PNB 2265 Blood Questions With 100% Correct Answers.

What type of tissue is blood? - ️️Connective tissue What does blood consist of (4 things)? - ️️-Plasma: 46-63% -Formed elements: 37-54%, red blood cells, white blood cells, platelets What happens when blood is spun at a fast rate in a centrifuge? - ️️Red blood cells collect at the bottom, a Buffy coat of white blood cells collects in the middle, and the fluid blood plasma collects at the top What is the purpose of blood? - ️️-Transport medium which carries materials through out the body through the vasculature system powered by the heart -Regulation of pH, osmolarity, temperature (38 degrees C), and fluid loss from injury -Protection What is hematocrit? - ️️The packed cell volume/ proportion (percentage) of whole blood volume that is made up of red blood cells What are the normal hematocrit values for men and women? Why is it higher for men? - ️️Men: 40-50% Women: 36-44% Higher for men because they have higher levels of testosterone, which activates EPO hormone, which makes RBCs What is a blood smear used for? - ️️To prepare a slide blood can be viewed under a microscope What are platelets? - ️️Cell fragments that originate from a type of leukocyte (megakaryocyte) What is the typical composition of blood plasma? - ️️92% water, 7% proteins, 1% other solutes What types of proteins are found in blood plasma (4)? What roles do they play? - ️️Albumin: regulates water movement between the blood and interstitial fluid at the capillary level -Globulins: transport lipids and ions, act as antibodies that immobilize pathogens -FIbrinogen: Helps with blood clotting -Regulatory proteins: enzymes, proenzymes, and hormones What solutes are found in blood plasma (5)? What roles do they play? - ️️- Electrolytes: establish and maintain membrane potentials, pH, and osmosis-Nutrients: energy source -Respiratory gases: Oxygen and CO2 -Wastes: urea, biliruben -Regulatory substances: hormones, chemical signals Define homeostasis as it relates to blood plasma. - ️️Keeping many of the constituents of blood plasma within narrow limits What are erythrocytes? What is their basic structure? - ️️Red blood cells, small/biconcave disks with flattened area in center Does an RBC have a nucleus or organelles? What does this allow them to contain/specialize in? - ️️No, RBCs are anuclear and lack organelles. This allows them to contain hemoglobin and therefore specialize in oxygen transport. This also limits their ability to synthesize proteins. What is the role of cytoskeletal proteins (specrtin) in RBCs? Why is this so important? - ️️They allow RBCs to assume the biconcave shape. This allows for more surface area than a normal sphere has, thus allowing maximum oxygen transportation both into and out of the RBC. Explain the basic structure and conformation of hemoglobin. - ️️Hemoglobin is composed of 4 polypeptide globin chains, 2 alpha chains and 2 beta chains. Each has a tertiary, 3D folded structure/conformation. Each chain is associated together to produce the complicated Quaternary structure. Explain the composition of a globin chain. - ️️Each globin chain has their own heme portion. Heme is a ringed molecule with an iron ion in the center Why is the iron in a heme important? - ️️The iron binds reversibly with oxygen, which allows for oxygen transport. How many molecular oxygens can a hemoglobin molecule transport? - ️️4 Explain how carbon monoxide interferes with hemoglobin's transport of oxygen. - ️️CO displaces O2 from heme because it has 200 times more affinity (binds more tightly). It binds to hemoglobin to form carboxyhemoglobin, HBCO, which is a stable compound, so it does not usually revert to regular hemoglobin. Therefore O2 cannot be transported to tissues. How is carbon monoxide produced? Why is it so dangerous? - ️️CO is produced whenever fossil fuels are burned. It is colorless, odorless, tasteless, and non irritating, so it is very difficult to detect. Also, it does not change the amount of oxygen in the blood, so the body cannot sense that anything is wrong.Explain how cyanide interferes with hemoglobin's transport of oxygen. - ️️Similar to CO. Cyanide binds to iron in heme, prevents O2 from binding, thus preventing hemoglobin from carrying oxygen to tissues. What is hemopoeisis? - ️️Blood cell formation What is a hemocytoblast? What 2 lines does it differentiate into? - ️️The stem cell found in red bone marrow from which all blood cells arise from. It differentiates into the myeloid line and the lymphoid line. What three processes occur