composition of the blood: plasma, buffy coat, red blood cells
plasma: water, proteins, nutrients, hormones, etc.
buffy coat: platelets, white blood cells
hematocrit: red blood cells
normal blood for males: 37%-47% hematocrit
normal blood for females: 42%-52%
anemia: depressed hematocrit %
polycythemia: elevated hematocrit %
Hemopoiesis is the proliferation and differentiation of the formed elements of blood.
red blood cells are disk-shaped, with edges thicker than the center of the cell
the biconcave shape of RBCs allow gases to move more rapidly into and out of the RBC as compared to a flat disc of the same size
RBCs live for 120 days in males, and 110 days in females
primary function of RBCs: transport oxygen from lungs to various tissues of the body and help transport carbon dioxide from tissues to lungs
hemoglobin: pigmented protein responsible for rbc's red color
1 protein chain (globin) is bound to 1heme (red pigmented molecule)
1 rbc contains many molecules of hgb, allowing for transport of sufficient oxygen to the cells of the body. hgb picks up oxygen in the lungs and releases oxygen in other tissues
arterial: oxygenated blood (hgb bound to oxygen), bright red color
venous: deoxygenated blood (hgbnot bound to oxygen), dark red color
rbc production depends on the presence of several vitamins and minerals
vitamin B12 (cobalamin) and B9 (folate): for cell division that produces newrbcs
iron: hgb production
old/abnormal/damaged rbc's are removed through phagocytosis in the spleen and liver (components are either recycled or excreted from the body)
white blood cells are spherical cells without hgb
white blood cells are larger than rbcs
white blood cells have a nucleus
white blood cells functions:
protect the body against invading microorganisms and other pathogens
remove dead cells and debris from the tissues by phagocytosis
white blood cells are not similar in shape
types of WBCs:
neutrophil
basophil
eosinophil
lymphocyte
monocyte
neutrophil: most common; with 3-4 lobes; phagocytize microorganims
basophil: least common; large granules that stain blue or purple; releases histamine and heparin
eosinophil: granules that stain bright red; with 2-lobed nucleus; associated with allergies and parasitic infection
lymphocyte: smallest wbc; important role in immune response
monocyte: largest wbc; this becomes a macrophage once it leaves the blood and enter the tissues
platelets: minutefragments of cells consisting of small amount of cytoplasm surrounded by a cell membrane
platelets are produced in the redbonemarrow from megakaryocyte (large cells)
platelets: small fragments break off from the megakaryocytes and enter the blood as platelets
function of platelets: clot formation, thereby preventing blood loss
ABO blood grouping: used to categorize human blood
ABO blood grouping uses antigen on the surface of red blood cells