Question | Answer |
the lymphoid system plays a central role in the | body's defense against viruses, bacteria and other microorganisms |
the lymphatic system consists of | lymphatic circulatory vessels that carry lymph |
the immune system contains the...which are involved in the body's... | lymphocytes, lymphoid tissue, and lymphoid organs...defense against disease |
lymphoid structures can be classified as | primary (containing stem cells) or secondary (containing immature or activated lymphocytes) |
lypmh is...which is similar to... | excess tissue fluid..plasma but contains a lower concentration of proteins |
lymphatics or...pick up...and return it to... | lymphatic vessels...lymph...the great veins at the root of the neck |
lymphatics...the lymphoid... | interconnect...organs and tissues |
lymphatics produce... | maintain and distribute lymphocytes |
lymphocytes are cells that | attack invading organisms, abnormal cells, and foreign proteins |
lymphatic vessels help maintain | blood volume and eliminate local variations in the composition of the interstitial fluid |
lymphatic vessels also retrieve | blood proteins that leak from capillaries and return these proteins to the bloodstream |
the vessels of the lymphatic system, from smallest to largest, are... | lymphatic capillaries, lymphatic collecting vessels (with lymph nodes), lymph trunks, and lymph ducts |
lymphatic capillaries are also called | terminal lymphatics |
lymphatic caps weave through | the loose CT of the body |
these(lymphatic caps)...are highly...to entering.. | closed-end tubes...permeable...tissue fluid and proteins |
lymphatic caps are highly permeable to entering tissues and proteins because their.. | endothelial cells are loosely joined and overlap to act as a one-way valve, preventing fluid from returning to their intercellular spaces |
...and...enter the permeable lymphatic caps and spread... | disease-causing microorganisms...cancer cells...widely through the lymph vessels |
lymphatic caps called..absorbe | lacteals...digested fat from the small intestine |
superficial and deep lymphatic collecting vessels run | alongside arteries and veins |
the difference in superficial and deep collecting vessels is that they have | thinner walls and many more valves than do veins |
as a result of the closely spaced valves within these collecting vessels, they resemble a | string of beads |
lymph flows...though lymphatic vessels and empty into the.. | very slowly...thoracic duct and the right lymphatic duct |
what maintain flow in the lymphatic collecting vessels | normal body movements, contractions of skeletal muscles, arterial pulsations, and contraction of smooth muscle in the wall of the lymphatic vessel |
lymphatic..prevent.. | valves..backflow |
lymph nodes are clustered along the...bean shaped lymph nodes remove | lymphatic collecting vessels...infectious agents and cancer cells form the lymph nodes |
lymph enters the node via...and exits via... | afferrent lymphatic vessels...efferent vessels at the hilum |
in between, the lymph...where macrophages remove... | percolates through lymph sinuses...lymph-borne pathogens |
the lymph trunks (...) each draing a... | (lumbar, intestinal, bronchomediastinal, subclavian, and jugular)...large body region |
all except the...are paired | intestinal trunk |
the right lymphatic duct, and/or the nearby trunks, drains... | lymph from the superior right quarter of the body |
the thoracic duct, and/or the nearby trunks, drains | lymph from the rest of the body |
the thoracic and right lymphatic ducts empty into the | junction of the internal jugular and subclavian veins |
the thoracic duct starts at the...and ascends along the... | cisterna chyli at L1-L2...thoracic vertebral bodies |
lymphoid organs and lymphoid tissues house... | millions of lymphocytes which are important cells of the immune system that recognize specific antigens |
lymphocytes have 3 types.. | b cells, t cells, and NK cells |
b and t lymphocytes fight | infectious microorganisms in the loose and lymphoid CT of the body |
b cells are...derived and produce | bone marrow...antibody-secreting plasma cells |
b cells and...are best at... | antibodies...destroying bacteria and bacterial products |
b cells can differentiate into | plasmocytes which produce and secrete antibodies that react with specific chemical targets called antigens |
immunoglobulins are | antibodies in body fluids |
b cells are responsible for | antibody-mediated immunity |
memory b cells are activated if the | antigen appears again at a later date |
t cells or...are..dependent and directly kill... | cytotoxic cells...thymus...antigen-bearing cells which are foreign cells or body cells that have been infected by viruses |
t cells are best at | destroying eukaryotic cells that express surface antigens such as virus-infected cells and grafted and tumor cells |
t cells provide | cell-mediated immunity |
regulatory t cells(...) regulate and coordinate the.. | (helper and suppressor)...immune response |
