Cardiology Midterm

Which of the following contains blood with the lowest oxygen contact?

• a. aorta

  e. systemic arterioles

• b. left atrium

• c. right ventricle

• d. pulmonary veins

• e. systemic arterioles

If other factors are equal, which of the following vessels have the lowest resistance?

• length = l cm radius = 1 cm

• length = 4 cm radius = 1 cm

• length = 8 cm

  radius = 1 cm

• length = 1 cm

  radius = 2 cm

• length = 0.5 cm

  radius = 2 cm

Which of the following correctly ranks pressure during isovolumetric contraction of a normal cardiac cycle?

• left ventricular > aortic > left atrial

• aortic > left atrial > left ventricular

• left atrial > aortic > left ventricular

• aortic > left ventricular > left atrial

• left ventricular > left atrial > aortic

Considered as a whole, the body's capillaries have

• smaller cross-sectional area than the arteries

• less total blood flow than in the veins

• greater total resistance than the arterioles

• slower blood velocity than in the arteries

• greater total blood flow than in the arteries

Which of the following would not result in tissue edema?

• an increase in the concentration of plasma proteins

• an increase in the pore size of systemic capillaries

• an increase in venous pressure

• blockage of lymph vessels

• a decrease in the protein concentration of the plasma

Which statement comparing the systemic and pulmonary circuits is true?

• the blood flow is greater through the systemic

• the blood flow is greater through the pulmonary

• the absolute pressure is higher in the pulmonary

• the blood flow is the same in both

What is mainly responsible for the delay between the atrial and ventricular contractions?

• the shallow slope of AV node pacemaker potentials

• slow action potential conduction velocity of AV node cells

• slow action potential conduction velocity along atrial muscle cell membranes

• slow action potential conduction velocity in the Purkinje network of the ventricles

• greater sympathetic nerve firing to the ventricles to the atria

Which of the following pressures is closest to the mean arterial blood pressure in a person whose systolic blood pressure is 135mmHg and pulse pressure is 50mmHg?

• 110mmHg

• 78mmHg

• 102mmHg

• 152mmHg

• 85mmHg

Which of the following would help restore homeostasis in the first few moments after a person's mean arterial pressure became elevated?

• a decrease in baroreceptor action potential frequency

• a decrease in action potential frequency along parasympathetic neurons to the heart

• an increase in action potential frequency along sympathetic neurons to the heart

• an increase in action potential frequency along sympathetic neurons to the arterioles

• a increase in total peripheral resistance

which is false about L-type Ca2+ channels in cardiac ventricular muscle cells?

• they are open during the plateau of the action potential

• they allow Ca2+ entry that triggers sarcoplasmic reticulum Ca2+ release

• they are found in the T-tubule membrane

• they open in response to depolarization of the membrane

• they contribute to the pacemaker potential