LYMPHATIC SYSTEM Flashcards
sites where lymphocytes are reproduced, reside, and come in contact with pathogens
Lymphoid organs and tissues
Where do the cells of the immune system originate?
Bone marrow
Migrate to tissues or circulate through the blood and lymphatic system and enter tissues when needed
Leukocytes
Multi-lobed nucleus, pale-staining granules, phagocyte pathogens
Neutrophil
Round nucleus, no granules, include B cells and T cells
Lymphocyte
Large cell, u-shaped nucleus, no granules, become macrophages in tissues
Monocyte
Bi-lobed nucleus, red-staining granules, fight parasites and contribute to allergies
Eosinophil
Blue-staining granules, least common of the leukocytes, release histamine and other inflammatory chemicals
Basophil
List the types of leukocytes from most to least common
Neutrophil, lymphocyte, monocyte, eosinophil, basophil
engulf and destroy pathogens, dead cells and debris. Neutrophils and macrophages primarily perform this task
Phagocytes
process and present antigens to T cells
Antigen-presenting cells (APCs)
capture antigens in the periphery, migrate to lymph nodes, and present these antigen to T cells
Dendritic cells
Effector cells of adaptive community
B cells and T cells
perform various other function in host defenses
Mast cells
What are the primary lymphoid organs?
Bone marrow and thymus
Where T cells mature
Thymus
Where B cells mature
Bone marrow
Organs that are strategically located at potential sites of invasion. they house macrophages and other immune system cells
Secondary lymphoid organs
Low-pressure, pumpless system that ensure blood and lymphatics do not backflow
Lymphatic vessels
____ collect excess interstitial fluid that leaves capillaries and accumulates in the tissues
Lymphatic capillaries
when lymphatic vessels do not function properly causing fluid to build up in tissues
Lymphedema
lymphatic capillaries in the intestine
Lacteals
True or false. The lymphatic vessels return excess tissue fluid and any leaked proteins to the urine
False. They return fluid to blood, not urine.
are oval or bean-shaped secondary lymphoid organs arrayed along lymphatic vessels
Lymph nodes
What are the main purpose of lymph nodes?
Removes antigens and are sites of activation for B and T cells
carry antigen-containing lymph from the tissues into the node
Afferent lymphatic vessels
carry lymph away form a lymph node
Efferent lymphatic vessels
Lymph nodes are covered by a ___ tissue capsule
Dense connective
bundles of collagen fibers that separate lymph nodes into sections
Trabeculae
found beneath the capsule, where the afferent lymphatic vessels empty into
Subcapsular sinus
area just below the subcapsular sinus
Outer cortex
lighter staining central areas in the follicles, formed by B cells proliferating in response to antigen
germinal centers
lymphocytes exit blood vessels and enter here
Deep cortex
shaped into elongated masses of cells called medullary cords
Central medulla
contain both types of lymphocytes as well as macrophages and plasma cells, which are derived from B cells
Medullary cords
a shallow indentation where efferent lymphatic vessel and blood vessels are found
Hilum
fist-sized,blood rich organ located to the left of, and dorsal to the stomach. It performs the same cleansing function for the blood as the lymph nodes do for the lymph
Spleen
Stores platelets and breakdown product of erythrocytes and allows intimate contact between blood and lymphocytes
Spleen
filtering and processing of red blood cells and pathogens occur
Red pulp
surround the central arteries, it is made up of collections of lymphocytes
White pulp
Blood trickles through the spaces within these cords and squeezes into the ___, this returning to the venous circulation
venous sinusoids
recognize and remove aged erythrocytes and platelets
Macrophages
True or False. In stained splenic tissue, the red pulp looks darker than the white pulp because of the many darkly staining nuclei of densely packed lymphocytes
False. White is darker then red pulp
the red pulp is primarily responsible for removing old ___
Erythrocytes
the white pulp is the site of ___ between antigen and lymphocytes
immune interactions
What does MALT stand for?
mucosa-associated lymphoid tissues
found at the posterior end of the oral cavity, they trap microorganisms that enter the body through the oral or nasal cavities
Tonsils
is embedded in the wall of the nasopharynx
Pharyngeal tonsil or adenoids
a collection of lymphoid nodules at the base of the tongue
lingual tonsil
True or False. Tonsils can become overwhelmed by bacteria, becoming sites that harbor, rather than kill the organisms
True
a blind sac stemming from the wall of the first part of the large intestine. Its walls contain a large concentration of lymphoid follicles
Appendix
True or False. If the mouth of the appendix becomes plugged, the pressure inside falls
False. The pressure rises
found in the mucosa of the distal portion of the small intestine
Peyer’s patches
site for differentiation of lymphocytes into mature T cells
Thymus
Where is the thymus located?
Mediastinum
as we age, the thymus decreases in size and activity as the thymus tissue is gradually replaced by fat and connective tissue.
Thymic atrophy
Thymic lobes are divided into
lobules
clusters of keratinized epithelial cells with a whorled appearance that are scattered throughout the medullary area
Thymic corpuscles
