Review Sheet -- Test 1, number 2:  Tissues         Biology 2212         Dr. Adams
            ALSO for first LAB PRACTICAL

Chapter 4 -- Tissues
    Tissue: Group of similar cells functioning together as a unit.
Four major classes
  I. Epithelial
     Characteristics: very cellular, avascular, cells held together with tight junctions, free 
            surface, highly regenerative, basal lamina (part of basement membrane)
  A. Simple
     1. Simple Squamous: Location -- lining of circ. system, alveoli, part of serous membs.
         Functions -- rapid exchange, filtration, reduction of friction
     2. Simple Cuboidal: Location -- glands, kidney tubules; Functions -- secretion 
            (virtually all glandular epithelium is simp. cub.; see * below), exchange (in kidney)
     3. Simple Columnar: Location -- digestive system (what parts?), oviducts, resp. tract 
            (part); Function -- absorption, secretion. In some places, simple columnar epith. has
                 microvilli (small intestine) or cilia (uterine tubes); goblet cells often associated.
     4. Pseudostratified (ciliated) columnar -- respiratory system (what parts?); 
            Functions -- secretion (mucus), movement of unwanted garbage
                Goblet cells often associated

  B. Stratified
     1. Stratified Squamous: Location -- skin, digestive system (what parts?), vagina
         Function -- resist abrasion (protection)
     (2. Stratified cuboidal: Uncommon, in some gland ducts; rarely > 2 cell layers)
     (3. Stratified columnar: Uncommon, in larger excretory ducts and epithelial junctions.)
     4. Transitional: Location -- Pelvis of kidney, ureters; urinary bladder
             Function -- distension.
  *C. Glandular --  MAINLY Simple cuboidal, NOT a different type from above
             cells secretory, with lots of Golgi, ER (and mitochondria)
         (1. Endocrine)
         2. Exocrine -- open into cavities (mucus membranes) or onto surface of body
             a. goblet cells (unicellular)
             b. multicellular: secretory units (tubular, alveolar) with ducts (simple, compound)
          classified by function:  merocrine, holocrine

   II. Connective -- Characteristics: common embryonic origin (mesenchyme); cells and 
                matrix (extracellular material [ground substance, fibers] secreted by the cells)
         Fiber types: collagen, reticular, elastic
   A. Connective Tissue Proper -- cell types: fibroblasts and -cytes, others in some
                 (macrophages, mast cells); usually vascular; connects tissues
     1. Loose
         a. Areolar -- most widely distributed; all three fiber types, mast cells, 
                    macrophages, occasional adipose cells; just underneath epithelium in 
                 all three types of epithelial membranes (see below*)
         b. Adipose -- very cellular (adipocytes)
         c. Reticular -- reticular fibers; mainly in lymph nodes, bone marrow, spleen, 
                    liver, lungs

     2. Dense
         a. Regular -- collagenous; tendons and ligaments (with slightly more elastin)
         b. Elastic -- lots of elastin fibers (duh!); vocal cords, stroma of lungs
         c. Irregular -- collagenous; dermis, many other internal coverings
   B. Cartilage -- cell types: chondroblasts and -cytes; avascular and no nerves; 
                    used for support
     1. Hyaline -- collagen (regular); most widely distributed; absorbs shock
     2. Fibrocartilage -- strongest type; intervertebral disks, some menisci    
        3. Elastic -- more elastin; outer ear and ear canal, epiglottis
   C. Bone -- cell types: osteocytes and -blasts/-clasts; lots of collagen and inorganic 
                    calcium salts; vascular, with bone marrow (yellow/red)
   D. Blood  -- cell types: hematocytes (white and red); matrix: plasma (see below)

Membranes -- coverings and linings: simple organs; overlying epithelium and underlying
    connective tissue
     A. cutaneous -- skin; Ep. always stratified squamous (the epidermis; underlying CT
                lis a little areolar rapidly "densifying" into large layer of dense irregular (dermis)
                under the dermis is the adipose hypodermis
     B. mucous -- lines cavities open to outside; epithelium varies, but CT always areolar;
                (this CT of mucous membranes called lamina propria)
     C. serous -- lines internal cavities (doubled membranes: one layer lines organ 
                [visceral] and other layer lines cavity [parietal]; Ep -- simple squamous,
              underlying CT -- areolar 

  III. Muscle -- well vascularized, for movement (actin/myosin microfilaments)
  A. Skeletal -- cells striated, multinucleate, voluntary
  B. Cardiac -- cells branched and interconnected (intercalated discs), uninucleate, 
            striated, involuntary
  C. Smooth -- cells not striated, uninucleate; in walls of involuntary (hollow) organs

  IV. Nervous -- Cell types:
  A. Neurons (conducting cells; 10 % of nervous tissue)
  B. Glial (supporting cells; 90 % of nervous tissue)

            Nerve -- many nerve cells discretely packaged by connective tissue

Tissue Repair: Either by regeneration or fibrosis (scarring) (READ TEXT)