Adaptive Immunity & Neoplasia

• Adaptive immunity develops during life from exposure to disease organisms.
• Adaptive immunity is specific for particular diseases encountered by natural exposure or vaccines.
• The immune system consists of cells in blood, lymphatic system and other tissues.
• The immune system recognizes foreign invaders, gets rid of them, and monitors the body for abnormal cells like cancer.
• The immune system can overreact to cause allergies and reactions to one's own tissues causing autoimmune diseases.

Neoplasia

• Neoplasia means abnormal, uncontrolled tissue growth, a tumor.
• A benign neoplasm does not spread to other tissues, although it may cause damage.
• An invasive neoplasm that can metastasize is called malignant, commonly known as cancer.
• Carcinoma is a malignant tumor that involves epithelial tissue.
• Adenocarcinoma is a tumor in glandular epithelium where adeno means "gland".
• Melanoma is a cancer of pigmented epithelial cells.
• Sarcoma refers to a neoplasm in connective or muscle tissue.
• Neoplasms of the blood, lymphatic, and nervous systems are classified by clinical features.
• A cyst is often mistaken for malignancy; it is a sac or pouch filled with fluid but is non-cancerous.
• Common sites for cysts: breasts, sebaceous glands, and ovaries.
• Cyst formation can be due to infection or duct blockage.

Terminology Key Terms

• Acute: Sudden, severe, having a short course.
• Benign: Not recurrent or malignant, favorable for recovery, describing a tumor that does not metastasize.
• Carcinoma: A malignant neoplasm composed of epithelial cells.
• Chronic: Of long duration, progressing slowly.
• Cyst: An abnormal filled sac or pouch resembling a bladder or gallbladder (root: cyst/o).
• Edema: Accumulation of fluid in the tissues, swelling. Adjective: edematous.
• Etiology: The cause of a disease.
• Gram stain: Divides bacteria into two groups: gram-positive (purple) and gram-negative (red).
• Hernia: Protrusion of an organ through an abnormal opening.
• Immunity: All defenses against infectious disease.
• Inflammation: Localized response to tissue injury with heat, pain, redness and swelling.
• Lesion: Distinct area of damaged tissue, an injury or wound.

Responses to Disease

• Inflammation is a response to infection or injury.
• Injured cells release chemicals that allow cells to move into tissues causing:
  • Heat
  • Pain
  • Redness
  • Swelling
• -itis indicates inflammation
• Edema is either swelling or accumulation of fluid in tissues.
• Edema is due to fluid blockage, heart failure, or body fluid composition imbalance.

Phagocytosis

• Phagocytosis removes microorganisms, damaged cells, and harmful debris.
• White blood cells engulf and destroy problematic material.
• Phagocytic cells circulate in the blood, tissues, and lymphatic system
• Pus consists of fluid and white blood cells from phagocytosis.

Immunity

• Immunity refers to all defenses against infectious diseases.
• Inflammation and phagocytosis are examples of immunity.
• Other defenses include mechanical barriers, such as skin and mucous membranes, body secretions, stomach acid, and enzymes.

Common Infectious Organisms

• Chlamydia: Bacteria growing in living cells, susceptible to antibiotics. Causes conjunctivitis, pelvic inflammatory disease (PID), etc.
• Rickettsia: Bacteria growing in living cells, susceptible to antibiotics. Causes typhus, Rocky Mountain spotted fever.
• Viruses: Submicroscopic agents reproducing only within living cells. Causes colds, herpes, influenza, AIDS.
• Fungi: Simple, non-green plants, some which are parasitic. Includes yeasts and molds. Causes candidiasis and skin infections. Single fungus is known as FUN-gus.
• Protozoa; Single-celled animals. Single protozoan: pro-to-ZO-on. Causes dysentery, Trichomonas infection, malaria.
• Helminths: Worms. Causes trichinosis, roundworms, pinworms and hookworms.

Bacteria

• Bacteria can enter the body through damaged skin, respiratory, digestive, urinary, and reproductive tracts.
• Infected people spread diseases through air, food, etc.
• Microorganisms produce disease by toxins.
• Presence of harmful organisms/toxins is sepsis.
• Bacteria shapes:
  • Round (cocci)
  • Rod shaped (bacilli)
  • Curved (vibrios and spirochetes)
• Bacteria are named by shape and arrangement.
• Bacteria are described by dye uptake in a lab.
• Chlamydia and Rickettsia are small bacterial groups which on live inside of host cells.