TopHat Blood Questions
Why is hemoglobin found inside red blood cells, instead of as a plasma protein?
If not encased in a RBC membrane, the Hb is rapidly cleared from the body by the kidney. Encasing the Hb within a cell allows for the environment inside the cell to be different than the environment outside the cell, improving the regulation of oxygen binding to Hb.
What would be the impact of an erythrocyte losing its biconcavity or flexibility?
Loss of biconcavity would reduce surface area for gas exchange, and negatively impact the physical properties of erythrocytes (flexibility, stackability, etc.).
In developing countries where it is common for the poor to survive on a single crop, e.g. unfortified rice, the incidence of pernicious anemia is much greater than in the United States. How would the mean corpuscular volume (MCV) of someone afflicted by pernicious anemia compare to that of someone who received ample B12 in his diet? a. MCV would be lower in the anemic individual b. MCV would be higher in the anemic individual c. MCV would be the same in both individuals
b. MCV would be higher in the anemic individual Abnormally large red blood cells are characteristic of megaloblastic anemias, including pernicious anemias. As MCV measures the average size of red blood cells, it would be higher in someone with pernicious anemia.
The shape of an erythrocyte is ________. a. spherical b. biconcave c. biconvex d. long and flat
b. biconcave Red blood cells are disc-shaped, but the edges are thicker than the middle. This is described as a biconcave disc.
Because of their unique shape, red blood cells _______________. Select all that apply. a. have a decreased surface to volume ratio b. flex as they navigate through narrow capillaries c. experience greater shear stress d. are able to "stack" their mitochondria
b. flex as they navigate through narrow capillaries c. experience greater shear stress The biconcave disc provides the red blood cell with a large surface are to volume ratio and gives it great flexibility; the increased flexibility allows it to withstand shearing forces. Red blood cell lack internal organelles (like mitochondria), providing more space for hemoglobin.
Place the following classes of leukocytes in order of increasing abundance. monocytes eosinophils neutrophils basophils lymphocytes
basophils eosinophils monocytes lymphocytes neutrophils Neutrophils (50-70%) and lymphocytes (25-40% are the most common types of leukocyte. Monocytes (4-8%) and eosinophils (2-4%) are less common. Basophils (<1%) are the least common type of leukocyte.
Place the following cells in order, starting with the most undifferentiated and ending with the most mature cell. proerythroblast orthochromatic erythroblast erythrocyte myeloid stem cell basophilic erythroblast hematopoietic stem cell reticulocyte polychromatic erythroblast
hematopoietic stem cell myeloid stem cell proerythroblast basophilic erythroblast polychromatic erythroblast orthochromatic erythroblast reticulocyte erythroblast During erythropoiesis hematopoietic stem cells divide and differentiate through a series of stages, culminating in the release of reticulocytes from red bone marrow. Reticulocytes then matures into erythrocytes.
Place the following stages of neutrophil differentiation in order, starting with the most mature and ending with the most undifferentiated cell. myelocyte myeloid stem cell neutrophil promyelocyte neutrophilic band cell myeloblast
neutrophil neutrophilic band cell myelocyte promyelocyte myeloblast myeloid stem cell Hematopoietic stem cells differentiate into myeloid stem cells; once fated to become leukocytes they're now called myeloblasts. Myeloblasts become promyelocytes, then myelocytes,, then band cells, and finally the mature leukocyte (in this case a neutrophil).
What changes occur in the orthochromatic erythroblast that cause it to take on a biconcave shape?
Binconcavity occurs as the cell ejects its organelles. During this time, hemoglobin is becoming the most abundant protein within the cell.
Can a CBC be used to diagnose Human Immunodeficiency Virus (HIV)?
Not really. HIV infects a specific type of lymphocyte (helper T cells). Since the entire population of lymphocytes only account for around one third of the total number of white blood cells, and because white blood cells are so lowly abundant to begin with, changes in the level of helper T cells are not easily detected by the CBC. In fact, the number of WBC on a CBC would likely appear normal. When interested in a specific population of leukocytes, a CBC with differential is often used instead. In any case, the most trusted method of HIV detection involves directly testing for viral proteins.
