PHYSIO AND PATHOPHYSIO

• Three main factors affecting diffusion

  • Concentration
  • Temperature
  • Pressure
• Diffusion


  Random movement or motion of molecules dissolved in water
• Facilitated Diffusion


  Uses transport proteins to move other ions and small molecules across the plasma membrane
• Diffusion in water and Facilitated Diffusion doesn't require energy input
• Active Transport Pump: Na+/K+ ATPase Pump maintains sodium and potassium levels. It is an enzyme that catalyzes the breakdown of an energy-storing molecule
• Osmosis


  Diffusion of water across a semi-permeable membrane, regulating water movement across the plasma membrane maintaining homeostasis
• Recap: Diffusion is the movement of molecules from high concentration to low concentration. Osmosis is the movement of molecules through a semipermeable membrane which maintains homeostasis. Cells react to maintain homeostatic environment in hypertonic and hypotonic solutions
• Transport of Large Particles is also known as "Bulk Transport"
• Facilitated Diffusion


  • Channel Proteins: Water-filled transport protein that opens and closes to allow diffusion through the plasma membrane
  • Carrier Proteins: Changes shape as diffusion continues
• Uses transport proteins to move other ions and small molecules across the plasma membrane
• Dynamic Equilibrium


  A condition with continuous movement but no overall changes
• Passive Transport


  Transport of molecules without the need for energy input
• Types of Solutions Displaying Osmosis

  • Isotonic Solution
  • Hypertonic Solution
  • Hypotonic Solution
• Diffusion


  Movement of molecules from an area of high concentration to an area of lower concentration
• Active Transport

  Movement of molecules going against the concentration gradient through the cell membrane, requiring energy
• Transport of Large Particles

  1. Endocytosis: The cell encloses a substance from the outside environment in a portion of the plasma membrane

  2. Exocytosis: Secretion of materials through the plasma membrane, reverse process with endocytosis
• Pseudostratified Columnar Epithelium

  • Simple columnar epithelium with cells extending varied distances from the basement membrane
• Connective Tissue


  • Most abundant and widely distributed tissue type
• Extracellular Matrix

  • Nonliving material between cells that distinguishes connective tissue
  • Secreted by cells
• Epithelial Tissue


  • Cells fit closely together to form membranes or sheets, bound by specialized junctions
  • Membranes always have one exposed surface called apical surface
  • Cells are attached to and supported by an adhesive basement membrane
  • Epithelial tissues are avascular
  • If well nourished, epithelial tissues can regenerate themselves
• Muscle Tissue


  • Specialized to contract and produce movement of body parts
• Ground Substance

  • Chiefly glycoproteins and large polysaccharide molecules
  • May be liquid, gel-like, or solid
• Transitional Epithelium

  • Stratified squamous epithelium formed of rounded cells with the ability to slide over one another to allow organ stretch
  • Found only in urinary system organs
• Fibers in Connective Tissue

  • Provide support including collagenic (white) fibers, elastic (yellow) fibers, and reticular (fine collagenic) fibers
• Nervous Tissue

  • Composed of neuroglia (supporting cells) and neurons (specialized to receive stimuli and conduct impulses)
• Body tissues


  group of cells with similar structures and functions that work together to perform specific tasks in the body
• Lacunae 


  spaces in which bone cells are present
• Apical surface


  have one exposed surface or free edge
• Basement membrane 


  Cells are attached and supported
• Avascular


  No blood supply
• Epithelial tissue 


  covers the body's surfaces, lines organs and cavities, and forms glands

  FUNCTION: protection, secretion, absorption, lining
• Simple squamous epithelium 


  allows for diffusion and filtration

  found in areas where rapid diffusion/filtration occurs (air sacs of lungs, walls of capillaries)
• Simple cuboidal epithelium 


  secretion and absorption

  found in kidney tubules, glands, and covering ovaries
• Stratified squamous epithelium 


  Protection against abrasion

  found in the skin, mouth and esophagus
• Stratified cuboidal epithelium 


  Protection and secretion

  Found in ducts of sweat glands, and mammary glands
• Stratified columnar epithelium 


  Protection and secretion

  Found in male urethra, and parts of the pharynx
• Pseudostratified columnar epithelium

  False stratification
• Pseudostratified columnar epithelium


  protection and secretion

  often has cilia for moving mucous, found in the respiratory tract
• Transitional epithelium 


  Allows for stretching

  Found in the urinary bladder
• Connective tissue 


  Provides support and structure to the body

  FUNCTION: binding and supporting other tissues, protection, insulation, and transportation of substances