The hormonal stimulus that prompts red blood cell formation is
All of the following are true of RBCs except
A)biconcave disc shape
B)life span of approximately 120 days
Blood proteins play an important part in
C)maintenance of blood volume
D)all of the above
The white blood cell that releases histamine and other inflammatory chemicals is the
The blood cell that can become an antibody-secreting cell is the
Which of the following does NOT promote multiple steps in the clotting pathway?
Suppose your blood was found to be AB positive. This means that
A)agglutinogens A and B are present on your red blood cells, there are no anti-A or anti-B antibodies in your plasma, and your blood is Rh+
B)there are no anti-A or anti-B antibodies in your plasma
C)all of the above
(a) Define formed elements and list their three major categories.
(b) Which is least numerous?
(c) Which compromise(s) the buffy coat in a hematocrit tube?
Discuss hemoglobin relative to its chemical structure, its function, and the color changes it undergoes during loading and unloading of oxygen.
Hemoglobin is made up of the protein globin bound to the pigment heme. Each molecule contains four polypeptide chains (globins) and four heme groups, each bearing an atom of iron in its center. Its function is to bind oxygen to each iron atom. When oxygen is loaded (bound to hemoglobin), the hemoglobin becomes bright red. When oxygen is unloaded from the iron, the hemoglobin becomes dark red. (p. 635)
If you had high hematocrit, would you expect your hemoglobin determination to be high or low? Why?
What nutrients are needed for erythropoiesis?
(a) Describe the process of erythropoiesis.
(b) What name is given to the immature cell type released to the circulation?
(c) How does it differ from a mature erythrocyte.
a. In the process of erythropoiesis, a hemocytoblast is transformed into a proerythroblast, which gives rise to basophilic, then polychromatic erythroblasts, orthochromatic erythroblasts, and reticulocytes.
b. The immature cell type released to the circulation is the reticulocyte.
c. The reticulocyte differs from a mature erythrocyte in that it still contains some rough ER. (p. 636)
Besides the blood's ability to move by amoeboid motion, what other physiological attributes contribute to the function of White blood cells in the body?
(a) If you had a severe infection . would you expect your WBC count to be close to 5000, 10,000, or 15,000/ul
(b) What is this condition called?
(a) Describe the appearance of platelets and state their major function.
(b) Why should platelets not be called cells?
a. Platelets appear as small discoid fragments of large, multinucleated cells called megakaryocytes. They are essential for the clotting process and work by clumping together to form a temporary plug to prevent blood loss.
b. Platelets should not be called “cells” because they are only fragments of cells. (p. 645)
(a) Define homostasis.
(b) List the 3 major steps of coagulation. Explain what each phase and what the phase accomplishes.
(c) In what general way do the intrinsic and extrinsic mechanisms of clotting differ?
(d) Which ion is essential to virtually all stages of coagulation.
a. Literally, hemostasis is “blood standing still” because it refers to clotted blood. It encompasses the steps that prevent blood loss from blood vessels. (p. 646)
b. The three major steps of coagulation include the formation of prothrombin activator by a cascade of activated procoagulants, the use of prothrombin activator enzymatically to release the active enzyme thrombin from prothrombin, and the use of thrombin to cause fibrinogen to form fibrin strands. (pp. 647–648)
c. The intrinsic pathway depends on substances present in (intrinsic to) blood. It has many more steps and intermediates, and is slower. The extrinsic mechanism bypasses the early steps of the intrinsic mechanism and is triggered by tissue factor (thromboplastin) released by injured cells in the vessel wall or in surrounding tissues. (pp. 647–648)
d. Calcium is essential to virtually all stages of coagulation. (p. 647)
(a) Define fibrinolysis.
(b) What is the importance of this process?
(a) How is clot overgrowth usually prevented?
(b) List two conditions that may lead to unnecessary (and undesirable) clot information.
How can liver dysfunction cause bleeding disorders?
(a) What is a transfusion reaction and why does it matter?
(b) What are its possible consequences?
a. A transfusion reaction involves agglutination of foreign RBCs, leading to clogging of small blood vessels, and lysis of the donated RBCs. It occurs when mismatched blood is transfused.
b. Possible consequences include disruption of oxygen-carrying capacity, fever, chills, nausea, vomiting, general toxicity, and renal failure. (pp. 663–664)
How can poor nutrition lead to anemia
What blood-related problems are most common in the aged?
Cancer patients being treated with chemotherapy drugs designed to destroy rapidly dividing cells are monitored closely for changes in their RBC and WBC counts.
Mary Healy, a young woman with severe vaginal bleeding is admitted to the emergency room. She is three months pregnant, and the physician is concerned about the volume of blood she is losing.
(a) What type of transfusion will be probably be given to this patient?
(b) What blood tests will be performed before starting the transfusion?
a. Mary would probably be given a whole blood transfusion. It is essential that she maintain sufficient O2-carrying capacity to serve fetal needs and blood volume to maintain circulation.
b. The blood tests that would be performed include tests for ABO and Rh group antigen and cross matching. (pp. 652–653)
Alan Forsythe, a middle-aged college professor from Boston, is in the Swiss Alps studying astronomy during his sabbatical leave. He has been there for two days and plans to stay the entire year. However, he notices that he is short of breath when he walks up steps and tires easily with any physical activity. His symptoms gradually disappear, and after two months he feels fine. Upon returning to the US, he has a complete physical exam and is told his erythrocyte count is higher than normal.
(a) Attempt to explain this finding.
(b) Will his RBC’s remain at this high level? Why or why not?
a. Polycythemia accounts for his higher erythrocyte count because of the need to produce more RBCs to increase his O2 binding and transport ability in the high-altitude (thinner air) environment of the Alps. Enhanced production of RBCs was prompted by an increased production of erythropoietin, in response to chronic hypoxia.
b. His RBC count will, with time, return to normal. This is because the conditions at lower altitudes make it easier for oxygen to enter the blood, resulting in elevated plasma O2. Elevated plasma O2, coupled with the high number of RBCs, inhibits erythropoietin production by the kidneys. (p. 640)
A young child is diagnosed as having acute lymphocytic leukemia. Her parents cannot understand why infection is a major problem for Janie when her WBC count is so high.
Can you provide an explanation for Janie’s parents?
Mrs. Ryan, a middle-aged woman, appears at the clinic complaining of multiple small hemorrhagic spots in her skin and severe nosebleeds. While taking her history, the nurse notes that Mrs. Ryan works as a rubber glue applicator at a local factory. Rubber glue contains benzene, which is known to be toxic to red bone marrow.
Using your knowledge of physiology, explain the connection between the bleeding problems and benzene.
A reticulocyte count indicated that 5% of Tyler’s red blood cells were reticulocytes. His blood test also indicated he had polycythemia and a hematocrit of 65%.
Explain the connection between these three facts.
In 1998, the US Food and Drug Administration approved the nation’s first commercial surgical glue to control bleeding during certain surgeries. This glue called Tisseel forms a flexible mesh over an oozing blood vessel to help stem bleeding within five minutes. This sealant is made from two blood proteins that naturally cause blood to clot when they react together.
Name these two proteins.
Jenny, a healthy young woman, had a battery of tests during a physical for a new job. Her RBC count was at the higher end of normal range, but four weeks later it was substantially elevated beyond that. When asked if the circumstances had changed in her life she admitted to taking up smoking.
How might her new habit explain her higher RBC count?
Mr Chu has been scheduled for surgery to have his arthritic hip replaced. His surgeon tells him he must switch from aspirin to acetaminophen for pain control before his surgery.