Module 3: Immune System

how does the lymphatic system contribute to homeostasis?

take up excess fluid, transport of lacteal proteins, defense against disease

what makes us the lymphatic system?

lymphatic vessels and lymph, lymphocytes (T, B, NK cells), primary lymphoid tissue and organs (red bone marrow, thymus), secondary lymphoid tissue and organs (lymph nodes, spleen, appendix, tonsils, lymphoid nodules, MALT)

movement of lymph depends on what?

muscle contractions

where is lymph found?

lymphatic vessels

what is lymph made up of?

cells that have leaked out of capillaries

what is the purpose of the valves in lymphatic vessels?

prevent back flow of fluid

how does edema occur?

if fluid leaked from capillaries is not picked up

what duct serves both lower extremities, abdomen, left arm, and left side of head/neck?

thoracic duct

the base of the thoracic duct expands into..

cisterna chyli

the thoracic duct is __ to the vertebral column

anterior

what duct serves the right arm, right side of head/neck, and right thoracic area?

right lymphatic duct

both the thoracic duct and right lymphatic duct feed into the __ veins

subclavian

what are lymphoid nodules?

densely packed lymphocytes in areolar tissue

where can lymphoid nodules be found?

tonsils, lymph nodes, spleen, and the digestive, urinary, and reproductive tracts

what does MALT stand for?

mucosa associated lymphoid tissue

groups of lymphoid nodules are known as..

peyer’s patches

where are peyer’s patches found?

intestines, appendix, tonsils

what are tonsils?

three pairs of large lymphoid nodules

name the pairs of tonsils

pharyngeal (adenoids), palatine, lingual

what is the first to encounter pathogens? where do they encounter pathogens?

tonsils; by ear, mouth, or nose

what do lymph nodes contain?

lymphocytes and macrophages

what are the function of lymph nodes?

clean and filter lymph, destroy invaders and worn out cells

what functions as an early warning system?

lymph nodes

can causes “swollen glands”?

injury or illness

where are lymph nodes found?

in clusters near joints

the thymus gland is larger in who?

children

where do T lymphocytes mature?

thymus gland

what hormone does thymus gland produce?

thymosin

functions of spleen

remove damaged rbcs, store iron from recycled cells, initiate immune response due to antigens

where is spleen found?

upper left region of abdomen

what is hilum filled with?

splenic arteries, veins, lymphatics

what is the spleen made up of?

red and white pulp

what does spleen’s red pulp have?

rbcs and macrophages

what does the red pulp do?

help purify the blood by removal of dead and damaged cells

what does the white pulp have?

lymphocytes

what does the white pulp do?

perform immune functions

what happens if the spleen is damaged?

hard to repair and usually removed with splenectomy

what might be needed if spleen is removed?

lifelong antibiotic therapy

name the nonspecific defenses

physical barriers, phagocytes, immunological surveillance, interferons, complement, inflammatory response, fever

barriers to entry include..

skin/hairs, mucous membranes, oil/sweat glands, cilia, acidic pH, good bacteria

neutrophils and eosinophils are..

microphages

phagocytes include..

microphages and macrophages

what are fixed macrophages?

monocytes that have entered the tissues and stay put

where are fixed macrophages found?

dermis, subarachnoid space, bone marrow

what are free macrophages?

monocytes that migrated to injury/infection

where are free macrophages found?

they wander, some found in lung tissues

the ability to squeeze out of capillaries is..

diapedesis

cell attraction or repelling via chemicals is known as..

chemotaxis

cells sticking to foreign invaders is known as..

adhesion

what do NK cells do?

recognize and destroy abnormal cells

what do NK cells kill?

virus-infected cells and tumors

what is the downside of NK cells?

they have no specificity nor memory

what do NK cells release and what does it do?

perforins that poke holes in cell membranes of invaders or abnormal cells and then destroy cells

small proteins released by lymphocytes, macrophages, and by infected cells are..

interferons

what do interferons prevent?

nearby cells from becoming infected and viral replication

what do interferons stimulate?

macrophages and NK cells

example of interferons

cytokines: chemical messengers released by cells for cell to cell communication

what makes up the complement system?

protective and plasma proteins

what amplifies the inflammatory process?

complement system

what attracts macrophages or pokes holes in cells?

complement system

opsonization makes abnormal cells..

look good

what are the physical signs of inflammation?

redness, heat, swelling, pain

what is released when damage occurs?

histamine and kinins

after histamine and kinins are released, __ dilate, skin __ and is __

capillaries; reddens; hot

after capillaries dilate, skin reddens and is hot, capillaries are more __ so fluids escape and __ begins. this __ free nerve endings and __ kicks in

permeable; swelling; irritates; pain hw

what causes pus to form?

as infection is fought, neutrophils die and mix with dead bacteria

how do you treat and inflammatory reaction?

anti histamines and anti inflammatory agens

what does PRICE stand for?

protect, rest, ice, compression, elevation

you have a fever when temperature is over..

99 degrees

circulating proteins that are released from macrophages are known as..

pyrogens

what do pyrogens do?

resets thermostat in hypothalamus by increasing the temperature to inhibit and kill viruses and bacteria

when the nonspecific methods fail what starts?

specific defenses

where do B lymphocytes mature?

bone marrow

what do B cells produce?

plasma cells and antibodies

what do T lymphocytes do?

attack non-self cells

describe innate immunity

genetics

what is acquired/adaptive immunity due to?

expose

what immunity is due to accidental exposure?

natural

immunity produced by deliberate exposure like vaccines?

induced/artificial

active immunity uses..

antigens

passive immunity uses..

antibodies

when does naturally active immunity occur?

after infection

what is an example of induced/artificial active immunity?

vaccines

what are vaccines?

pathogens/products but are treated so they are non-virulent

what cells kick in with vaccines?

memory B cells

natural passive immunity is..

temporary

how is natural passive immunity passed on?

mom to baby through placenta

colostrum/milk have __ that prolongs immunity

antibodies

what is induced/artificial passive immunity?

antibodies are injected to act quickly

properties of immunity: specificity

antibod/antigen match

properties of immunity: versatility

ready for any antigen at any time

properties of immunity: memory

minimizes reinfection of the same bug

properties of immunity: tolerance

not everything triggers immune response

in what immunity are antigens presented to T cells?

cell mediated immunity

what do T cells do in cell mediated immunity?

activate to destroy similar cells (tumors)

all T cells have what marker?

cd3

what are CD markers?

class of proteins

what other markers besides CD3 do some T cells have?

cd8, cd4

what type of T cells destroy antigen-bearing cells?

cytotoxic T cells

what do helper T cells do?

regulate immunity, secrete cytokines, stimulate cytotoxic T cells