Ch 3 Tissue Level Organization 19 01 2010 19 13 00 Tissues collections of specialized cells and their cell products that do something specific beased on the types 4 types epithelia connective muscle neural epithelial tissue cells compromising tissues which cover surfaces lines body cavities and form glands glands are secreory units derived from epithleia characteristics o tightly joined cell groups that are polarized one side heavier than the other o apical surface face some environment o bottom anchored to basal lamina o lateral surfaces meet other similar cells joined by junction complexes o continuously being replaces by mitosis o are an avascular layer or cell no bood vessels that go through functions o physical protection o control of permeability o provide sensationby detecting changes in the environment and sending this info to the N S o produces specialized secretion through glands glandular cells specialization o microvilli like fingers of a comb increase S A and involved in absorption has actin o stereocilia longest of specialization only ones that branch but not motile only in male reproduction has actin remove stuff in spermatooza o cilia no branching but motile 9 2 arrary junction complex o occur on lateral sides to keep cells close and occurs in 3 s o the 3 together is the junction complex o meant to prevent things from making their way to the top of the cell ways to classify epithelial o number of cell in the epithelial if one layer simple if multiple layers stratified o shape of the surface layer of the cell squamous thin flat and scale like cells cuboidal cell is as wide as it is tall columnar taller than it is wide simple epithelial o simple squamous vascular system body covities bowmens capsule respiratory spaces in lung o simple cubodial small ducts of exocrine system surface of ovaries kidneys tubules thyroid follicles o simple columnar small intestine and colon stomanch lining and gastric glands gall bladder o pseudostratified columnar trachea ductus deferens efferent ductules of epididymis stratified o stratirfied squamous epidermis oral cavity and esophagus vagina o stratified cuboidal o transitional can have some stretching bladder is full compared to when bladder is empty kidneys ureter bladder urthera o stratified columnar gland o exocrine glands secretion discharged through ducts onto skin or epithelial cells serous glands produce a thin watery secretion mucous glands produce a viscous sticky secretion mixture glands produce both o unicellular songle cells by themselves goblet cells multi cellular secretory sheet merocrine eccrine secretion salivary glands and merocrine sweat glands most common by exocytosis loss secretory products aprocrine secretion mammary gland apocrine sweat glands loss of secretory production as well apical cytoplasm as well odor producing glands in the armpit or pubic holocrine secretion in sebaceous glands whole cell bursts and becomes the secretion all organelles are lost so everything is secreted o endocrine glands secrete hormones ductless Connective Tissue All contain o Specialized cells o Extracellular fibers o Ground substance mucopolysaccharides Functions o Forms structural framework o Transport fluids and dissolved materials o Protects organs o Support surrounds connects other tissues o Store energy reserves o Defend body from invasions Broken down into connective tissue proper fluid and supportive CT proper o Fixed cells have a permanent zip code Fibroblasts most common and always present Fusitom spindle shaped Responsible for the production and maintenance of extracellular fibers most commonare the collagne Macrophages Eat foreign objects Adipocytes Fat cells single large droplet most common type of fat cells Mesenchymal cells Stem can which delevlop into all types of CT cells Melanocytes Produce pigment o Wandering cells Macrophages can wander too Mast cells secrete histamine and other substances that act at blood vessels Lymphocytes Go where tissue infection or inflammation occurs o Fibers Collagen fibers Reticular fibers type III collagen Elastic fibers made from elastin Branching and wavy Can stretch and recoil o Types of CT proper Loose CT fills space between organs cushions organs and support epithelium Areolar Adipose fat under skin Reticular in liver Dense CT mainly collagenous fibers Regular tendons and ligament Irregular different directions and in dermis and covering of bone and cartilage Supporting CT o Cartilage and bone Support and body Less diverse o Cartilage Covered by perichondrium dense irregular CT Matrix is a firm gel Chondroblasts form it and chondrocytes maintain it but cannot undergo mitosis Avascular no blood supply gets nutrients through diffusion and have poor capacity for repair mostly needs replacements Hyaline cartilage Elastic cartilage Fibrocartiliage o Bone Matrix composed of collagen fibers ca2 salts osteocytes cells in lacunae Spongy bone makes marrow Compact bone structural support Has the capacity to repair fractions but is not flexible Membranes Composed of a epithelial layer and underlying CT Forms a barrier to cover and protect under lying structure and tissues 4 types o mucous o serious o cutaneous o synovial Fascia Superficial fascia separates skin from underlying tissues and organs o Subcutaneous layer Deep fascia Muscle Tissue Specialized for contraction they contract and relax slowly Skeletal o No branching with long cylindrical muscle fibers o Multinucleated at the edge of the muscle fiber o Striated o Under voluntary control o Satellite cells stem cells provide a limited repair of muscle fibers Cardiac Individual cells that show branching Single nucleus that is in the center Striated Involuntary require ANS No satellite cells no little or no regeneration repair Smooth o Short tapered individual cells o Single nucleus that lies at the center o Not striated o Involuntary ANS controls o Can divide and undergo mitosis and regulate themselves Neural Tissues Receive and transmit electrical impulses Two types o Neurons structural and functional units of central and PNS Cell body soma Dendrites branching end bring info into cell Axon insulated and conducts impulses away from the cell only one o Neuroglia assist the neurons o o o o o 19 01 2010 19 13 00 19 01 2010 19 13 00