1. The buffy coat of centrifuged blood consists mainly of
a. the ejected nuclei of red blood cells
b. gamma globulins
c. ruptured red blood cells whose hemoglobin has sunk to the bottom
d. white blood cells and platelets
e. serum
d. white blood cells and platelets
The formed elements that are fragments of larger cells called megakaryocytes are
a. neutrophils
b. lymphocytes
c. erythrocytes
d. thrombocytes
e. plasma proteins
d. thrombocytes
Type AB blood contains
a. only antibody a
b. only antibody b
c. neither antibody A nor B
d. both antibody A and B
c. neither antibody A nor B
1.Blood flows from the superior vena cava into the
a. right atrium
b. inferior vena cava
c. left atrium
d. aorta
e. pulmonary trunk
a. right atrium
During the normal cardiac cycle, the atria contract when they are directly stimulated by the
a. SA node
b. AV node
c. conduction myofibers
d. baroreceptors
e. vagus nerve
a. SA node
The first heart sound (the lubb of lubb-dupp) is caused by the
a. closure of the semilunar valves
b. contraction of the two atria
c. contraction of the right ventricle
d. closure of the mitral and tricuspid valves
e. all answers are correct
d. closure of the mitral and tricuspid valves
The tunica interna of a blood vessel is made of
a. smooth muscle
b. cardiac muscle
c. skeletal muscle
d. endothelium
e. dense connective tissue
d. endothelium
Blood flow increases if
a. vasodilation increases
b. sympathetic stimulation to vessels with alpha adrenergic receptors increases
c. blood viscosity increases
d. net filtration pressure increases
e. parasympathetic stimulation to the heart increases
a. vasodilation increases
Hormones that cause vasoconstriction are
a. angiotensin II
b. angiotensin
c. epinephrine
d. vasopressin
e. all answers are correct
e. all answers are correct
Anterior to the elbows, the median cubital veins connect
a. axillary and brachial veins
b. cephalic and brachial veins
c. radial and ulnar veins
d. cephalic and basilica veins
e. basilica and brachial veins
d. cephalic and basilica veins