Chapter 20 Flashcards
The lymphatic system is the system of what?
System of immunity
What is the main function of the lymphatic system?
returns fluids that leaked from blood vessels back to blood
What does the lymphatic system consist of?
Network of lymphatic vessels, lymph, lymph nodes
what are lymphatic vessels also called
lymphatics
what are lymphatic vessels similar to?
more like veins
what is lymphs
fluid in the vessels
what is lymph similar to?
Similar to blood in circulatory system
what do lymph nodes do?
cleanse lymph
what is a major difference between circulatory and lymphatic system?
circulatory system does not have filters, but lymphatic system does-lymph nodes
what do the lymphoid organs and tissues do?
provide structural basis of immune system, house phagocytic cells and lymphocytes
are the lymphoid structures visible in dissection?
most are very small and not visible
what are phagocytic cells
cells that eat other things
what structures are included in the lymphatic system
spleen, thymus, tonsils, lymph nodes, other lymphoid tissues
what are the lymphoid organs and tissues apart of?
MALT system
what is the MALT system?
Mucosa Associated Lymphoid Tissue which includes many structures
what do lymphatic vessels do?
return interstial fluid and leaked plasma proteins back to blood
what is interstitial fluid?
surrounds the cells
how much fluid is in the lymphatic vessels per day
3L
What is the interstitial fluid called once in enters the lymphatics?
called lymph
The lymphatic system transports large or small molecules?
Big
What is a con to the lymphatic transport system?
The system will transport proteins and lipids, but it can also transport viruses and bacteria
What type of system is the Lymphatic system-specifically referring to the vessels?
One way system
where does the lymph flow?
towards the heart
what do the lymphatic vessels include?
Lymphatic capillaries, collecting lymphatic vessels, lymphatic trunks and ducts
where are lymphatic capillaries not found
bones, teeth, bone marrow, CNS- mostly places where fluid is not common
what are lacteals
specialized lymph capillaries present in intestinal mucosa
where are the lacteals located in the intestinal mucosa
within the villi of the intestines
what do the lacteals do
absorbs digested fat and delivers fatty lymph chyle to the blood
what is chyle
lymph fluid
what are lymphatic collecting vessels similar to?
veins
why are lymphatic collecting vessels different from veins?
thinner walls, more internal valves, anastomose more frequently
where are the lymphatic collecting vessels located
travel with superficial veins
where do deep lymphatic collecting vessels travel
with the arteries, more internally
where do lymphatic collecting vessels get nutrients from
branching vasa vasorum
what are the vasa vasorum
lymphatic circulatory system
what do lymphatic trunks form from
form from union of largest collecting ducts
where are the lymphatic trunks in the body
paired lumbar
paired bronchomediastinal paired subclavian
paired jugular trunks
single intestinal trunks
where is lymph delivered
into 1 of 2 large lymphatic ducts
what are the two lymphatic ducts
right lymphatic duct and thoracic duct
what does the right lymphatic duct do
drains right upper arm and right side of head and thorax
what does the thoracic duct do?
arises as cisterna chyli drains rest of body
what are cisterna chyli
lower lumbar area
where do the lymphatic ducts empty
empties lymph into venous circulation at junction of internal jugular and subclavian veins on it own side of body
is the separation between left and right side of lymphatic system even
no, does not divide evenly
Are we born with lymphatic organs
yes, but not everyone keeps them
when is the thymus most active
when we are born, shrivels as you grow
what does thymus do
puts lot of immune cells into our system
what does spleen do
filtering organ
peyers patches do what
filter things that we either breathe in or eat
does the appendix have a function
to some degree
how many lymph nodes do we have
we have a couple hundred lymph nodes in our body
what do lymph nodes do?
filter lymph, immune system activation
what happens when lymph is filtered
macrophages destroy microorganisms and debris
what are macrophages
big eaters, part of WBC army
what happens during immune system activation
lymphocytes activated and mount against antigens
what are antigens
indentifying proteins that signal
what does a lymph node look like
varys in shape and size but usually bean shaped
what do lymph nodes have externally
external fibrous capsule composed of connective tissue
what is insie the lymph node
trabeculae
what are the trabeculae
extend inward and divide node into compartments for increasing surface area
what are the 2 regions of the lymph node
cortex and medulla
what does the cortex of the lymph node have
contains follicles with germinal centers and heavy with dividing B cells
what are B cells
B stands for bone, talking about where they were forred, formed from bone tissue
what encapsulates the follicles in lymph nodes
dendritic cells
what does the cortex in the lymph node have
houses T cells in transit
what are T cells
formed from thymus
what do the T cells in the lymph nodes do?
T cells circulate continuously among blood, lymph nodes and lymph
In a lymph node what extends from the cortex
medullary cords extend inward from cortex and contain B cells, T cells, and plasma
what is a lymph sinus
contains macrophages
what type of sinuses do lymph nodes have
lymph sinuses
