White Blood Cells Flashcards
Define hematopoiesis. Where does it occur in the fetus and in an adult? What is leucopoesis?
hematopoises - formation of new blood cells
- fetal - flat bones, long bones, vertebrae, liver, spleen
- adult - flat bones, epiphyses of longs bones, vertebrae
leucopoiesis - formation of WBC
- all white blood cells drive from same common cells as RBC - hematocytoblast
Describe formation of the different WBC
all comes from hematocytoblast like RBC
can either become:
- lymphoid - then becomes a lymphocyte
- myeloid - all other WBC: monocytes, granulocytes
Describe the size, nucleus, and presence/lack of granules in a neutrophil. What are its functions?
12-15 microns (2x size RBC)
distinctive multi lobular nucleus
contains granules - fine, light pink
- lysosomal and bactericidal enzymes
70% of total WBC
phagocytosis - non specific defense - lysosomes and proteases
- leave post capillary venues via diapedesis
increases during bacterial infections - pus, lining membrane
Describe the size, nucleus, and presence/lack of granules in an eosinophil. What are its functions?
12-15 microns in diameter
bilobed, horseshoe like nucleus
contains granules - moderately sized, salmon colored
functions:
- phagocytic cells interact with antigen-antibody complexes
- releases enzymes that destroy parasites
- breaks down histamine (released by basophils/mast cells), allergens
- increases in parasitic infection, allergies, diseases of spleen/CNS
2-5% of total WBC
Describe the size, nucleus, and presence/lack of granules in a basophil. What are its functions?
10-12 microns in diameter
irregular surface of nucleus - similar to lymphocytes but granulated
large, dark blue/pink granules that obscure nucleus
functions:
- secrete histamine, heparin - associated with asthma, allergies
- increases in chickenpox, DM, polycythemia, sinusitis
- bind to dock of Y of IgE to release histamine and heparin
LEAST COMMON WBC - nonphagocytic
Describe the size, nucleus, and presence/lack of granules in a lymphocyte. What are its functions?
8-10 microns in diameter
round nucleus surrounded by thin rim of clear cytoplasm - uniform stain of blue/purple
no granules
function: SPECIFIC IMMUNITY
- T cells: granzymes and perforin, non phagocytic
- B lymphocyte: releases antibodies, phagocytic, may function as APC
- natural killer cells - large, nonspecific T cells that release granzymes and perfori
Describe the size, nucleus, and presence/lack of granules in a monocyte. What are its functions?
16-20 microns in diameter - largest
nucleus late, bilobed/kidney shaped, blue stained
function:
- differentiates into macrophages - phagocytic APC’s
- can become dendritic cell
- increase in viral infections and inflammation
- synthesizes tumor necrosis factor and interleukin-1
differentiation occurs in CT outside of bloodstream
- macrophage: alveolar (lung), Kupffer (liver
- dendritic cell
- microglia
What is the order of most common to least common WBC? how do WBC relate to RBC?
RBC - mostly function within blood stream
WBC - use blood stream to get to where they need to go
- interstitial fluid, CT, organs
neutrophils > lymphocyte > monocyte > eosinophil > basophil
Describe lymphatic capillaries. What kind of ET, and what kind of system?
wall of simple squamous ET with restricted basement membrane for cells
- very permeable, loosely joined endothelial cells
- collagen filaments anchored to endothelial cells increase openings s interstitial fluid increases
- can absorb cell debris, pathogen, cancer cells
considered part of an open system
- anything that can cross capillary membrane into extracellular space can enter the lymphatic system
Describe the different pressures between cardiovascular capillaries, lymphatic capillaries, and interstitial fluid. What will have a higher hydrostatic P, the arterial or venous system?
P capillaries > P extracellular > P lymphatic capillaries
arterial system has high P and flows out - increases [albumin]
- increased [albumin] on venous side encourages uptake, but not enough to offset H2O loss on arterial side
- causes increase in extracellular fluid - picked up by lymphatics
Describe the following lymphatic vessels: collecting vessels, trunks, ducts
collecting vessels - have same 3 tunics as veins with less tunica media
- have more valves - prevent back flow
- branch and anastomose more frequently
trunks - paired with lumbar, bronchomediastinal, subclavian, jugular and single intestinal trunk
ducts
- R lymphatic duct: drains R upper extremity, R side of head and thorax
- L lymphatic trunk: originates from cisterna chyli and drains the rest of the body
Where do the R and the thoracic duct empty? What is the cisterna chyli?
where the external jugular vein and subclavian vein meet on both sides
- both enter on respective subclavian vein
cisterna chyli - drains R and L lumbar trunks, intestinal trunk and emptied into the thoracic duct
What are the lymphoid cells?
T lymphocytes, B lymphocytes, macrophages and reticular cells
What are the functions of T lymphocytes? Where do they arise and where do they mature?
function: manage the immune response
- directly attacks on foreign cells
- T killer cells (cytotoxic T cells) attach directly to tumor cells
arrive in the red bone marrow
mature in the thymus
What are the functions of the B lymphocytes? Where do they arise and where do they mature?
function: protect against antigens by producing antibodies
- APC
- attack from afar
- becomes plasma cell in spleen, lymph, or extracellular fluid
arise in the red bone marrow
mature in the bone marrow and lymph nodes
