Module 2: Lecture 3 Flashcards
what is a leukocyte?
a white blood cell
what gives RBCs their pigment?
the heme group
what is the pigment in WBC?
none; they are colourless
what is the mobile unit of the bodys immune system?
white blood cells; leukocytes
in general, what is a system?
- organs. tissues, cells are all involved
- proteins, secretions
- work together and communicate and help each other
- what is an immune system?
- made up of leukocytes, their derivatives, and variety of plasma proteins and immune organs
- protects us from invading pathogens
- recognizes and destroys or neutralizes materials within body that are foreign to “normal self”
- identifies and destroys cancer cells that arise in the body
- removes worn-out cells and tissue debris
(wound healing and tissue repair)
what cell in the spleen cleans up all the dead RBCs?
the macrophages
the size of white blood cells is bigger or smaller than red blood cells?
bigger than RBCs
there are five major types of circulating leukocytes. they vary in?
structure, function and number
per mL of blood, how many leukocyte?
7 million/mL blood
what are the five major different types of circulating leukocytes?
- neutrophils
- eosinophils
- basophils
- monocytes
- lymphocytes
which types of leukocytes are polymorphonuclear granulocytes?
- neutrophils
- eosinophils
- basophils
which types of leukocytes are mononuclear agranulocytes?
- monocytes
- lymphocytes
which type of leukocytes does not have granules?
monocytes
what is the most abundant type of circulating leukocyte?
- neutrophils (60-70%)
- lymphocyte (25-33%)
what is the least abundant type of circulating leukocyte?
- basophil (0.25-0.5%)
- eosinophil (1-4%)
- what does polymorphonuclear granulocytes mean?
polymorphonuclear - many-shaped nucleus
granulocytes - granule-containing cells
what is a neutrophil?
- most abundant circulating WBC
- PHAGOCYTE!
- phagocytic specialist (specifically bacteria)
- has ONE nucleus with MANY SHAPES
- engulf and destroy bacteria intracellularly
which circulating white blood cell is the MOST MOST abundant?
neutrophil
which circulating white blood cell is the LEAST LEAST abundant?
basophil
what does granules contain?
lots of toxic substances
how are granules used in regards to neutrophils?
they release toxic substances when neutrophils engulf bacteria to destroy and damage the bacteria. HOWEVER, they also destroy and damage the cell so the cell will also die. the chromatin (DNA) is then released into the extracellular space (N.E.T.s)
when DNA is thrown into extracellular space after a neutrophil dies (N.E.T.s), what happens?
the bacteria sticks to the DNA which will have the toxic granules which will kill the bacteria as well
OR
the bacteria sticks to the DNA and then other phagocytes will come and destroy it
the release web of extracellular fibers that contain bacteria-killing chemicals are called what?
neutrophil extracellular traps (NETs)
what are eosinophils good for?
killing parasites
- killing of antibody coated parasites through release of granule contents
is an eosinophil a phagocyte?
no. it attached to the surface of the parasite(only if it is coated with antibodies) and release its granules
how does an eosinophil know what parasite to go to?
has to be a special kind of antibody coating that is specific to a parasite
- increase in circulating eosinophils (eosinophilia) is associated with?
- allergic conditions such as asthma and hay fever
- internal parasite infestations, such as worms (attach to worm and secrete substances to kill it)
what is the main function of basophils?
- fight parasitic infections
- also synthesize special chemicals that eosinophils don’t do (histamines and heparin)
which leukocyte is the least numerous and most poorly understood?
basophils
what special chemicals does basophil synthesize and store?
histamine: release is important in allergic reactions
heparin: speeds up removal of fat particles from blood after fatty meal
what is a monocyte?
- mononuclear agranulocytes leukocyte
- phagocyte
- largest circulating immune cell
- can eat larger numbers of bacteria
what can monocytes produce?
- many other proteins called cytokines (cell movement)
what can cytokines do?
can kill a pathogen directly or can activate another immune cell
what do monocytes do if they are called upon a tissue?
they change and mature into macrophages
what will allow a monocyte to live longer?
if it becomes a macrophage
what will make a monocyte die sooner?
if it gets activated and start eating bacteria
what are generally the first cells that are alerted to an infection?
macrophages
what happens when there is an invading microorganism?
tissue resident macrophages are the first to sense invading microorganisms –> secrete cytokines/chemokines –> recruit neutrophils and other leukocytes
what are the two types of lymphocytes?
- Large Granular Lymphocytes
- Small lymphocytes of adaptive immune response (two more types of these)
what are the natural killer (NK) cells?
large granular lymphocytes
what do NK cells do?
extremely good at killing virally infected cells
- not adaptive or advanced
- they will kill any cell that seems stressed
- release lytic granules to kill the cell
the small lymphocytes are apart of?
the adaptive immune response
true or false: we have many small lymphocytes but they take a long time to become activated
true
what do small lymphocytes do?
- they are our best immune cells (they do everything)
- cytokine production
- antigen recognition
- antibody production
- memory
- cytotoxicity
what are the two types of small lymphocytes?
- B Lymphocytes
- T Lymphocytes
- what are B lymphocytes?
- type of small lymphocyte
- called humoral immunity
- produce antibodies * (as a plasma cell)
- responsible to anti-body mediated immunity
what are T lymphocytes?
- type of small lymphocytes
- called cell-mediated immunity
- do not produce antibodies
- directly destroy specific target cells (like cancer cells or virally infected cells) by releasing chemicals that punch holes in the victim cell
- target cells include body cells invaded by viruses and cancer cells
- the commanders
which immune cell is the “general” (captain) if the immune response?
T Lymphocytes
- they make cytokines to tell macrophages what to do
- they command everything
- all blood cells ultimately originate from same undifferentiated ________ ___________ _____ ____ in red bone marrow
pluripotent hematopoietic stem cells
where are granulocytes and monocytes produced?
ONLY in bone marrow
total number of white cells and percentage of each type may vary considerably to?
meet changing defense needs
most new lymphocytes are actually produced how?
by lymphocytes already in lymphoid tissues such as lymph nodes, spleen and tonsils
