BIO 360 - Exam 3 - Chapter 14 Summary Questions

Question 1

The human ______ ______ consists of a ______ that pumps ______ through a closed system of blood vessels.

Answer 1

cardiovascular system / heart / blood

Question 2

The primary function of the cardiovascular system is?

Answer 2

the transport of nutrients, water, gases, wastes, and chemical signals to and from all parts of the body.

Question 3

Blood vessels that carry blood away from the heart are called ______. Blood vessels that return blood to the heart are called ______. ______ in the heart and veins ensure unidirectional blood flow.

Answer 3

arteries / veins / Valves

Question 4

The heart has four chambers: two ______ and two ______.

Answer 4

atria / ventricles

Question 5

The ______ ______ goes from the right side of the heart to the lungs and back to the heart.
The ______ ______ goes from the left side of the heart to the tissues and back to the heart.

Answer 5

pulmonary circulation / systemic circulation

Question 6

Blood flows down a ______ ______, from the highest pressure in the ______ and arteries to the lowest pressure in the ______ ______ and ______ ______.

Answer 6

pressure gradient (delta P) / aorta / venae cavae / pulmonary veins.

Question 7

In a system in which fluid is flowing, pressure ______ over distance.

Answer 7

decreases

Question 8

The pressure created when the ventricles contract is called the ______ ______ for blood flow.

Answer 8

driving pressure

Question 9

______ of a fluid flowing through a tube increases as the length of the tube and the ______ (thickness) of the fluid increase, and as the radius of the tube decreases. Of these three factors, ______ has the greatest effect on resistance.

Answer 9

Resistance / viscosity / radius

Question 10

If resistance increases, flow rate ______.
If resistance decreases, flow rate ______.

Answer 10

decreases / increases

Question 11

Fluid flow through a tube is proportional to the ______ ______.
A pressure gradient is not the same thing as the absolute pressure in the system.

Answer 11

pressure gradient

Question 12

F______ r______ is the volume of blood that passes one point in the system per unit time.

Answer 12

Flow rate

Question 13

______ is the distance a volume of blood travels in a given period of time. At a constant flow rate, the velocity of flow through a small tube is faster than the velocity through a larger tube.

Answer 13

Velocity

Question 14

The heart is composed mostly of ______ or ______. Most cardiac muscle is typical ______ muscle.

Answer 14

cardiac / myocardium / striated

Question 15

The signal for contraction originates in ______ ______ in the heart. ______ ______ are ______ ______.

Answer 15

autorhythmic cells / Autorhythmic cells / noncontractile myocardium

Question 16

______ ______ that supplies blood to the heart muscle originates at the beginning of the aorta and drains directly back into the chambers of the heart.

Answer 16

Coronary circulation

Question 17

Myocardial cells are linked to one another by ______ ______ that contain gap junctions. The junctions allow depolarization to spread rapidly from cell to cell.

Answer 17

intercalated disks

Question 18

In contractile cell excitation-contraction coupling, an action potential opens ______ channels. ______ entry into the cell triggers the release of additional ______ from the sarcoplasmic reticulum through ______-______ ______ ______ .

Answer 18

Ca2+ / calcium-induced calcium release

Question 19

The force of cardiac muscle contraction can be graded according to how much ______ enters the cell.

Answer 19

Ca2+

Question 20

The action potentials of myocardial contractile cells have a rapid depolarization phase created by ______ influx, and a steep repolarization phase due to ______ efflux. The action potential also has a plateau phase created by ______ influx.

Answer 20

Na+ / K+ / Ca2+

Question 21

Autorhythmic myocardial cells have an unstable membrane potential called a ______ ______. This is due to ______ ______ that allow net influx of positive charge.

Answer 21

pacemaker potential / If channels

Question 22

The steep depolarization phase of the autorhythmic cell action potential is caused by ______ influx.

The repolarization phase is due to ______ efflux.

Answer 22

Ca2+ / K+

Question 23

Action potentials originate at the ______ ______ and spread rapidly from cell to cell in the heart. Action potentials are followed by a wave of contraction.

Answer 23

sinoatrial node (SA node)

Question 24

The electrical signal moves from the SA node through the ______ ______ to the ______ ______, then into the ______ ______, ______ ______, terminal ______ ______, and myocardial contractile cells.

