cardio (blood) system: summary Flashcards
BLOOD
transports: O2, CO2, nutrients, hormones, heat & metabolic wastes. Regulates: pH, body temp, and water content of cells. Proctects: clotting, combating toxins (WBCs & plasma). pH 7.35-7.45, 4-6 L, 38C. Plasma: water and solutes inc; nutrients vitamins, hormones, electrolytes. Formed elements: RBC, WBC & platelets. HEMATOCRIT % of blood RBC.
HEMOPOIESIS
Formation of blood cells from hemopoietic stem cells in RBM. The pluripotent stem cells of RBM give rise to lymphoid stem cells & myeloid stem cells. Myeloid: RBCs, platelets, mast cells, granulocytes, monocytes.
Lymphoid: lymphocytes (in RBM) - lymphatic tissue.
ERYTHROCYTES
Heme- ringlike, contains iron that binds to O2.
Globin- 4 polypeptide chains that each have a ‘heme’
After 120dys, macrophages phagocytise RBCs and recycled.
ERYTHROPOIESIS
Begins in RBM. Reticulocytes enter blood stream - mature to erythrocytes. Creation same place as destruction. Stim by hypoxia.
ABO
Agglutinogens found on RBCs, they differentiate A B O. Antigen A/B presence. Plasma has anti-A/B antibodies called agglutinins. Incompatible- recipients antibodies bind to donated antigens causing agglutination (blood clumping).
Leukocytes
Have nucleus.
Eosinophils- 3 nucleus
Basophils- bilobed nucleus, intensifies inflammatory reac Neutrophils- 3-5 lobes.
Lymphocytes- sky blue, immune, Bcells- bacteria, Tcells- viruses etc. Natrual killer- microbes & tumor cells.
Monoctyes- blue-gray (mature- macrophages)
WBC can leave blood stream- emigration.
CHEMOTAXIS (WBC)
pathogens & inflamed tissue release chemicals that attract phagocytic neutrophils (1st responders) and macrophages. They ingest and dispose of pathogens and dead matter during phagocytosis.
PLATELETS
Thrombopoietin stims myeloid stem cells - megakaryocytes - splinter (2k-3k fragments) - thromocyte. Clot, ‘plug’ vessel walls.