Bombay blood is a rare blood disorder. Affected individuals are unable to make antigen H, a precursor that is required for the synthesis of Antigen A and Antigen B. What implications would the Bombay phenotype have on the ability to donate or receive blood? What happens if these individuals are blood typed following the procedure described above?
The inability to produce AB antigens would increase the compatibility as a donor. However, because they produce antibodies against antigen H, which is a precursor to A and B antigens, individuals with Bombay blood are very difficult to transfuse. They can only receive blood from other individuals with Bombay blood disorder.
Match the following blood types with the antigens expressed on the plasma membrane. Blood Type: a) Blood type A b) Blood type B c) Blood type AB d) Blood type O Antigens: A antigen and B antigen B antigen No antigens A antigen
a) A antigen b) B antigen c) A antigen and B antigen d) No antigens Blood type is determined by the antigens on the surface of red blood cells. Type A has A antigens, type B has B antigens, type AB has both A antigens and B antigens, type O has neither A antigens or B antigens.
Match the following blood types with the antibodies found in the plasma. Blood Type: a) Blood type A b) Blood type B c) Blood type AB d) Blood type O Antibodies: Anti-A and anti-B antibodies Anti-B antibody No antibodies Anti-A antibody
a) Anti-B antibody b) Anti-A antibody c) No antibodies d) Anti-A and anti-B antibodies Your blood plasma contains antibodies against whichever antigens (A or B) are not present on the surface of your red blood cells. Type A has anti-B antibodies, type B has anti-A antibodies, type Ab has neither of these antibodies, and type O has both of these antibodies.
Match each of the following results with the correct parameter from the complete blood count (CBC). Results: a) a patient has red blood cells that are abnormally large b) a patient is fighting an infection c) a patient is unable to clot her blood d) a patient does not have enough hemoglobin within her red blood cells e) a patient is not producing enough hemoglobin f) the size of a patient's red blood cells is not uniform CBC Parameters: hemoglobin (HGB) white blood cell count (WBC) mean corpuscular volume (MCV) red cell distribution width (RDW) mean corpuscular hemoglobin concentration (MCHC) platelet count (PLT)
a) MCV b) WBC c) PLT d) MCHC e) HGB f) RDW MCV measures the average size of RBCs; white blood cells fight infection, platelets participate in clotting; Mean Corpuscular Hemoglobin Concentration measures the concentration of hemoglobin per red blood cell; HGB measures the concentration of hemoglobin in the blood; RDW is a measure of the range of RBCs sizes.
Decide whether each of the following promotes clot formation or dissolution. a) endothelin b) ADP c) thrombin d) tPA e) fibrinogen f) Ca2+
a) formation b) formation c) formation d) dissolution e) formation f) formation Tissue plasminogen activator (tPA) is involved with the fibrinolytic pathway, that leads to clot dissolution. All the remaining listed factors are involved with the stages of hemostasis that lead clot formation.
Match the following terms with the fraction of blood in which they are located. Terms: a) erythrocytes b) globulins c) leukocytes d) ions e) albumins f) thrombocytes g) hormones Blood locations: formed elements plasma
a) formed elements b) plasma c) formed elements d) plasma e) plasma f) formed elements g) plasma
Classify the following leukocytes based upon their histology. Leukocytes: a) neutrophils b) basophils c) eosinophils Histology: nuclei have two lobes, stain dark blue nuclei have two lobes, stain red many-lobed nuclei, stain light purple
a) many-lobed nuclei, stain light purple b) nuclei have two lobes, stain dark blue c) nuclei have two lobes, stain red Neutrophil, eosinophils, and basophils are all granulocytes. Neutrophils can have 2-6 lobed nuclei and have small granules that stain a light purple. Eosinophils have bi-lobed nuclei and granules that stain red. Basophil nuclei are also bi-lobed, but are often obscured by large dark staining granules.
Classify the following leukocytes based upon their histology. Leukocytes: a) lymphocytes b) monocytes Histology: large U-shaped nuclei, stain blue and purple nuclei take up majority of cell volume, stain blue and purple
a) nuclei take up majority of cell volume, stain blue and purple b) large U-shaped nuclei, stain blue and purple Lymphocytes and monocytes are both agranulocytes. Lymphocytes have large nuclei that occupy most of the cell volume. Monocytes have smaller nuclei (relative to lymphocytes) that are U-shaped.