Answer 24

internodal pathway / atrioventricular node (AV node) / AV bundle / bundle branches / Purkinje fibers

Question 25

What sets the pace of the heartbeat? What happens if it malfunctions?

Answer 25

The SA node sets the pace of the heartbeat. If the SA node malfunctions, other autorhythmic cells in the AV node or ventricles take control of heart rate.

Question 26

An ______ (___) is a surface recording of the electrical activity of the heart. The ______ ______ represents ______ ______. The ______ ______ represents ______ ______. The ______ ______ represents ______ ______. ______ ______ is incorporated in the QRS complex.

Answer 26

electrocardiogram (ECG) P wave / atrial depolarization QRS complex / ventricular depolarization T wave / ventricular repolarization Atrial repolarization

Question 27

An ECG provides information on what four things?

Answer 27

heart rate and rhythm, conduction velocity, and the condition of cardiac tissues.

Question 28

One cardiac cycle includes one cycle of contraction and relaxation. ______ is the contraction phase; ______ is the relaxation phase.

Answer 28

Systole / diastole

Question 29

Most blood enters the ventricles while the atria are ______. Only 20% of ventricular filling at rest is due to atrial ______. The volume of blood at the end of ventricular filling is called the ______-______ ______.

Answer 29

relaxed /contraction / end-diastolic volume (EDV).

Question 30

The ______ ______ prevent ______ ______ of blood into the atria. Closure of the ______ ______ during ______ ______ set up vibrations that create the ______ ______ ______.

Answer 30

AV valves / back flow / AV valves / ventricular contraction / first heart sound

Question 31

During ______ ______ ______, the ventricular blood volume does not change, but pressure rises. When ventricular pressure exceeds arterial pressure, the ______ ______ open, and blood is ejected into the arteries.

Answer 31

isovolumic ventricular contraction / semilunar valves

Question 32

The volume of blood in the ventricles at the end of contraction is called the ______-______ ______. When the ventricles relax and ventricular pressure falls, the ______ ______ close, creating the ______ ______ ______.

Answer 32

end-systolic volume (ESV) / semilunar valves / second heart sound

Question 33

The amount of blood pumped by one ventricle during one contraction is known as the ______ ______. ______ ______, the percent of EDV ejected with one contraction (stroke volume/EDV), is one measure for evaluating ventricular function.

Answer 33

stroke volume / Ejection fraction

Question 34

______ ______ is the volume of blood pumped per ventricle per unit time. It is equal to heart rate times stroke volume. The average cardiac output at rest is 5 L/min.

Answer 34

Cardiac output

Question 35

Homeostatic changes in cardiac output are accomplished by?

Answer 35

varying heart rate, stroke volume, or both.

Question 36

______ activity slows heart rate. ______ activity speeds it up. ______ and ______ act on ______ ______to speed up the rate of the pacemaker depolarization. ______ activates muscarinic receptors to hyperpolarize the pacemakers.

Answer 36

Parasympathetic / Sympathetic / Norepinephrine / epinephrine / B1 receptors / Acetylcholine

Question 37

The longer a muscle fiber is when it begins to contract, the greater the force of contraction. The Frank-Starling law of the heart says...

Answer 37

that an increase in end-diastolic volume (EDV) results in a greater stroke volume.

Question 38

Epinephrine and norepinephrine increase the force of myocardial contraction when they bind to ______ receptors. They also shorten...

Answer 38

B1 / the duration of cardiac contraction.

Question 39

_______-______ ______ and ______ are determined by ______ ______. Venous return is affected by what three things?

Answer 39

End-diastolic volume / preload / venous return skeletal muscle contractions, the respiratory pump, and constriction of veins by sympathetic activity.

Question 40

______ of the heart is enhanced by catecholamines and certain drugs. Chemicals that alter contractility are said to have an ______ effect.

Answer 40

Contractility / inotropic

Question 41

What is afterload? What does it reflect? What is a clinical indicator of afterload?

Answer 41

Afterload is the load placed on the ventricle as it contracts. Afterload reflects the preload and the effort required to push the blood out into the arterial system. Mean arterial pressure is a clinical indicator of afterload.