Chapter 19 &20 A&P BIO Mcgraw Hill

Cardiac output equals the

heart rate multiplied by stroke volume.

Which type of muscle cell exhibits a longer refractory period?

Cardiac muscle cell

Which segment of the ECG reflects the plateau phase of ventricular muscle cells' action potentials?

S-T segment

What part of the cardiac conduction system is located in the posterior wall of the right atrium, adjacent to the entrance of the superior vena cava?

SA node

In an ECG, the P wave is generated when the

atria depolarize.

Just prior to atrial contraction,

all four chambers are at rest and AV valves are open.

Most of the calcium that triggers contraction of cardiac muscle comes

from the sarcoplasmic reticulum of the cell.

Cardiac output is usually expressed in

liters per minute.

The main functions of the cardiovascular system include the transport and exchange of respiratory gases, nutrients, and wastes throughout the body.

True

Like skeletal muscle cells, cardiac muscle cells have an absolute refractory period prior to repolarization.

True

Cardiac muscle is able to use a variety of fuel types for cellular respiration.

True

What is the sequence of events in the transmission of an impulse through the heart muscle?

c, d, a, b, f, g, e

Large doses of certain stimulants can lead to dangerous increases in heart rates. Such a stimulant is a

positive chronotropic agent.

Immediately prior to atrial contraction, blood continues to enter the atria from the venae cavae and pulmonary veins.

True

Occlusion of blood vessels tends to lead to

inadequate blood supply and damage to body tissues.

The main functions of the cardiovascular system include the transport and exchange of respiratory gases, nutrients, and wastes throughout the body.

True

Which type of muscle cell exhibits a longer refractory period?

Cardiac muscle cell

Most of the calcium that triggers contraction of cardiac muscle comes

from the sarcoplasmic reticulum of the cell.

Parasympathetic innervation influences the heart rate, but generally tends to have no direct effect on the force of contractions.

True

Though the autonomic innervation by autonomic centers in the brainstem cannot initiate a heartbeat, it can increase or decrease the heart rate.

True

Immediately prior to atrial contraction, blood continues to enter the atria from the venae cavae and pulmonary veins.

True

During a cardiac cycle, how many of the four chambers contract at any one time?

2

Sympathetic innervation of the heart

a, c

Like skeletal muscle cells, cardiac muscle cells have an absolute refractory period prior to repolarization.

True

During ventricular contraction

the semilunar valves open and the AV valves close.

The membrane of a contractile cardiac muscle cell contains

fast voltage-gated sodium channels and slow voltage-gated calcium channels.

The shutting of the semilunar valves occurs during which phase?

Isovolumic relaxation

The opening and closing of the heart valves is caused by

pressure changes of alternating contraction and relaxation during the cardiac cycle.

Oxygen and carbon dioxide are transported between the blood and interstitial fluid by way of

diffusion from areas of higher concentration to lower concentration

Which statement accurately compares filtration and reabsorption

filtration involves bulk flow of fluid out of the blood, whereas reabsorption is nulk flow back into the blood

Some large molecules, such as fatty acids, are transported between capillaries and tissues by vesicular transport

True

If someone’s blood pressure were listed as 125/75 mmHg, then their pulse pressure would be

50 mmHg

Which statement is accurate?

Filtration dominates at the arterial end of a capillary bed, and is driven by hydrostatic pressure

blood colloid osmotic pressure is largely due to 

the proteins in the blood, and it promotes reabsorption

Atherosclerosis involves a

sustained increase in resistance that leads to increase in arterial pressure to maintain adequate blood flow

If someone were to have abnormally low levels of protein in their blood, then net filtration pressure would

be higher than normal

Blood flow is

directly related to the pressure gradient but inversely related to the resistance

Atrial natriuretic peptide stimulates

vasodilation, increased urine output, and therefore decreased blood pressure

Net filtration pressure NFP is equal to the

net hydrostatic pressure minus the net colloid osmotic pressure 

Blood hydrostatic pressure in systemic capillaries is greater than interstitial fluid hydrostatic pressure

True

Increases in angiotensin II levels cause decreases in blood pressure

False

If someone’s blood pressure were listed as 110/65 mmHg, then their mean arterial pressure MAP would be

80 mmHg

Aldosterone and atrial natriuretic peptide have _____ effects on blood pressure 

opposite

Imagine yourself sitting in an awkward position in an uncomfortable chair that is depriving part of your leg from normal blood flow.

buildup of carbon dioxide and hydrogen ions will cause vasodilation

A vasodilator causes a decrease in local blood flow at a capillary bed

False

considering the bulk flow that occurs at capillary beds, the lymphatic system is needed to

reabsorb excess fluid from the interstital fluid

Filtration and reabsorption are processes that involve water (a solvent) but not solutes

False

Renin converts

angiotensinogen to angiotensin I

Epinephrine, aldosterone, and antidiuretic hormone each cause an increase in blood pressure

True

Low blood pressure may cause the net hydrostatic pressure of a capillary to be less than normal. This will result in an ____ net filtration pressure

decreased