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2. chapter
10 Blood and Hemopoiesis
148
I. OVERVIEW—BLOOD
A. Blood is a specialized connective tissue that consists of formed elements (erythrocytes,
leukocytes, and platelets) and a fluid component called plasma.
B. The volume of blood in an average human adult is approximately 5 L.
C. Blood circulates in a closed system of vessels and transports nutrients, waste products, hor-
mones, proteins, ions, oxygen (O2), carbon dioxide (CO2), and formed elements.
D. It also regulates body temperature and assists in regulation of osmotic and acid–base balance.
E. Blood cells have short life spans and are continuously replaced by a process called hemo-
poiesis.
II. BLOOD CONSTITUENTS
A. Plasma consists of 90% water; 9% organic compounds (such as proteins, amino acids, and
hormones); and 1% inorganic salts, dissolved gases, and nutrients.
1. Main plasma proteins
a. Albumin, a small protein (60,000 molecular weight), preserves osmotic pressure in the
vascular system and helps transport some metabolites.
b. -Globulins are antibodies (immunoglobulins) (see Chapter 12).
c. -Globulins and -globulins transport metal ions (e.g., iron and copper) and lipids (in
the form of lipoproteins).
d. Clotting proteins, including fibrinogen, a soluble protein that is converted into fibrin
during blood clotting.
e. Complement proteins (C1–C9) are part of the innate immune system, and they function
in nonspecific host defense and initiate the inflammatory process.
2. Serum is the yellowish fluid that remains after blood has clotted. It is similar to plasma
but lacks fibrinogen and clotting factors.
B. Formed elements of blood (Table 10.1 and Figure 10.1)
1. Erythrocytes (red blood cells [RBCs])
a. General features
(1) RBCs are round, anucleate, biconcave cells that stain light salmon pink with either
Wright or Giemsa stains (Figure 10.1).

3. 5. Which of the following is derived form
CFU-GM?
(A) Red blood cell
(B) Lymphocyte
(C) Platelet
(D) Neutrophil
(E) Basophil
6. Which of the following is associated with
demarcation channels?
(A) Red blood cell
(B) Lymphocyte
(C) Platelet
(D) Neutrophil
(E) Basophil
7. Which of the following is derived from
myeloblasts?
(A) Red blood cell
(B) Lymphocyte
(C) Platelet
(D) Monocyte
(E) Basophil
8. Which one of the following cells is associ-
ated with antibody production?
(A) Red blood cell
(B) Lymphocyte
(C) Monocyte
(D) Neutrophil
(E) Basophil
1. Which of the following proteins
associated with the erythrocyte plasma
membrane is responsible for maintaining
the cell’s biconcave disk shape?
(A) HbA1
(B) HbA2
(C) Porphyrin
(D) Spectrin
(E) -Actinin
2. Which of the following is an
immunocompetent cell?
(A) Red blood cell
(B) Lymphocyte
(C) Platelet
(D) Neutrophil
(E) Basophil
3. Which of the following is derived form
CFU-Meg?
(A) Red blood cell
(B) Lymphocyte
(C) Platelet
(D) Neutrophil
(E) Basophil
4. Which of the following is derived from
CFU-E?
(A) Red blood cell
(B) Lymphocyte
(C) Platelet
(D) Neutrophil
(E) Basophil
Review Test
Directions: Each of the numbered items or incomplete statements in this section is followed by
answers or completions of the statement. Select the ONE lettered answer that is BEST in each
case.
160

4. 9. Which of the following possesses specific
and azurophilic granules?
(A) Red blood cell
(B) Lymphocyte
(C) Platelet
(D) Neutrophil
(E) Monocyte
10. Which of the following is derived from
reticulocytes?
(A) Red blood cell
(B) Lymphocyte
(C) Platelet
(D) Neutrophil
(E) Basophil
11. A 4-year-old boy is taken by his parents
to the pediatrician because of vomiting,
headaches, and tenderness in the bones of
his arms and legs. On palpation, the physi-
cian notes that many lymph nodes are
enlarged, as is the liver. The pediatrician
should order a complete blood count in
order to determine whether or not the child
may have
(A) chronic leukemia.
(B) infectious mononucleosis.
(C) von Willebrand disease.
(D) acute leukemia.
(E) pernicious anemia.
Chapter 10 Blood and Hemopoiesis 161

