Chapter 20 Flashcards

T Cells
Terms Definitions
What are the three main parts of the lymphatic system
A network of lymphatic vessels called lymphaticsLymphLymph Nodes
What is the main function of the lymphatic system
to return interstitial fluid and leaked plasma proteins back to the blood.
Once interstitial fluid enters lymphatics it is known as
Lyphoid organs and tissues provide the structural basis for
immune system
What is a function of the lymphatic system that is involved with the digestive tract
Fat absorbtion from the digestive tract, LACTEALS
What direction does lymph flow
toward the heart
What are 3 different lymph vessels
Lymphatic capillariesLymphatic collecting vesselsLymphatic trucks and ducts
Lymphatic capillaries are similar to blood capillaries except
they are very permeable (take up cell depris, pathogens, and cancer cells)andEndothelial cells overlap to form one way minivalves. They are anchored by collagen filaments, preventing collapse of capillaries.
Where are Lymphatic capillaries not found
Bones, teeth, bone marrow, and CNS
What are lacteals
Specialized lymph capillaries present in intestinal mucosa
What is the functin of lacteals
absorb digestied fat and deliver fatty lymph called CHYLE to the blood.
Lymphatic collecting vessels are similar to veins except
they have thinner walls, more internal valves and Anastomose more frequently
Collecting vessles in the skin travel with_______Deep collecting vessels travel with ________
How are nutrients suppplied to the lymphatic connecting vessels?
Vasa Vasorum
What are lymphatic trunks formed by?
the union of the largest collecting ducts
What are the two ducts in which lymph can be delivered?
Right lymphatic ductThoracic duct
What does the right lymphatic duct drain?
the upper right upper arm and the right side of the head and thorax
What does the thoracic ducts arise from?What do they drain?
Arise from cisterna chyliDrane the rest of the body.
Where is lymph emptied into?
Venous circulation via the junction of the inter jugular and subclavian veinsThroacic left Right duct Right
How is lymph propelled?
Pulsations of nearby arteriesCOntraction of smooth muscle in the walls of the lymphatics.
What are the main warriors of the immune system
T Lymphocytes B Lymphocytes
What is the function of T Cells
Manage the immune responseDestroy foreign cells
What is the function of Bcells
Produce plasma cells which in turn secrete antibodies
What are antigens
Anything the body perceives as foreign
What do macrophages do
phagocytize foreign substances and help activate T cells
What do dendritic cells do
capture antigens and deliver them to lymph nodes
What do reticulocytes do
Produce stroma that supports other cells in lyphoid organs examination
What are the two types of lymphoid tissue
Diffuse Lyphatic tissue Lymphatic follicles
What is the function of lymphoid tissue
Houses and provides a proliferation site for lymphocytesFurnishes a surveillance vantage point
Diffuse lymphatic tissue comprises _________ _________ __________ elements in every body organ
scattered reticular tissue
Where are there large collections of diffuse lymphatic tissue fouund
Lamina propria of mucous membranes and lymphoid organs
WHat are lymphatic follicles
Nodules solid spherical bodies of tightly packed reticular elements and cells
What is a germinal center composed of What is it part of
dendritic and B cellsLymphatic follicles
What are lymph Nodes
Principal Lymphoid organs of the body
Where are lymph nodes embedded?
in connective tissue, in clussters along lymphatic vessels. Near the body surface in inguinal, axillary, and cervical regions of the body
What are the functions of lymph nodes
Filter lymph-macrophages destroy mircroorganisms and debrisImmune system-lymphocytes are activated and moint an attack against antigens
What is the shape of a lymph node
Bean shaped
What are two histologically distinct regions of a lymph node
Cortex and Medulla
What extend inward and divide lymph nodes into compartments
What does the cortex of a lymph node contain
Fillicles with germinal centers, heavy with dividing B Cells
What do dendritic cells do?
Nearly encapsulate the follicles and present antigens to tcells and bcells
What does the Deep cortex house
T cells in transit
Where do t cells circulate
They circulate continuously among the blood, lymph nodes, and lymphatic stream
What extend inward from the cortex and contain b cells and t cells and plasma cells
Medullary cords
Lymph Sinuses contain
What does afferent mean
Where does lymph exit lymph nodes
at the hilus via efferent vessels
What does the fact that there are only a few efferent efferent vessles do to the lymph flow
Fewer efferent vessels cause flow of lymph to stagnate which allows lymphocytes and macrophages to carry out functions.
What are 4 other lymphoid organs
Spleen, Thymus gland, tonsils, and peyers patches
What are lymphoid organs composed ofFunction?
Reticular connective tissueHelp protect the body.
What is the only thing that filters lymph?
Lymph Nodes
What is the largest lymphoid organ
What are the functions of the spleen
Site of lymphocyte proliferation and immune surveillance and response Cleanses blood of aged cells and platelets and debris
What does the spleen store
Break down products of RBCsBlood Platelets
where does fetal erythrocyte production occur
What phagocytes does the spleen contain
lymphocytes, macrophages, and huge number of erythrocytes
What are two distinct areas of the spleen
What pulp and Red pulp
Where is white pulp loc, func, and comp
loc: Around central arteriesfunct: involved in immune functionComp:Mostly lymphocytes on retuclar fibers
Red pulp loc, func, and comp
located: in venous sinuses and splenic cordsComp:rich in macrophates for disposal of worn out RBCs and blood born pathogens.
When does the thymus stop growing
during adolescence then begins to atrophy
What do thymic lobes contain
Outer cortex and inner medulla
What does the cortex of a thymic lobe contain
densly packed lymphocytes and scattered macrophates
What does the medulla of a thymic lobe contain
fewer lymphocytes and thymic corpuscles
what are corpuscles involved in
regulatory T cell development
In what ways does the thymus differ from other lymphoid organs
It functions strictly in T lymphocyte maturationIt does not directly fight antigensThe stoma have star shaped epithelial cells not reticular fibers
________ provide the environment in which T lymphocytes become immunocompetent.
What is the siplist lymphoid organs
What do the tonsils form a ring aroudn?
The pharynx
What are 4 different tonsils
Palatine-back of mouth Lingual-base of tonguePharyngeal-posterior wall of nasopharynx Tubal-surrounding the oppenings of the auditory tubes ito the pharynx
Tonsils contain follicles with
Germinal centers
Crypts of tonsils do what
trap and destroy bacteria and particulate matter
What are peyer's patches
Clusters of lymphoid follicles
Where are peyers patches found
in the wall of the distal portion of the small intestine and in the appendix
Peyers patches in the appendix function
destroy bacteria, preventing them from breaching intestinal wall, Generate memory lymphocytes
What does MALT stand for
Mucosa associated lymphatic tissue
What are the peyers patches, tonsils, and the appendix associated with
MALT the digestive tract
What are lymphoid nodules associated with
in the walls of the bronchiRespiratory tract
Function of MALT
Protects the digestive and respiratory systems from foreign matter
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