Cardio Problems... HELP?

eutopia

Can someone help me answer these questions?!? thanx!@

Explain why blood pressure and heart rate differ when measured in a reclining position and in a standing position.

Explain why high blood pressure is a health concern.

High blood pressure can lead to many other cardiovascular complications.

Explain why an athlete must exercise harder or longer to achieve a maximum heart rate than a person who is not as physically fit.

Explain why smoking causes a rise in blood pressure.

Moonbear

Are you in the same class as this person? The questions are the same.

http://www.physicsforums.com/showthread.php?t=70969

saltydog

Interesting questions. The first I'd attribute to gravity and work effort. Second one I pretty much found on the web:

To compensate for increased blood pressure, the heart must work harder to pump blood, and so its muscles thicken (called hypertrophy), usually in the left side (called left-ventricle dysfunction). These thickened muscles pump inefficiently, and over time, the force of their contractions weakens. The heart muscles then have difficulty relaxing and filling the heart with blood. The heart begins to fail.

The failing heart then triggers a number of hormonal and neurochemical mechanisms to correct imbalances in blood pressure and flow. This response, called remodeling, is helpful in the short run but very destructive and irreversible over time.

As part of the remodeling process, the heart muscle cells elongate. The muscular walls of the heart dilate and become thinner and inefficient. The cells themselves undergo molecular changes that result in calcium loss, a mineral crucial for healthy heart contractions.

The end-result of remodeling is that the volume of blood pumped to the kidneys falls, and the kidneys respond by retaining water and salt, which, in turn, increases fluid build-up in the body.

To make matters worse, the body's arteries respond to a lower blood volume by constricting; this forces the heart to work even harder to pump blood through these narrowed vessels, thereby increasing blood pressure, and the cycle continues.

I'd like to know the relationship between smoking and blood pressure. Suppose I could web-out that one too.

saltydog

Well, I'm just cookin' with kerosine people:
On the web:

"Although smoking increases the risk of vascular complications (for example, heart disease and stroke) in people who already have hypertension, it is not associated with an increase in the development of hypertension. Nevertheless, smoking a cigarette can repeatedly produce an immediate, temporary rise in the blood pressure of 5 to10 mm Hg. Steady smokers however, actually may have a lower blood pressure than nonsmokers. The reason for this is that the nicotine in the cigarettes causes a decrease in appetite, which leads to weight loss. This, in turn, lowers the blood pressure"

Can I make a plug for exercising and a healthy life style now? Alright, nevermind.