Maintenance of the Body
Blood cells develop from blood islands derived from mesoderm.
Fetal blood contains hemoglobin F. A±er birth, hemoglobin A is
Te major blood-related problems associated with aging are
leukemia, anemia, and thromboembolic disease.
Developmental Aspects of Blood
Fetal hematopoietic sites include the yolk sac, liver, and spleen. By
the seventh month of development, the red bone marrow is the
primary blood-forming site.
(Some questions have more than one correct answer. Select the best
answer or answers from the choices given.)
Te blood volume in an adult averages approximately
Te hormonal stimulus that prompts red blood cell formation is
All of the following are true of RBCs except
life span of approximately 120 days,
Te most numerous WBC is the
Blood proteins play an important part in
maintenance of blood volume,
all of the above.
Te white blood cell that releases histamine and other
inﬂammatory chemicals is the
Te blood cell that can become an antibody-secreting cell is the
Which of the following does not promote multiple steps in the
Te normal pH of the blood is about
Suppose your blood is AB positive. Tis means that
agglutinogens A and B are present on your red blood cells,
there are no anti-A or anti-B antibodies in your plasma,
your blood is Rh
all of the above.
Short Answer Essay Questions
(a) Deﬁne formed elements and list their three major categories.
(b) Which is least numerous? (c) Which comprise(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.
If you had a high hematocrit, would you expect your hemoglobin
determination to be low or high? 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?
Besides the 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 closest to 5000, 10,000, or 15,000/μl? (b) What is this
(a) Describe the appearance of platelets and state their major
function. (b) Why should platelets not be called “cells”?
(a) Deﬁne hemostasis. (b) List the three major phases of
coagulation. Explain what initiates 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) 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
How can liver dysfunction cause bleeding disorders?
(a) What is a transfusion reaction and why does it happen?
(b) What are its possible consequences?
How can poor nutrition lead to anemia?
What blood-related problems are most common in the aged?
and Clinical Application
Cancer patients being treated with chemotherapeutic drugs
designed to destroy rapidly dividing cells are monitored closely
for changes in their red and white blood counts. Why so?
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 probably be given to this
patient? (b) Which blood tests will be performed before starting
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 a±er two months he feels ﬁne. Upon
returning to the United States, he has a complete physical exam
and is told that his erythrocyte count is higher than normal. (a)
Attempt to explain this ﬁnding. (b) Will his RBC count remain at
this higher-than-normal level? Why or why not?
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 marrow. Using your knowledge of physiology, explain the
connection between the bleeding problems and benzene.
A reticulocyte count indicated that 5% of ²yler’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.