Lymphatic System Flashcards
What is this?

Lymph node follicle
What are the 2 functions of the lymphatic system?
protect the body from pathogenic organisms
&
remove cells underdoing natural or induced degeneration
What is spleen red pulp?
makes up interior of spleen & has rbc’s stored & taveling thru sinuses along w macrophages
What is the paracortical tissue of a lymph node and what does it contain?
tissue in btwn follicles w hi endothelial blood vessels
What are the primary organs for lymphoid stem cell differentation?
Bone marrow
Cloacal Bursa
Thymus
What is C?

Microfold cells (GALT)
What are the sites called where antigens can enter & APC’s can induce an immune repsonse? (general)
Mucosal-Associated Lymphoid Tissue
What lymphatic organ involutes after sexual maturity and is repplaced by adipocytes?
Thymus
What are thymic (Hassall’s) corpuscles?
large central calcified cells surrounded by concentric circles of keratinized cells; classic for thymus
What are primary follicles of the lymph node cortex?
follicles that have never been stimulated before
What is C & what does it contain?

Medulla; less dense containing stromal cells, macrophages, dead cells
What is B?

Thymus medulla (light bc less lymphocytes)
What is unique about a lymph node compared to other escondary lymphatic organs?
contains afferent AND efferent lymph vessels with valves to ensure 1-way flow of lymph
What is this organ?

spleen
What organ is this?

Thymus
Where are lymphoid stem cells located?
in the bone marrow
What is white pulp?
congregation of lymphoid cells in specific arrangement
What is C?

lymphatic nodules of tonsils
What is F?
What does it contain?

Lymph node medulla - at one side or to center, lighter in color comared to cortex containing medullary cords & sinuses
Process of antigen presenting in a lymph node:
(4 steps)
- antigen presented in follicle in cortex
- T & B lymphocytes are activated
- Anitgen Presenting Cells present antigen
4a. follicular dendritic cells use MCH II to brign to surface of cell
OR
4b. macrophages phagocytose & bring to T or B cell to start immune response
What is the cortical sinuses?
open network of channels from efferent vessels that leaves sinus lumen to neihgboring tissue toward hilus
What is B?

Smooth muscle of bronchiole of the bronchiolar associated lymphoid tissue
What is C?
Where are they located?

Lymph node follicle located in cortex
What is this image and what does it contain? (general)

Cloacal Bursa contains multiple nodules composed of lymphoid cells
What are the 3 secondary lymphatic organs?
What happens in these organs?
lymph nodes, spleen, mucosal associated lymphoid tissue; where lymphocytes are stored
What is B & what does it contain?

Cortex; more dense w lymphoid cells
What makes up a lymph node?
lymph vessels, sinuses, cortex, medulla
What is a lymphatic vessel?
What are they lined by?
What do they do?
blind-ended tube lined by endothelial cells
- take fluid from interstitium & pass back into blood stream
- move inflammatory cells & antigens from tissues to local lymph node for immune response
What are the two mechanisms of action by the lymphatic system?
- phagocytosis by macrophages
- production of immunologically compentent cells
What is the subscapular sinus?
area under the capsule that takes lymph from the afferent sinus (to the trabecular sinus, to the medullary sinsus, to the efferent vessels)
What is A?

Lymph node capsule - composed of dense irregular CT
What are the 3 structures in GALT that are associated with the lymphoid system?
- Peyer’s Patches
- Lacteals
- Microfold cells
What is an educated T cell and where does it settle?
a mature T cell that matured in the thymus and settes at secondary lymphatic organ via the blood
When lymphoid stem cells enter the thymus, what type of cell does it differentiate into?
T cell
What is the spleen white pulp arrangement?
Central arteriole
Periarterial lymphoid sheath w T cells
Follicular area w B cells
Capsule

Where are lymphatic vessels NOT located?
eye
cartilage
bone
bone marrow
spleen
CNS
What is A & what type of cells?

mucosa covered in PSEUDOSTRATIFIED COLUMNAR EP w mature lymphoid cells
What is this? (related to lyphatic system)

Bronchiolar Associated lymphoid tissue
What is A?

Spleen capsule
At what level does the thymus have the blood-thymus barrier?
Cortex
What is E?

macrophages of the bronchiolar associated lymphoid tissue
What is C?

Spleen trabeculae vein (or will have artery)
What is D?

