the __________, ___________ and the ___________ The junctional complex consists of (a) the ________ that form a seal, thus preventing entry of materials between cells; (b) the _______ that provide firm adhesion between cells; and (c) the _______ that protect against shearing stress Basally, ____________ attach cells to the basement membrane, and __________ selectively allow diffusion of molecules and cell-to-cell communication  Simple Squamous Epithelium Single layer of _____ cells Includes the lining of the external surfaces of digestive organs, lungs and the heart called the _______________ Also includes the inside of heart chambers, blood vessels and lymphatic vessels called the _______________ Functions in reduction of _______________, passive transport by _____________, and _____________  Simple Cuboidal Epithelium Single layer of cells that are as ______ as they are _______, and have __________ nuclei Lines and protects small __________ of various organs Apical surfaces of the ______________ of the kidney are lined with a brush border consisting of ___________ and transports and ____________ filtered materials  Simple Columnar Epithelium Single layer of _____ cells, sometimes lined by __________ Cells display an apical __________ and a basal ____________ Lines the ___________ of digestive organs- namely the _________, ___________, ____________ and ____________ In the stomach, secretes protective ________ In the small intestine, functions in _______________ with the help of _____________ In the uterine tubes and uterine cavity, consists of cells with motile ________  Stratified Epithelia Formed by _________ cell layer/s but _______________ determines the specific subtype Stratified squamous epithelia have superficial ______ cells, intermediate __________ cells and basal ____________ cells Underlying connective tissue extends and indents the lower surface of epithelium forming _________ - characteristically absent in the ________ Unlike keratinized squamous epithelium, which protects the _______ against ________, __________ and __________, non-keratinized squamous epithelium has ______________ and forms a moist, protective layer in the ___________, _________, __________, and ___________ Stratified cuboidal epithelium lines and protects large _________ in the ________, _______ and ______ Pseudostratified Columnar Epithelium All cells reach the _______, but not all reach the ________ Consist of ___________ cells interspersed with oval, mucus-secreting ________ cells In the airways, function in __________ and ____________ In the Fallopian tubes and efferent ducts of testes, transport __________ across cell surfaces Those lining the epididymis and vas deferens, and the inner ear both have ____________, which help in _____________ and _______________, respectively  Transitional Epithelium Exclusively found in the ____________, ___________, _____________ and _____________ of the urinary system Changes its ____________ in response to _____________ - appears ________ when contracted and ___________ when stretched Forms a protective _____________ barrier between hypertonic _______ and the underlying tissue Which lies directly under the epithelium? Basement membrane Blood vessels Connective tissue Muscle tissue Nervous tissue The epithelium that protects the airways from particulate matter is Pseudostratified Stratified squamous, keratinized Striated Stratified squamous, nonkeratinized Stratified columnar Which modification is best suited for cells absorbing nutrients and fluids? Cilia Hemidesmosomes Microfilaments Microvilli Stereocilia  The epithelium that allows distension in an organ is Columnar Cuboidal Pseudostratified Squamous Transitional  Which function is attributed to the basement membrane? Attaching to and supporting epithelial cells Forming desmosomes in epithelial cells Forming hemidesmosomes for the attachment of cells to connective tissues Facilitating increased absorption of fluids and nutrients by epithelial cells Forming tight junctions in the apical regions of cells  Summary Epithelial tissues are found in external and internal surfaces, are mostly avascular and exhibit a high mitotic rate. The basement membrane is found at the junction of the epithelium and the underlying connective tissue. Epithelial modifications found in the apical surface include cilia, microvilli and stereocilia. Those at the lateral surface make up the junctional complex and include tight junctions, adhering junctions and desmosomes. Basally, we find the hemidesmosomes and gap junctions. Based on stratification and morphology, epithelial tissues may be one of eight (8) possible types, each subserving a function related to its thickness and shape.