Lymphatic System Flashcards
What is lymph?
Fluid within lymphatic system
What are the 2 functions of the lymphatic system?
return interstitial fluid and leaked protein back into the blood
forms structural basis of immune system
The lymphatic system is a ________ system that carries blood to the heart.
One way
Where are lymphatic capillaries located?
between tissue cells and blood capillaries, in loose CT
What is the structure of lymphatic capillaries?
blind ended and more permeable than blood caps
lining = leaky endothelium
has overlapping edges which form valves
What do the tiny valves in lymphatic capillaries respond to?
they are one way
open and close in response to surrounding pressure
What is function of lymphatic caps?
collect excess interstitial fluid/proteins
What are lacteals?
Where found and what do they do?
Specialized lymph caps in villi of small intestine
absorb digested fats and deliver chyle to blood
Chyle?
fatty lymph
What are collecting vessels formed by? What are the parallel with? How do they compare to veins? What are the branching vasa vasorum for? When two join what do the form?
2nd smallest joining of lymph caps parallel to BV thin walls lots of valves and anastomoses nutrient provision by branching vasa vasorum join to form lymphatic trunks
How big are Lymphatic Trunks? How are they formed? What trunks drain into cistrna chyli? What drains into upper body and head? What do they join to form?
2nd largest joining lymphatic collecting vessels R&L lumbar trunks and intestinal R&L bronchomediasinals, subclavian and jugulars R& L Lymphatic Ducts
Where does the Right Lymphatic duct collect from?
where Does it drain into?
R upper arm and right head/ thorax
into junction of right internal jugular and subclavian Vein
Where does thoracic duct collect from?
Where does it drain into?
rest of body
into junction of left internal jugular and subclavian
How does lymph transport compare to venous?
What does its movement depend on?
slower, no pump(valves instead –> no backflow)
Contraction of skeletal/resp muscles
pulsation of arteries
contraction of smooth muscle in walls of trunks and thoracic duct
Lymphedema?
Swelling of tissues from blockage of flow, accumulates distally
What are examples of lymphoid cells?
Lymphocytes B&T Cells Macrophages Dendritic Cells Reticulare cells
Where are lymphocytes formed?
What do they do?
What are they active in?
What are the 2 kinds?
Red bone marrow
defend against foreign antigens
immune defenses
B&T
Where do B Cells Mature in? What do they produce?
Bone marrow
plasma Cells that form antibodies
Where do T Cells Mature? What is their function in immune response? What are some capable of?
Thymus
Management of it
Attack and destroy cells directly
What do Macrophages do?
phagocytize foreign antigens
activate T Cells
What do dendritic Cells Do and How?
Activate defense (early warning system) by capturing antigens and delievering them to lymph nodes
What do reticular cells form?
What does this produce?
internal skeleton
stroma which supports other cells
What kind of tissue for Lymphoid?
What does Lymphoid tissue house and provide a site for?
Which lymphoid organ isn’t it found in?
What lives on its fibres?
reticular CT
lymphocyte survalience and multiplication
thymus
macrophages
WWhat are the two Types of Lymphoid Tissues?
Diffuse and follicles
What kind of lymphoid tissue is found in most organs?
What does it include?
Diffuse Tissue
small scattered clusters of reticular tissue
What kind of tissue has solid spheres of reticular elements and cells with no capsule?
It has germinal layers where ____ cells multiple and form plasma cells.
What does this tissue form parts of?
Follicle Tissue
B
Lymph organs or scatters
What is a lymph node?
principal lymphoid organ.
Lie singly along lymph vessels or in clusters where vessels join forming trunks
What do macrophages do in the lymph node?
What about Lymphocytes?
Filter and remove foreign particles from lymph
prevents spread and entrance of pathogens into blood
Monitor and attack antigens
activate immune system
What is the structure of a lymph node?
Bean shaped
capsule of dense CT
Trabeculae - divide nodes into compartments
stroma (dense reticular fibers with attached cells)
Cortex - (outer: follicles wrapped in dendritic cells and germinal cells for B cells) (deep Cortex:Tcells on patrol circulating continuously.)
medullary cords - b/t/plasma cells
Lymph Sinuses (house macrophages)
What is the circulation through a lymph node?
afferent vessels –> sub capsular sinus –> smaller sinuses –> exits via efferent @ hilus,
slow flow due to fewer efferents than afferents
Allows time for cleaning of lymph by macrophages and lymphocytes
What is the Spleen function in?
Lymphocyte proliferation/surveillance Cleans blood of debris/foreign Stores breakdown products of RBC Site of rbc in fetus stores blood platelets
What is Spleen enclosed in? (and thats characteristics)
What cells does it contain?
What types of pulp does it contain?
Capsule which has Trabeculae and sinuses, capsule is thin
lymphocytes, macrophages RBC
White Pulp - WBC , form cluster around central arteries
Red Pulp - RBC 9venous sinuses and splenic cords
Bone marrow and liver take over functions?
splenectomy
What is thymus?
Primary Lymphoid organ
in neck
as age shrinks
has two lobes divided into lobules
Outer cortex contains T cells and scattered macrophages
inner medulla - few lymphocytes, has hassall’s corpuscles regulating T cell development
Stroma is composed of thmocytes secreting thmosin and thymopoietin
hormones stimulate T Cell Maturation
no Bcells , no direct role in fighting antigens
Red Mone Marrow?
Primary lymphoid org, site of B cell maturation
What is simplest Lymphoid organ?
Tonsils
have follicles with germinal centers producing B cells
have crypts that trap and destroy matter
important in early life
Aggregates of lymphoid Follicles(MALT)?
mucosal associated lymphoid tissue
protects passages that open to outside from invaders
many different memory cells generated.