in the myeloid line? - ️️Erythropoeisis (RBCs), thrombopoiesis (platelets), and leukopoisis (WBCs) What two types of cells result from the lymphoid line? - ️️B and T cells What is the clinical word for a blood clot? - ️️Thrombus What three things are critical for erythropoeisis? - ️️Iron, Vitamin B12, and follic acid What hormone is responsible for directing a hemocytoblast into an erythrocyte? - ️️EPO, erythropoeitin In what stages of erythropoeisis is a nucleus present? Why is it there/what does this make it capable of? - ️️Progenitor cell, proerythroblast, early erythroblast, late erythroblast. Present because DNA transcription, translation, and protein synthesis (including the hemoglobin that will be in the final RBCs) occurs in these stages. This makes it capable of mitosis. What occurs in the normoblast stage of erythropoeisis? - ️️The nucleus shrinks and is ejected, some hemoglobin production occurs here but the cells are no longer capable of mitosis. What are reticulocytes? What can they cause if a surplus of them circulate in the blood stream? - ️️Immature RBCs that can carry O2 and may circulate. If too many of them enter the blood stream, they may cause anemia What differentiates reticulocytes from erythrocytes? - ️️Mature RBCs do not contain ribosomes or RNA, have the biconcave shape, and are more acidophilic so they stain differently. Explain how oxygen levels in the blood regulate erythropoeisis. - ️️If hypoxia (low O2 levels) occurs, the kidneys releases EPO to stimulate the red bone marrow to produce RBCs, therefore increasing blood O2 levels.How long do erythrocytes typically live for? What organs catabolize them after this period of time? - ️️3-4 months (120 days). Macrophages in the liver and spleen catabolize them, which is why there is such rich circulation to these areas. What happens to iron when an RBC is catabolized? - ️️The iron is recycled. It travels with a transport protein (transferrin) to the marrow. A small amount of excess is stored as ferritin or hemosiderin in the liver. What happens to the heme (minus the iron) when an RBC is catabolized? - ️️It is converted to biliverdin, then biliruben, then released into the blood where it binds to albumin and is later excreted by the liver and secreted in bile, feces, and urine. What happens to the RBC membrane and the hemoglobin protein when an RBC is catabolized? - ️️They are broken down into amino acids, some of which are used to make new RBCs What is anemia? What is it caused by? - ️️A condition characterized by decreased oxygen delivery to the tissues. Can be caused by a low RBC count, abnormal hemoglobin that cannot carry sufficient oxygen, or low hemoglobin levels in an RBCs. What would cause a RBC to have low hemoglobin levels? - ️️Iron deficiency, either caused by a lack of iron in the diet or an inability to absorb the iron due to a vitamin B12 deficiency. What is Thalassemia B caused by? What does it result in? - ️️Caused by a mutation in the gene that calls for production of the beta globin protein. Results in a reduced amount of functional hemoglobin and microcytic/ hypochromic RBCs. What does the term microcytic refer to? - ️️Abnormally small red blood cells What does the term hypochromic refer to? - ️️Abnormally pale red blood cells What causes sickle cell anemia? What does it result in? - ️️Caused by a single wrong base substitution which causes a wrong amino acid. Inherited from both parents (homozygous recessive). Results in crescent moon shaped RBCs. What are some of the disadvantages to having sickle shaped RBCs? - ️️-They cannot move through the blood stream easily, thus clumping together and obstructing capillaries. This prevents O2 from reaching tissues. -The cells are very fragile and tend to rupture, causing hemolytic anemia What happens if an individual only inherits sickle cell from one parent and is heterozygous for the trait? - ️️The person is a carrier. This actually gives them an advantage for resisting malaria.What is polycythemia? What is the difference between abnormal, functional, and artificial polycythemia? - ️️An increase in the RBC count. -Abnormal: not beneficial, caused by things such as led poisoning, cancer, bone marrow abnormalities. Thickens blood and can cause clots and death. -Functional: caused by hypoxia leading to erythrocyte production, happens if someone is in a high altitude -Artificial: blood doping, infusion of packed RBC by taking erythropoeitin supplement or training in high altitudes, hidden by drinking water and saline IV injections, causes death