Unit 2: Tissues

Unit 2: Tissues

1. Epithelial Tissue

   • Squamus tissue
     • Thin, flat cells
     • Simple Squamous Epithelium
       • Single layer of very thin Squamous Cells
       • Used for diffusion, secretion, and filtration
         • In the lungs, glands, and kidneys
     • Stratified squamous Epithelium
       • Multiple layers of epithelial cells with Squamous being the first, may be keratinized
       • used for protection
         • In the epidermis, mouth, tongue, and vagina
   • Cuboidal tissue
     • Simple Cuboidal Tissue
       • Single Layer of Cuboidal Cells
       • Used for secretion and absorbtion
         • In the small glands, kidney tubules, and ovary surface
     • Stratified Cuboidal Tissue
       • Multiple layers of epithelial cells with cuboidal being the first
       • Used for Protection
         • In the sweat, mammary, and salivary glands
     • Cube Shaped Cells
   • Columlar tissue
     • Stratified Columnar Epithelium
       • Multiple layers of epithelial cells with columnar being the first, very rare
       • Used for protection and secretion
         • In the urethra, ducts, and conjunctiva
     • Simple Columnar Epithelium
       • Single layer of columnar cells
       • Used for absorption and secretion
         • non ciliated are found in the digestive tract and duct linings, ciliated is found in the small bronchi and uterine tubes
     • Elongated Cells with an oval nucleus, may be ciliated
   • Simple pseudostratified
     • Single Layer of cells which are attached to the basement membrane, cells and nuclei are at different heights, may be ciliated
     • Used for secretion and movement of mucus
       • Ciliated are found in the bronchi
   • Stratified Transitional tissue
     • Several layers of cells that can be stretched
     • allows for distention of the urinary organs
       • In the bladder, ureters, and urethra
   • Used for protection, secretion, absorbtion, excretion
     • In Skin, Glands, Lungs, and filtration
   • Lacks blood vessels, cells readily divide and are closely packed together

2. Muscle Tissue

   • contracts, moving structures attached to it,
   • Skeletal Muscle Tissue
     • Long, threadlike cells with striations and many nuclei
       • Voluntary, contract when stimulated by a nerve cell
         • Most of the body's muscle
   • Smooth Muscle Tissue
     • Spindle shaped cells with no striations and a single nucleus.
       • involuntary control, nervous stimulation
         • found in hollow internal organs, stomach, intestines, bladder, and blood vessels
   • Cardiac Muscle Tissue
     • Striated, branched cells which are joined end to end and a single nucelus
       • involuntary control, may function without nervous stimulation
         • pumps blood through the heart and blood vesseles
       • Contains a specialized intercalated disk as a cellular junction

3. Nervous Tissue

   • Neurons
     • Sense types of changes in their surroudings
       • Dendrites receive information and Axon sends to the next neuron or gland
     • Coordinate, regulate, and integrate body functions
   • Neuroglia
     • Neural support Cells
       • Biind and support, carry out phagocytosis, connect neurons to blood vessels, and are involved in cell to cell communication

4. Connective Tissue

   • Connective tissue Cell Types
     • Mast Cells
       • Produce Collagen and elastic Fibers
     • Macrophages
       • Phagocytes or "eating cells"
     • Fibroblasts
       • may release heparin and histamine
   • Connective Tissue Fiibers
     • Collagen Fibers
       • Have great tensile strength
     • Elastic FIbers
       • composed of elastin and are streachy
     • Reticular Fibers
       • fine collagen fibers
   • Categories of Connective tissue
     • Loose Connective Tissue
       • Areolar
         • thin membranes between organs
           • Beneath skin and around organs
       • Adipose
         • stores fat, cushions, and insolates
           • beneath skin, abdominal membranes, around organs and joints
       • Reticulara
         • Thin Branched Reticular Fibers
           • supports wall of liver and spleen
     • Dense Connective Tissue
       • Dense regular
         • Strong collagen fibers that bind structures as parts of tendons and ligaments
       • Dense Irregular
         • Thicker, randomly distributed collagen fibers that are found in the dermis
       • Elastic
         • Elastic fibers that make up hollow internal organs like the lungs and blood vessels
     • Specialized Connective Tissue
       • Cartilage
         • Provides support, made of fibers and a gel like substance
           • lacks a blood supply, slow to heal
           • Found at the ends of various bones, in the ear, larynx, and padding between bones
       • Bone
         • Matrix of mineral salts and collagen
           • Compact and spongy bones, heals rapidly
       • Blood
         • Cells Suspended in fluid
           • Produced in the hollow parts of some bones