unit 10 lymphatic and immune systems- animal biology

What are the three main functions of the lymphatic system?

Returning excess tissue fluid to the bloodstream, absorbing fats from the digestive tract, and defending the body against disease.

What is lymph?

Fluid inside lymphatic vessels that is absorbed from interstitial fluid.

What begins the lymphatic vessel system?

Lymphatic capillaries.

What are lymphatic capillaries composed of?

Thin walls made of simple squamous epithelium.

What do lymphatic capillaries absorb?

Excess interstitial fluid, which contains water, nutrients, electrolytes, hormones, enzymes, and waste products.

What are the two main ducts of the lymphatic system?

Thoracic duct and right lymphatic duct.

What does the thoracic duct do?

Returns lymph from the body below the thorax, left arm, and left side of the head and neck into the left subclavian vein.

What does the right lymphatic duct do?

Returns lymph from the right arm and right side of the head and neck into the right subclavian vein.

What is edema?

Localized swelling caused by the accumulation of fluids in the tissues.

What are primary lymphoid organs?

Organs where lymphocytes develop and mature, such as red bone marrow and thymus.

What are secondary lymphoid organs?

Organs where lymphocytes become activated, such as the spleen and lymph nodes.

What happens to T cells in the thymus?

They mature, with only 5% exiting the thymus, and those that react to the body's own cells undergo apoptosis.

What is the role of macrophages in lymph nodes?

They engulf pathogens as lymph moves through and help in the immune response.

What is innate immunity?

The body's ability to remove or kill foreign substances without previous exposure.

What are the four types of innate immunity mechanisms?

Physical and chemical barriers, inflammatory response, phagocytes and natural killer cells, and protective proteins.

What triggers the inflammatory response?

Physical or chemical trauma to tissue or pathogens.

What are phagocytes?

Cells that engulf and digest pathogens, including neutrophils and monocytes.

What do natural killer (NK) cells do?

Kill virus-infected and cancer cells by cell-to-cell contact.

What is the complement system?

A group of plasma proteins that enhance immune responses, including amplifying inflammation and attracting phagocytes.

What is adaptive immunity?

Immunity that occurs when innate defenses fail, recognizing and responding to specific antigens.

What is clonal selection?

The process where specific lymphocytes divide in response to an antigen binding to their receptors.

What is the role of B cells in immunity?

They are activated in lymph nodes or spleen to produce antibodies, a process known as antibody-mediated immunity.

What happens to activated B cells?

Most become plasma cells that produce antibodies.

What distinguishes 'self' from 'nonself' in the immune system?

The immune system can recognize and usually does not react against the body's own normal cells.

What is apoptosis in the context of lymphocyte development?

The process of programmed cell death that eliminates lymphocytes that react with 'self' antigens.

What is the significance of cytokines in the immune response?

They are chemical messengers that influence the activities of other immune cells.

What is the function of the spleen in the immune system?

It removes old and defective blood cells and contains lymphatic tissue where lymphocytes can react to foreign invaders.

What are lymph nodes?

Small, ovoid structures along lymphatic vessels that filter lymph and contain B and T cells.

What is metastasis?

The spreading of cancer cells through the lymphatic system to other regions of the body.

What do most B cells become after activation?

Plasma cells that produce and secrete antibodies.

What is the function of memory B cells?

They provide long-term immunity and quickly produce plasma cells upon re-exposure to the same antigen.

What are antibodies also known as?

Immunoglobulins (Ig).

Describe the structure of an antibody.

Y-shaped with two arms, each arm having a heavy (long) and light (short) chain, with constant (C) and variable (V) regions.

What are the two types of T cells?

Helper T (TH) cells and Cytotoxic T (TC) cells.

How do TH cells recognize antigens?

They recognize antigens presented by antigen-presenting cells (APCs) with MHC class II molecules.

What is the role of TC cells?

They kill virus-infected cells and cancer cells.

What is cell-mediated immunity?

Defense provided by TH and TC cells.

What is active immunity?

Immunity developed when an individual produces an immune response against an antigen.

What is passive immunity?

Immunity received from another individual's antibodies or immune cells.

