Heart

Front 1

What does a cardiac cycle include?

Back 1

Inclusive period of time from the start of one heartbeat to the initiation of the next.

Front 2

What is the contraction of a heart chamber called?

Back 2

systole

Front 3

During systole, the myocardium forces blood where?

Back 3

Either into another chamber (atrium to ventricle) or into a blood vessel (from a ventricle into the attached larger artery)

Front 4

The relaxation phase of a heart chamber is termed what?

Back 4

diastole, during this period the myocardium of each chamber relaxes between contraciton phases and the chamber fills with blood.

Front 5

During diastole, what happens within the chambers of the heart?

Back 5

the myocardium relaxes between contraction phases and the chamber fills with blood.

Front 6

AtAt the beginning of the cardiac cycle what contracts simultaneously?

Back 6

L and R atria

Front 7

when atrial systole occurs blood is forced into what chamber through what structure of the heart?

Back 7

Forced into the ventricles through the OPEN AV valves.

Front 8

When blood is forced into the ventricles through the AV valves when the atria contract, what is happening in the right atrium?

Back 8

Blood is still returning to the right atrium from the superior vena cava, the inferior vena cava, and the coronary sinus and the left atrium from the pulmonary veins.

Front 9

When atria contract and blood goes out into the ventricle, how is blood getting back into the atria?

Back 9

Right atria: s and i vena cava, coronary sinus
L atria: from pulmonary veins

Front 10

After atrial diastole, what occurs?

Back 10

contraction of the L and R ventricles occur simultaneously.

Front 11

How many chambers will contract at one time?

Back 11

only 2 of the 4 (either atria or ventricles)

Front 12

What do the AV valves do as the ventricles contract?

Back 12

close as blood is pushed against the cusps of the AV valves and their edges meet to form a seal.

Front 13

What prevents the valve leaflets from everting?

Back 13

papillary muscles and the chordae tendiinae

Front 14

When does blood enter the pulmonary trunk and aorta?

Back 14

After the ventricles contract and the AV valves close

Front 15

When the semilunar valves are forced open blood enters into what strucutures of the heart?

Back 15

semilunar valves

Front 16

In ventricular diastole, most of the blood flows from what structure to what?

Back 16

Flows from the relaxing atria into the ventricles through open AV valves.

Front 17

When are all four chambers of the heart in diastole together and how does this happen?

Back 17

when the ventricles are relaxing during the cardiac cycle, most of the blood flows passively from the relaxing atria into the ventricles through open AV vlaves.

Front 18

What is the cardiac cycle?

Back 18

consists of all of the events that occur within a single heart beat! HOLY POOP!

Front 19

What happens to the blood in the chambers as the heart chambers cyclically contract and relax?

Back 19

The pressure of the blood increases and decreases

Front 20

The cardiac valves ensure that blood flows how through the heart?

Back 20

unidirectionally

Front 21

under high or low pressure does blood flow from veins into both atria?

Back 21

low pressure

Front 22

How does blood flow from veins into both atria? sporadically?

Back 22

Continuously!

Front 23

Blood only passes from the atria into the ventricles if what structures are open?

Back 23

AV valves

Front 24

Is Most of the ventricular filling passive or does it occur when the atria contract?

Back 24

Passive (about 70%), occuring when both chambers are relaxing (in diastole) and the atrial pressure is greater than the ventricular pressure

Front 25

What happens when the atrial pressure is greater than the ventricular pressure?

Back 25

Most of the ventricular filling

Front 26

The final 30% of ventricular filling occurs when what happens?

Back 26

atrial systole

Front 27

When the ventricular pressure rises significantly, what happens?

Back 27

AV valves Close and the semilunar valves are forced open

Front 28

When is blood free to enter the large arterial trunks?

Back 28

When ventricular pressure rises and the AV valves close and the semilunar valves are forced open

Front 29

What is any abnormality in the rate, regularity, or sequence of the cardiac cycle called? (both names)

Back 29

cardiac arrhythmia (dysrhthmia)

Front 30

What is an atrial flutter? What does it lead to?

Back 30

occurs when the atria attempt to beat at a rate of 200 to 400 times per minute, conseq bombards teh AV node with muscle impulses leads to atrial fibrillation

Front 31

How does atrial fibrulation differ from atrial flutter?

Back 31

Muscle impulses are significantly more chaotic, leading to an irregular heart rate. (The atria doesn't beat)

Front 32

What are PVC's?

Back 32

Premature ventricular contractions: often result from stress, stimulants such as caffeine, or sleep deprivation. They occur

Front 33

What is the most serious arrhythmia?

Back 33

Vfib

Front 34

What happens in Vfib?

Back 34

Can't pump blood out of heart--flat lining occurs (difibrulators needed) stop heart, the hope is SA node picks up signal to reset SA node.

Front 35

What can Vfib lead to?

Back 35

Cardiac arrest

Front 36

What is Vfib?

Back 36

a rapid, repetitious movement of the ventricular muscle that replaces normal contraction.

Front 37

What is cardiac arrest?

Back 37

Because the contractions of a heart in fib are uncoordinated, the heart does no pump blood, and blood circulation stops. the cessation of cardiac activity.

Front 38

What is bradycardia?

Back 38

an atypically slow heartbeat of less than 50 bpm

Front 39

What is a beneficial adaption resulting from a muscular heart, heathy circulatory system, and excellent lung capacity?

Back 39

athlete's bradycardia.