What is blood composed of?
- 55% Plasma -90% water + 10% solids (proteins and electrolytes)
- 45% formed elements (RBC, WBC, & platelets)
What is the sedimentation rate? what are its units?
it is how quickly RBCs (erythrocytes) settle to the bottom of a test tube in one hour (mm/hr)
Explain why the sedimentation rate is altered (increases) in a pregnant animal and what is the physiological advantage?
during pregnancy blood volume increases by 50% in order to meet the demands of the growing uterus. Plasma increases more during pregnancy and can lead to anemia. Increase in RBCs= increase need for iron.
What is found in the "buffy coat" at the top of a hematocrit?
white blood cells and platelets rise to the top
Pregnancy would cause you to have a ______ hematocrit and a ______ in blood plasma.
Decreased hematocrit and increase in blood plasma
How does coagulation occur?
Platelets produce a substance that combines with calcium ions to form thromboplastin --> converts prothrombin into thrombin. Thrombin (enzyme) converts fibrinogen into fibrin which forms a network of minute threadlike structures called fibrils --> causes blood plasma to gel--> form clot.
What can happen if you have LOW numbers of platelets (thrombocytes) in your blood? what could cause this?
it could make you more vulnerable to bleeding (reduced clotting).
- autoimmune diseases
- genetic disorders (ex: Haemophilia)
- viral infections
What can happen if you have HIGH numbers of platelets in your blood? what is this called? what complications could this create?
could make you more vulnerable to blood clots. this is called thrombocytosis.
conditions and complications:
- essential thrombocythemia
- heart attack
- formation of blood clots
where are blood platelets produced? how long do they live?
produced in bone marrow. live less than a week (7 days)
what are the 5 types of WBCs (leukocytes) ? what are there functions?
- Neutrophils: phagocytosis of bacteria and cellular debris
Esinophils: break down blood clots and kill parasites
Basophils: synthesis histamine & heparin (anticoagulant)
Lymphocytes: produce antibodies
Monocytes: phagocytosis (macrophages)
which WBCs are known as granulocytes, agranulocytes?
Granulocytes (produced in bone marrow)
Agranulocytes (white blood cells)
- lymphocytes and monocytes
explain how to use a circular hematocrit reader to read a PCV.
- line hematocrit tube up with groove and put the clay end towards the center
- spin the bottom plate so it lines up with 100
- line the curved line up with the top of the plasma
- spin the entire thing (without moving just the upper) until the curved line meets up with the top of the RBCs. Read the measure.
what does a PCV represent?
packed cell volume= % of red blood cells in plasma
how would dehydration or anemia affect an animal's hematocrit reading?
dehydration= less plasma (less water)= higher hematocrit reading
anemia= less RBCs = lower hematocrit reading
What effect did each saline solution have on blood cell size and shape? what caused the effect?
the higher the saline solution the more shrunk they were because water was leaving the cells they were hyperosmotic. Osmosis caused the effect.
Does temperature affect clotting time?
The blood tube at a higher temperature clotted much faster, whereas the ones on ice didn't clot at all (very, very slow)
does surface material contacting the blood affect clotting time?
glass clotted faster than plastic
what happened to the tube that had heparin in it? why might this be?
Heparin is an anticoagulant so the blood did not clot
Do isolated RBCs have all the required elements to clot?
No because they do not have platelets or clotting factors
How are plasma components different than those of serum?
Plasma clotted quickly, serum did not clot because serum lacks fibrinogen