What is the role of cytokines in the immune system?

They are signaling molecules that regulate white blood cell formation or function.

What are monoclonal antibodies?

Antibodies produced from a single clone of B cells, used in diagnostics and therapies.

What triggers an allergic reaction?

Hypersensitivity to harmless substances called allergens.

What is anaphylactic shock?

A severe allergic reaction characterized by a sudden drop in blood pressure due to histamine release.

What determines a person's blood type in the ABO system?

The presence or absence of type A and type B antigens on red blood cells.

What is the universal donor blood type?

Type O, which has no A or B antigens.

What is the Rh factor?

An antigen present on red blood cells that determines Rh-positive or Rh-negative blood type.

What is the consequence of an Rh-negative mother carrying an Rh-positive baby?

The mother may produce anti-Rh antibodies that attack the baby's red blood cells in subsequent pregnancies.

What is tissue rejection?

The immune response against transplanted organs due to differences in MHC proteins.

What is xenotransplantation?

The use of animal organs for transplantation into humans.

What is an autoimmune disease?

A condition where the immune system attacks the body's own cells.

What is an example of an immunodeficiency disease?

Acquired Immune Deficiency Syndrome (AIDS).

What role do interleukins play in the immune system?

They stimulate T cells and natural killer (NK) cells.

What is the purpose of vaccines?

To induce an immune response by exposing the body to an antigen.

What is the difference between active and passive immunity?

Active immunity is produced by the individual's immune response, while passive immunity is received from another individual.

What is the function of perforins released by TC cells?

To form pores in the membranes of abnormal cells, leading to cell death.

What is the significance of memory T cells?

They provide a rapid immune response upon re-exposure to a previously encountered antigen.

What does AIDS stand for?

Acquired Immune Deficiency Syndrome

What is primary immunodeficiency?

A condition where a child inherits a missing or impaired immune system.

What is Severe Combined Immunodeficiency Syndrome (SCID)?

A condition where both antibody- and cell-mediated immunity are lacking or inadequate.

How has gene therapy impacted SCID patients?

Gene therapy has helped some SCID patients improve their condition.

What are the main components of the lymphatic system?

Includes lymphatic ducts, lymph nodes, tonsils, red bone marrow, thymus, and spleen.

What is the role of histamine in the inflammatory response?

Histamine causes capillaries to dilate and increases blood flow to the injured area.

What cells are involved in the phagocytosis of pathogens during inflammation?

Resident macrophages and dendritic cells.

What happens to neutrophils and monocytes during inflammation?

They squeeze through the capillary wall and phagocytize pathogens.

What is the function of the membrane attack complex?

It forms holes in the pathogen's membrane, allowing fluids and salts to enter, leading to cell lysis.

What triggers B cell activation?

Binding of an antigen to a B cell receptor (BCR) that matches the antigen.

What do activated B cells undergo after antigen binding?

Clonal expansion, producing many plasma cells and memory B cells.

What is the function of plasma cells?

They secrete antibodies specific to the antigen.

What is the role of memory B cells?

They recognize the antigen in future infections for a quicker response.

What is the structure of an antibody?

It consists of light and heavy chains with variable and constant regions.

What is the role of cytotoxic T cells in cell-mediated immunity?

They bind to infected cells and induce apoptosis.

What is the primary response in immunization?

The initial immune response to the first exposure to a vaccine.

What is the process of producing monoclonal antibodies?

Spleen cells from immunized mice are fused with myeloma cells to create hybridoma cells that produce specific antibodies.

What indicates a previous exposure to Mycobacterium tuberculosis?

Formation of a swollen, red area 2 to 3 days after injection of antigens into the skin.

What happens when type A blood is transfused to a type B recipient?

Agglutination occurs due to anti-A antibodies in the type B recipient's blood.

What causes hemolytic disease of the newborn?

Antibodies from an Rh-negative mother attacking Rh-positive red blood cells of the fetus.

What is the consequence of an Rh-negative mother producing antibodies against Rh-positive blood?

These antibodies can cross the placenta and cause hemolysis in a subsequent Rh-positive child.