memory t cells are activated if | the antigen appears again at a later date |
natural killer cells or...do not... | large granular lymphocytes...recognize specific antigens but rapidly attack and kill foreign cells, tumor cells, and virus-infected cells |
nk cells provide | immunological surveillance |
mature lymphocytes patrol | CTs throughout the body by passing in and out of the circulatory vessels (recirculation) |
lymphocytes have a long.. | life span |
lymphocytes arise from | stem cells in the bone marrow |
t cells develop | immunocompetence in the thymus |
b cells develop | immunocompetence in the bone marrow |
immunocompetence is the ability to | recognize antigens |
millions of different lymphocytes, which retain the ability to...,allow the body to... | divide...be prepared for any antigen |
immunocompetence lymphocytes then circulate to the | loose and lymphoid CTs, where antigen binding leads to lymphocyte activation |
goal of immune response | destruction or inactivation of pathogens, abnormal cells, and foreign molecules such as toxins |
the antigen challenge involves an | interaction among lymphocytes being activated, an antigen presenting cell and a helper t lymphocyte |
events in the antigen challenge; antigen-presenting cells result when...which then.. | antigens are engulfed by macrophages...present the antigens to T cells so they can begin differentiating |
a newly activated t cell or b cell divides... | quickly to produce many short-lived effector lymphocytes and some long-lived memory lymphocytes |
recirculating memory lymphocytes provide | long term immunity |
lymphopoiesis involves the | bone marrow, thymus, and peripheral lymphoid tissues |
lymphoid tissue is an | often-infected reticular CT in which many b and t lymphocytes gather to fight pathogens or become activated |
lymphoid tissue is located in the | mucous membranes -as MALT (mucosa associated lymphoid tissue) and in the lymphoid organs (except the thymus) |
lymphyoid tissue contains...in which... | lymphoid follicles with germinal centers ...lymphocytes are densely packed in an area of loose CT |
each follicle contains | thousands of b lymphocytes all derived from one activated b cell |
lymphoid organs includes the | thymus, lymph node, spleen, tonsils, aggregated lymph nodes |
the thymus is located in the...and is a... | superoanterior thorax and neck...primary lymphoid organ that is most active during youth |
the thymus'...which are secreted by... | thymic hormones...epithelial (reticular) cells, signal the contained t lymphocytes to differentiate and gain immunocompetence |
blood-thymus barrier does not | allow free exchange between the interstitial fluid and the circulation; thus protecting the t cells from being prematurely activated |
the thumus has...each with an...packed with... | lobules...outer cortex...maturing t cells and inner medulla containing fewer t cells and degenerative thymic corpuscles |
the thymus undergoes | involution which is a decrease in size after puberty |
the thymus neither | directly fights antigens nor contains true lympoid tissue |
within a lymph node | encapsulated masses of lymphoid tissue lie between the sinuses |
deep cortex of the lymph node is dominated by | t cells |
outer cortex and medulla of lymph node contain | b cells arranged into medullary cords |
lymph glands are the | largest lymph nodes, found where peripheral lymphatics connect with the trunk |
locales are | cervical, axillary, popliteal, inguinal, thoracic abdominal, intestinal and mesenterial lymph nodes that serve to protect vulnerable areas of the body |
this lymphoid tissue receives | some of the antigens that pass through the node, leading to lymphocytes activation and memory-lymphocytes production |
the spleen has | two main functions |
the adult spleen contains | the largest mass of lymphoid tissue in the body |
diaphragmatic surface of the spleen lies | agaisnt the diaphragm |
visceral surface of the spleen lies | agaisnt the stomach and kidney, and contains a groove called the hilum |
the cellular components of the spleen form | the pulp of the spleen |
the spleen removes | antigens from the bloody which is performed by the white pulp |
white pulp of the spleen consists of | sleeves of lymphoid tissue, each surrounding a central artery |
white pulp resembles | lymphoid nodules |
white pulp is surrounded by | a high concentrationh of macrophages |
the spleen destroys | worn out red blood cells which is performed by the red pulp |
red pulp of the spleen consists of | venous sinuses and strips of blood filled reticular CT called splenic cords whose macrophages remove worn out blood cells |
red pulp contains | large number of RBCs with lymphocytes scattered throughout |
the tonsils in the...aggregated lymphoid nodules in the...and the...are parts of... | pharynx...small intesting...wall of appendix...MALT in which the lymphoid tissue contains an exceptionally high concentration of lymphocytes and follicles |