Atrial Contractions

kab55 asked:


this may sound stupid but i just really want it to make sense in my head so pls help!

this is about S1, S2 compared to an ECG..

i understand that S1 is heard when the AV valves close caused by the contraction of the ventricles. S2 is heard when the semilunar valves close caused by the contraction of the atria.

i also understand that the P wave represents the atrial depolarization (which then equals to atrial contraction) and QRS to ventriclular depolarization (ventricle contraction).

thus, QRS basically is when you hear the S1 sound and P is when you hear the S2 sound.

now how come we hear it as “lub dub” (S1 and then S2) but when we look at the monitor, it looks like a “dub lub” (S2 or P wave first; then S1 or QRS)? why is P closer to QRS versus QRS closer to the next P so that it looks like a lub dub?

i understand that the first electrical impulse comes from the SA node and so the atria contracts first but why do we HEAR it to the order of S1 (QRS) to S2 (P) which would technically be lub (gap) dub (versus lub-dub)

i dont know. i guess i’m just confused about how in the monitor, there seems to be a longer gap between QRS to P (where T and U come in) versus P to QRS.

sorry if it’s confusing..

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thaiger306 asked:


The tricuspid valve is closed
A)during active filling of the ventricles.
B)when the mitral valve is open.
C)while the atria are contracting.
D)during systolic ejection.
E)during passive filling of the ventricles.

As soon as left ventricular pressure exceeds the pressure in the aorta, the
A)AV valves open.
B)aortic semilunar valve opens.
C)atria pump blood into the ventricles.
D)ventricles pump blood into the atria.
E)pulmonary semilunar valve closes.

During the isovolumic contraction period of the cardiac cycle,
A)AV and semilunar valves are closed.
B)the atria are contracted.
C)ventricular volume increases.
D)blood is pumped into the large arteries.
E)pressure in the ventricles decreases.

When ventricular pressure exceeds atrial pressure, the
A)ejection occurs.
B)atria pump blood into the ventricles.
C)ventricle is in diastole.
D)blood is pumped into the atrium.
E)the first heart sound (S1) is heard.

Which of the following is true?
A)Blood enters the right and left atria only during diastole.
B)Most ventricular filling occurs before the atria contract.
C)During ventricular systole, the AV valves open.
D)The semilunar valves remain closed throughout ventricular systole.
E)Most of end-diastolic volume comes from active filling.

Having some trouble with these questions on my homework and having some trouble finding the answers.
Thanks to all!

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Duhh_hh asked:


List the sequence of events that results in atrial and ventricular contraction.

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klnelli asked:

Kim Nelli breathing through contractions, waiting for Kaden’s arrival. It was an amazing experience. When I go back to watch the video I am surprise on how good it sounded…if only it felt so good! Wish I was one of those who had an orgasmic birth. it will have to be next time. www.getfitforbirt.com

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Pinche Gabacha asked:


Around what point is it normal or average for Braxton Hicks contractions to start? Thanks.

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himcrucified asked:


I feel like I’m having increasingly painful contractions now. I’m 38 weeks along. I feel the pain intensify and relax but I have a small degree of constant pain. It is in my back and abdomen. I am using a contraction calculator but how do I know when they start and stop…Should I be pain free in the middle of them? Should I just feel my uterus to see when it’s soft or hard?

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. asked:


Should I use CONTRACTIONS in a FANTASTY type booK?
During dialoguE?

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kaitlyn asked:


I have been having painful contractions since Saturday after two trips to the hospital I was told both times I was not in active labor the contractions are 5-10 min apart and have not let up. How long can I have these for before I am in active labor?

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cursosdeinglesats asked:

How to use contractions in questions using the verb to be

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worknow07 asked:

so this is early in the day during a contraction—ooo the pain

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