lymphocyte production; involves the bone marrow, thymus, and peripheral lymphoid tissues
connective tissues dominated by lymphocytes
an area of loose connective tissue where lymphocytes are densely packed
important lymphoid nodules
aggregated lymphoid nodules - tonsils and appendix
where is the appendix
beneath the lining of the intestine
where are the tonsils
in the walls of the pharynx
important lymphoid organs
lymph nodes, thymus, spleen
encapsulated masses of lymphoid tissue
divisions of lymph nodes
deep cortex, outer cortex, medulla
what dominates deep cortex?
what do outer cortex and medulla contain?
B cells arranged into medullary cords
the largest lymph nodes
where are lymph glands found?
where peripheral lymphatics connect with the trunk
where are lymph nodes found?
throughout the body, with the exception of the brain
where are lymphoid tissues and nodes located?
in areas particularly susceptible to injury or invasion by microorganisms
lymph nodes that serve to protect vulnerable areas of the body?
1. cervical lymph nodes, 2. axillary lymph nodes, 3. popliteal lymph nodes, 4. inguinal lymph nodes, 5. thoracic lymph nodes, 6. abdominal lymph nodes, 7. intestinal lymph nodes, 8. mesenterical lymph nodes
glands that are checked during medical examination to determine infection?
cervical, parotid, submandibular, and submental
where is the thymus located?
posterior to the manubrium, in the posterior mediastinum
what produces thymic hormones?
epithelial cells scattered among the lymphocytes
what do thymic hormones do?
promote the differentiation of T cells
prevents free exchange between the interstitial fluid and the circulation, protecting the T cells from being prematurely activated
process by which the size of the thymus gradually decreases after puberty
contains the largest mass of lymphoid tissue in the body (ADULT); performs same functions for the blood that lymph nodes perform for the lymph
where in the body does the diaphragmatic surface of the spleen lie?
against the diaphragm
visceral surface of the spleen
lies against the stomach and kidney; contains a groove called the hilus
formed by cellular components of the spleen
pulp that contains large amounts of red blood cells
pulp that resembles lymphatic nodules
what does the region surrounding white pulp contain?
large concentration of macrophages
what is scattered throughout the red pulp?
often caused by infection, inflammation, cancer
what clinical symptoms indicate a blockage in right lymphatic duct?
edema of the right arm and upper chest
what happens to immune system with age?
becomes less effective at combating disease