Tissues Groups of cells with common structure and function.CellsTissuesOrganOrgansystems
Categories of Tissues
Epithelial Tissue Tightly-joined closely-packed cells. One side of epithelium exposed to air or internal fluid, otherside attached to a basement membrane Covers the outside of the body and lines the internal organsand cavities. Barrier against mechanical injury, invasivemicroorganisms, and fluid loss. Provides surface for absorption, excretion and transport ofmolecules.
Simple Squamous– Lining of lungs, blood vessels, urinary Stratified Squamous– Protection – lining ofesophagus, vagina, mouth, skin Cuboidal Epithelium– Kidney tubules– Duct and small glands– Surface of ovary Columnar Epithelium Elongated cells, much longerthan they are wide. Simple Columnar Epithelium Pseudo stratified ciliatedcolumnar epithelium Pseudostratified CiliatedColumnar - trachea
Types of Epithelial TissueCell shapeSquamousCuboidalColumnarNumber of cell layersSimplePseudostratifiedColumnar Squamous epithelium is flattened cells. Cuboidal epithelium is cube-shaped cells. Columnar epithelium consists of elongated cells.SquamousCuboidalColumnar
Types of Epithelial TissueSquamousCuboidalColumnarApical surfaceBasal surfaceApical surfaceBasal surfaceSimpleStratified
Connective Tissue Characterized by the cells widely separated from each otherin a matrix that is produced by the cells. Tissue protects and supports. Cell Matrix composed of two regions– Ground• Liquid (sol), Gel, Gum or solid– Fibers• Non-elastic (White or Collagen)• Elastic (Yellow fibers)Types of Connective TissueA. Loose (Areolar)Connective TissueB. AdiposeC. BloodD. Fibrous Connective TissueE. CartilageF. Bone
Loose Connective Tissue Contain fibers and fibroblasts Fibroblasts produce and secrete thefibers. Loosely arranged in a semi fluidsubstance. Acts as the framework forepithelium. Forms a protective layer over muscle,nerves, and blood vessels.Elastic FibersCollagen FibersFibroblast nuclei
Adipose Tissue Adipose cells contain a large vacuole which in the livecell contains lipids. Cell nucleus and cytoplasm are pushed out to edgeof cell membrane. Adipose tissue has enlarged fibroblasts storing fats andreduced intracellular matrix. Adipose tissue facilitates energy storage andinsulation.
Blood connective tissue Red blood cells (erythrocytes) carry oxygen. White blood cells (leukocytes) function in the immunesystem. Plasma transports dissolved glucose, wastes, carbondioxide and hormones, as well as regulating the waterbalance for the blood cells. Platelets are cell fragments that function in blood clotting.
Fibrous Connective Tissue Many fibers of collagen occurs in Tendons, connect muscle to bone. Ligaments connect bone to bone at a joint. Contains elastic fibers that allow movement at joints
Cartilage Tissue• Cells are called chondrocytes.• Cells lie in small chambers called lacunae,separated by a matrix.• Also called hyaline cartilage.• Hyaline Cartilage – nose, trachea, ends of bonesChondrocytes Matrix
Solid connective tissue Ground of matrix is Solid. Has blood supply and nerves running through theHaversian canal systems. Bone has calcium salts in the matrix, giving itgreater strength. Bone also serves as a reservoir (or sink) for calcium.
Muscle Tissue Composed of cells that contract when stimulated Helps move the body and specific body parts Skeletal, cardiac, smooth Muscle fibers are multinucleated, with the nuclei locatedjust under the plasma membrane. Most of the cell is occupied by striated, thread-likemyofibrils.Skeletal Muscle Smooth Muscle Cardiac Muscle
Skeletal (striated) Muscle These cells function in conjunction with the skeletalsystem for voluntary muscle movements. Located in muscles that attach to bones. Long, cylindrical cells are striated. Cells are bundled closely together in parallel arrays.
Smooth Muscle These cells function in involuntary movements and/orautonomic responses (such asbreathing, secretion, ejaculation, birth, and certainreflexes). Spindle shaped cells that form masses. These fibers are components of structures in the digestivesystem, reproductive tract, and blood vessels.
Cardiac Muscle A type of striated muscle found only in the heart. The cell has a bifurcated (or forked) shape, usually withthe nucleus near the center of the cell. The cells are usually connected to each other byintercalated disks.
Nervous Tissue Dendrites receiveinformation from anothercell and transmit themessage to the cell body. The cell body contains thenucleus, mitochondria andother organelles typical ofeukaryotic cells. The axon conductsmessages away from thecell body.