Chapter 05 Review
5.1: Introduction Similar cells with a common function are called tissues. The study of tissues is called histology. There are four (4) primary or major tissue types: 1. Epithelial Tissue 2. Connective Tissue 3. Muscle Tissue 4. Nervous Tissue 2
5.2: Epithelial Tissue General Characteristics Covers organs and body surface/lines cavities and hollow organs Have a free surface on one side and basement membrane on other Usually lack blood vessels Cells readily divide Cells are tightly packed Classified according to cell shape and number of cell layers Shapes squamous (flat), cuboidal (cube shaped), columnar (tall) Layers simple (one layer of cells), stratified (more than one layer of cells) 3
Epithelial Tissue Types Simple squamous: Single layer of flat cells Substances pass easily through Lines air sacs Lines blood vessels Lines lymphatic vessels Simple cuboidal: Single layer of cube-shaped cells Lines kidney tubules Covers ovaries Lines ducts of some glands Secretes, absorbs Free surface of tissue Simple squamous epithelium Basement Nucleus Connectiv e tissue Lumen Connectiv e tissue Nucleus Basement membrane Free surface of tissue Simple cuboidal epithelium b,d: Ed Reschke b: The McGraw-Hill Companies, Inc./Al Telser, photographer 4
Epithelial Tissue Types Simple columnar: Single layer of elongated cells Nuclei usually near the basement Membrane at same level Sometimes possesses cilia Sometimes possess microvilli Often has goblet cells (secrete mucus) Lines uterus, stomach, intestines Pseudostratified columnar: Single layer of elongated cells Nuclei at two or more levels, giving the appearance of being stratified Often has cilia Often has goblet cells Lines respiratory passageways Nucleus Cytoplasm Cilia (free surface of tissue) Cytoplasm Microv illi (free surface of tissue) Mucus Goblet cell Basement membrane Connectiv e tissue Goblet cell Nucleus Basement membrane Connectiv e tissue b: The McGraw-Hill Companies, Inc./Dennis Strete, photographer b: The McGraw-Hill Companies, Inc. Alvin Telser, photographer, PhD 5
Epithelial Tissue Types Stratified squamous: Many cell layers Top cells are flat Can accumulate keratin Outer layer of skin Lines oral cavity, vagina, and anal canal Cell sloughing off Free surface of tissue Squamous cells Stratified cuboidal: 2-3 layers Cube-shaped cells Lines ducts of mammary glands, sweat glands, salivary glands, and the pancreas Stratified cuboidal epithelium Nucleus Lumen Free surface of tissue Basement membrane Connectiv e tissue Layer of dividing cells Basement membrane b: The McGraw-Hill Companies, Inc./Al Telser, photographer. Connective tissue 6 b: The McGraw-Hill Companies, Inc./Al Telser, photographer
Epithelial Tissue Types Stratified columnar: Top layer of elongated cells Cube-shaped cells in deeper layerst Lines par of male urethra and part of pharynx Transitional: Many cell layers Cube-shaped and elongated cells Line urinary bladder, ureters, and part of urethra Free surface of tissue Unstretched transitional epithelium Lumen Free surface of tissue Stratified columnar epithelium Basement membrane Basement membrane Underlying connective tissue Connectiv e tissue Free surface of tissue Stretched transitional epithelium Basement membrane b: The McGraw-Hill Companies, Inc./Al Telser, photographer Underlying connective tissue (c) b,d: Ed Reschke (d) 7
Glandular Epithelium Composed of cells that are specialized to produce and secrete substances There are two (2) types: Endocrine glands secrete into tissue fluid or blood Exocrine glands secrete into ducts Unicellular exocrine gland: Composed of one cell Goblet cell Multicellular exocrine gland: Composed of many cells Sweat glands, salivary glands, etc. Simple and compound 8
Structural Types of Exocrine Glands Copyright The McGraw -Hill Companies, Inc. Permission required for reproduction or display. Tissue surface Duct Secretory portion Simple tubular Simple branched tubular Simple coiled tubular Simple branched alveolar Compound tubular Compound alveolar 9
Types of Glandular Secretions Merocrine Glands Fluid product Salivary glands Pancreas gland Sweat glands Apocrine Glands Cellular product Portions of cells Mammary glands Ceruminous glands Holocrine Glands Secretory products Whole cells Sebaceous glands Intact cell Secretion Pinched off portion of cell (secretion) Disintegrating cell and its contents (secretion) New cell forming by mitosis and cytokinesis Merocrine gland Apocrine gland (c) Holocrine gland 10
5.3: Connective Tissues General characteristics: Most abundant tissue type Many functions: Bind structures Provide support and protection Serve as frameworks Fill spaces Store fat Produce blood cells Protect against infections Help repair tissue damage Have an extracellular matrix made of protein fibers and ground substance Have varying degrees of vascularity Have cells that usually divide 11
Connective Tissue Major Cell Types Fibroblasts Fixed cell Most common cell Large, star-shaped Produce fibers Macrophages Wandering cell Phagocytic Important in immunity and prevention of infection Mast cells Fixed cell Release heparin Release histamine 12
