11.9 Glossary

Acquired immunodeficiency syndrome (ādz ăk-wīrd ĭm-yū-nō-dĕ-FISH-ĕn-sē sĭn-drōm) (AIDS): A disease caused by HIV leading to a significant weakening of the immune system. (Chapter 11.6)

Adaptive immune response (ă-dăp-tĭv ĭ-mūn rĭ-spŏns): It is activated when the innate immune response is insufficient to control an infection. It requires exposure to a pathogen to recognize it as a threat, leading to the development of memory cells for future defense​​. (Chapter 11.5)

Adenoidectomy (ăd-ĕ-noid-ĔK-tŏ-mē): The surgical removal of the adenoid, which is located behind the nasal cavity, often performed along with a tonsillectomy. (Chapter 11.7)

Allergens (AL-ĕr-jĕnz): Substances that are usually harmless but can cause allergic responses in some people. Common allergens include pollen, dust mites, pet dander, certain foods, and insect venom​​. (Chapter 11.6)

Allergist (AL-ĕr-jist): A physician specializing in the study and treatment of allergies. (Chapter 11.7)

Allergy (AL-ĕr-jē): An inflammatory response due to hypersensitivity to a substance that most people’s bodies perceive as harmless, such as pollen or certain foods. Histamine release during the immune response is a primary cause of allergy symptoms​​. (Chapter 11.6)

Anaphylaxis (ăn-ă-fĭ-LĂK-sĭs): A severe, potentially life-threatening allergic reaction. Treatment often involves epinephrine administration​​. (Chapter 11.6)

Antibodies (ANT-i-bod-ēz): Proteins that are very specific to the antigens they recognize and destroy, fitting onto the antigen like a key to a lock​​. (Chapter 11.5)

Antigens (ĂN-tĭ-jĕnz): Markers that tell the immune system whether something in the body is harmful or not, found on viruses, bacteria, cancer cells, and even normal cells of the body​​. (Chapter 11.5)

Apoptosis (ap-ŏp-TŌ-sĭs): Programmed cell death that is disrupted in some cancers, allowing malignant cells to avoid natural cell death and continue uncontrolled growth​​. (Chapter 11.6)

Autoimmune disease (OT-ō-im-yūn diz-ĒZ): The inability of the body to distinguish its own cells from foreign invaders, resulting in the production of antibodies that attack its own tissues​​. (Chapter 11.6)

Autoimmune reactions (ŏ-tō-ĭ-mūn rē-ăk-shŏns): Responses within the body where the immune system mistakenly initiates a response against the body’s own healthy cells, tissues, or organs, failing to distinguish them from harmful invaders​​. (Chapter 11.6)

B cells (B sĕlz): A type of lymphocyte that plays a significant role in the humoral immune response. (Chapter 11.4)

Benign (bĭ-nīn): Cells that overgrow and divide in a controlled manner, remaining localized to a certain area. They are less dangerous compared to malignant cells because they do not metastasize​​. (Chapter 11.6)

Bone marrow (bōn MAR-ō): The primary lymphoid organ where B cells and T cells mature and are selected to attack pathogens. All blood cells, including lymphocytes, are formed in the red bone marrow​​. (Chapter 11.5)

Cancer (KĂN-sŏr): Abnormal cells that overgrow and have the ability to invade and harm tissues. Malignant cells differ from benign cells in that they exhibit uncontrolled growth and have the potential to metastasize​​. (Chapter 11.6)

CD4 T cells (sē-dē fôr tē sĕlz): Helper T cells whose levels decline steadily in HIV-positive individuals, leading to weakened immune response. (Chapter 11.6)

Cell-mediated response (Sĕl-mēd-ē-āt-ed rĭ-spŏns): An immune response that involves T cells destroying abnormal cells when nonspecific innate immunity and humoral immunity are not effective​​. (Chapter 11.5)

Chyle (kīl): A milky bodily fluid consisting of lymph and emulsified fats, absorbed from the intestines during digestion​​. (Chapter 11.4)

Cytokines (SĪ-tō-kīnz): Proteins secreted by cells that act as chemical messengers in immune responses, directing immune cells to respond to and initiate inflammation​​. (Chapter 11.5)

Equilibrium (ē-kwĭ-lĭb-rē-ŭm): In a medical context, it often refers to a state of balance or stability, particularly in physiological or biochemical processes. (Chapter 11.5)

Fever (FĒ-vŏr): A part of the inflammatory response that results in an overall increase in body temperature, enhancing the innate immune response by stimulating white blood cells to kill pathogens​​. (Chapter 11.5)

Graft (grăft): Transplanted tissue or organ. (Chapter 11.6)

