Lymphatic system Histo Flashcards
COmponents of the LYmphatic ystem
Diffuse Lymphatic Tissue Lymphatic Nodule Lymph nodes Spleen Bone Marrow Thymus Lymphatic Vessels
Major function of the lymph system
Drain excess interstitial fluid (return also to maintain normal blood volume) Provde an alternative transportation route for hormones, nutrients, and waste produces Immune response (produce, maintain, distribute lymphocytes)
what happens to the flow of fluid in and out of capillary beds
Excess fluid is pushed out than is absorbed and builds up around the capillaries
How much lymph is returned to the blood stream on a daily basis
3 Liters
where are lymphatic capillaries found
In loose connective tissues
permiability of lymphatic capillaries compared to blood
Lymph more permiable
Size of Lymphatic endothelial cells
A bit larger than that of Blood vessels
where is the thoracic duct
Along the vertebral bodies
where do Lymphatic vessels get back into venous circulation
At the venous angle
where does the left Thoracic duct empty
Between the Left subclavian and left jugular veins (venous angle)
what does the left thoracic duct drain
Lower limbs, lumbar region, left thorax, neck, head, and arm
what does the right lymphatic duct drain
Right thorax, right arm, right head and neck
what lines lymphatic cappilaries
Enodthelial cells with a discontinuous basal lamina with increasing connective tissue
what causes lymph to flow
Compression of skeletal muscles
what causes lymph to flow in one direction
Valves
why does lymph stain well
Because it has a lot of prot and stuff
what is the definitive cell of the Lymphatic system
Lymphocytes
Types of Lymphocytetes
B cells
T cells
NK cells
where were B cells first recognized
In the bursa of Fabricius in birds
Roll of B cells
Produce and secrete anitbodies
Immunity given by b cells
invovled in humoral immunity
Derivative cell of B cells
Plasma cells
how many lymphocytes are B cells
20-30%
where do T cells differentiate
In the thymus
Roll of T cells
Attach and destroy cells
what type of immunity do T cells do
Cell-mediated immunity
amount of T cells
60-80% of circulating lymphocytes
roll of NK cells
Kill certain transformed cells
Amount of NK cells
5-10%
Supporting cells in the Lymphatic system
Reticular Neutrophils Dendritic Epithelioretiular Monocytes Basophil Follicular dendritic Macrophages Eosinophils Langerhans'
What do reticular cells do
Secrete Reticular cells for type 3 collagen for the lymph node, nodles, and spleen
What does Diffuse Lymphatic tissue have in its lamina propria
Accumulations of lymphocytes in the lamina propria with no strucutre or anything holding them together
Where is Diffuse Lymphatic tissue found
In the alimentary canal also respiratory, urinary and reproductive tracts
what surrounds diffuse lymphatic tissue
No surrounding capsule
what cells are also found in Diffuse Lymphatic tissue
Pmphatic nodules foundlasma cells and eosinophils
Other name for Lymphatic Nodules
Lymphatic Follicles
what are Lymphatic Nodules
Accumulations of lymphocytes with no surrounding capsule but is sharply defined with a reticular fibers
where are Lymphatic Nodules found
In wall of alimentary canal, respiratory, urinary and reproductive tracts
what cells are found in the lymphatic nodule
Lymphocytes, plasma cells, eosinophils
Types of Lymphatic Nodules
primary Nodule
Secondary Nodule
aggregations of primary small lymphocytes
PRimary Nodule
what are the zones of the secondary nodule
Germinal center with a mantle zone
where are dendritic cells in the secondary nodule
Dendritic cells (FDCs)
are lymphatic nodules an organ
No because not surrounded with a capsule
are Primary nodules active
No, just waiting for a antigen
what are Secondary Nodules responding to
An antigen
are lymphatic nodules normally grouped tother
No, normally randomly dispersed but in alimentary canal they are grouped together
where Lymphatic nodules are all alone
solitary lymphatic nodules
when Lymphatic nodules touch
Aggregated lymphatic nodules
where are Aggregated Lymphatic nodules
Tonsils
Peyer’s patches
Appendix
how do aggregated lymphatic nodules look in the tonsils
Create a ring around entrance to the oropharynx and nasopharynx
