The Lymphatic System Flashcards
What are the functions of the lymphatic system?
1) recovery of excess tissue fluid
2) monitoring the body for pathogens
3) producing immune cells and activating immune responses
4) absorption of dietary lipids
What is the bodily components of the lymphatic system?
- lymphatic vessels
- lymphoid tissues
- red bone marrow
- tonsils
- thymus
- spleen
- lymph nodes
Lymphatic vessels are connected at the ____ veins in the shoulder.
subclavian
How do blood capillaries exude fluid into the tissues?
capillary filtration
How much fluid is reabsorbed by the capillaries, and much is absorbed by the lymphatic vessels?
reabsorbed - 85%
absorbed by LVs - 15%
What is the fluid called in lymphatic vessels?
lymph
____ in the lymph nodes phagocytize impurities and cleanse the lymph, and further monitor it for pathogens.
macrophages
The lynmphatic system primariliy recovers water, if this reccovery were not functioning properly, 2-3 liters of water would accumulate every single day. What is this condition called where excessive swelling occurs due to a malfunction in the lymphatic system?
edema
potentially leading to gangrene
Sometimes when when have a masectomy, the auxillary (armit) lymph node is severed to prevent metastasis. When lymph flow is chronically obstructed it can lead to overly-swollen limbs. This can be cause by mosquito-borne parasitic worms. What is this disease called?
elephantiasis
(ellie-fan-tee-aye-sis)
How does mosquito-borne parasitic worms infect the lymphatic system leading to elephantasis?
The larva of the worms are introduced via the saliva of mosquitoes, moves into the lymphatic vessels, and matures into a thread-like filaria worm, blocking lymph flow.
What is the overgrowth of fibrous scar tissue called?
fibrosis
lmost common in legs, breasts, and scrotum
Which kind of cells populate the lymphatic system which can help the immune system and combat harmful bacteria, viruses, toxins and other disease agents?
lymphocytes and macrophages
What special lymphatic vessels in the small intestine help absorb dietary fats, cholesterol, and fat-soluble vitamins?
lacteals
In the lymphatic system, which component is similar to blood vessels, but do not form a complete circuit around the body?
lymphatic vessels
Lymphatic vessels beging with ____ ____ and grow larger and larger until they lead to the subclavian veins.
lymphatic capillaries
Where do lymphatic vessels converge before they lead to the lymph nodes?
collecting vessels
Collecting vessels converge to form six lymphatic ____ which drain into a specific region of the body.
trunks
In the lymphatic system, what are aggregations of lymphocytes found within the connective tissues of various organd, especially in loose connective tissue?
lymphatic tissue
Where is lymphatic tissue the most abundant? What is this tissue called?
mucous membranes; mucosa-associated lymphatic tissue (MALT)
In some places, MALT becomes concentrated into especially dense masses of lymphocytes called what?
lymphatic nodules
Located in the ileum (small intestine) what keeps the intestinal flora at appropriate levels and the pathogens at bay, thereby preventing a large number of infections?
peyer patches
associated with food allergy in the small intestine
In what systems of the body do mucous membranes open up in to?
- digestive
- respiritory
- reproductive
- urinary
In the lymphatic system, what is a mass of lymphatic tissue that is wholly or at least partially enclosed in a fibrous capsule?
lymphatic organ
List the lymphatic organs.
- red bone marrow
- tonsils
- thymus
- lymph nodes
- spleen
What are the four primary cells that populate the lymphatic system?
- Natural killer cells (NK cells)
- B lymphocytes (B cells)
- T lymphocytes (T cells)
- Antigen-presenting cells (APCs)
Which kind of cell in the lymphatic system attacks only host cells that have either turned cancerous or have been antigenically modified by a viral infection?
Natural killer (NK cells)
10-15% of lymphocytes
Which kind of cell in the lymphatic system are small lymphocytes that originate in the bone marrow and become immunocompetent there?
B lymphocytes (B cells)
What do B cells devlop that all them to respond to foreign antigens?
antigen receptors
B cells are responsible for ____ immunity.
humoral (antibody-based)
Some B cells develop a large amounts of what organelle? What cell does this further develop?
rough endoplasmic reticulum; plasma cell
Some B cells become ____ B cells which “remember” the antigen.
memory
Which kind of lymphatic cells are small lymphocytes that achieve their immunocompetence (antigen sensitivity) in the thymus?
T lymphocytes (T cells)
65-75% of lymphocytes
T cells are responsible for ____ immunity.
cellular (cell-mediated)
Which kind of T cells recognize antigen fragments (epitopes) presented tot hem by APCs? Which kind of peptides do they secrete?
Helper T (Th) cells; lymphokines
targeted to HIV
Which kind of T cells directly attack and destroy foreign cells including bacteria and transplated tissues and organs? Which kind of enzymes do these release?
Cytotoxic T (Tc) cells; granzymes
Which kind of T cells prevent excessive responses by Th and Tc cells and normally prevents attacks against own tissues?
Regulatory T (Tr) cells
Which kind of T cells are preprogrammed to respond quickly if one is reexposed to the same antigen that triggered their initial formation?
memory T cells
Which kind of lymphocytes phagocytize anitgens, digest them, and then display antigenically active fragments of them, called epitopes?
Antigen-presenting cells (APCs)
What are the three kinds of APCs?
- B cells
- macrophages
- dendritic cells
Which kind of vessel in the lymphatic system consists of a single layer of endothelial cells forming a sac?
lymphatic capillaries
How are lymphatic capillaries attches to surrounding tissue?
anchoring filaments