Exam 3 ch 19, 20,22 Flashcards
lacteals
-lymphatic capillaries in the digestive system which play a role in absorbing digested fats from the intestine and produce chyle to be carried to the blood stream
lymphangitis
inflamed lymphatic vessels , congestion of related blood vessels and swollen tender areas
lymphedema
-edema of the lymphatics occur because of blockage of a tumor or removed part of lymphatics(cancer)
buboes
- swollen lymph nodes that are full of large # of infected bacteria, symptom of Bubonic plague
tonsillar crypts
-in tonsils:invaginations of overlying epithelium to trap bacteria and particulate matter which then work their way into lymphoid tissue and most destroyed
elephantiasis
where your lymphatics in lower limbs accumulate with parasitic worms
Hodgkin’s disease
- malignancy of lymphoid tissue, causing swollen but non-painful lymph nodes
- fatigue, fever & sweating
- B cells are malignantly transformed into giant Reed-sternberg cells
- treated with chemo and radiation therapy
lymphoma
any tumor of the lymphoid tissue
how does lymph travel throughout the body
lymphatic capillaries
lymphatic collecting vessels
lymphatic trunks
lymphatic ducts
What are 3 functions of lymph
- returns extra fluid to blood stream
- returns leaked proteins to the blood
- carry absorbed fats from intestine to blood
What are 2 functions of lymph nodes
- Filter lymph- using macrophages to destroy microorganisms and other debris
- help activate the immune system- strategically located sites where lymphocytes encounter antigens and are activated to mount attack against them
T cells
directly attack and destroy infected cells
b cells
produce plasma cells that then secrete antibodies
lymphoid macrophages
- phagocytize foreign substances and help activate T cells
spleen function
- largest lymphoid organ
1) cleanse blood by extracting RBCs + has phagocytes that remove debris and foreign matter
2) stores and releases the breakdown products of hemoglobin ex. Iron
3) stores platelets
4) acts as hematopoietic site in the fetus
thymus function
- most active during youth
- where T cells precursors will mature
- no B cells, no follicles
- does not directly fight antigens
tonsils
- the simplest lymphoid organ
- trap pathogens from food and air
- contain tonsillar crypts
peyer’s patches
- aggregated patches in distal portion of sm. intestine
- destroy bacteria before it can breach the intestinal wall and generate memory cells for long term memory
macrophage
- derived from monocytes (WBCs) that leave the bloodstream and enter the tissues
phagosome
- forms when phagocyte adheres to a pathogen or debris , engulfs it using pseudopods
opsonization
- to make tasty
- complement proteins or antibodies will coat (bind) foreign particles, makes it easier for macrophages to phagocytize
respiratory burst
-helper T cells release chemicals that stimulate macrophages to release chemicals like hydrogen peroxide and bleach to kill invaders
natural killer cells
-“police” blood & lymph to find cancer cells and virus-infected body cells
-they recognize the lack of self surface receptors(glycoproteins) and surface sugars of the target cells and kill target cells directly by causing apoptosis
+ secrete chemicals to enhance imflammatory response
toll-like receptors
- surface membrane receptors on macrophages that recognize specific classes of attacking microbes
- trigger release of cytokines that promote inflammation and attract WBCs
mast cells
release histamine
-aids in inflammatory process
interferons IFNs
- help protect uninfected cells from viral infection by synthesize proteins proteins that interfere with viral replication
- reduce inflammation
- activate macrophages
- mobilize natural killer cells
complement
-a group pf 20 plasma proteins that are normally inactive in the blood, but when activated release chemicals that will modify inflammation and induce bacterial cell lysis
membrane attack complex MAC
- complement protein that is inserted into a cell membrane, response to C3b molecules activating it
- insertion of MAC makes a hole in the membrane, and lets water in causing the cell to lyse
pyrogens
-secreted by leukocytes and macrophages, the body responds to foreign substances by increasing body temperature
antigens
substances that can mobilize the adaptive immune response and provoke it
-proteins found on foreign substances
immunogenicity
- the ability to stimulate proliferation to specific lymphocytes and antibodies
reactivity
the ability to react with activated lymphocytes and antibodies
-complete antigens include foreign proteins, polysaccharides, lipids, pollen grains, microorganisms
haptens
- incomplete antigens
- small molecules such as peptides, nucleotides and hormones are not immunogenic but are reactive
- incl. certain drugs like penicillin + chemicals in poisin ivy , animal dander
MHC proteins
- self antigens
- the antigens on an individual’s own cells are strongly antigenic to other individuals
- MHC proteins are glycoproteins that mark the cell as self and are coded for by genes in the major histocompatibility complex MHC
active immunity
when B cells encounter antigens and produce antibodies
Acquired 2 ways: 1. naturally acquired 2. artificially acquired
passive immunity
- antibodies taken from a serum that (animal or human) is immune
- only lasts as long as antibodies do
CD4
- effector CD4 cells are helper or regulatory T cells
- they can only bond to antigens linked to Class II MHC proteins on surfaces of APCs
CD8
- usually become cytotoxic cells
- can bind only to antigens linked to Class I MHC proteins found on the surface of APCs
costimulation
- eventhough binding to an antigen begins the process, another signal is also required to begin the process of T cell proliferation
- T cells must bind to additional surface receptors on the APC
- costimulation induces the release of cytokine chemicals, which induce the activated T cells to proliferate & differentiate