Lymph node cortex - milky white in natural appearance, contains follicles
Where do all the efferent vessels meet up to put cells into blood stream to allow cells to be delivered to the place that started the immune repsonse?
thoracic duct
What is E?

Lymph node paracortex
What is D?

Bronchiolar associated lymphoid tissue
What is the lymph node hilus?
slight invagination where arteries enter to bring in new lymphocytes & where efferent lymphatics & veins exit lymph node
What is the function of the spleen? (4)
filter blood, mounts the immune repsonse, location of hematopoiesis in fetus, storage for rbcs & platelets
What are the medullary cords of the lmyph node?
cords of cells in the medulla
What is the trabeculae of the spleen made up of?
collagen, elastic fibers, muscle cells, central artery or vien
What is E?

Spleen red pulp
What is D?

Spleen white pulp
Stromal cells of the bone marrow porduce what?
cytokines
What is Peyer’s Patch?
aggregated lymphatic follicles w lyphocytes, macrophages, plasma cells
What is B?

Peyer’s Patches (GALT)
What are secondary follicles of the lymph node cortex?
follicles w pale centers that hav been stimulated before
What is D?

dense CT separating nodules
What is A?

Bronchiole of the bronchiolar associated lymphoid tissue
What are the 3 types of Antigen Presenting Cells?
Dendritic Cells
Macrophages
B Cells
What do antigen presenting cells do?
What is needed to do this?
take in material and present it on it’s surface
MHCII is needed to present the engulfed material
What are the hi endothelial blood vessels?
sinus where new lymphocytes leave to regulate lymph nodes
What organ is this?

Lymph node
What exits at the corticomedullary junction? What are they carrying?
venules carrying educated T cells
What is number 1?

Lymphatic vessel
What is a chylothorax?
milky white subsetance from throacic duct rupture
What is A & what type of cells?

mucosa covered in PSEUDOSTRATIFIED COLUMNAR EP w mature lymphoid cells
Pathway of blood vessels in the thymus:
- arteries carry immature cells that devel into T cells into thymus at corticomedullary junction
- artery divides into aterioles then capillaries
- at level of cortex capillaries have blood-thymus barrier
- Educated T cells leave thru postcapillary venules at corticomedullary junction
- Educated T cells enter blood and settle at secondary lymphatic organ
What is the lymph node stroma composed of?
reticular cells & fibers to support lymphocytes & macrophages & plasma cells
What is A?

Epithelial reticular cell of the thymus medulla
What is the trabecular sinus?
invagination of the capsule where lymph is brought to from subscapular sinus
What are the medullary sinuses of a lymph node?
empty spaces w macrophages
What is kind of cells are A?

STRATIFIED SQUAMOUS EP of tonsils
What is A?

Lacteal (GALT)
What is B?

Spleen trabeculae
Where is the thymus located?
mediastinum cranial to heart
What is B?

crypts of tonsils
What is B?
What does it contain?

Lymph node trabeculae - extensions from capsule into cortex & medulla for structural support containing vessels, nerves, surrounded by sinuses
What is a microfold cell?
specialized cells over epithelium of ilium, associated with Peyer’s Patches
What is a fixed macrophage?
line sinuses and does job locally in liver, spleen, lymph nodes, bone marrow
What makes up lymph?
Flow?
extracellular fluid & lymphatic cells that flow in one direction from periphery to heart
When lymphoid stem cell stays in bone marrow or go to the cloacal burse what does it differentiate into?
B cell
What is C?

artery
What are the primary lymphatic organs?
What happens in these organs? (general)
Bone marrow, cloacal bursa (bursa of fabricius), thymus; where lymphocytes develop
What are tonsils?
What do they produce?
aggregated lymphoid tissue in the pharynx that produce lymphoid cells & antibodies
What is this tissue?

Tonsils
What is A?

Thymus cortex (darker bc more lymphocytes)
What is the capsule of the spleen made of?
What does it give rise to?
made of dense CT w underlying smooth muscle that gives rise to trabeculae
What is B?

Thymic (Hassall’s) Corpuscles of the thymus medulla; classic for thymus
What is the role of a lymph node?
filter antigens from lymph that are in sinuses before returning it to the blood stream
What is a lacteal?
blunt ended lymphatic vessel w/in villi that take in fat products in form of chylomicrons
What species does not have a storage spleen?
cats
What is the thymus composed of? (6)
cortex, medulla, multiple nodules, dense CT separating them, stromal cells producing cytokines, T cells in spaces btwn stromal cells
NO ep lining