Rick Study guide

• Pain


  Unpleasant sensation, a feeling of discomfort resulting from stimulation of pain receptors in the body when tissue damage occurs or is about to occur
• Somatic pain


  • Arises from skin or deeper structures from sensory nerves
  • Examples: bone or muscle
• Visceral pain


  • Originates in the organs from sympathetic fibers
  • Examples: bladder pain or IBS
• Pain receptors


  Also called nociceptors
• Pain receptors


  • Stimulated by thermal, chemical, or mechanical/physical
• Pain fibers


  • Afferent
  • Myelinated A delta fibers
  • Unmyelinated C fibers
• Myelinated A delta fibers


  • Transmits very fast
  • Acute pain
• Unmyelinated C fibers

  • Transmits slowly
  • Chronic pain
• Efferent pain fibers


  1. Reflex response at spinal cord

  2. Quick

  3. No thought

  4. Motor impulse to back

  5. Contract away from pain source

  6. Contract to guard against movement
• Spinothalamic bundle in the spinal cord

  • Neospinothalamic tract is fast impulse/acute pain
  • Paleospinothalamic tract is slow impulse/chronic pain
• Referred pain

  Pain that is perceived at a site distant from the source
• Phantom pain


  Perceived pain, itching, and tingling occurring in lost limb
• Central pain


  Caused by dysfunction or damage to the brain or spinal cord
• Neuropathic pain


  Caused by trauma or disease involving the peripheral nerves
• Ischemic pain


  Pain as a result of sudden loss of blood flow to an organ or tissue
• Inflammation


  The body's nonspecific response to injury that involves increased blood to the area to localize and remove an injurious agent
• Cardinal signs of inflammation


  • Redness
  • Swelling
  • Warmth
  • Pain
  • Loss of function
• Systemic effects of inflammation


  • Fever due to the release of pyrogens
  • Malaise
  • Fatigue
  • Headache
  • Anorexia
• Lines of defense


  • First line: Nonspecific or general defense mechanism is a mechanical barrier
  • Second line: Nonspecific process of phagocytosis and inflammation
  • Third line: Specific defense mechanism in the body
• First line of defense


  • Skin, mucous membranes, sweat, or tears
• Second line of defense


  • Neutrophils, macrophages inflammation, or interferons
• Third line of defense


  • T cells and B cells
• Cellulitis


  • An infection of the dermis and subcutaneous
  • Secondary to an injury of a furuncle, or ulcer
  • Causative organism is Staphylococcus aureus
  • Occurs frequently in legs/lower trunks in individuals with restricted circulation in the extremities; also in immunocompromised individuals
• Infection


  When microorganisms reproduce in or on body tissues
• Basic structure of a bacterium

  • Outer cell wall
  • Cell membrane
  • DNA strand
  • Cytoplasm
• Gram negative bacteria


  • Thin peptidoglycan with an outer cell membrane (protects against antibacterials)
  • Endotoxins (released on death)
• Gram positive bacteria


  • Thick peptidoglycan no outer cell membrane
  • Exotoxins (released while the bacteria is alive)
• Endospores


  Protecting mechanism where bacterium goes inactive making them highly heat resistant, and resistant to many disinfectants
• Endospores


  • Anthrax, Tetanus, and Botulism
• Bacterial duplication


  Binary fission
• Bacteria with traits of viruses

  • Chlamydia
  • Rickettsiae
  • Mycoplasma
• Chlamydia


  • Common sexually transmitted disease that causes pelvic inflammatory disease and sterility in women
  • Two forms: elementary and reticulate body
• Rickettsiae


  Tiny gram-negative bacteria that live inside a host cell (obligate intracellular parasites)
• Mycoplasma


  • Common cause of pneumonia
  • They are the smallest cellular microbes
• Virus


  • Small obligate intercellular parasites (requires a host)
  • Structure: Protein coat or capsid, Core of either DNA or RNA
• Virion


  A virus that is extracellular
• Interferons


  Used to inhibit virus replication
• Prions


  Protein-like agents that are transmitted by consumption of contaminated tissues such as muscle or the use of donor tissues contaminated with the protein
• Fungi


  • Eukaryotic
  • Singles or chain of cells
  • Long filaments or strands of a fungus are hyphae, which intertwine to form a mass called the mycelium
• Fungal infection


  • Fungal or mycotic infection results from single-celled yeasts or multicellular molds
  • Few fungi are pathogenic
  • Majority of fungal infections are opportunistic