ANIMAL HISTOLOGY(动物组织学)课件

1、HISTOLOGYThe study of tissuesTissues- group of similar cells performing a specific functionClassifications of Animal TissuesEpithelial Tissues- many forms & functionsConnective Tissues - connection & supportMuscle Tissues- movementNervous Tissues- communication1. Epithelial TissuesCharacteristics:co

2、ver the surface and internal cavities of the bodyprovided with basal membranemay be simple or stratifiedform parts of sense organsgive rise to gland structuresTypes of Epithelial Tissues(based on structure & function)Glandular epitheliumspecialized for producing fluid secretion (enzymes, mucin)e.g.

3、goblet cells of the mucous layer of small intestineCovering epithelium- for covering body surface, lining body cavities (mesothelium), lining of blood & lymph vessels (endothelium)Epithelial TissuesTypes (based on shape & # of layers):Simple squamous epithelium 1 layer; thin flat polygonal cellse.g.

4、 in Air sacs of lungs, lining of blood vesselsStratified squamous epithelium - several layers; ; polygonal cellseg. Skin, mouth lining, vaginal lining, esophageal lining3. Simple columnar epithelium 1 layer; cells are taller than wide e.g. in lining of intestine & upper part of respiratory tractin l

5、ining of intestine Epithelial Tissues4. Simple cuboidal epithelium 1 layer; cube-likein linings of kidney tubules; gland ducts2. Connective TissuesFunctions: join other tissues; support the body & its organs; protect underlying organsconsist of: 1. cells - fewa. fibroblasts produce fibersb. Macropha

6、ges act as phagocytes2. fibers a. collagen (white)b. elastic (yellow) contain elastinc. reticular more branched forming delicate supporting network3. amorphous ground substance in matrix; glycoprotein of liquid to solid consistency Connective TissuesTypes:I. Connective Tissue ProperA. Loose/Areolar

7、CT- elastic yellow fibers (widely distributed under the epithelia of human body)B. Dense CT densely packed collagen fibers (eg. tendons, ligaments, dermis of skin)Connective TissuesII.Specialized Connective TissueA. Elastic tissue thick bundles of parallel elastic (yellow) fibers (in yellow ligament

8、s of vertebral column; lung tissue & large arteries)B. Adipose tissue used to store fats (subcutaneous layer; pads around certain internal organs)C. Mucous CT abundant in amorphous ground substance made up chiefly of hyaluronic acid ; jellylike tissue containing collagen, few elastic or reticular fi

9、bers (e.g. principal component of umbilical cord in mammals (Whartons jelly), in pulp of young teeth)Specialized Connective TissuesD. Vascular tissue/Blood - for transport of materials-composed of formed elements & a liquid matrix (plasma)a. plasma liquid portionb. formed elements: Erythrocytes (RBC

10、) carries oxygenLeucocytes (WBC) for immune systemThrombocytes (platelets) - for blood clotting; small ovoid or circular cells lacking nucleusSpecialized Connective Tissuesred blood cells and plateletsConnective TissuesneutrophileosinophilConnective TissuesbasophilSpecialized Connective TissuesAgran

11、ulocytes/mononuclear leucocytes a. Lymphocyte nucleus almost occupying the entire cell (20-25%)- elicits antibody responseb. Monocyte with bean-shaped nucleus (2-6%)- acts as phagocytesConnective TissueslymphocyteConnective TissuesIII. Supporting Connective tissueA. Cartilage intercellular substance

12、 with inorganic substances1. hyaline cartilage substance is translucent; without fibers (in nose, larynx & trachea; end of long bones)2. elastic cartilage with branched elastic fibers (external ear, epiglottis)3. fibro-cartilage with unbranched collagenous fibers (intervertebral disks; pubic symphys

13、is, disks of knee joint)B. Bone or osseus tissue with hydroxyapatite crystalsSupporting Connective Tissueshyaline cartilageSupporting Connective TissuesfibrocartilageSupporting Connective TissuesHaversian System or OsteonBone or osseus tissue- for supportAn Osteon or Haversian System ( structural &

14、functional unit of a compact bone)Consists of:Bone matrix calcified (calcium hydroxyapatite & CaCO3)Cells:osteocytes bone cells found in cavities or lacunaeosteoblasts- synthesize org. components of the matrixosteoclasts- resorption & remodeling of bone tissuesLamelae concentric layers in matrixHave

15、rsian canal central cavityCanaliculi cylindric spaces in matrix; permits intercellular connection The Structure of a Muscle TissueTHE STRUCTURE OF A MUSCLE TISSUESarcolemma/Plasmalemma muscle membraneSarcoplasm- muscles cytoplasmSarcoplasmic reticulum muscles endoplasmic reticulumMuscle Fibers =Musc

16、le Cells - the contractile cells of muscle tissues Myofibril- are small contractile filaments located within the cytoplasm of striated muscle cells. -consist of bands of alternating high and low refractive index giving the distinctive striped appearance of muscles (striated)Myofibril consists of two

17、 types of protein filaments:1) Myosin - thick filaments”2) Actin - thin filamentsThe thick filaments and the thin filaments within myofibrils overlap in a structured way, forming units called Sarcomeres.Sarcomere - the functional (contractile) unit of a myofibrilCoverings of Muscle TissuesFascia - s

18、heets or broad bands of fibrous connective tissue that cover the entire muscle organSuperficial fascia- cover adjacent muscle organsDeep Fascia cover muscle organs found beneathEpimysium (Fascia) - surrounds the total bundle of many fasciclesPerimysium - the fibrous sheath that surrounds and protect

19、s individual fasciclesEndomysium - the fine connective tissue that surrounds and protects each individual muscle fibre (between fibers)The Structure of a Muscle TissueTHE STRUCTURE OF A MUSCLE TISSUETypes of Muscle Tissues Skeletal striated and voluntary Smooth non-striated and involuntary Cardiac s

20、triated and involuntaryMuscular TissuesTYPES:1. Skeletal muscle tissue- attached to skeleton- elongated and filamentous- many nuclei per muscle cell- striated- Voluntary contractionMuscular Tissues2. Smooth muscle tissue- walls of digestive tract- spindle-shaped or fusiform- one nucleus per cell- No

21、n-striated- involuntary contractionMuscular Tissues3. Cardiac muscle tissue- muscle tissue of the heart- elongated fibers that branch- One nucleus per cell (cell junctions are called intercalated disks)- Striated- Involuntary contractionNervous Tissue specialized for reception and transmission of impulses consists of: 1. neurons (nerve cell) - conduct impulses cell body- w/ large central nucleusdendrite conducts signals toward the cell bodyaxon conducts signal away from the cell body 2. glial cells supporting cellsa. neuroglia