Lymphatic System Flashcards
What is an abscess?
A swollen area in the body containing an accumulation of pus.
Where do T cell originate? What must they do to become activated?
From red bone marrow. They must go to the thymus to become active.
What are cytotoxic T-cells?
Lymphocytes involved in cell-mediated immunity that kill target cells by direct contact or by the secretion of lymphotoxins; also called killer T cells and TC cells
What do helper T-cells do?
They stimulate the responses of both T cells and B cells.
Why are helper T-cells important?
They must activate B cells before the B cells can produce antibodies.
What are regulatory T-cells?
Population of T lymphocytes that suppress the immune response.
What are memory T-cells?
T lymphocytes that provide immunologic memory, enabling an enhanced immune response when reexposed to a specific antigen.
What do B-cells divide into? (2)
- Plasma cells. 2. Memory B-cells.
What do plasma cells do?
Activated B cells that secrete antibodies.
What kind of immunity do B-cells provide?
Antibody-mediated immunity.
What are immunoglobulins?
Circulating antibodies.
What kind of immunity do T cells provide?
Cell-mediated immunity.
What do NK cells do?
They attack foreign cells, normal cells infected with viruses, and cancer cells that appear in normal tissues.
What is immune surveillance?
The constant monitoring of peripheral tissues by NK cells and cytotoxic T cells.
What is mucosa-associated lymphoid tissue (MALT)?
The extensive collection of lymphoid tissues linked with the epithelia of the digestive, respiratory, urinary, and reproductive tracts.
What are tonsils?
Lymphoid nodules in the wall of the pharynx; the palatine, pharyngeal, and lingual tonsils.
What are aggregated lymphoid nodules?
Clusters of lymphatic nodules in the mucosal lining of the small intestine.
What is a lymph node?
Lymphoid organ that monitors the composition of lymph.
What is the hilum?
Where blood vessels and nerves enter and exit the lymph node at.
What do afferent vessels do?
They bring lymph to the node from peripheral tissues.
What are the functions of the spleen? (3)
- Removing abnormal blood cells and other blood components through phagocytosis. 2. Storing iron. 3. Initiating immune responses by B cells and T cells in response to antigens in the circulating blood.
What does the red pulp of the spleen do?
Forms splenic cords, which contain large quantities of red blood cells
What does the white pulp of the spleen do?
Forms lymphatic nodules
What is the thymus?
Lymphoid organ, site of T cell development and maturation.
What is a granuloma?
A collection of immune cells known as macrophages that forms when the immune system attempts to wall off substances it perceives as foreign but is unable to eliminate.
