Presentation on theme: "Vertebrate/Human Tissues Epithelial = sheet of cells; attached to basement “membrane” of collagen and other protein (covers surfaces; avascular) Connective."— Presentation transcript:
Vertebrate/Human Tissues Epithelial = sheet of cells; attached to basement “membrane” of collagen and other protein (covers surfaces; avascular) Connective = cells scattered in an acellular matrix (binds, supports, & protects; vascular or avascular) Nervous / Neural = neurons and their supporting cells (transports electric signals; technically vascular) Muscle = elongate cells that contract (causes more rapid movement; vascular)
Extracellular Fibrous Proteins Collagen = complex triple-coil proteins - Type I Collagen = unbranched; more “tough” (form “collagen fibers”) - Type II Collagen = unbranched (form most basic “cartilage fibers”) - Type III Collagen = branched; more flexible (form “reticular fibers”) - Type IV Collagen = branched; (form much of basal lamina of epithelia) Elastin = Proteins that coil; can pull straight & return to coiled shape (elastic fibers)
Epithelial Tissues Basement membrane = 2-layered sheet to which epithelial cells are attached Basal lamina = type IV collagen & other components secreted by epithelial cells Reticular lamina = type III collagen & other components secreted by underlying connective tissue cells basal surface = basement membrane (b. m.) surface (attached to connective tissue) apical surface = surface opposite b.m., exposed externally or to an internal cavity
Epithelial Tissues - Cells simple = one layer of cells stratified = more than one layer of cells cuboidal = cells about as wide as tall columnar = cells taller (apical-basal) than wide squamous = cells wider than tall (a. to bas.) pseudostratified columnar epithelium = technically simple because all cells contact b.m., few “cuboidal” cells at b.m., columnar cells reach from b.m. to apical surface transitional epithelium = stratified irregular cells, some apical cells large & binucleate
Connective Tissues Defined by the abundant extracellular matrix. (Blood is often the odd one.) Most connective tissue (all except mature blood) have collagen fibers. All connective tissues have cells and ground substance. Ground substance is primarily water with proteins and carbohydrates. It may be very fluid (blood), semisolid (cartilage), or solid (bone).
Connective Tissue Cells Fibroblasts = fibrous connective tissue cells with tapered ends Adipocytes = fat cells; store fats Chondrocytes = rounded cartilage cells (chondroblasts → chondrocytes) Osteocytes = bone cells w/ small processes (osteoblasts → osteocytes) Osteoclasts = dissolve bone; bone remodeling Mesenchyme cells = stem cells that divide to repair or grow tissue
Connective Tissue Types Conn. Tissue (example) Most Common Cells FibersGround Substance Areolar (in hypodermis) Fibroblasts, Few adipocytes Much type I collagen & elastin Gel-like Adipose (in hypodermis) Few fibroblasts, Adipocytes Much type I collagen & elastin Gel-like Reticular (in spleen) Fibroblasts, Many leucocytes Much type III collagen (reticular) Gel-like Dense Regular (in tendons) Fibroblasts Much type I collagen Small amount of gel-like Dense Irregular (in dermis) Fibroblasts Much type I collagen Gel-like Elastic (in arteries) Fibroblasts Much elastin & some type I collagen Gel-like
Connective Tissue Types Conn. Tissue (example) Most Common Cells FibersGround Substance Hyaline Cartilage (larynx cartilages) Chondrocytes Type II collagen; No elastic Chondroitin sulfate semi-solid gel Fibrocartilage (knee meniscus) Chondrocytes Type I AND type II collagen;; Little or no elastic Chondroitin sulfate semi-solid gel Elastic Cartilage (ear cartilages) Chondrocytes Type II collagen AND much elastin Chondroitin sulfate semi-solid gel Bone (bones) Osteocytes Much type I collagen; No elastin CaPO 4 BloodLeucocytes; Erythrocytes ABSENT Liquid/fluid (plasma) Mesenchyme (developmental) Mesenchyme Multiple types of collagen Gel-like
Nervous/Neural Tissues Cells that send electrical then chemical signals and any associated cells. Neuron = Cells with long processes that can receive and send signals. Axon Dendrites Glial Cells = Cells that support or assist neurons
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