5. Answers and Explanations
1. D. Spectrin is associated with the erythrocyte cell membrane and assists in maintaining
its biconcave disk shape (see Chapter 10 II B).
2. B. Lymphocytes are immunocompetent cells (see Chapter 10 VI G).
3. C. Platelets are derived from CFU-Meg (see Chapter 10 VI F).
4. A. Red blood cells are derived from CFU-E (see Chapter 10 VI C).
5. D. Neutrophils are derived from CFU-GM (see Chapter 10 VI D).
6. C. Platelets are derived from megakaryocytes, and those cells possess demarcation chan-
nels (see Chapter 10 VI F).
7. E. Basophils are derived from myeloblasts (see Chapter 10 VI D).
8. C. Lymphocytes and plasma cells manufacture antibodies (see Chapter 10 VI G).
9. D. Neutrophils possess both azurophilic and specific granules (see Chapter 10 II B 2).
10. A. Red blood cells are derived from reticulocytes (see Table 10.5).
11. D. Acute leukemia is a disease of children with symptoms that include headaches; vomiting;
swollen lymph nodes, liver, and spleen; and the sensation of tenderness in bones. Chronic
leukemia is a disease that usually affects adults. von Willebrand disease is a coagulation
disorder and does not have the same symptoms as acute leukemia. Infectious mononucle-
osis affects mostly young adults of high school and college age. Pernicious anemia is caused
by vitamin B deficiency, and its symptoms do not resemble those of acute leukemia (see
Chapter 10 II B 2 Clinical Considerations).
162

6. chapter
11 Circulatory System
163
I. OVERVIEW—BLOOD VASCULAR SYSTEM
The blood vascular system consists of the heart, arteries, veins, and capillaries. This system
transports oxygen and nutrients to tissues, carries carbon dioxide and waste products from the tis-
sues, and circulates hormones from the site of synthesis to their target cells.
A. The heart is a four-chambered pump composed of two atria and two ventricles and is sur-
rounded by a fibroserous sac called the pericardium.
Tetralogy of Fallot
Tetralogy of Fallot is a congenital malformation consisting of a defective
interventricular septum, hypertrophy of the right ventricle (due to a narrow pulmonary artery or
valve), and transposed (dextroposed) aorta. It should be repaired surgically early in life, before the
pulmonary constriction becomes exacerbated.
CLINICAL
CONSIDERATIONS
The heart receives sympathetic and parasympathetic nerve fibers, which modulate the rate of the
heartbeat but do not initiate it. It also produces atrial natriuretic peptide, a hormone that
increases secretion of sodium and water by the kidneys, inhibits renin release, and decreases
blood pressure.
1. Cardiac layers
a. Endocardium lines the lumen of the heart and is composed of simple squamous
epithelium (endothelium) and a thin layer of loose connective tissue. Subendocardium,
a connective tissue layer that contains veins, nerves, and Purkinje fibers, underlies it.
b. Myocardium consists of layers of cardiac muscle cells arranged in a spiral fashion
about the heart’s chambers and inserted into the fibrous skeleton. The myocardium
contracts to propel blood into arteries for distribution to the body. Specialized cardiac
muscle cells in the atria produce several peptides, including atrial natriuretic polypep-
tide, atriopeptin, cardiodilatin, and cardionatrin, hormones that maintain fluid and elec-
trolyte balance and decrease blood pressure.
c. Epicardium, the outermost layer of the heart, constitutes the visceral layer of the peri-
cardium. It is composed of simple squamous epithelium (mesothelium) on the exter-
nal surface. Beneath the mesothelium lies fibroelastic connective tissue, containing
nerves and the coronary vessels, and adipose tissue.
2. The fibrous skeleton of the heart consists of thick bundles of collagen fibers oriented in
various directions. It also contains occasional foci of fibrocartilage.
3. Heart valves
a. Atrioventricular (AV) valves are composed of a skeleton of fibrous connective tissue,
arranged like an aponeurosis, and lined on both sides by endothelium. They are
attached to the annuli fibrosi of the fibrous skeleton. The right AV valve is formed of

