Secondary lymphoid structures Flashcards
Describe the function of secondary lymphoid structures.
Secondary lymphoid structures do not form lymphocytes but house them and other immune cells, serving as sites for immune response initiation.
List the types of secondary lymphoid structures.
Secondary lymphoid structures include lymph nodes, spleen, tonsils, lymphatic nodules, and mucosa-associated lymphoid tissue (MALT).
Explain the organization of secondary lymphoid structures.
Secondary lymphoid structures are organized into lymphoid organs and aggregates of lymphoid nodules, housed within a reticular connective tissue matrix.
How do lymph nodes filter lymph?
Lymph nodes filter lymph by removing unwanted substances as lymph flows through them.
Define the components of a lymph node.
A lymph node consists of afferent lymphatic vessels, an efferent vessel at the hilum, a dense connective tissue capsule, trabeculae, an outer cortex, and an inner medulla.
What is the role of the outer cortex in a lymph node?
The outer cortex contains lymphoid nodules supported by reticular fibers, housing proliferating B lymphocytes and some macrophages.
Describe the structure and function of the medulla in a lymph node.
The medulla contains medullary cords made of connective tissue fibers that support B-lymphocytes, T-lymphocytes, and macrophages, along with medullary sinuses lined with macrophages.
How does lymph flow through a lymph node?
Lymph enters through several afferent vessels, creating pressure that pushes it through the node to a single exit vessel, where it is monitored for foreign material.
Identify the specific lymph nodes and their drainage areas.
Cervical lymph nodes receive lymph from the head and neck, axillary lymph nodes from the breast, axilla, and upper limb, and inguinal lymph nodes from the lower limb and pelvis.
Explain the significance of the germinal center in lymph nodes.
The germinal center within lymphoid nodules is where B lymphocytes proliferate, supported by reticular fibers.
What types of cells are found in the mantle zone surrounding the germinal center?
The mantle zone contains T-lymphocytes, macrophages, and dendritic cells.
Describe the role of macrophages in lymph nodes.
Macrophages in lymph nodes line the cortical sinuses and medullary sinuses, removing foreign debris from lymph and monitoring for the presence of foreign material.
Describe the role of lymphocytes in the immune response.
Lymphocytes initiate the immune response and proliferate, especially in germinal centers.
Explain the significance of enlarged lymph nodes.
Enlarged lymph nodes can be palpated in the neck and axilla, indicating potential immune activity or malignancy.
How does lymph exit a lymph node?
Lymph exits a lymph node through the efferent vessel.
Define malignant neoplasm in the context of lymphoid structures.
A malignant neoplasm from lymphoid structures can present as a nontender, enlarged lymph node.
What are common symptoms associated with lymphoma?
Possible symptoms include night sweats, fever, and weight loss.
How can Hodgkin lymphoma be treated if caught early?
It can be cured by excision, radiation, and chemotherapy.
Identify the age groups most affected by Hodgkin lymphoma.
Hodgkin lymphoma primarily affects young adults and individuals over 60.
Differentiate between Hodgkin lymphoma and Non-Hodgkin lymphoma.
Non-Hodgkin lymphoma is more common, with some types being aggressive and others slow-growing.
Describe the location and function of the spleen.
The spleen is the largest lymphoid organ located in the left upper abdominal quadrant, filtering and monitoring blood.
What is the hilum of the spleen?
The hilum is the indentation where blood vessels and nerves enter the spleen.
Explain the blood supply to and drainage from the spleen.
The splenic artery supplies blood to the spleen, while the splenic vein drains it.
What is the structure surrounding the spleen?
The spleen is surrounded by a connective tissue capsule.
What is found in the white pulp of the spleen?
The white pulp contains clusters of T- and B-lymphocytes and macrophages around the central artery.
Define the components of the spleen’s internal structure.
Trabeculae from the capsule extend into the spleen, dividing it into red and white pulp.
Describe the contents of the red pulp in the spleen.
The red pulp contains erythrocytes, platelets, macrophages, and B-lymphocytes.
What are splenic cords and sinusoids?
Splenic cords are made of cells and reticular connective tissue in red pulp, while splenic sinusoids are very permeable capillaries.
What is the function of the spleen in relation to blood?
The spleen filters and monitors blood, not lymph, for foreign materials and bacteria.
How do macrophages in the spleen contribute to immune function?
Macrophages in the sinusoids of red pulp remove particles by phagocytizing bacteria, debris, and defective erythrocytes and platelets.
Outline the path of blood flow through the spleen.
The path of flow is: splenic artery, central artery, sinusoids, venules, and splenic vein.
Summarize the functions of the spleen.
The spleen eats foreign particles, clears defective erythrocytes and platelets, and stores erythrocytes and platelets.
What role does the spleen play during the first five months of fetal life?
In the first five months of fetal life, the spleen makes blood cells.
List reasons for surgical removal of the spleen.
Surgical removal may be performed due to a ruptured spleen, infection, cyst, tumor, lymphoma, or blood disorders.
What are the potential risks after spleen removal?
Individuals may be more prone to life-threatening infections after spleen removal.
Describe the location and function of the pharyngeal tonsil.
The pharyngeal tonsil is located in the nasopharynx and is called adenoids when enlarged. It plays a role in immune surveillance of inhaled substances.
Explain the characteristics of palatine tonsils.
Palatine tonsils are located in the posterolateral oral cavity and are the most commonly affected during acute tonsillitis.
How do lingual tonsils differ from other tonsils in terms of location?
Lingual tonsils are located along the posterior one-third of the tongue, distinguishing them from the pharyngeal and palatine tonsils.
Define acute tonsillitis and its common symptoms.
Acute tonsillitis is the inflammation and infection of the tonsils, commonly presenting with symptoms such as fever, chills, sore throat, and difficulty swallowing.
What are tonsillar crypts and their significance?
Tonsillar crypts are invaginations in the tonsils that trap material and contain lymphoid nodules, contributing to immune function.
Explain the role of lymphoid nodules in the immune system.
Lymphoid nodules are clusters of lymphoid cells that help defend against infection and are found in various body organs.
Describe the structure and function of MALT.
MALT, or mucosa-associated lymphoid tissue, is located in the gastrointestinal, respiratory, genital, and urinary tracts, helping to defend against foreign substances.
How do Peyer patches contribute to the immune system?
Peyer patches are large collections of lymphoid nodules within the wall of the GI tract, particularly prominent in the ileum, and play a crucial role in immune defense.
What might be a treatment option for chronic tonsillitis?
Chronic tonsillitis may require a tonsillectomy, which is the surgical removal of the tonsils.
Explain the difference between diffuse lymphoid tissue and lymphoid nodules.
Diffuse lymphoid tissue consists of scattered lymphoid nodules that are not completely surrounded by a connective tissue capsule, while lymphoid nodules are more organized clusters of lymphoid cells.
