Hematologic System: Bohr Effect vs. Haldane Effect

Hematologic System What’s Inside of Blood?: 55% of the blood is made up of plasma (which includes 90% water, 8% is proteins such as Albumin, Antibodies, and Fibrinogen, and 2% is hormones, electrolytes, and nutrients), <1% is white blood cells and platelets, and 45% of the blood RBCs (most dense) Serum is everything plasma has but without clotting factors and fibrinogen Hematocrit tells you a percentage of RBCs present in the blood ( !"#$%& "( )*+ ,"-.# !"#$%& ) Polycythemia is a high amount of RBCs per total volume Anemia is a low amount of RBCs per total volume 1. 2. 3. Hemoglobin moves O2 & CO2: Oxygen moves from the alveolus (chamber of air in the lungs) and into the blood vessel (into a RBC specifically) Remember, as each O2 binds to hemoglobin, it makes it easier for more O2 to bind (this is known as cooperativity) Some O2 is also dissolved in the plasma (not that much though compared to those that are bound to hemoglobin) A couple reasons for O2 to enter cells: Low partial pressure of O2 (pO2) H+ binding competes with O2 for binding of Hb (lower pH causes the Hb to let go of O2) CO2 competes with O2 for Hb High oxygen concentration causes the increase of Hb binding for O2 in the lungs Bohr Effect vs. Haldane Effect: Bohr Effect shows how CO2/H+ affects the affinity of Hb for O2 Haldane Effect shows how O2 affects the affinity of Hb for CO2/H+ In order to increase O2 delivery, you need less oxygen located in that tissue CO2 doesn’t bind Hb in a cooperative manner like O2 does Blood Types: A and B parts of the cell surface are NOT proteins, they are glycolipids Some people have A, B, AB, or neither The body has antibodies that mark things for destruction and our bodies work to not make antibodies against ourselves Type AB blood is a universal recipient and type O blood is a universal donor How do we make blood clots?: Endothelial cells make up the walls of a blood vessel If the walls of the blood vessel are damaged or broken in a way that causes a leak, blood will rush out of the vessel → in order to combat this, the blood makes platelets (a tiny piece of a cell without a nucleus) which clogs up any leaks in the blood vessel Collagen is found outside of the blood vessels (not found within it) and when it interacts with platelets, it causes them to stick together (hence in the case of a damaged/leaky vessel) Since the platelet plug isn’t that strong, there is a second step needed which involves fibrin (a protein that interacts with platelets by forming a mesh over it and keeping it nice and tight) → fibrinogen is simply an analog that doesn’t stick to one another in the blood Fibrinogen only converts to fibrin by tissue factors (recruits others exponentially) found outside of the vessel Coagulation Scale: Fibrinogen and NOT fibrin is found in the blood, because if it was fibrin it would polymerize in the blood (which is bad bro) Haemophilia is a mostly inherited genetic disorder that impairs the body's ability to make blood clots, a process needed to stop bleeding (3 types, A (factor VIII), B (factor IX), and C (factor XI) Too much information, not necessarily important - - Life & Times of RBCs & Platelets: About 5 million RBCs in 1 µL of blood (RBCs last about 120 days on average) About 200,000 platelets in 1 µL of blood (last a couple of days) These regenerate in the bone marrow Erythropoiesis is the process of generating new red blood cells from red bone marrow Platelets come from megakaryocytes (bud off of the megakaryocyte) The spleen is the organ most responsible for recognizing and taking out old RBCs and platelets Monocytes in the spleen are responsible for phagocytosing old RBCs in order to reuse eventually (i.e. recycling iron and amino acids in the old RBC) → also occurs in the liver Erythropoietin is a glycoprotein stimulated by the kidney under low O2 levels, triggering erythropoiesis 1. a. b. 2. a. Blood Cell Lineages: Pluripotent stem cells give rise to any of the 10 types of blood cells and gives rise to two lineages Myeloid lineage gives rise to RBCs, megakaryocytes, and macrophages (technically monocytes before they turn into macrophages) Also neutrophils, eosinophils, and basophils Mast cells come from the myeloid lineage (release histamine and cause allergic reactions) Lymphoid lineage give rise to lymphocytes (B and T cells) → B cells make antibodies Also gives rise to a natural killer cell Dendritic cells can come from lymphoids or the monocyte