ANPS20 EXAM hw

What best describes afterload?

Afterload refers to the back pressure exerted by arterial blood, or the pressure that must be overcome for the ventricles to eject blood. Tension the ventricle needs to produce to open the aortic valve and eject blood

EDV-ESV=?

SV

Norepinephrine acts on the heart by ________. causing more rapid depolarization of pacemaker cells blocking the action of calcium causing a decrease in stroke volume decreasing heart contractility

causing more rapid depolarization of pacemaker cells

The baroreceptors in the carotid sinus and aortic arch are sensitive to which of the following? changes in arterial pressure a decrease in carbon dioxide a decrease in oxygen levels an increase in oxygen levels

changes in arterial pressure

A patient with essential hypertension might have pressures of 200/120 mm Hg. This hypertensive state could result in all of the following changes except ________.

decreased size of the heart muscle

What pressure is responsible for reabsorption and for pulling fluids into the venous end of capillaries?

osmotic pressure in capillary (OPc) Osmotic pressure is based on the concentration of dissolved materials that attract water across a membrane. The osmotic pressure in a capillary (OPc) is the force drawing fluid into the blood at the venous end.

Which of the following would NOT move by diffusion across a capillary endothelium to or from the surrounding interstitial fluid and tissues? proteins lipid-soluble substances carbon dioxide oxygen

proteins Large substances like proteins cannot diffuse directly through endothelial cells, which form the capillary endothelium. These molecules typically leave the blood by active transport in pinocytic vesicles.

Which of the following blood pressure readings would be indicative of hypertension? 120/80 170/96 110/60 140/90

170/96

true or false As pressure in the aorta rises due to atherosclerosis, more ventricular pressure is required to open the aortic valve.

True

Why is it important that blood pressure drop to lower levels as it reaches the capillary beds?

because capillaries are fragile and extremely permeable Low capillary pressures are desirable because capillaries are fragile and high pressures would rupture them. Most capillaries are extremely permeable and thus even the low pressure forces solute-containing fluids out of the bloodstream into the interstitial space.

Which of the following would increase cardiac output? high blood pressure decreased calcium during contraction epinephrine parasympathetic stimulation

epinephrine Sympathetic stimulation leads to the release of epinephrine and norepinephrine, both of which increase heart rate and increase contractility, which increases stroke volume. Increasing heart rate and stroke volume increases cardiac output.

TRUE OR FALSE Increasing end-diastolic and end-systolic volume will increase stroke volume.

false Increasing end-diastolic volume will increase stroke volume. However, increasing end-systolic volume will decrease stroke volume.

A muscle that is being regularly contracted during exercise will attract blood flow by dilating arterioles. Which of these factors would contribute to the effect?

increased levels of carbon dioxide

The pulse pressure is ________.

the difference between systolic pressure and diastolic pressure