Bio Ch 33 Flashcards
(56 cards)
Immune System
protects us from all sorts of harmful invaders, including bacterial and viral pathogens, various toxins, and perhaps even cancerous cells that occasionally arise
PAMPs
pathogenic-associated molecular patterns; when receptors bind to these, they trigger an immune reaction, increasing the odds that the pathogen can be eliminated
Innate Immunity
type of host defense; can recognized common microbial invaders very quickly but show no sign of an increased response upon repeated exposure to the same invader
Adaptive immunity
most vertebrate animals exhibit this, characterized by the production of a very large number of diverse receptors that are found on the surface of specialized white blood cells (such as B and T lymphocytes in humans)
Antigens
foreign substance, usually a protein or a polysaccharide, that stimulates the immune system to react, such as to produce antibodies
Lymphatic system
closely associated with the cardiovascular and immune systems; includes the lymphatic vessels and the lymphoid organs; 3 main functions that contribute to homeostasis - (1) capillaries that absorb excess tissue fluid and return it to the bloodstream, (2) lacteals absorb fats in the form of lipoproteins and transport them in the bloodstream, & (3) organs & vessels are sites of production and distribution of lymphocytes, which help defend the body against pathogens
Lymphatic vessels
form a one-way system that begins with ____ capillaries
Lymphatic capillaries
tiny, closed-ended vessels that take up excess tissue fluid
Lymph
fluid inside lymphatic capillaries
Lymphoid (lymphatic) organs
organ other than a lymphatic vessel that is part of the lymphatic system; lymph nodes, tonsils, spleen, thymus gland, and bone marrow
Primary lymphoid organs
bone marrow, thymus
Secondary lymphoid organs
sites where some lymphocytes are activated by antigens
Red bone marrow
major primary lymphoid organ; spongy, semisolid red tissue where hematopoietic stem cells divide and produce all the types of blood cells, including lymphocytes
B cells
type of lymphocyte that begins development in the red bone marrow and remains there until they are mature
T cells
type of lymphocyte; immature, migrate from the bone marrow via the bloodstream to the thymus, where they mature
Thymus
soft, bilobed; primary lymphoid organ located in the thoracic cavity between the trachea and the sternum ventral to the heart
Lymph nodes
small ovoid structures occurring along lymphatic vessels; major type of secondary lymphoid organ
Spleen
oval secondary lymphoid organ with a dull purplish color; located in the upper left side of the abdominal cavity posterior to the stomach; most of this contains red pulp that filters and cleanses the blood
Immunity
capability of removing or killing foreign substances, pathogens, and cancer cells from the body
Inflammatory response
when tissues are damaged by a variety of causes, including pathogens, a series of events known as this occurs
Histamine
substances, produced by basophils in blood and mast cells in connective tissue, that causes capillaries to dilate
Mast cells
connective tissue that releases histamine in allergic reactions
Neutrophils
able to leave the bloodstream and phagocytize bacteria in tissues
Eosinophils
can be phagocytic but they are better known for mounting an attack against animal parasites such as tapeworms that are too large to be phagocytized
