lymphatic system lecture 2 unit 2

lymphatic system

transports fluids and helps fight infection

lymph

watery fluid in lymphatic vessels carrying tissue fluid, proteins, and immune cells back to blood

what leaks from blood capillaries

fluid/lymph

lymph vessels… 

return fluid to venous circulation 

what would happen without lymphatic drainage

edema/fluid build up

merging of lymphatic vessels

lymphatic capillaries —> lymphatic vessels —> lymphatic trunk —> lymphatic ducts

afferent lymphatic vessles

carry lymph into lymphatic node (bring in)

efferent lymphatic vessels

carry lymph out of lymphatic node (brings out)

lymphatic ducts

right lymphatic duct and thoracic duct

thoracic ducts

drains lower body left arm/head/neck/and thorax —> empty into left subclavian vein and internal jugular vein

right lymphatic duct

drains right arm/head/neck/and thorax —> empty into right subclavian vein

what are the types of lymphocytes 

t lymphocytes (t cells) B lymphocytes (B cells) natural killer (NK cells)

what do the lymphocytes do

search for harmful antigens to fight

helper T cells

secrete cytokins to activate all the other lymphatic vessles (on switch)

B cells

become plasma cells producing antibodies

memory B cells 

are activated b cells and through mitosis produce plasma cells and memory cells 

what do the memory cells do

provide long term immunity remembering each virus

natural killer cells

can respond to more then one type of antigens without prior exposure to virus

MALT (mucosa - associated lymphoid tissue)

lymphoid tissue in mucous membranes that gives local immune defense

example of MALT

peyer patches in ileum 

tonsils

clusters of immune cells mainly in pharynx trapping antigens and antigen identification

lymphatic organs vs nodules

organs have capsules surrounding them —> thick wall keeping cells internal

lymphoid nodules 

filter and attack antigens 

germinal center 

center of lymphoid nodules with B cells 

T lymphocytes

surround germinal center

thymus

where T cells mature

thymus activation

grows until puberty then begins to lessen in size and function

lymph nodes 

found in clusters to filter antigens and initiate immune response 

spleen function

filter antigens from blood

white pulp in spleen

clusters of T and B cells encountering antigens to initiate that immune response

red pulp in sleen

has splenic cords and splenic sinusoids

splenic cords 

stores blood/erythocytes bc spleen is blood reservoir 

splenic sinusoids

cells enter spleen and old damaged RBC’s can pass through and be removed

regions that drain lymph from a specific body region

jugular,subclavian, bronchiomediastinal, intestinal and lumbar

jugular trunk

head and neck

subclavian trunk

upper limbs breasts and superficial thoracic wall

bronchiomediastinal trunk

deep thoracic structures

intestinal trunks 

most abdominal structures 

lumbar trunks

lower limbs abdominopelvic wall and pelvic organs