Medsci142 MCQs Exam Questions And Correct Answers
stimulation of the SA node by norepinephrine but no effect on the cardiac muscle fibers
of the ventricles.
stimulation of muscarinic receptors by acetylcholine on the SA node and cardiac muscle
fibers of the ventricles. - ANSWER stimulation of the SA node by norepinephrine and of
the beta receptors on the cardiac muscle fibers of the ventricles.
During your dissection of the sheep heart you used scissors to remove the apex of the
heart. Among the structures cut with the scissors at that time were the:
aortic valve cusps
papillary muscles
interatrial septum
left and right auricles
fossa ovalis - ANSWER papillary muscles
The corpus luteum produces:
mucus
progesterone
,testosterone
All of the options are correct
menstrual fluid - ANSWER progesterone
During the menstrual cycle, LH is at its highest levels:
just after ovulation.
just prior to ovulation.
during the menstrual phase.
levels of LH never change.
just before menstruation begins. - ANSWER just prior to ovulation.
The vasomotor region of the cardiovascular center directly controls:
total blood volume by regulating release of ADH from the posterior pituitary gland.
peripheral resistance by changing the diameter of blood vessels.
peripheral resistance by altering blood viscosity.
heart rate by stimulating the SA node.
stroke volume by controlling total blood volume. - ANSWER peripheral resistance by
altering the diameter of blood vessels.
The following pairs of terms contrast the left side of the sheep heart with the right side.
Of the choices given below which is the INCORRECT pair?
,left and right pulmonary veins - right anterior, left anterior and posterior vena cavae
ventricle crescent-shaped in cross section - ventricle circular in cross-section
thick-walled ventricle - thin-walled ventricle
aortic valve - pulmonary valve
mitral valve - tricuspid valve - ANSWER ventricle crescent-shaped in cross section -
ventricle circular in cross-section
In the sheep heart, blood which enters the coronary arteries has just passed through
the:
pulmonary valve
tricuspid valve
aortic valve
bicuspid valve
mitral valve - ANSWER aortic valve
Which type of blood vessel exerts the major control of systemic vascular resistance?
Capillaries
, Vena Cava
Aorta
Arterioles
Venules - ANSWER Arterioles
With respect to pre- and post-natal circulation, select the CORRECT statement.
Immediately after birth the ductus arteriosus closes to become the ligamentum
arteriosum due to the ingrowth of connective tissue into its lumen.
The foramen ovale of the fetal heart has a flap valve on the right side of the interatrial
septum.
Before birth, the foramen ovale allows blood to flow from the left atrium, at relatively
higher pressure, into the right atrium, at relatively lower pressure.
If the ductus arteriosus had not closed postnatally, blood would have been shunted from
the pulmonary trunk into the aorta.
After birth, the overall effect on the pulmonary system if the foramen ovale were to
remain patent would be the same as if the ductus arteriosus were also to remain patent.
ANSWER After birth, the overall effect on the pulmonary system if the foramen ovale
were to remain patent would be the same as if the ductus arteriosus were also to remain
patent.
stimulation of the SA node by norepinephrine but no effect on the cardiac muscle fibers
of the ventricles.
stimulation of muscarinic receptors by acetylcholine on the SA node and cardiac muscle
fibers of the ventricles. - ANSWER stimulation of the SA node by norepinephrine and of
the beta receptors on the cardiac muscle fibers of the ventricles.
During your dissection of the sheep heart you used scissors to remove the apex of the
heart. Among the structures cut with the scissors at that time were the:
aortic valve cusps
papillary muscles
interatrial septum
left and right auricles
fossa ovalis - ANSWER papillary muscles
The corpus luteum produces:
mucus
progesterone
,testosterone
All of the options are correct
menstrual fluid - ANSWER progesterone
During the menstrual cycle, LH is at its highest levels:
just after ovulation.
just prior to ovulation.
during the menstrual phase.
levels of LH never change.
just before menstruation begins. - ANSWER just prior to ovulation.
The vasomotor region of the cardiovascular center directly controls:
total blood volume by regulating release of ADH from the posterior pituitary gland.
peripheral resistance by changing the diameter of blood vessels.
peripheral resistance by altering blood viscosity.
heart rate by stimulating the SA node.
stroke volume by controlling total blood volume. - ANSWER peripheral resistance by
altering the diameter of blood vessels.
The following pairs of terms contrast the left side of the sheep heart with the right side.
Of the choices given below which is the INCORRECT pair?
,left and right pulmonary veins - right anterior, left anterior and posterior vena cavae
ventricle crescent-shaped in cross section - ventricle circular in cross-section
thick-walled ventricle - thin-walled ventricle
aortic valve - pulmonary valve
mitral valve - tricuspid valve - ANSWER ventricle crescent-shaped in cross section -
ventricle circular in cross-section
In the sheep heart, blood which enters the coronary arteries has just passed through
the:
pulmonary valve
tricuspid valve
aortic valve
bicuspid valve
mitral valve - ANSWER aortic valve
Which type of blood vessel exerts the major control of systemic vascular resistance?
Capillaries
, Vena Cava
Aorta
Arterioles
Venules - ANSWER Arterioles
With respect to pre- and post-natal circulation, select the CORRECT statement.
Immediately after birth the ductus arteriosus closes to become the ligamentum
arteriosum due to the ingrowth of connective tissue into its lumen.
The foramen ovale of the fetal heart has a flap valve on the right side of the interatrial
septum.
Before birth, the foramen ovale allows blood to flow from the left atrium, at relatively
higher pressure, into the right atrium, at relatively lower pressure.
If the ductus arteriosus had not closed postnatally, blood would have been shunted from
the pulmonary trunk into the aorta.
After birth, the overall effect on the pulmonary system if the foramen ovale were to
remain patent would be the same as if the ductus arteriosus were also to remain patent.
ANSWER After birth, the overall effect on the pulmonary system if the foramen ovale
were to remain patent would be the same as if the ductus arteriosus were also to remain
patent.
