Cytoplasmic Organelles and Microbial Cells

Cytoplasmic Organelles

  • Lysosomes:
    • Contain enzymes for breaking down damaged organelles and pathogens.
    • Function optimally in acidic conditions.
  • Peroxisomes:
    • Contain enzymes that break down toxic substances like alcohol, formaldehyde, and hydrogen peroxide (H<em>2O</em>2H<em>2O</em>2).
    • Abundant in liver and kidney cells.
  • Protein Filaments:
    • Support structures within the cytoplasm.
    • Finer filaments: Form the cytoskeleton, maintaining cell shape and strength.
    • Additional filaments: Stabilize organelles, connect cells, or create plasma membrane extensions.
    • Larger hollow filaments (tubules): Important for cell shape changes and cell division.
    • Thick and thin filaments: Essential for muscle cell contraction.
  • Microvilli:
    • Short extensions of the plasma membrane that increase surface area for absorption (e.g., in intestinal or kidney cells).
  • Cilia:
    • Longer extensions that act as sensors and move materials (e.g., mucus in the respiratory tract).
  • Flagella:
    • Found only in sperm cells.
    • Provide motility.

Microbial Cells

  • Microbes constitute a significant portion of cells in the body's normal microbiome.
  • Microbiome composition varies individually.
  • Include bacteria, viruses, fungi, protozoa, archaea, and helminths.
  • Functions:
    • Bacteria: Break down food, release nutrients, neutralize toxins (e.g., E. coli).
    • Viruses: Infect and destroy invading bacteria.
    • Fungi: Role in normal health still under research (e.g., Candida albicans).
    • Protozoa: Role in normal health still under research (e.g., Giardia).
    • Archaea: Similar to bacteria; produce methane (e.g., methanogens).
    • Helminths: Worms; role in normal health under research.
  • Microbial functions in body systems:
    • Gastrointestinal tract: Energy production, medication metabolism, vitamin K formation, immune response.
    • Integumentary system: Prevents non-resident bacteria invasion and fungal infections.
    • Oral cavity: Prevents pathogen establishment and aids digestion.
    • Respiratory tract: Resists pathogens and stimulates immune response (e.g., MRSA in the nose).
    • Vagina: Maintains acidic environment to prevent bacterial pathogen growth.
  • Nursing implications:
    • Microorganism composition varies among individuals.
    • Contact with a patient's normal microorganisms (e.g. E. Coli, Candida albicans, MRSA) can be harmful to healthcare workers, if those microorganisms are not part of their microbiome balance.
    • Hand hygiene and PPE are crucial for protection.