Connective Tissue Fibers Collagenous fibers Thick Composed of collagen Great tensile strength Abundant in dense CT Hold structures together Appear white in abundance Reticular fibers Very thin collagenous fibers Highly branched Form delicate supportive networks Elastic fibers Bundles of microfibrils embedded in elastin Fibers branch Elastic Appear yellow in abundance 13
Connective Tissues Connective Tissue Proper: Loose connective tissue Areolar Adipose Reticular Dense connective tissue Dense regular Dense irregular Elastic Specialized Connective Tissue: Cartilage Bone Blood 14
Connective Tissue Types Areolar Connective Tissue Mainly fibroblasts Gel-like ground substance Collagenous fibers Elastic fibers Binds skin to structures Beneath most epithelia Blood vessels nourish nearby epithelial cells Adipose Connective Tissue Adipocytes Cushions Insulates Stores fats Beneath skin Behind eyeballs Around kidneys and heart Between muscles Fat droplet Collagenous fiber Fibroblast Cell membrane Nucleus Ground substance Elastic fiber b: The McGraw-Hill Companies, Inc./Dennis Strete, photographer b: The McGraw-Hill Companies, Inc./Al Telser, photographer
Connective Tissue Types Reticular Connective Tissue Composed of reticular fibers Supports internal organ walls Walls of liver, spleen Dense Regular Connective Tissue Closely packed collagenous fibers Elastic fibers Fibroblasts Very strong Binds body parts together Tendons, ligaments, dermis Poor blood supply; slow to heal Collagenous fibers Fibroblasts W hite blood cell Collagenous fibers Fibroblast b: The McGraw-Hill Companies, Inc./Al Telser, photographer b: The McGraw-Hill Companies, Inc./Dennis Strete, photographer 16
Connective Tissue Types Dense Irregular C.T. Randomly organized, thick, interwoven collagenous fibers Dermis of skin Around skeletal muscles Stratified squamous epithelium Elastic Connective Tissue Abundant in elastic fibers Some collagenous fibers Fibroblasts Attachments between bones Walls of large arteries, airways, heart Dense irregular connective tissue Collagenous fibers Fibroblast Elastic fibers Adipose tissue 17 b: The McGraw-Hill Companies, Inc./Al Telser, photographer The McGraw-Hill Companies, Inc./Al Telser, photographer
Connective Tissue Types Cartilage Rigid matrix containing gel-like ground substance Chondrocytes in lacunae Poor blood supply Covered by perichondrium Three (3) types: Hyaline Cartilage Elastic Cartilage Fibrocartilage Hyaline cartilage Most abundant Fine collagenous fibers Ends of bones Nose, respiratory passages Embryonic skeleton Elastic cartilage Flexible due to elastic fibers External ear, larynx Fibrocartilage Very tough due to many collagenous fibers Shock absorber Intervertebral discs Pads of knee and pelvic girdle 18
Connective Tissue Types Three (3) types of cartilage: Elastic fibers Nucleus Lacuna Nucleus Lacuna Chondrocyte Chondrocyte Extracellular matrix Extracellular matrix b: The McGraw-Hill Companies, Inc./Al Telser, photographer Hyaline Cartilage b: The McGraw-Hill Companies, Inc./Al Telser, photographer Elastic Cartilage Chondrocyte Nucleus Collagenous fiber Extracellular matrix 19 b: The McGraw-Hill Companies, Inc./Al Telser, photographer
Connective Tissue Types Bone (Osseous Tissue) Solid matrix Supports Protects Forms blood cells Attachment for muscles Skeleton Osteocytes in lacunae Osteon Lamella Central canal Lacuna Canaliculi Lacuna Osteocyte (c) b: The McGraw-Hill Companies, Inc./Dennis Strete, photographer; c: Prof. P. Motta/ Univ. La Sapienza /Photo Researchers, Inc. 20
Connective Tissue Types Blood Fluid matrix called plasma Red blood cells White blood cells Platelets Transports Defends White blood cell Red blood cells Plasma (extracellular matrix of blood) Platelet b: The McGraw-Hill Companies, Inc./ Dennis Strete, photographer 21
5.4: Types of Membranes There are four (4) types of epithelial membranes: 1. Serous Membranes Line body cavities that do not open to the outside Reduce friction Inner lining of thorax and abdomen Cover organs of thorax and abdomen Secrete serous fluid 2. Mucous Membranes Line tubes and organs that open to outside of body Lining of digestive, respiratory, urinary, and reproductive tracts Secrete mucus 3. Cutaneous Membranes Covers body Skin 4. Synovial Membranes Composed entirely of connective tissue Lines joints 22
5.5: Muscle Tissues General characteristics: Muscle cells also called muscle fibers Contractile Three (3) types: Skeletal muscle Smooth muscle Cardiac muscle Skeletal muscle tissue Attached to bones Striated Voluntary Smooth muscle tissue Walls of organs Skin Walls of blood vessels Involuntary Non-striated Cardiac muscle tissue Heart wall Involuntary Striated Intercalated discs 23
Muscle Tissue Striations Cytoplasm Nucleus Nuclei Portion of a muscle fiber b: The McGraw-Hill Companies, Inc. Alvin Telser, photographer, PhD b: The McGraw-Hill Companies, Inc. Alvin Telser, photographer, PhD Skeletal Muscle Smooth Muscle Striations Nucleus Intercalated disc Cardiac Muscle b: The McGraw-Hill Companies, Inc. Alvin Telser, photographer, PhD 24
5.6: Nervous Tissue Found in brain, spinal cord, and peripheral nerves Functional cells are neurons Neuroglial cells support and bind nervous tissue components Cellular process Cytoplasm Nucleus Nucleolus Cell membrane Sensory reception Nuclei of neuroglia b: The McGraw-Hill Companies, Inc. Alvin Telser, photographer, PhD Conduction of nerve impulses 25