Cardiovascular System: blood :red_flag: (Coagulation: a process that…
Cardiovascular System: blood :red_flag:
: a process that requires numerous substances, including Ca, clotting factors, platelets, and vit K.
: most clotting factors are inactive enzymes produced by the liver. Forming a clot involves a cascade of changes that activates several clotting factors at different intervals in response to damage to a blood vessel.
Platelet clot formation
: as platelets start to stick together, their morphology changes and they become activated. Their cytosol degranulates, releasing chemicals that assist with hemostasis.
Repair of blood vessels as platelets secrete substances to stimulate epithelial tissue, smooth muscle, and fibroblasts to replicate.
: stimulate coagulation
ADP and thromboxane A2
: facilitate the degranulation and release of these chemicals in other platelets
Serotonin and thromboxane A2
: prolongs vascular spasms.
: to destroy the fibrin network of the clot, plasmin degrades the fibrin strand. Begins within 2 days of the clot formation and occurs slowly over a number of days.
Fibrin clot formation
: fibrin is a tough protein substance, it is formed from fibrinogen, a soluble protein that is produced by the liver and found in blood plasma. When tissue damage results in bleeding, fibrinogen is converted at the wound into fibrin by the action of thrombin, a clotting enzyme. This meshwork of proteins traps other elements of the blood to form a clot.
Platelet plug formation
: second phase of hemostasis. When a blood vessel is damaged, the collagen fibers within the vessel wall become exposed. Platelets begin to stick to the exposed collagen fibers.
: first phase of in hemostasis. Blood vessels constrict suddenly limiting the amount of blood that leaks out of vessel.
: occurs in in the red bone marrow of long bones in adults, most bones in young children.
: type of pluripotent cell, able to differentiate and develop into many different kinds of cells.
gives rise to B and T lymphocytes
Lymphoid stem cell
: spawn natural killer cells.
Myeloid stem cell
: progenitor cell, monoblast, promonocyte, monocyte.
: progenitor cell, myeloblast, promyelocytes, differentiates into eosinophilic, basophilic, neutrophilic myelocyte, eosinophil, basophil, neutrophil.
: progenitor cell, megakaryoblast, promegakaryocyte, megakaryocyte, proplatelet, platelets.
: progenitor cell, proerythroblast, early erythroblast, late erythroblast, normoblast (nucleus ejected), reticulocyte, erythrocyte.
: help clot the blood and prevent blood loss from damaged vessels. (150,000-400,000 per cubic mm).
: contribute to protecting the body against pathogens. (4,500-11,000 per cubic mm).
: approx. 2-8% of WBC. Exit blood vessels and become macrophages. Phagocytize pathogens, cellular fragments, dead cells, and debris.
: approx. 20-40% of WBC. Coordinate immune cell activity, produce antibodies. Attack pathogens, abnormal and infected cells.
: least popular of WBC, 0.5-1%. Release histamine, a vasodilator that increases capillary permeability. Also releases heparin, an anticoagulant during inflammatory reactions.
: approx. 1-4% of WBC. Phagocytize antigen-antibody complexes and allergens (allergic reactions). Attack parasitic worms.
: most abundant WBC making up approx. 50-70% of all leukocytes. Phagocytize bacteria. Release enzymes that target pathogens.
: transport respiratory gases in the blood thanks to the hemoglobin protein. (4.8 million to 5.4 million per cubic mm).
Major Functions of blood
: leukocytes can be found circulating in the blood to help protect the body against potentially harmful substances.
: there is a constant exchange of fluid between blood plasma and capillaries. Blood contains proteins and ions that exert osmotic pressure to pull fluid back into the capillaries to help maintain normal fluid balance.
: by absorbing acid and base from body cells, blood helps maintain the pH of cells. Buffers such as proteins and bicarbonate can be found in blood to bind and release hydrogen ions to maintain blood pH.
: by absorbing heat from body cells, blood helps regulate body temp. Heat is then released from blood at the body surface as blood is transported through blood vessels of the dermis.
: blood transports formed elements and dissolved molecules and ions throughout the body. It carries O2 from the lungs and CO2 to the lungs, nutrients absorbed, hormones released, heat and waste products.