59 terms

ch. 23 The lymphoid system

lymph fluid
conn. tissue monitored by this system
what is lymph fluid carried by?
lymphatic vessels
cells suspended within lymph fluid
lymphatic fluid consists of:
-interstitial fluid(like blood plasma)
-lymphocytes-cells responsible for immune response
-macrophages of various types
Functions of lymphatic system
1-produce, maintain, and distribute lymphocytes
2-maintain normal blood volume and eliminate local variations in the chemical composition of interstitial fluid
3-Provide an alternative route for the transport of hormones, nutrients, and waste products
Lymphatic vessels, or lymphatics do...?
carry lymph from peripheral tissues to the venous system
lymphatic capillary walls?
endothelial cells that overlap instead of being tightly bound to one another; acts as a one way valve to let fluid in but not letting it escape
lymphatic capillaries in the small intestine that transport lipids absorbed by the digestive tract
any lymphatics in bones or cns?
what gives lymph vessels beaded appearance?
interstitial fluid pressure?
lower than venous pressure
vascular capillaries lets out fluid but lymph system cant remove it; tissues become swollen
superficial lymphatics?
found in subcutaneous layer of skin, loose con. tissue of mucous membranes lining the digestive, reproductive, respiratory and urinary tracts, and loose con. tissue of serous membranes lining pleural, pericardial, and peritoneal cavities
deep lymphatics?
large lymph vessels that accompany deep arteries and veins, that collect lymph from skeletal muscles and other deep stuff
what lymphatic trunks r there?
lumbar trunks, intestinal trunks, bronchomediastinal trunks, subclavian trunks, and jugular trunks
lymphatic ducts
two collecting vessels that deliver lymph to venous circulation
thoracic duct
collects lymph from both sides of body inferior to the diaphragm and from the left side of the body superior to the diaphragm
cisterna chyli
an enlarged pouch on the thoracic duct that serves as a storage area for lymph moving toward its point of entry into the venous system
lymphocytes respond to what
1-invading organsisms
2-abnormal body cells
3-foreign proteins
T cells are...
thymus dependant
B cells are...
bone marrow derived
NK cells are...
natural killer cells
Cytotoxic T cells
attack foreign or body cells w/ virus
cell mediated immunity
when immunity relies on lymphoctyes, like helper and killer t cells, the first type of t cells activating the latter, which ruptures macrophage and kills the infected cell
who assists in regulation and coordination of immune response?
helper t cells and suppressor t cells
memory T cells
remain "on reserve" in case the same antigen appears in the body at a later date
when does a b cell differentiate in to a plasmocyte?
when stimulated by exposure to an antigen
killer cells
smallest artery in body where oxygen is still in blood
lymphatic capillaries
absorb interstitial fluid, dissolve solutes viruses and bacteria
lymphatic vessels
carry lymph from peripheral tissue to venus system
prevent backflow
lymph nodes
lymphoid organs that monitor the composition of lymph
largest lymph organ, removes abnormal blood cells and other stuff through phagocytosis, storage of iron recycled from broken down rbc's, and initiation of immune responses by B cells and T cells in response to antigens in the circulating blood
Thymus gland
posterior of sternum; site of T cell formation
Microscopic connection to circulatory system
begin in bone marrow
then thymus cells
T cells
attack abnormal cells in body
macroscopic connection to circulatory system(collecting vessels)
lymphatic trunks(empty into collecting vessels)
thoracic duct(collects from most of left body and some right)
cisterna chyli(base of lymphatic duct collects from inferior of body
right lymphatic duct(collects lymph from right upper body
cortex of lymph node
outside layer or portion of organ
core of lymph node
afferent vessels
bring lymph to node
efferent vessels
bring lymph out of node
when blood vessels and nerves attach to lymph node and make an indentation
cells responsible for immune response
enlargement of lymph nodes
"swollen glands"
axillary nodes?
cervical nodes?
inguinal nodes
production of lymphocytes
cell mediated immunity
direct attack by activated T cells
antibody mediated immunity
attack by circulating antibodies released by the plasmocytes derived from activated B cells
Mucosa associated lymphoid tissue (MALT)
GI, urinary, respiratory, reproductive
peyers patch
gut-associated lymphatic tissue (in walls of intestines)
superior to heart, gets smaller as u age,
beginning of large intestine
pharyngeal tonsil(adenoids)
by nasal cavity, if it grows cant bring air in through nose
lingual tonsils
base of tongue
palatine tonsils
where you swallow, enlarged when sore throat, between folds on top of mouth
dendritic cells
collect antigens from the lymph and present them in their cell membranes