7. 5. Which of the following statements
concerning innervation of blood vessels is
true?
(A) Vasoconstriction is controlled by
parasympathetic nerve fibers.
(B) Acetylcholine acts directly on smooth
muscle cells.
(C) Acetylcholine acts directly on endothe-
lial cells.
(D) Vasodilation is controlled by
sympathetic nerve fibers.
(E) Nitric oxide acts as a vasoconstrictor.
6. Which of the following characteristics
distinguishes somatic capillaries from
visceral capillaries?
(A) Presence or absence of fenestrae
(B) Size of the lumen
(C) Thickness of the vessel wall
(D) Presence or absence of pericytes
(E) Thickness of the basal lamina
7. The blood–brain barrier is thought to
exist because capillaries in the central nerv-
ous system have which of the following
characteristics?
(A) Discontinuous basal lamina
(B) Fenestrae with diaphragms
(C) Fenestrae without diaphragms
(D) A few pinocytic vesicles
(E) No basement membrane
8. Which of the following statements about
healthy, intact capillaries is true?
(A) They control blood pressure.
(B) They are lined by a simple columnar
epithelium.
(C) They have a smooth muscle coat.
(D) They inhibit clot formation.
(E) Satellite cells share their basal lamina.
1. The epicardium is one of the three layers
of the heart. It is
(A) continuous with the endocardium.
(B) also known as the visceral pericardium.
(C) composed of modified cardiac muscle
cells.
(D) capable of increasing intraventricular
pressure.
(E) capable of decreasing the rate of
contraction.
2. The atrial muscle of the heart produces a
hormone that
(A) decreases blood pressure.
(B) increases blood pressure.
(C) causes vasoconstriction.
(D) facilitates the release of renin.
(E) facilitates sodium resorption in the
kidneys.
3. The generation of impulses in the normal
heart is the responsibility of which of the
following structures?
(A) Atrioventricular (AV) node
(B) AV bundle of His
(C) Sympathetic nerves
(D) Sinoatrial (SA) node
(E) Purkinje fibers
4. Metarterioles, vessels interposed between
arterioles and capillary beds,
(A) function to control blood flow into arte-
rioles.
(B) possess a complete layer of smooth
muscle cells in their tunica media.
(C) possess precapillary sphincters.
(D) receive blood from thoroughfare
channels.
(E) possess valves to regulate the direction
of blood flow.
Review Test
Directions: Each of the numbered items or incomplete statements in this section is followed by
answers or completions of the statement. Select the ONE lettered answer that is BEST in each
case.
174

8. 9. A patient complains of shortness of
breath even after only mild exercise. She
states that she has had this condition for 2
years but recently has noticed that it has
become more pronounced. Her medical his-
tory indicates that she had rheumatic fever
when she was a child. Auscultation indicates
an enlarged heart. What may the physician
expect to find with other diagnostic tests?
(A) Mitral valve stenosis
(B) Tetralogy of Fallot
(C) Pulmonary artery aneurysm
(D) Coronary heart disease
(E) Ischemic heart disease
10. Diagnostic tests for ischemic heart
disease usually reveal
(A) malformed heart valves.
(B) atherosclerosis of coronary arteries.
(C) irregular heartbeat.
(D) faulty SA valve.
(E) arteriosclerosis of coronary arteries.
11. Vasa vasorum function in a way that is
similar to
(A) AV valves.
(B) semilunar valves.
(C) coronary arteries.
(D) elastic arteries.
(E) metarterioles.
12. Which one of the following possesses a
distinct internal elastic lamina?
(A) Capillary
(B) Metarteriole
(C) Arteriole
(D) Muscular artery
(E) Vein
13. Ischemic heart disease is the usual
sequel to
(A) arteriosclerosis.
(B) abdominal aortic aneurysm.
(C) rheumatic fever.
(D) varicose veins.
(E) atherosclerosis.
Chapter 11 Circulatory System 175

