lymphatic system Flashcards
what consists of the lymph system?
lymph + lymph vessels + lymph tissue + organs
functions of the lymphatic system?
- immune defence (produces, houses, distributes WBCs)
- maintains blood volume (returns interstitial fluid to blood)
- transports dietary lipids (fatty lymph= chyle)
what are primary lymphoid tissues and organs?
where lymphocytes form and mature
what are secondary lymphoid tissues and organs?
where lymphocytes are activated and cloned
lymph is?
derived from interstitial fluid, less protein than plasma
- lots of lymphocytes
- circulates in lymph vessels
function of lymph vessels?
collect excess tissue fluid, return it to veins
lymphatic capillaries are?
blind ended microscopic vessels throughout the loose connective tissue of the body
-very permeable
what are lacteals?
special lymph capillaries that receive digested lipids from intestine
lymph collecting vessels?
collect lymph from lymph capillaries, run parallel to blood vessels
-like veins! have valves
superficial lymph vessels collect lymph from?
hypodermis and connective tissue under mucous membrane
deep lymph vessels?
run parallel to veins and arteries in muscles and organs
where do lymph vessels unite?
at lymph trunks which deliver lymph to collecting ducts
the two lymph collecting ducts?
right lymphatic duct and thoracic duct
what do the collecting ducts dump into?
jugular and subclavian veins
what is the right lymphatic duct collecting?
lymph from right arm and right side of head and read thoracic region
what is the thoracic duct collecting?
lymph from the rest of the body
how does lymph move
skeletal muscle and respiratory pump
-contraction of smooth muscle
as lymph passes through lymph nodes, it is filtered and surveilled by?
immune system before being return to blood
what are lymph nodes?
small organs, approx 500 in body clustered
-clustered in axillary, cervical, and inguinal regions
functions of the lymph nodes?
- house WBCs (lymphocytes and macrophages)
- filter lymph (remove pathogens, diseased cells)
- activation of specific immune defence cells
what is lymphodenopathy?
results from increased number of lymphocytes and monocytes in lymph nodes in response to bacterial and viral infection, or cancer. causes enlargement of lymph nodes.
the spleen is a lymph organ.. what is it contained with?
red pulp and white pulp
red pulp vs. white pulp
red pulp- many rbcs, macrophages filter old rbcs and pathogens
white pulp- lymphocytes, lymph tissue (immune surveilance and activation of T and B cells, reticular tissue)
functions of the spleen?
- remove old platelets and rbcs from circulation
- filter blood, stores platelets, rbcs, wbcs
- immune surveillance
- production of rbcs in developing fetus
what is the thymus gland
- located in mediastinum, on top of heart
- no B cells, immature T cells mature here from bone marrow
what are the T lymphocytes under the influence in the thymus gland?
thymic epithelial cells and thymic hormones called thymosins
thymus gland is also known as (for immune purposes)?
t cell bootcamp! tested before circulation, must learn to recognize your own cells and not target them…
only 2% released and survive
what is MALT
mucosa associated lymphoid tissue
-houses lymphocytes and associated with mucous membranes (provide protection against pathogens in gut and resp passages)
what are the 5 tonsils and where?
palatine- paired in oropharynx
lingual- paired under tongue
pharyngeal- single in the roof of the nasopharynx (adenoid)
structure of tonsils? (2)
“crypts” - pits that trap pathogens (can become infection)
lymph follicles house lymphocytes, remove pathogens
what are peyers patches?
aggregation of lymphoid follicles in wall of small intestine, protection from bacteria in intestinal lumen
what is the appendix?
aggregation of lymph follicles in a pouch near beginning of large intestine, protects from bacteria in intestinal lumen
-may be a bacterial reservoir for repopulating colonic bacteria
