E4 Ch. 21 Flashcards
main function of lymphatic system
return excess tissue fluid to blood vascular system
function of lymphatic vessels
collect tissue fluid from loose connective tissue and carry it to great veins in the neck
main function of immune system
protects from foreign organisms, immunity to disease
list the main components associated with the immune system
lymphocytes, lymphoid tissue, and lymphoid organs
which direction does lymph flow
only towards the heart
describe lymph capillaries and their function
smallest lymph vessels, highly permeable, and are the 1st to receive lymph
function of collecting lymphatic vessels
collect from lymph capillaries
where are lymph nodes found
scattered along collection vessels
function of lymph trunks
collect lymph from collecting vessels
function of lymph ducts
empty into veins of the neck
what type of molecules can enter capillaries
tissue fluid, protein molecules, bacteria, viruses, and cancer cells
what are lacteals, where are they located, and function
specialized lymphatic capillaries, located on villi of small intestines, receive digested fats
what is chyle
term used for fatty lymph
what are the mechanisms that are used to propel lymph
bulging of skeletal muscles, pulsing of nearby arteries, tunica media of lymph vessels, not aided by heartbeat
function of lymph nodes
cleanse lymph of pathogens
how many lymph nodes does the body contain
around 500
what regions of the body are superficial lymph nodes located
cervical, axillary, and inguinal regions
list the deep lymph nodes
tracheobronchial lymph nodes, aortic lymph nodes, and iliac lymph nodes
fibrous capsule
surrounds lymph nodes
trabeculae
connective tissue strands extend inward to divide lymph node into segments
afferent lymphatic vessels
convex aspect of a lymph node where lymph enters
efferent lymphatic vessels
area where lymph exits lymph node at the hilum
list the major lymph trunks
5; lumbar, intestinal, bronchomediastinal, subclavian, and jugular trunks
where do lumbar trunks receive lymph from
lower limbs
where do intestinal trunks receive chyle from
receives chyle from digestive organs
where does the bronchomediastinal trunk collect lymph from
thoracic viscera
where does the subclavian trunk receive lymph from
upper limbs and thoracic wall
where does the jugular trunk receive lymph from
head and neck
list the different types of lymph ducts
cisterna chyli, thoracic, and right lymphatic duct
where is the cisterna chyli located
at the union of lumbar and intestinal trunks
where does the thoracic duct empty into
venous circulation, unction of L internal jugular and L subclavian vein, drains three-qarters of the body
where doe the right lymphatic duct empty into
R internal jugular and subclavian veins
general function of the immune system
recognized foreign molecules, destroys pathogens, lymphocytes (key cells of immune system)
list the lymphoid organs
lymph nodes, spleen, thymus, tonsils, aggregated lymphoid nodules, and appendix
when infections organisms trigger an inflammatory response which are attacked by
macrophages, then lymphocytes
what are antigens
any molecules inducing a response from a lymphocyte
what are the two main classes of lymphocytes
B and T lymphocytes
what do B lymphocytes become
plasma cells
function of plasma cells
secrete antibodies which mark cells for destruction by marcopphages
B lymphocytes respond primarily to what
bacteria and bacterial toxins
where do lymphocytes originate
in bone marrow
which lymphocytes travel to the thymus gland
T lymphocytes
which lymphocytes stay in bone marrow
B lymphocytes
what are some characteristics of activated lymphocytes
able to recognize unique antigen, immunocompetence, travel bloodstream (meet/bind to specific antigen), proliferate rapidly
both T and B lymphocytes produce clones of
effector lymphocytes, and memory cells
describe effector lymphocytes
respond immediately, then die
describe memory cells
wait until body encounters antigen again, basis of acquired immunity, prevent subsequent infections of same illness
what are the primary lymphoid organs
bone marrow and thymus
what are the secondary lymphoid organs
lymph nodes, spleen, tonsils, aggregated lymphoid nodules, and appendix
what are lymphoid organs designed to do
gather and destroy infectious microorganisms and to store lymphocytes
function of thymus
secretes thymic hormones,
when is the thymus most active
in childhood
what happens to the thymus with age
functional tissue atrophies
what is the thymus composed of
cortex and medulla (contains thymic corpuscles)
how is the thymus different from other lymphoid organs
functions strictly in lymphocyte maturation, arises from epithelial tissue
function of lymph nodes
lymph percolates though lymph sinuses, site where most antigenic challenges occur
which is the largest lymphoid organ
spleen
what are the 2 main blood-clensing functions of the spleen
remove blood borne antigens and destruction of old/defective blood cells, site of hematopoiesis in fetus
what are the other functions of the spleen
destruction of antigens, phagocytosis of bacteria and worn-out RBC, WBC, and platelets, and storage of platelets
describe the white pulp
thick sleeves of lymphoid tissue that provides the immune function of the spleen where blood borne antigens destroyed as they activate the immune response
what is the red pulp composed of
venous sinuses, splenic cords, responsible for disposing of worn-out RBCs
what is the simplest lymphoid organ
tonsils
name the 4 groups of tonsils
palatine, lingual, pharyngeal, and tubal tonsils
describe how the structure of tonsils aid with its function
arranged in a ring to gather and remove pathogens
what is MALT and where is it found
mucosa associated lymphoid tissue; found in underlying lamina propria, fight invading bacteria, and generate wide variety of memory lymphocytes
aggregated lymphoid nodules location
peyer’s patches, located in distal part of small intestine
chylothorax
leakage of fatty lymph into thorax
lymphagitis
inflammation of a lymph vessel
mononucleosis
viral disease caused by epstein-barr virus, attacks B lymphocytes
hodgkins lymphoma
cancer of lymph nodes
non-hodgkin’s lymphoma
uncontrolled multiplication and metastasis of undifferentiated lymphocytes
where do lymphatic vessels and lymph nodes develop from
lymphatic sacs
thymus originates from
as an outgrowth of the endoderm
what arises from mesodermal mesenchyme
spleen, lymph nodes, and MALT
