Lymphatic System - Histo Flashcards
What are the three major functions of the Lymphatic System?
drain excess interstitial fluid to return blood to maintain blood volume
immune response
provide an alternative transportation route for hormones, nutrients and waste
What are the seven components of the lymphatic system?
- diffuse lymphatic tissue
- lymph nodules
- lymph nodes
- spleen
- bone marrow
- thymus
- lymphatic vessels
What is the definitive cell of the lymphatic system?
lymphocyte
What are three types of lymphocytes?
B cells, T Cells and NK cells
Which cell differentiate in the thymus, attach and destroy cells, are involved with cell-mediated immunity, and make up 60 - 80% of circulating lymphocytes?
T cells
What cell was first recognized in the bursa of Fabricius in birds, produce and secrete antibodies, are involved in humoral immunty and make up 20 - 30% of circulating lymphocytes?
B cells
___ ___ cells kill certain transformed cells and make up 5 - 10% of circulating lymphocytes.
Natural Killer
What tissue type has an accumulation of lymphocytes in the lamina propria of the alimentary canal, respiratory, urinary, and reproductive tracts?
diffuse lymphatic tissue
Diffuse lymphatic tissue has no surrounding ___ and houses ___ cells and ___.
capsule; plasma; eosinophils
Lymphatic nodules have no surrounding ___, are sharply defined, contain a meshwork of ___ fibers and have lymphocytes, plasma cells and eosinophils.
capsule, reticular
A secondary nodule has a ___ center with follicular ___ cells and a ___ zone.
germinal; dendritic; mantle
What is an aggregate of primarily small lymphocytes?
primary nodule
T/F. Normally, lymphatic nodules are found grouped together however in certain areas of the alimentary canal they are found randomly dispersed and my themselves.
False, Normally, lymphatic nodules are found randomly dispersed and by themselves however, in certain locations of the alimentary canal they are grouped together.
Give two examples of aggregated lymphatic nodules.
- Tonsils
2. Peyer’s patches
Which aggregated lymphatic nodule is found in the ileum?
Peyer’s patches
___ create a ring around the entrance to the oropharynx and the nasopharynx.
Tonsils
Where would you find lymph nodes and what is the function?
capsuled organs along pathways of lymphatic vessels function to filter system
What three areas of the lymph node make up the stroma?
capsule, trabeculae, and reticular tissue/meshwork
What parts make up the lymph node’s parenchyma?
cortex and medulla
Where are the germinal centers of a lymph node located?
Cortex - superficial (nodular) cortex - lymphatic nodules - secondary area
The ___ can be divided into the cords and sinuses.
medulla
What are the four cells of the reticular meshwork?
reticular cells, dendritic cells, macrophages, and follicular dendritic cells
List the flow of lymph through the lymph node.
afferent lymph vessel - subcapsular (cortical) sinus - trabecular sinus - medullary sinus - efferent lymph vessels
The thymus is the site of thymic cell ___, a process through which T cells mature and differentiate into immunocompetent T cells.
education
What is the function of the spleen?
it filters and monitors the blood immunologically
The ___ pulp of the spleen consists of blood-filled venous sinuses surrounded by cords of splenic tissue called splenic (___) cords, that contain RBCs, macrophages, lymphocytes, plasma cells, and granulocytes.
red; Billroth’s
What is the function of the red pulp?
blood filtration (removal of materials, antigens, and worn-out or defective RBCs, WBCs, and platelets)
White pulp consist mostly of ___ that aggregate around branches of the splenic ___ (called ___ ___) creating ___ ___ ___ (PALS).
lymphocytes; artery; central arteries; periarterial lymphatic sheaths
What is the function of the white pulp?
To carry out immune functions similar to lymph nodes
