Pectinate muscles

[chbare]

Hope this helps:

Normal RA pressure is around 8 or less. No surprise this is roughly equal to CVP.

Once we go into the ventricle, the dynamics change, and we have both systolic and diastolic influences: Normal RV systolic = 15-30, while RV diastolic = 8 or less. No surprise that this is consistent with RA pressure. In fact RV end diastolic and RA pressure should be nearly equal since this is where we get ventricular filling from. Then, the RV contracts, the tricuspid closes, and hopefully blood is ejected through the pulmonary valve.

Take care,

chbare.

[akflightmedic]

pectinate muscles The right atrium has a forward extension into its auricle. This space is lined by ridges of muscle called pectinate muscles and are not shown in the diagram

Blood leaves the right ventricle and passes through the pulmonary trunk to the lungs. Oxygenated blood returns to the left atrium of the heart from the lung through the pulmonary veins. The left atrium doesn't have much to talk about. There is an extension into the small auricles which have pectinate muscles in its walls.

The muscles line the atrium and look like the ridges of a leaf. They assist in providing additional contractile force for the atrium. If you look at any diagram of the heart or drawing and you will see in the atrium what looks like ridges in the drawing. those ridges are the pectinate muscles. It seems that all they do is to provide additional musculature to help the atrium contract a little more forceful.

What diagram?

What site did this come from, post a link so we all can read the full text and maybe learn a little more. Thanks

[mstovall]

Doc and Bare, do either of you know the pressure of the VC vs that of the Pulmonary vein? I can't find it in my books. Now that I can't find it it is driving me crazy. I'm just curious what the difference in pressure would be or would there be any real difference.

Michael

[chbare]

I am not quite sure what VC is? I will assume vena cava and you can correct me. The pressure in your vena cava is for all practical purposes your central venous pressure (CVP). Pulmonary venous pressure is a bit tricky. First, we do not directly measure pulmonary venous pressures. I think some research has been performed measuring these pressures; however, this would involve threading a catheter through an artery into the aorta, through the aortic valve, into the left ventricle, through the mitral valve, into the left atrium, and finally into one of the pulmonary veins. Obviously, this would place the patient at significant risk, especially since we are threading a catheter into the left ventricle.

However, we can indirectly look at pulmonary venous pressure. When we place a pulmonary arterial catheter, we can perform a procedure known as wedging. Essentially, we inflate a tiny balloon in the pulmonary artery and wedge it. What this does is block off input from the right ventricle. So, all we are looking at in the pulmonary artery, veins, left atrium, and left ventricle. We can make assumptions based on data gained from the PCWP or pulmonary capillary wedge pressure. In a normal person without lung, valve, or heart problems, the pressure in the pulmonary venous system should roughly approximate mean left atrial pressure or wedge pressure. Obviously, we are dealing with gradients, so variations will exist.

Here is an abstract on dog research that may help:

http://www.ncbi.nlm.nih.gov/pubmed/12112902

Here is a link on PCWP:

http://www.cvphysiology.com/Heart%20Failure/HF008.htm

Another helpful site is the pulmonary artery catheter education project

Take care,

chbare.

[mstovall]

Thanks bare. That is what I meant by VC, sorry. This also explains why I spent about an hour trying to find something that didn't really exist. I can also now understand why we don't have it with the complexity of obtaining it. I did see some studies on animals, just nothing on humans.

Thanks again,

Michael

[akflightmedic]

Never mind Ruff.

I found it here, great page for some info.

http://home.comcast.net/~wnor/thoraxlesson4.htm

Scroll down to this part and it describes it in detail with the diagram.

Internal Structure of the Chambers of the heart

[DwayneEMTP]

Yeah, I've noticed that posting without sources is becoming a major issue lately.

Ak has handled it much more delicately and diplomatically than I’m capable of, so here is my two cents.

Me and a few others have started Googling answers that we felt were a little surprising when coming from particular posters and have been disappointed to find with disturbing regularity that people are using found answers as their own. To me this is a particular kind of wicked.

Those of you that are doing so, so far have been given a free pass, until ak's post of course, but fair warning! If you (not 'you' Ruff, general you) insist on trying to look smarter than you are, and insist on using the hard work of others to do so, then I am going to start doing what I can to humiliate you publically. There is no one here that is so ignorant that they don’t know that they should site sources, nor have a reasonable excuse for “forgetting.”

Using others work is lazy, weak, dishonest, and perhaps most important, it really pisses me off. It's contrary to everything we try to do here.

We've found posts from two posters in the “Challenge” threads in the last few weeks that have done this, including the one from above. You know who you are, and I'm warning you that you should not continue to do so and expect to continue here with your dignity intact.

C’mon folks. We know what we know today. By participating honestly we’ll know more tomorrow. By lying we simply pollute the process for everyone, as well as set this horrible example.

Just sayin’….

Dwayne