blood cells and homeostasis

what are the functions of blood?

transport O2, nutrients, hormones, and other substances TO tissues. transport waste and CO2 AWAY from tissues. maintain homeostasis. contributes to immunity.

what is blood?

fluid connective tissue

what is the liquid medium blood is suspended in?

plasma

what are erythrocytes?

red blood cells (RBCs)

what is the function of erythrocytes?

transport oxygen and carbon dioxide

what are leukocytes?

white blood cells (WBCs)

what is the function of leukocytes?

protection against infection

what are thrombocytes?

blood platelets

what is the function of thrombocytes?

blood clotting

what are the plasma proteins?

albumins, globulins, fibrinogen

what is the purpose of albumin?

maintain osmotic pressure and acts as a transport protein

what is the purpose of globulins?

provide immune system functions

what is the purpose of fibrinogen?

blood clotting

what is serum?

plasma without clotting factors

what is the hematocrit?

the ratio of the volume of red blood cells to the total volume of blood

what is erythropoiesis?

production of red blood cells

what produces erythropoietin?

kidneys

what stimulus occurs for erythropoietin to be produced?

decreased oxygen delivery to kidneys

what is the primary function of erythrocytes?

transport O2 to tissues and CO2 to lungs

what is the formula for carbonic anhydrase?

CO2 + H20 <-> H2CO3 <-> HCO3- + H+

what is the average lifespan of erythrocytes?

120 days

what is hemoglobin?

protein in red blood cells containing iron that carries oxygen.

what is hemoglobin composed of?

4 heme, 4 iron, 4 globins

what is hemolysis?

destruction of red blood cells

which organs aid in hemolysis?

liver & spleen

what occurs during hemolysis?

1) phagocytosis by macrophages in spleen and liver (rbcs are broken into heme & globin groups)

2) heme pigments are metabolized to bilirubin and iron

what is jaundice caused by?

build up of bilirubin in the blood

what is hemostasis?

stoppage of bleeding

what is primary hemostasis?

platelet plug formation

what is secondary hemostasis?

coagulation cascade

what are the steps on hemostasis?

1) injury to vessel

2) smooth muscle contraction

3) platelet plug formation

4) activation of coagulation cascade

5) thrombus generation

6) activation of anticlotting systems

7) fibrinolysis

what is fibrinolysis?

breaking down of fibrin

what is the platelet plug formation?

process in which platelets stick to parts of damaged blood vessels, and become activated and accumulate large numbers.

what is the lifespan of platelets?

8-9 days in circulation

what do clotting factors require?

Vitamin K

what is the intrinsic pathway of coagulation cascade?

vessel damage

what is the extrinsic pathway of coagulation cascade?

tissue tramua

which way it more important?

intrinsic, even though slower

what is an anticoagulant?

substance that prevents blood from clotting

what is thrombolysis?

loosening or dissolving of a clot