BSCI201 Exam 2 Study Guide Tissues 4 types Epithelial Nervous Muscle Connective Epithelial Tissue o Characteristics Polarity Avascular Connective tissue underlies supports providing nutrients Highly Regenerative Supported by a basement membrane Innervated o 2 Main Classes Membranous v Glandular o Membranous covering and lining epithelia Simple Single Layer Stratified multiple layers Identify by Shape of Apical cell Squamous flat cell flat nucleus Cuboidal round plump cell round centrally located nucleus Columnar elongated cell nucleus towards base of cell Simple Squamous single layer made of squamous cells Location o Kidneys filtration membrane Function Filtration o Lungs Function Diffusion of Gases o Lines Structures in the Circulatory system cardiovascular and lymphatic system Specifically called the ENDOTHELIUM Function Provides a slick frictionless surface for the flow of blood and lymph o In serous membrane MESOTHELIUM Function Act as a lubricant to reduce friction as structures move in the ventral body cavity Simple Cuboidal single layer of cube like cells with large spherical central nuclei Location o Kidneys Proximal Convoluted Tibule PCT and Distal o Outer membrane on the surface of the ovaries Germinal Convoluted Tubule DCT Function Re absorption Epithelial Function Re absorption Ciliated of nutrients Non Ciliated Simple Columnar single layer of column shaped cells with an elongated nucleus towards o Respiratory Tract cilia propels mucus o Female Reproductive Tract propels ova eggs or zygote Non ciliated secretion of enzyme required for chemical digestion Pseudostratefied Columnar single layer of columnar calls of different heights with nuclei of varying heights BUT each cell is touching the basal membrane o Sperm Ducts phagocytize sperm that are not ejected through the urethral orifice Ciliated Referred to as respiratory epithelial o Lines most of the structures in the RESPIRATORY TRACT o Endowed with goblet cells that secrete mucin Stratified Squamous Epithelium several layers of epithelial cells with the cell on the apical surface being flattened with disc shaped centrally placed nuclei Keratinized Cells on apical surface are dead impregnated with tough fibrous protein called keratin very abrasive resistant o Epidermis of skin protects against wear and tear physical barrier against pathogens Non keratonized Cells are alive forms the superior part of the mucus membrane which lines the tracts of the body opening to the exterior o Gastrointestinal Tract entry oral cvity exit anal cavity Stratified Cuboidal Epithelial Tissue and Stratefied Columnar Epithelium Main function stratification confers protection o Protects internal surface of ducts and therefore involved in secretion Rare in human body Location ducts of multi cellular exocrine glands sweat glands and salivary glands Transitional Epithelium Urinary Tract o Undergoes a transition from 6 layers with cuboidal apical cells to 3 layers with flatten squamous like cells as these structures fill with urine o Glandular epithelial cells form the secretory portion of the duct system of multicelular exocrine glands Endocrine secretes their products directly into extracellular fluid Exocrine secretes product onto body s surface 2 types Unicellular and Multicellular o Uncellular goblet cells are scattered within membranous epithelial that secrete mucin o Multicellular Structural Classification Duct System simple glands unbranched duct compound glands branched ducts Shape of secretory portion alveolar v tubular Functional Classification mode of secretion Apocrine apex of sexretory cell pinches off to release accumulated product no ex in human body Merocrine secretory cell undergois exocytosis to release product Holocrine secretory cells ruptures to release accumulated product sebaceous glands Connective Tissue Mesenchyme gives rise to 4 types of cells that secrete connective tissue Consistency of Matrix Ground Substance o Fibroblasts gel like o Chondroblasts semi solid o Osteoblasts solid o Hemoepoeitc Stem Cells fluid Living portion cells derived from mesenchyme that secrete connective tissue Non living Portion extracellular matrix composed of ground substance and fibers o 3 types of Fibers Collagen Elastic Reticular o Ground Substance consists of intestinal fluid adhesions molecules and proteoglycans composed of glycosaminoglycons GAGs More GAGs in ground substance the more solid the matrix 4 Classes of Connective Tissue o Connective Tissue Proper Living portion secreted by fibroblasts Consistency of ground substance is gel like 2 sub classes Loose o Areolar supports structures in the body Referred to as packing material of the body Highly Vascularized Lamina Propria underlies epithelial tissue in the mucus membrane Makes up the papillary layer of the dermis Supports other tissues by providing nutrients Function By virtue of the presence of the immune cells microphages blood cells its involved in the immune response Edema excess intestinal fluid is held back by areolar connective tissue o Adipose also known as adipocytes Stores triglycerides Surrounds and supports all structures in the body Function Holds structures in correct anatomical position Provides Storage form of concentrated energy Cushioning o 1 g of glucose 4 kcal o 1 g of protein 4 kcal o 1 g of fat 9 kcal o Reticular found in lymphoid organs spleen thymus lymphoids forming a network called the stroma Lymphoid cells rside and proliferate in stroma to provide immunity By virtue of association involved in fighting off infection Dense high levels of fibers also referred to as fibrous connective tissue direction o Dense Regular bundles of collagen fibers arranged in one Can withstand stress applied in only one direction Forms tendons ligaments and aponeuroses sheet like tendons that connect muscles to muscles over skeletal structures Poorly vascularized not taking enough nutrients therefore takes a long time to repair tendons o Dense Irregular bundles of collagen fibers facing in all directions Can withstand stress applied from different directions Highly vascularized and provide nutrients to the structures it surrounds supplies o Elastic in areas where the stretch recoil is needed Ligamenta flave connect adjacent vertebra o Cartilage secreted by chondroblasts semi solid ground substance more GAGs Avascular Surrounded by PERICHONDRIUM composed of dense irregular CT that provides nutrients 3 Types Hyaline most abundant o Embrionic Epiphyseal Articular and Costal
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