Circulating Blood Flashcards
What is the technical classification of blood?
It’s connective tissue
What does blood develop from embryologically?
embryonic tissue mesenchyme
What are the CELLULAR components of peripheral blood?
- erythrocytes (RBCs)
- Leukocytes (WBCs)
- Platelets
- “dust” or hemoconia
- chylomicrons
What are the components of the intercellular material (plasma)?
- water - 90%
- proteins (albumin, globulins, etc.)
- Inorganic salts (Cl-, HCO3-, etc)
- organic compounds (amino acids, vitamines, hormones, etc.)
What is the difference between plasma and serum?
plasma clots while serum doesn’t because it lacks fibrinogen (and other clotting factors)
What is the life span of a RBC?
120-130 days
About how many RBCs are present in the body of a male?female?
male = 5x 10^6/mm3 female = 4.5x10^6/mm3
Which are more numerous, RBCs or WBCs?
RBCs by a lot (500 to 1000 times more numerous)
Describe the shape of a RBC.
It’s a biconcave disk
diameter is 7-8 um
width is 2 um
What is the shape of an RBC dependent on?
spectrin-ankyrin-actin interaction
List some of the organelles that RBCs lack.
nucleus, golgi, cnetrioles, lysosomes, RER
Because an RBC has few mitochondria, what system does it have to use for energy production?
It uses anaerobic glycolysis and the pentose phosphate pathway instead of oxidative phosphorylation
What is most of the cytoplasm made of in RBCs?
water 65%, hemoglobin 34%, organelles only 1 %
What is transported by the RBCs?
both O2 and CO2
Describe the ABO blood group system.
Type A - only antigen A
Type B - only antigen B
Type AB - both antigens
Type O - no antigens
What type is the universal acceptor? What type is the universal donor?
AB - acceptor
O - donor
What is the life span of a platelet?
8-10 days
What is the number of plateletes present in our body normally?
150,000-400,000/mm3
What are platelets derived from?
megakaryocytes in the bone marrow - it’s just membrane-bound fragments of that cell
Platelets contain a central ____ and a peripheral _____
central granulomere and peripheral hyalomere
What’s present in the granulomere of a platelet?
glycogen granules, mitochodnria, and electron-dense tubules
What is the function of platelets?
they aggregate to form a plug (clotting)
What are the 3 granulocytes/polymorphonuclear WBCs?
neutrophils
eosinophils
basophils
Which are capable of reproducing via mitosis after leaving the vascular system - granulocytes and agranulocytes?
agranulocytes can, granulocytes can’t
What are the two types of agranulocytes/mononuclear WBCs?
lymphocytes
monocytes
What is the process by which WBCs leave the vascular system?
diapedesis
How many hours do neutrophils circulate in the blood stream before migrating into CT?
6-12 hours
What are the characteristics of neutrophils and what percentage of the differential count do they typically make?
- they have a many lobed nucleus with specific granules in the cytoplasm
- comprise 50-70% of the differential
How many lobes are typically in the nucleus of a neutrophil? What holds them together?
2-5; held together by chromatin
What percentage of neutrophils are normally banded (or immature)?
1%
What are the three types of granules in the cytoplasm of neutrophils?
- azurophilic (primary)
- neutrophilic (secondary)
- tertiary
What do the axurophilic (primary) granules contain?
lysosomal enzymes and myeloperoxidase
What do the neutrophilic (secondary/specific) granules contain?
alkaline phosphatase and bacteriocidal substances
What do the tertiary granules contain?
gelatinase, cathepsins, and glycoproteins that can be inserted into the plasma membrane to aid in the phagocytic process
What molecules is in the plasma membrane of neutrophils facing the lumen of the phagosome to catalyze the formation of ROS to break bacteria down?
NADPH oxidase
What is the function of neutrophils?
they’re the first line of cellular defense agains tinvasion of microorganisms - they phagocytize and break down
What chemotactically attracts the neutrophils?
devitalized tissue, bacteria, and other foriegn bodies
What two mechanisms do the neutrophils use to break down bacteria?