Graft rejection (grăft rĭ-jĕk-shŏn):  A complication after graft surgery caused by the recipient’s immune response to antigens on the donated graft. (Chapter 11.6)

Histamine (HIS-tă-mēn): A chemical released during the inflammatory response, causing increased permeability of blood vessels, redness, heat, and swelling​​. (Chapter 11.5)

Hodgkin lymphoma (HŎJ-kĭn lim-FŌ-mă): Cancer originating from the lymphatic system, characterized by out-of-control growth of lymphocytes, causing swollen lymph nodes and growths throughout the body. (Chapter 11.6)

Human immunodeficiency virus (hū-măn ĭm-yū-nō-dĕ-FISH-ĕn-sē vī-rŭs) (HIV): A virus that can lead to acquired immunodeficiency syndrome (AIDS) and severely impair the immune system. (Chapter 11.6)

Human leukocyte antigens (hyū-măn lū-kō-sīt ĂN-tĭ-jĕnz) (HLAs): Proteins that are part of the immune system’s response to foreign substances and help distinguish “self” from “non-self.” (Chapter 11.7)

Human papilloma virus (hū-măn pă-pĭ-LŌ-mă vī-rŭs) (HPV): A virus that can cause cervical cancer, with vaccines available for prevention. (Chapter 11.6)

Humoral immunity (HYŌŌ-mŏr-ăl ĭ-mū-nĭ-tē): Part of the immune response that refers to the function of B cells and their production of antibodies that target antigens​​. (Chapter 11.5)

Hypersensitivity (hī-pĕr-sĕn-sĭ-TĬV-ĭ-tē): An exaggerated immune response triggered by exposure to a specific antigen, which can damage normal tissues and cause a range of health issues​​. (Chapter 11.6)

Immune system (ĭ-MŪN SĬS-tĕm): A complex collection of cells and organs that destroys or neutralizes pathogens, preventing infection, disease, or death​​. (Chapter 11.4)

Immunization (ĭm-yū-nĭ-zā-shŏn): A method to trigger an individual’s acquired immune response and prevent future disease, often through the administration of a vaccine​​. (Chapter 11.5)

Immunocompromised (ĭm-yū-nō-KŎM-prō-mīzd): Someone with an impaired or weakened immune system. (Chapter 11.6)

Immunodeficiency (ĭm-yŭ-nō-dĕ-FISH-ĕn-sē): Inadequate immune response due to immune system dysfunction. (Chapter 11.6)

Immunological memory (im-yŭ-NOL-ŏ-jē- kăl MEM-ŏ-rē): The adaptive immune response’s ability to mount a stronger and faster response upon reexposure to a pathogen, with memory B and T cells providing long-term protection​​. (Chapter 11.5)

Immunologist (ĭm-yŭ-NŎL-ō-jĭst): A physician who specializes in the diagnosis and treatment of immune system disorders. (Chapter 11.7)

Immunology (im-yŭ-NŎL-ŏ-jē): The study of disorders of the immune system. (Chapter 11.7)

Inflammation (ĭn-flă-MĀ-shŏn): A localized physical condition in which part of the body becomes reddened, swollen, hot, and often painful, especially as a reaction to injury or infection​​. (Chapter 11.5)

Inflammatory response (ĭn-FLĂM-ă-tŏr-ē ri-SPONS): A biological response to harmful stimuli, such as pathogens or damaged cells, characterized by redness, swelling, heat, and pain​​. (Chapter 11.5)

Innate immune response (ĭn-NĀT i-MŪN ri-SPONS): A nonspecific defense mechanism that begins immediately or within hours of an antigen’s appearance in the body​​. (Chapter 11.5)

Interstitial space (ĭn-tĕr-STISH-ăl spās): The space between individual cells in the tissues​​. (Chapter 11.4)

Kaposi’s sarcoma (kă-PO-sēz sär-KŌ-mă): A cancer caused by the herpes virus, typically observed in individuals with weakened immune systems. (Chapter 11.6)

Laparoscopic lymph node biopsy (lăp-ăr-ŏ-SKŎ-pĭk limf nōd BĪ-ŏp-sē): A minimally invasive procedure performed under general anesthesia, where a small tube with a light and camera is used to remove lymph node tissue. (Chapter 11.7)

Lymph (lĭmf): A clear-to-white fluid that transports immune system cells, dietary lipids, and fat-soluble vitamins absorbed in the small intestine​​. (Chapter 11.4)

Lymphatic system (lĭmf-ă-TĬK sĭs-tŭm): A network of organs, lymph nodes, lymph ducts, and lymph vessels that produce and transport lymph from tissue spaces to the bloodstream and is a major part of the body’s immune system​​. (Chapter 11.4)

