Human Bio Chapter 6: Blood

Transport function of blood

gas, nutrients, waste, and hormones; defense against invasion of pathogens, some white blood cells phagocytize microbes; protects against fluid loss by clotting

regulatory function of blood

body temp, buffers in blood regulate pH

composition of blood

liqued connective tissue made of formed elements (red and white blood cells and platlets) suspended in plasma

plasma

91% water and 9% salts, organic molecules (plasma proteins are most abundant and produced in the liver)

types of plasma proteins

albumins-most abundant, globulins, fibrinogen-form blood clots

Red blood cells (erythrocytes)

bioconcave shape, contain hemoglobin (pigment that binds oxygen), the heme portion of Hb binds up to four oxygens

production of red blood cells

produced in red bone marrow,but lose their nucleus and most organelles as produced. Without a nucleus, can’t make proteins for cell repair (only live about 120 days), removed from circulation by macrophages

erythropoietin (EPO)

a hormone produced by the kidneys when oxygen levels of the blood are low

blood doping

increasing the number of RBCs by injecting EPO to increase stamina and athletic performance

jaundice

accumulation of heme in the blood if the liver can’t excrete it

anemia

too few RBCs of too little hemoglobin

Iron-deficiency anemia

most common form, not enough dietary iron so cant make Hb

pernicious anemia

lack of vitamin b12 which is needed to make RBCs

folic-acid-deficiency anemia

need folic acid to make RBCs

hemolytic anemia

too much hemolysis (rupturing of the RBCs)

sickle-cell disease

genetic disease causing RBCs to become sickle shaped and prone to rupturing due to defective hemoglobin structure

white blood cells (leukocytes)

large, have a nucleus, fight infection and essential to immune system

types of white blood cells

neutrophils, lymphocytes, monocytes, eosinophils, basophils

granular leukocytes

contain noticeable granules, lobed nuclei; basophils, eosinophils, neutrophils

agranular leukocytes

no granules, nonlobular nuclei; lymphocyte, monocyte

neutrophils

50-70% of all WBCs, first responders to bacterial infections, engulf pathogens by phagocytosis

eosinophils

bilobed nucleus, function in parasitic infections and play a role in allergies

basophil

rarest WBC; in connective tissues basophils and mast cells release histamine during allergic reactions

histamine

dilates blood vessels but constricts breathing passageways

lymphocytes (both types)

B cells produce antibodies which mark a pathogen for destruction, T cells directly destroy pathogens

monocytes

largest of the WBCs, engulf pathogens, old cells, and debris

platlets

function in blood clotting/coagulation, plasma proteins prothrombin and fibrinogen are also involved in clotting, vitamin k is necessary for forming prothrombin

thrombocytopenia

too few platelets affect clotting, can be caused by leukemia or drugs

thromboembolism

when a thrombus (attached clot) forms, travels (becoming an embolism), and plugs another vessel

hemophilia

genetic deficiency of clotting factors, not exclusively platelets (cannot form clots)

antigen

a foreign substance that stimulates an immune response

how are blood types determined

by presence and/or absence of type A and B antigens

type A blood

type A antigen, anti-B antibodies

type B blood

type B antigen, anti-A antibodies

type AB blood

both A and B antigens, no anti A or B antibodies

type O blood

no A or B pathogens, both anti A and B antibodies

universal donor

type O

universal recipient

type Ab

Rh blood groups

if Rh factor antigen is/ isn’t present, blood is + or -