where are Peyer’s pathces found
In the ileum
where is the appendix
Cecum of the large intestin
GALT
Gut associated lymphatic tissue
BALT
Bronchus associated Lymphatic tissue
MALT
Mucous associated of Lymphatic tissue
Capsuled Organs along the pathways of Lymphatic vessels
Lymph nodes
Function of Lymph nodes
Filtering (phagosytosis and trigger immune response)
where do lymph nodes cluster
Cervical region
Axilla region
inguinal region
mesentaries
PArts of the Lymph node
Capsule Trabeculae Reticular tissue (meshwork) cortex Medulla
what makes up the stroma of the lymph node
Capsule
Trabeculae
Retiular tissue
what makes up the Parenchyma of the Lymph node
Cortex
Medulla
parts of teh cortex of the lymph node
Superficial (nodular) cortex Deep cortex (paracortex)
what is found in the superficial cortex of the lymph node
Lymphatic nodules both priimary and seconday
parts of the medulla of the lymph node
Medullary cords
Medullary sinuses
extension of the Lymph node capsule into the organ
Trabeculae
what part of the lymph node lacks a cortex
The hilum
Cells of the Reticular Meshwork
Reticular cells
Dendritic Cells
Macrophages
Follicular dendritic cells
where strcutres leave and enter the lymph node
The Hilum (artery, vein, and efferent lymphatic vessel) afferent lymphatic vessels enter at the capsule
where in the lymph node are t lymphocytes
In the deep cortex
where in the lymph node are b lymphocytes
In the nodulary cortex
what id found in the outer cortex
B cells
genrmal centers: B cells, Follicular cells, macrophages
what is found in the paracortex
T cells and Dendritic cells
What is found in the medullary cords
B cells
Plamsa cells
Macrophages
flow of cells in the lymph nodes
B Cells
T Cells
B cells
FLow of lymph in the lymph nodes
Afferent lymph vessels Subcapsular (cortical) sinus TRabecular sinus Medullary sinus Efferent Lymph Vessel
how do lymph cells come into the lymph nodes
10% from lymph vessels
90% from the blood
blood vessels that give to the Lymph nodes
High endothelial venules
where are High endothelial venules
deep cortex
What are the cells of the high endothelial venules
Cuboidal or columnar
the site of T cell education
Thymus
what is T cel education
T cells mature and differentiate to immunocompetent T cells
where is the THymus the most important
Childhood (Goes away after awhile)
what surrounds the Thymus
Capsule with TRabecula
What do the TRabecula form
Thymic lobules
The functional portion of the Thymic Lobule consists of
Developing T lymphocytes
supportive connective tissue is epithelial reticular cells
parts of the thymic lobules
Cortex
Medulla
what is found int he Cortex of the Thymic lobules
Immature T cells
where do Immature T cells go during thymic education
To the Medulla of the Thymic lobule
when do cells leave the thymus
Once they’ve become educated
where are diferent types of reticular cells of the Thymic lobule found
1-3 in the cortex
4-6 in the medula
what is the roll of eptihelioreticular cells
Forms meshwork of the thymus
what is the roll of type VI epithelioreticualar cells
Forms the thymic (Hassall’s) corpuscles
what happens to the Type VI epithelioreticular cells as they form the thymic corpuscles
Flatten and circularize to fill with keratin then die
Function of the spleen
Filter and Monitors the blood immunologically like a lymph nodes
Parts of the spleen
Red pulp
White pulp
What does the Red pulp consist of
Blood-filled Venous sinuses surrounded by cords of splenic tissue
what do splenic cords consist of
Red blood cells, macrophages, lymphocytes, plasma cells, and granulocytes
roll of the red pulp
Blod filtration (removal of particulate materials, removal of antigens, Removeal of worn out defective RBCs, WBC, and platelets
what is the White pulp made of
Lymphatic tissue consistning mainly of lymphocytes plus the central artery
where do white pulp lymphocytes aggregate
Brnaches of Splenic artery
white pulp aggregation of lymphocytes around the splenic artery
PEriarterial lymphatic sheaths
what is the capsule of the spleen made out of
Myofibroblastsdarker
Color of white pulp in staining
dark
what kind of Cappilaries are the spleenic sinus
Sinusoids (leaky)