Match the following plasma proteins with one of their functions. Plasma protein: a) albumins b) globulins c) fibrinogens d) hormones Functions: 1) prevent fluid loss during injury 2) defend the body against foreign pathogens 3) serve as ligands for receptors throughout the body 4) prevent swelling and shrinkage of cells
a) prevent swelling and shrinkage of cells b) defend the body against foreign pathogens c) prevent fluid loss during injury d) serve as ligands for receptors Amongst the many functions of albumin is regulation of osmolarity; unregulated blood osmolarity would lead to uncontrolled osmosis into or out of blood cells. Immunoglobulins form the structural basis of antibodies and are essential to immune responses. Fibrinogens are important clotting factors. Hormones are signaling molecules that use the blood as a transport medium.
Decide whether each of the following promotes clot formation, inhibits clot formation, or promotes clot dissolution. a) plasmin b) tissue factor c) nitric oxide d) heparin e) protein C
a) promotes clot dissolution b) promotes clot formation c) inhibits clot formation d) inhibits clot formation e) inhibits clot formation Tissue factor promotes clot formation via the extrinsic pathway. Nitric oxide, heparin, and protein C are anticoagulants that inhibit clot formation. Plasmin promotes dissolution of the clot as part of the fibrinolytic pathway.
Classify the following leukocytes based upon their function. Leukocytes: a) neutrophils b) monocytes c) basophils d) eosinophils e) lymphocytes Functions: effective at fighting pathogens other than bacteria, regulate inflammation phagocytic cells, common outside of the bloodstream secrete hydrolytic enzymes, effective against bacteria responsible for attacking invading cells and antibody production do not attack foreign cells, regulate inflammation
a) secrete hydrolytic enzymes, effective against bacteria b) phagocytic cells, common outside of the bloodstream c) do not attack foreign cells, regulate inflammation d) effective at fighting pathogens other than bacteria, regulate inflammation e) responsible for attacking invading cells and antibody production
Which of the following are features of blood? Select all that apply. a. delivers oxygen and nutrients to tissues to promote cellular respiration b. removes carbon dioxide and metabolic wastes from tissues c. easily changes pH and temperature to maintain homeostasis d. prevents fluid loss through clotting
a, b, c, AND d The blood does more than just transport respiratory gases, nutrients, and metabolic wastes. All of these are functions of the blood.
Blood is a component of which fluid compartment? a. extracellular fluid b. intracellular fluid c. interstitial fluid d. transcellular fluid
a. extracellular fluid Blood is an extracellular fluid. Intracellular fluid is inside cells, interstitial fluid surrounds cells inside tissues, and transcellular fluid is secreted by epithelial cells into the body's spaces and cavities.
In comparison to women, men have a ______ blood volume and _________ hematocrit. a. higher; higher b. higher; equal c. higher; lower d. lower; higher e. lower; equal f. lower; lower
a. higher; higher Blood volume is proportional to body size, so average values are higher in men than in women. Men also tend have a larger concentration of red blood cells, so their hematocrit is higher.
A 33-year old man was brought to the emergency room by his distraught wife. The physical examination revealed that the patient was pale and going in and out of consciousness, with dangerously low blood pressure. In speaking with his spouse, she related that he had come home from work, appearing to be fine, playing with their son, eating dinner, watching TV, and then getting ready for bed. It was then that he complained about not feeling well and collapsed. Lab work revealed an elevated level of reticulocytes (immature erythrocytes) with normal levels of lymphocytes. What do you think is wrong with this patient? a. internal bleeding b. severe anemia c. blood cancer d. blood sepsis (bacterial infection)
a. internal bleeding Reticulocytes are nearly mature erythrocytes released into circulation, which then mature into erythrocytes. An elevated level of reticulocytes is an indicator of increased erythropoiesis, occurring in response to blood loss.
