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• Anatomy


  The biological form of an organism
• Physiology


  The biological functions an organism performs
• As animals increase in size


  • Thicker skeletons are required for support
• Convergent evolution often results in similar adaptations of diverse organisms facing the same challenge
• Exchange with the environment

  Nutrients, waste products, and gases must be exchanged across the cell membranes of animal cells
• Rate of exchange


  Proportional to a cell's surface area while amount of exchange material is proportional to a cell's volume
• A single-celled organism living in water has sufficient surface area to carry out all necessary exchange
• Multicellular organisms with a saclike body plan have body walls that are only two cells thick, facilitating diffusion of materials
• In flat animals (e.g.tapeworms), most cells are in direct contact with its environment
• Interstitial fluid


  Allows for the movement of material into and out of cells in vertebrates
• Histology


  The microscopic study of tissues
• Main categories of tissues

  • Epithelial
  • Connective
  • Muscle
  • Nervous
• Epithelial tissue (Epithelium)


  Covers the outside of the body and lines the organs and cavities within the body
• Epithelial tissue


  • Cells fit closely together and often form sheets
  • The apical surface is the free surface of the tissue
  • The lower surface of the epithelium rests on a basement membrane
  • Avascular (no blood supply)
  • Regenerate easily if well nourished
• Simple epithelium


  One layer of cells
• Stratified epithelium


  More than one layer of cells
• Epithelial cell shapes


  • Squamous (flattened)
  • Cuboidal (cube-shaped)
  • Columnar (column-like)
• Simple squamous epithelium


  • Air sacs of the lungs, kidney glomeruli, lining of heart, blood vessels, and lymphatic vessels
• Function of simple squamous epithelium


  Allows passage of materials by diffusion and filtration
• Simple cuboidal epithelium


  • Kidney tubules, ducts and small glands, and surface of ovary
• Function of simple cuboidal epithelium


  Secretion and absorption
• Simple columnar epithelium


  • Lines digestive tract, mucus-producing goblet cells, gallbladder, and excretory ducts of some glands
• Function of simple columnar epithelium


  Absorption, enzyme secretion
• Pseudostratified epithelium


  • Lines bronchi, uterine tubes, and some regions of the uterus
• Function of pseudostratified epithelium


  Propels mucus or reproductive cells by ciliary action
• Stratified squamous epithelium


  • Lines esophagus, mouth, and vagina. Keratinized variety lines the surface of the skin.
• Function of stratified squamous epithelium


  Protects underlying tissues in areas subject to abrasion
• Stratified cuboidal epithelium


  • Lining of the larger excretory ducts of exocrine glands such as the salivary glands
• Transitional epithelium


  • Lines organs of the urinary system
• Connective tissue


  Found everywhere in the body, includes the most abundant and widely distributed tissues, functions to bind body tissues together, support the body, and provide protection
• Connective tissue


  • Contains sparsely packed cells scattered throughout an extracellular matrix
  • The matrix consists of fibers in a liquid, jellylike, or solid foundation
  • Three types of connective tissue fiber (all made of protein): collagenous fibers, reticular fibers, and elastic fibers
  • Contains cells including fibroblasts and macrophages
• Types of connective tissue

  • Loose connective tissue, fibrous connective tissue, bone, adipose tissue, blood, cartilage
• Osseous tissue/Bone


  Composed of bone cells or osteocytes that lie in lacunae, hard matrix of calcium salts, and large numbers of collagen fibers
• Function of bone


  Supports, protects, provides lever system for muscles to act on, stores calcium and fat, and forms blood cells
• Cartilage


  A hard yet flexible tissue that supports structures, cells called chondrocytes lie within spaces called lacunae that are surrounded by a rubbery matrix that chondroblasts secrete
• Hyaline cartilage


  Most common type of cartilage, composed of abundant collagen fibers and rubbery matrix
• Cartilage


  • Strong and flexible support material
• Major types of connective tissue


  • Osseous tissues/bone
  • Cartilage
  • Dense connective tissue
  • Loose connective tissue
  • Blood/vascular tissue
• Osseous tissues/bone


  Composed of bone cells or osteocytes that lie in lacunae, hard matrix of calcium salts, and large numbers of collagen fibers
• Osseous tissues/bone


  • Supports, protects, provides lever system for muscles to act on, stores calcium and fat, and forms blood cells