Histo Lymph Flashcards
What is the difference b/w stroma & parenchyma?
Stroma is the network or framework within the organ. Parenchyma are the cells found w/i that framework that function. Ex: liver…stroma: CT–collagen; parenchyma: hepatocytes
What is the stroma like in lymph nodes? In the thymus?
Lymph nodes–fibrous; reticular fibers
Thymus–cellular; epithelial-reticular cells
What happens if your lymph system isn’t working properly–not talking about immunity…
Edema.
Peripheral–in the limbs.
Pulmonary–in the lungs…affects cardiac function
What’s the deal with this lymphatic system stuff & chylomicrons?
Chylomicrons can’t be absorbed directly into the bloodstream b/c they are too big. Must go thru the lymphatic system. Important to get into system b/c important for nerves.
Which lymphatic organs are primary & which are secondary?
Primary–Thymus, Bone Marrow, Fetal liver
Secondary–Tonsils, Spleen, Lymph nodes, diffuse lymphatic tissue
What happens to lymphocytes in primary lymphatic organs?
They undergo antigen-independent differentiation.
What happens to lymphocytes in secondary lymphatic organs?
They undergo antigen-dependent activation.
Are lymphatic vessels found in places such as hair, nails, cornea, cartilage? Why or why not?
No. B/c they are avascular structures. They are also not found in the CNS or bone marrow.
Lymphatic vessels also have afferent & efferent vessels. Which direction do these travel?
Afferent–going to the tissue or organ
Efferent–going away from the tissue or organ
Lymphatic nodules are the primary structural unit of which types of tissues?
Diffuse lymphatic tissue; tonsils; lymph nodes, spleen; GALT (gut associated lymphatic tissue); MALT (mucosal associated lymphatic tissue); BALT (bronchia associated lymphatic tissue).
Where are lymphatic nodules not found?
thymus
What are lymphatic nodules primarily composed of?
B cells, lymphoblasts, plasma cells, memory cells
What is the different b/w a primary & secondary lymphatic nodule?
Primary: one that hasn’t seen any antigen, appears uniform
Secondary: one with a germinal center in response to antigen
What are germinal centers?
In secondary lymphatic nodules…when they have seen antigen a lot of mitosis of B cells occurs in the middle…produces a ton of Plasma cells & memory cells
What do lymphatic nodules NOT have?
CT capsules.
Where are Peyer’s Patches found?
in the ileum they are found in the lamina propria & they extend down into the mucosa
When tonsils are surgically removed…which ones are usu taken out?
nasopharyngeal & palatine
When you take out tonsils why is it important to take out the entire tonsil?
B/c if you don’t–it will grow back!!
You should remove it such that you only have a CT cup left.
Where are the crypts found in tonsils? What is their purpose?
They are indentations on the surface of the tonsil…of epithelium…they are supposed to trap antigen.
Explain the basic structure of a single tonsil.
lymphatic nodules grouped around crypts…epithelium over the whole tonsil…incomplete CT capsule at the back.
M Cells…only efferent lymphatic vessels (no afferent)
What is Waldeyer’s Ring?
The group of tonsils that protect the GI & Resp system. Trap antigen w/ their lymphatic tissue.
What is the purpose of the CT capsule that surrounds the tonsil?
Keeps the antigen from escaping into important spaces.
Different tonsils have different forms of covering epithelium. What are the different types of the main tonsils?
Palatine & Lingual: stratified squamous
Nasopharyngeal: Pseudostratified ciliated columnar
How can you tell a palatine tonsil from a lingual tonsil on a histo slide?
Both have stratified squamous BUT the lingual also has skeletal muscle at the base.