When analyzing the CBC of someone with iron deficiency anemia, you would expect _______. a. mean corpuscular volume (MCV) to be low and mean corpuscular hemoglobin concentration (MCHC) to be low b. mean corpuscular volume (MCV) to be low and mean corpuscular hemoglobin concentration (MCHC) to be high c. mean corpuscular volume (MCV) to be high and mean corpuscular hemoglobin concentration (MCHC) to be low d. mean corpuscular volume (MCV) to be high and mean corpuscular hemoglobin concentration (MCHC) to be high
a. mean corpuscular volume (MCV) to be low and mean corpuscular hemoglobin concentration (MCHC) to be low Insufficient iron availability decreases synthesis of hemoglobin, so MCHC decreases. Less hemoglobin packed inside erythrocytes cause them to decrease in size, so MCV decreases.
Two males volunteer to donate 50mL of blood, one is 6'2" and weighs 250lbs, the other is 5'5" and weighs 140 lbs. Assuming both are healthy, the hematocrit of the larger individual should be _________. a. higher b. lower c. the same
c. the same The larger male volunteer will have larger volume of blood overall. However, their hematocrits should be similar since this it is the percentage of blood volume occupied by erythrocytes, which account for 95% of the entire formed element fraction and more than 40% of the volume of whole blood.
When analyzing the CBC of someone with leukemia, you would expect which of the following to be true? a. white blood cell count (WBC) to be low and hematocrit (HCT) to be low b. white blood cell count (WBC) to be low and hematocrit (HCT) to be high c. white blood cell count (WBC) to be high and hematocrit (HCT) to be low d. white blood cell count (WBC) to be high and hematocrit (HCT) to be high
c. white blood cell count (WBC) to be high and hematocrit (HCT) to be low Leukemia is excessive production of white blood cells, so WBC will go up. Since the same population of hematopoietic stem cells is used during erythropoiesis, this may decrease production of red blood cell, so hematocrit will go down.
How many oxygen molecules can one hemoglobin carry? a. 2 b. 1 c. 3 d. 4 e. 16
d. 4 Hemoglobin is a protein with aquaternary structure. It is composed of four subunits called globins. Each of the four globin subunits has a central heme group that binds to an oxygen molecule. Therefore, one hemoglobin molecule binds four oxygen molecules.
Biliverdin reductase is the enzyme responsible for biliverdin conversion. Individuals with biliverdin reductase deficiency might have decreased _______. a. biliverdin b. stercobilin c. heme d. bilirubin
d. bilirubin Biliverdin is a product of bile metabolism, so biliverdin reductase metabolizes biliverdin into bilirubin and stercobilin.
The Bohr effect __________. a. refers to the change in hemoglobin shape after binding oxygen b. is a decrease in hemoglobin affinity for oxygen caused by a basic pH c. is an increase in hemoglobin affinity for oxygen d. is a decrease in hemoglobin affinity for oxygen
d. is a decrease in hemoglobin affinity for oxygen Carbon dioxide does not bind competitively with oxygen because it does not bind to iron. However, the binding of carbon dioxide molecules (or protons that are formed from the dissociation of carbonic acid) to hemoglobin does promote oxygen release.
An 8-year-old boy with sickle cell syndrome is referred to the emergency room because of frequent blood infections, strep throat, and multiple viral illnesses over the past few months. A physical examination reveals a normal-looking young boy who is slightly underweight and has normal blood pressure. The physician orders an MRI examination of the thorax and peritoneal regions along with a blood workup. What do you expect to see in the MRI or the blood workup? a. damage to his liver b. increased blood levels of complement c. increased blood clotting factors d. no spleen
d. no spleen The spleen acts as a physical filter, removing damaged erythrocytes from the blood. In a patient with sickle cell syndrome, the excess levels of altered and damaged erythrocytes leads to a physical blockage of capillaries and arterioles in the spleen, leading to reduced oxygen and nutrients to splenic cells. This ultimately leads to a progressive loss of spleen tissue, until the spleen completely dies and is absorbed. The MRI would reveal the complete lack of the spleen - or asplenia. The spleen is a primary lymphatic organ and its loss would decrease the ability of the immune system to repel infections by bacteria and viruses.