Lymphoid System Components Flashcards
Thymus growth pattern?
regress after childhood
Thymus reticulum framework - _______ (from _____)
epithelium (from endoderm)
What components make the blood-thymus barrier?
(cortical barrier only)
- continuous capillaries
- sheathed by epithelial reticular cells
_____ are found in the medulla of the thymus, good diagnosis feature for identification of the medulla.
Hassall’s corpuscles
_____ = dense irregular connective tissue covered with mesothelium (in thymus)
splenic capsule (thymus)
reticular framework of the lymph nodes is derived from ______
mesoderm
lymph node cortex contains:
______ - B lymphocytes
______ - T lymphocytes
follicles
perifollicular
lymph node medulla contains:
_____ and _____
cords and sinuses
_____ - single site for blood entry and exit within lymph nodes
Hilum
what differentiates lymph nodes from spleen and thymus?
lymph nodes have both afferent and efferent lymphatic vessels
what is a structural characteristic and the role of the subcapsular space of lymph node?
complete endothelium lining on capsule side and incomplete on parenchymal side.
Facilitates lymphocytes from lymph flow of afferent lymphatics to interact with lymphocytes in nodes.
_____ ______ allow for filtration of lymph within lymph nodes
reticular fibers
______ - sites where blood-borne lymphocytes enter the node.
High endothelial venules (HEV)
HEV have more _____ than typical venule endothelium
cuboidal cells
______ - selectively endocytose antigens and transport them to the underlying lymphocytes and dendritic cells
M cells
primary function of the spleen is to ______
filter blood, NOT lymph
spleen has no _____, so it cannot filter the lymph
afferent lymphatics
white pulp of spleen contains: ___, ____, ____.
central artery, periarteriolar lymphatic sheath, follicles - b lymphocytes
red pulp of spleen contains: ____, _____, _____.
venous sinuses, Billroth’s strands/cords (splenic strands), and marginal zone
two circulation options in spleen and both come off the arterioles of the so called _______
penicillar arteries
what are the two circulation options in spleen
- closed: circulation typical of that in other organs
- open: no capillary nor venous sinus after the arteriole. the penicillar arteries dump whole blood into the splenic strands in the extravascular regions to stress red blood cells.
______ - Picket-fence type endothelial cells of vascular sinus in spleen
Littoral cells
penicillary arteries are located in the _______ within the spleen
marginal zone