- enzymatic (with the digestive materials in the azurophlic granules)
- formation of ROS in the phagosomes
Dead neutrphils form what?
pus of an abscess
What characterizes eosinophils? WHat percentage of the differential?
has large eosinic granules in the cytoplasm; bilobed nucleus
1-4% of the differential
What are the two types of granules in eosinphils?
- eosinophilic (specific)
2. azurophilic
Why are the specific granules so eosinophilic?
they have a large amount of arginine in the protein, which picks up the eosine dye
What is the general function of eosinphils?
mediate reactions to allergies, inflammation and especially parasitic infections
What will result in the migration of eosinophils to the site of reaction?
binding of histamine, leukotriens, and eosinophil chemotactic factor (from mast cells, basophils, and neutrophils) to the eosinophil plasma membrane receptors
How do eosinophils kill worms?
They have major basic proteins and eosinophil cationic proteins to bore holes in the pellicles of worms, allowing ROS to enter the parasite and kill it
When will the differential count of eosinophils increase?
allergies like hay fever, asthma, parasite infections
How do eosinophils act as a sort of break to regulate local inflammatory response?
they will degrade chemical mediators like leukotrienes and histamine released by mast cells and basophils
What characterizes basophils? What percentage of the differential?
An irregular nucleus that doesn’t appear lobated. Only 0.5% of the differential.
What do the specific granules contain in basophils?
heparin, histamine, eosinophil chemotactic factor, neutrophil chemotactic factor, and peroxidase
What is the general function of basophils?
mediating allergy and inflammatory reactions (similar to mast cells) - will bind antigens and release histamine and leukotrienes
When will basophils increase in the differential?
- along with other leukocytes in leukemia
- chicken pox, smallpox, sinus inflammation
What antibody type will basophils bind to the Fc portion of?
IgE
What happens when antigens bind the IgE on the basophil surface?
it triggers basophils to release the specific granule contents into the extracellular space
Where in the body are lymphocytes produced?
lymphatic nodules/nodes, spleen, thymus, tonsils and bone marrow
What percentage of the differential is made of lymphocytes?
20-40%
What are the size categories of lymphocytes and what group is most prevalence?
small (90%)
large (10%)
What do we think the large lymphocytes probably are?
probably partially differentiated plasma cell precursors
What are the nuclear characteristics of lymphocytes?
the nucleus is spherical (or slightly indented on one side)
chromatin is densely packed with a hill and valley pattern
nucleolus present, but not seen because of the clumped chromatin
How are the lymphocytes subdivided?
It’s based on function, NOT on morphological features.
What percentage of circulating lymphocytes are B-cells?
15%
Where in the body are B cells made?
in the bone marrow
What are the two groups of cells B-lymphocytes will differentiate to?
plasma cells and memory cells
What do plasma cells do?
they produce antigen-specific circulating immunoglobulins
What do memory cells do?
they stay in the lymphatic tissue and wait to be stimulated by re-exposure to an antigen
What percentage of lymphocytes are T-cells?
80-90%
Where are T-lymphocytes made?
they originate from the yok sac embrologically and then seed the thymus via liver and bone marrow, where they multiply and differentiate
What happens to the T lymphocytes in the thymus?
they develop an individual antigenic specificity
What is required for T-lymphocyte activation?
- the appropriate antigen
2. macrophages must process the antigen for presentation
What are the 3 subsets of T cells?
cytotoxic T cells
T helper cells
T suppressor cells
What are the null cells?
the lymphocytes that aren’t B or T cells - the natural killer cells are an example
What percentage of the differential are monocytes?
2-8%
What characterizes a monocyte?
- their relatively large size
- nucleus is eccentrically placed - may be oval, kidney, or horseshoe shaped
- chromatin less condensed than in lymphocyte, so nucleus is lighter staining
What are the functions of monocytes?
they diapedese and develop in the blood stream where they become known as macrophages - phagocytes
What are monocytes called in the CNS? in the liver? in the lungs?
CNS = microglia liver = kupffer cells lungs = alveolar macrophages
What are chylomicrons?
they are fat combined with plasma proteins
What is hemoconia?
it’s basically junk - consists of broken down RBCs, endothelial cells and ingested material not filtered out in the spleen
What’s the chief element of lymph?
lymphocytes (and few granulocytes) plus plasma
