General Pathology

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General Pathology

• Dr. Edward Smith
• Office 2119
• Phone X1764

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September 10th

• On this day in 1897, a 25-year-old London taxi
  driver named George Smith becomes the first
  person ever arrested for drunk driving after
  slamming his cab into a building. Smith later
  pled guilty and was fined 25 shillings.

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Pathology

• The study (-logos) of suffering (-pathos).
• The study of the structural and functional
  changes in molecules, cells, tissues, organs and
  organisms that underlie disease.

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Pathology studies

• Etiology- the cause
• Pre-eighteenth century- illness was the fault of
  the sufferer (sin, offending (the) god(s) or
  exposure to outside agents (bad smells (miasma),
  cold, evil spirits, etc.).
• 20th Century-illness was causes by either
  intrinsic abnormalities (a genetic defect or
  abnormal development) or an acquired defect due
  to exposure to some injurious agent (trauma,
  carcinogens, toxins, etc.)
• 21st Century- illness is caused by a
  sophisticated interaction between intrinsic and
  acquired characteristics
• Pathogenesis- the mechanism, development and
  response to disease.
• Morphologic changes- the alterations of
  molecules, cells, tissues, organs, organ systems
  and the organism sufferer from the disease.
• Clinical significance- the functional
  consequences of 3, and what the signs and
  symptoms mean to their treatment and prognosis.

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General pathology

• The focus of general pathology is the cell
• Cell theory
• 1. All living things are made of cells,
• 2. The functional unit of all living things is
  the cell
• 3. Cells only arise from other cells.

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Biological Levels of Organization

• Multi-cellular organisms have an immense
  repertoire of abilities but they sacrifice
  independence, they depend on other cells to
  function.

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The Father of Pathology

• Virtually all forms of organ injury begin with
  molecular or structural alterations of cells
• Virchow, 1885

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Brief Review of Cell Anatomy
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Cell Anatomy

• Cell membrane semipermeable barrier
• Phospholipid bilayer
• Asymmetric lipid composition
• Cholesterol stabilizes bilayer
• Membrane proteins (50 of a cells protein)
• Integral proteins span the membrane
• Receptors
• Transports
• Peripheral proteins exposed on one side
• May have only a transient association with the
  membrane

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Cell Anatomy

• Nucleus
• Controls cellular activity
• DNA in the form of chromosomes (protein DNA)
• Euchromatin working DNA
• Heterochromatin condensed chromatin
• Nucleolus center for rRNA synthesis, exported
  to cytoplasm for ribosome formation
• Nuclear envelope- double lipid bilayer studded
  with nuclear pores for communication with the
  cytoplasm

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Cell Anatomy
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Cell Anatomy

• Ribosomes
• Composed of two RNA protein subunits
• Convert genetic information in mRNA into protein
  (proteins do everything).

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Cell Anatomy

• Endomembrane system
• ER interconnecting tubular membranous sacks
• SER lipid, steroid and carbohydrate synthesis
• RER ribosome studded ER for the synthesis of
  proteins for internal use and external export
• Golgi apparatus
• membranous organelle for modification and
  packaging of material for export
• vesicles from ER join cis face are modified as
  they move to the trans-face
• Secretory vesicles bud off Golgi and are
  transported to specific destinations

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Cell anatomy

• TEM of a Golgi body

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Cell Anatomy

• Mitochondria major source of ATP
• Double membrane
• Outer membrane
• Inner membrane highly folded (cristae)
• Inner membrane space is the location of a proton
  concentration gradient that is harnessed to
  generate ATP
• Possess unique DNA and ribosomes

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Cell Anatomy

• Cytoskeleton involved in maintenance of cell
  structure (both internal external), cell
  movement and mitotic apparatus.
• Microtubules
• Microfilaments
• Intermediate filaments

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Cell Anatomy

• Membrane specializations
• Membrane junctions
• Tight junctions seen in epithelia, serve as
  water tight junctions between cells (keep outside
  out)
• Desmosomes anchor cells to each other and
  basement membrane
• Gap junctions direct connections between cells
  for ions and very small molecules important in
  cardiac muscle, some nerves and embryonic tissue

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Cell Anatomy

• Membrane specializations
• Microvilli serve to increase absorptive surface
  area
• Cilia- 92 microtubular structure, coordinated
  function moves material across the epithelial
  surface.

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Cell Anatomy

• Lysosomes
• Vesicles of hydrolytic enzymes that are involved
  in digestion of
• Phagocytized material
• Worn out cell components
• May contain indigestible material (residual
  bodies)

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Cell AnatomyVarious cells stained with organelle
specific fluorescent antibodies
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Cell anatomy

• Understanding the pathology of the cell and its
  response explains the pathology of the organ and
  organism.
• Virchow, 1885

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Brief Review of Cell Anatomy
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