Lymphedema (limf-e-DĒ-ma): Inappropriate accumulation of fluid in interstitial spaces, often caused by damage to the lymphatic system​​. (Chapter 11.4)

Lymph nodes (limf nōdz): Small bean-shaped organs located throughout the lymphatic system that store immune system cells and filter lymph fluid to remove foreign material​​. (Chapter 11.4, Chapter 11.6)

Lymphocyte (LIM-fō-sīt): A type of white blood cell in the vertebrate immune system​​. (Chapter 11.4, Chapter 11.5)

Lymphoma (lĭm-FŌ-mă): Cancer that originates from the lymphatic system. (Chapter 11.6)

Malignant (mă-lĭg-nănt): Malignant cells exhibit uncontrolled growth and rapidly divide, subsequently invading and causing damage to normal functioning cells​​. (Chapter 11.6)

Metastasize (mĕ-tăs-tă-sīz): The spread of malignant cells through the blood or lymphatic system and invasion in other areas of the body​​. (Chapter 11.6)

Needle biopsy (NĒ-dĭl BĪ-ŏp-sē): A procedure where a needle is inserted into a lymph node, typically under local anesthesia and guided by ultrasound or CT scan, for tissue examination. (Chapter 11.7)

Non-Hodgkin lymphoma (nŏn-HŎJ-kĭn lim-FŌ-mă) (NHL): A diverse group of blood cancers that includes all types of lymphoma except Hodgkin’s lymphomas, less predictable than Hodgkin lymphoma, and more likely to metastasize. (Chapter 11.6)

Open lymph node biopsy (Ō-pĕn limf nōd BĪ-ŏp-sē): A surgical procedure to remove all or part of a lymph node, usually performed if the lymph node is large enough to be felt on physical exam. (Chapter 11.7)

Opportunistic infection (ŏp-ŏr-tū-NĬS-tĭk ĭn-FĔK-shŏn): Infections that occur more often or are more severe in people with weakened immune systems. (Chapter 11.6)

Passive immunity (PĂS-ĭv im-Ū-nĭt-ē): A type of immunity obtained by receiving antibodies produced by someone else, such as through the placenta from the mother to the infant or via injection of antibodies​​. (Chapter 11.5)

Pathogens (PĂTH-ō-jĕnz): Bacteria, viruses, or other microorganisms that can cause infection and disease​​. (Chapter 11.5)

Phagocytosis (făg-ō-sī-TŌ-sĭs): The process by which a cell uses its plasma membrane to engulf a large particle, forming an internal compartment known as a phagosome​​. (Chapter 11.5)

Sentinel lymph node biopsy (SĔN-tĭ-nĕl limf nōd BĪ-ŏp-sē): A procedure used to find the best lymph nodes to biopsy, involving the injection of a radioactive tracer or dye near the tumor. (Chapter 11.7)

Seroconversion (sē-rō-kŏn-VĔR-zhŏn): The presence of detectable anti-HIV antibodies in a person’s blood, indicating a positive HIV test. (Chapter 11.6)

Severe combined immunodeficiency disease (sē-vēr kŏm-BĪND ĭm-yū-nō-dĕ-FISH-ĕn-sē dĭ-zēz) (SCID): A serious disease caused by genetic defects leading to impaired B cell and T cell functioning. (Chapter 11.6)

Spleen (splēn): An organ in the upper far left part of the abdomen, to the left of the stomach, which filters blood and is involved in immune response​​. (Chapter 11.4)

Splenectomy (splĕ-NĔK-tŏ-mē): The surgical removal of a diseased or damaged spleen. Individuals who have had a splenectomy are at increased risk of infection for the remainder of their lives due to the spleen’s role in the immune system. (Chapter 11.7)

T cells (T sĕls): A type of lymphocyte involved in cell-mediated immunity. (Chapter 11.4)

Thymus gland (THĪ-mŭs gland): A specialized primary lymphoid organ of the immune system where T cells mature​​. (Chapter 11.4)

Tissue typing (TĬSH-ū tī-pĭng): A process to ensure organ compatibility between a donor and recipient, involving the identification of unique human leukocyte antigens (HLAs). (Chapter 11.7)

Tonsillectomy (tŏn-sĭl-ĔK-tŏ-mē): The surgical removal of the tonsils, often performed to address recurrent cases of tonsillitis or breathing issues. (Chapter 11.7)

Tonsillitis (tŏn-sĭl-Ī-tĭs): Inflammation of the tonsils, often due to infection. (Chapter 11.7)

Tonsils (TŎN-sĭls): A pair of soft tissue masses located at the rear of the throat, part of the immune system​​. (Chapter 11.4)