9. Answers and Explanations
1. B. The pericardium is a fibroserous sac that encloses the heart. The innermost layer of the
pericardium, the epicardium, is also known as the visceral pericardium (see Chapter 11 I A 1).
2. A. Atrial natriuretic peptide, which decreases blood pressure, is produced mainly by car-
diac muscle cells of the right atrium. It inhibits the release of renin and causes the kidneys
to decrease the resorption of sodium and water (see Chapter 11 I A 1 b).
3. D. Impulses are generated in the sinoatrial node, which is the pacemaker of the heart.
They are then conducted to the atrioventricular (AV) node. The bundle of His and Purkinje
fibers conduct impulses from the AV node to the cardiac muscle cells of the ventricles.
Sympathetic nerves can increase the rate of the heartbeat but do not originate it (see
Chapter 11 I A 4 a).
4. C. The proximal portion of a central channel is known as a metarteriole, whereas its distal
portion is the thoroughfare channel. Blood from metarterioles may enter the capillary bed
if their precapillary sphincters are relaxed. If the precapillary sphincters of metarterioles
are constricted, blood bypasses the capillary bed and flows directly into thoroughfare
channels and from there into a venule (see Chapter 11 I B 1 d).
5. C. Acetylcholine stimulates the endothelial cells of a vessel to release nitric oxide
(endothelial-derived relaxing factor), which causes relaxation of smooth muscle cells.
Thus, acetylcholine does not act directly on smooth muscle cells (see Chapter 11 I B 2).
6. A. Somatic (continuous) capillaries lack fenestrae, whereas visceral (fenestrated) capillar-
ies are characterized by their presence. Both types of capillary possess a continuous basal
lamina and are surrounded by occasional pericytes (see Chapter 11 I C 2).
7. D. Capillaries in the central nervous system are of the continuous type and thus lack fen-
estrae but have a continuous basal lamina. In contrast to continuous capillaries in other
parts of the body, they contain only a few pinocytic vesicles; this characteristic is thought
to be partly responsible for the blood–brain barrier (see Chapter 11 I C 2).
8. D. The smooth endothelial lining of intact, healthy capillaries inhibits clot formation.
Capillaries do not control blood pressure (see Chapter 11 I C 2).
9. A. A person who has had rheumatic fever as a child may develop heart valve disease later in
life. Although the mitral valve is the one most commonly affected, the other valves may also
be involved. The mitral valve becomes inflamed, fibrotic, and eventually incompetent or
stenotic. This condition leads to respiratory hypertension and edema, which restricts respi-
ratory function. The key is a history of rheumatic fever, because those individuals are predis-
posed to developing heart valve diseases (see Chapter 11 I A 3 Clinical Considerations).
10. B. Diagnostic tests for ischemic heart disease reveal atherosclerosis of the coronary
vessels. Over time, excessive plaque composed of cholesterol and fats is layered beneath
the intima of these vessels, thus restricting blood flow to the myocardium of the heart,
leading to angina pectoris, an infarction, or perhaps sudden death (see Chapter 11 I B 1
Clinical Considerations).
11. C. Vasa vasorum are the small blood vessels that serve the walls of elastic and muscular
arteries with oxygen and nutrients just as the coronary arteries provide for the walls of the
heart (see Chapter 11 I B 1).
176

10. Chapter 11 Circulatory System 177
12. D. The muscular artery possesses a distinct internal elastic lamina. Elastic arteries possess
an incomplete internal elastic lamina, whereas capillaries, arterioles, metarterioles and
veins do not possess an internal elastic lamina (see Table 11.1 and Chapter 11 I D).
13. E. Ischemic heart disease is usually caused by coronary atherosclerosis, resulting in
decreased blood flow to the myocardium. It may develop into angina pectoris, myocardial
infarction, chronic ischemic cardiopathy, or sudden cardiac death. On the other hand,
arteriosclerosis (hardening of the arteries) usually attacks renal arteries and is related to
hypertension and diabetes mellitus (see Chapter 11 I B Clinical Considerations).
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