lymphatics Flashcards
functions of lymphatic system
return ISF and leaked plasma proteins back into blood
associated organs provide structural basis of the immune system and house phagocytic cells and lymphocytes
primary lymphoid organs
thymus
bone marrow
secondary lymphoid organs
spleen
tonsils
lymph nodes
MALT
peyer’s patch
appendix
lymph
ISF that enters lymphatics
originates from ISF
responsible for fluid balance, immune response, and transport of nutrients and waste
formed by the filtration of blood plasma through capillaries into the interstitial spaces
followed by the uptake of ISF and other proteins by lymphatic capillaries
lymphatic capillaries
similar to blood capillaries
very permeable
form minivalves
anchored via collagen filaments
pathogens travel throughout body via lymphatic capillaries
lymphatic collecting vessels
similar to veins
have thinner walls and more valves
vessels in the skin travel w/ superficial veins
deep vessels travel with arteries
lymphatic trunks
formed by the union of collecting ducts
lymphatic collecting ducts
includes 2 main ducts that lymph is delivered into (right lymphatic duct and thoracic duct)
empties lymph into venous circulation at junction of internal jugular and subclavian veins
right lymphatic duct
drains right upper arm and right side of head and thorax
thoracic duct
arises as cisterna chyli
drains rest of body
lymph nodes
principle lymphoid organ
embedded in clusters along lymphatic vessels
found in inguinal, axillary, and cervical regions of body
filter lymph and activate immune system
contain trabeculae and external fibrous capsule
divided into cortex (dividing B cells) and medulla (macrophages)
contain medullary and lymph sinuses
fewer efferent vessels
spleen
largest lymphoid organ
lymphocyte proliferation and immune surveillance and response
cleaneses blood and platelets
removes debris
iron recycling
storage of platelets and monocytes
thymus
produces immunocompetent cells
thymic corpuscles involved in regulating T cell development
does not directly fight antigens
teaches lymphocytes to recognize self from non-self antigens
tonsils
simpliest lymphoid organ
gather and remove pathogens in food or air
include palatine, lingual, pharyngeal, and tubal tonsils
contains tonsilar crypts, but capsule absent
peyer’s patches
clusters of lymphoid follicles
destroy bacteria
found in distal portion of small intestine
generate lymphocytes
sentinel lymph nodes
first nodes that receive lymph from suspected cancerous regions
a good indicator of cancer metastasis
lymph circulation
convex side via afferent lymphatic vessels->large subscapular sinus and smaller sinuses->medullary sinuses->concave side at hilum via efferent vessels
lymphatic trunks
paired lumbar, bronchomediastinal, subclavian, jugular trunk
single intestinal trunk
white pulp
around central arteries
mostly lymphocytes in recticular fibers
involved in immune functions
red pulp
in venous sinuses and splenic cords
rich in RBCs and macrophages
composed of splenic cords and sinusoids
MALT
includes tonsils, peyer’s patches, and appendix
in mucosa of respiratory, and genitourinary organs; rest in digestive tract
lymphoid tissue
recticular CT
contain germinal centers (proliferating B cells)
lymph transport
milking action of skeletal muscle
pressure changing in thorax during breathing
valves to prevent backflow
pulsations of nearby arteries
contractions of SM in walls of lymphatics
lacteals
highly specialized lymphatic capillaries found in the intestinal mucosa
trabeculae
divide lymph nodes into compartments
lymph sinuses
large lymphatic capillaries spanned by crisscrossing recticular fibers
recticular cells
produce fiber stroma of lymphoid organs
pathway of lymph
lymph capillaries-> collecting lymph vessels-> lymphatic trunks-> lymphatic ducts
dendritic cells
trap antigens and transports them to lymph nodes
recticular fibers
found in sinuses of lymph nodes
macrophages would most likely be found in this portion of the spleen
splenic cords
