Exam 2: Oxygen Transport & Anemia Flashcards
What are the features of normal composition of blood?
55% plasma, 45% of formed elements (leukocytes, erythrocytes, platelets)
What is the composition plasma?
91.5% water, 7% proteins (albumin, globulins)
What is Hematopoiesis?
formation of blood components, blood cells
What is Lymphopoiesis?
formation of lymphocytes
What is the structure of Hemoglobin?
two alpha and two beta polypeptide chains (proteins), four heme groups
How does hemoglobin differ between fetal and adult?
both have two identical alpha subunits, fetal hemoglobin has 2 gamma subunits, adults have 2 beta subunits
What is the purpose of Iron?
Major component of hemoglobin that carries oxygen throughout body
How much oxygen can bind to 1 hemoglobin?
4
How does the regulation of erythropoiesis work?
kidneys secrete erythropoietin which stimulates RBC production the the bone marrow
How does hemoglobin degradation work?
hemoglobin broken down into globin (goes to amino acids) and heme (with iron), heme breaks into iron (goes to red bone marrow) and biliverdin, biliverdin converted to bilirubin and excreted
What is the main form of oxygen transportation?
Hemoglobin
What is the main form of Carbon Dioxide transportation?
bicarbonate ion (or dissolved in blood or carbaminohemoglobin)
What is Affinity?
Hemoglobin–oxygen affinity is the relationship between the oxygen tension of blood and its oxygen content, ability to hold onto oxygen, higher affinity = more binding
What causes a left shift on the oxygen -hemoglobin disassociation curve?
increase pH (less H+), decrease PCO2 (partial pressure of CO2), decrease temperature
What causes a right shift on the oxygen-hemoglobin disassociation curve?
decrease pH (more H+), increase PCO2, increase in temperature
What does a right shift mean on the oxygen-hemoglobin disassociation curve?
decreased affinity for oxygen, oxygen actively unloads (at the tissues)
What does a left shift mean on the oxygen-hemoglobin disassociation curve?
increased affinity for oxygen, less likely to let go of oxygen, more oxygen saturation (the lungs)
What is the Erythropoietin feedback circuit?
decreased red cell mass and decreased arterial oxygen saturation leads to increase erythropoietin, increased red cell mass leads to decreased erythropoietin (from kidneys)
What is anemia?
when the body lacks enough healthy RBC to carry adequate oxygen
Relative (Dilutional) Anemia
Pregnancy
Examples of decreased production of RBCs
Iron deficiency, B12/folate deficiency, thalassemia, aplastic, chronic renal failure
Examples of increased destruction of RBCs
sickle cell/ Spherocytosis, antibody-mediated Drug Rxn
Iron Deficiency Anemia
Hypochromic/Microcytic, presents as GI bleeding in men and menorrhagia in women, most common anemia
What is Hypochromia?
not enough hemoglobin, less color when RBC is examined
What does microcytic mean?
RBCs are smaller than usual
Meaning of MCV/MCH/MCHC
MCV and MCH- size
MCH - shape, hemoglobin per RBC
MCHC - level of hemoglobin relative to size
B12/ Folate Deficiency
Macrocytic (big cells), Pernicious anemia (decreased production RBC), increased size, normal MCHC
What are red blood cell indices?
size, shape, quality
Amenia of Chronic Kidney Disease
less production of RBC due to Kidneys failing to produce erythropoietin, burr cells: projections, serrated appearance
Thalassemia
genetic mutation that leads to deficient synthesis of globin chains, hypochromic/ Microcytic, decreased RBC indices, common in people of Mediterranean descent
Sickle Cell anemia
Valine (amino acid) -> glutamic acid error in the beta chain, blood low in oxygen
Hereditary Spherocytosis
rather than a disk they are a sphere, more fragile RBCs, hemolytic anemia due to RBCs breaking down faster
What will the Red Cell Indices look like for Acute Blood loss?
decreased in the number of RBCs…
Is acute blood loss immediately detectable on CBC?
It is not immediately detectable
What are the general clinical manifestations of anemia?
sometimes asymptomatic, pallor, fatigue, loss of stamina, weakness, tachycardia, exertional dyspnea, orthostatic hypotension, dizziness/syncope
What is Polycythemia?
having a high concentration of RBCs (dehydration)
How does Primary Polycythemia present? (Polycythemia vera)
idiopathic myeloproliferative disorder, RBC hyperplasia, increased blood viscosity, hypertension/ thrombosis/ hemorrhage, hepatomegaly/ night sweats/ post-bathing pruitus
How does secondary Polycythemia present?
increased production of RBCs secondary to chronic hypoxia, maybe from altitude or lung disease, clinical manifestations are those of increased blood viscosity and underlying disease
Clinical manifestations of Hyper-viscosity syndrome
visual disturbances, dizziness, claudication, stroke, myocardial infarction
What terms describe decrease in RBC count/quality (anemia and risks)?
Microcytic/Hypochromic, normocytic, other shape, macrocytic
