heart

"heart" is also a: user

(thing) by birdonmyshoulder* (6.2 y) (print) ? Wed Jun 07 2000 at 3:54:29

An organ consisting of the right atrium, right ventricle, left atrium, and left ventricle. Non-oxygenated blood enters the heart through the precava and postcava (large veins from the rest of the body) and oxygenated blood leaves through the aorta. Pulmonary arteries and veins carry the blood over the lungs in order for it to become oxygenated and recycled through the body.

If you have ever held a heart in your hand (the closest I have ever come is a cat's heart during Biology class), you will know that it is a beautiful, perfect, powerful thing.

(thing) by amiawakeyet (4.6 y) (print) ? Thu Jul 20 2000 at 16:42:45

Symbolic location of one's empathy, love, & compassion. When healthy, it moves us to proaction.

(thing) by alex.tan (3.8 y) (print) ? 2 C!s Sat Aug 26 2000 at 8:30:59

Anatomy of the human heart

The heart is a big muscular pump that operates throughout life, pumping blood through the body's dual circulation (pulmonary and systemic). It lies in the mediastinum in the chest, sort of between the anterior chest wall and the lungs.

The human heart is surrounded by a thin layer of tissue known as the pericardium and the space between the heart and pericardium is filled with a small amount of pericardial fluid. The human heart is made up of four chambers. The right atrium receives deoxygenated blood from the body via the superior vena cava and the inferior vena cava. This blood passes to the right ventricle, where it is pumped out along the pulmonary arteries to the lungs. Oxygenated blood returns to the heart from the lungs via the pulmonary veins which end in the left atrium. This blood is pumped to the left ventricle and is then pumped into the systemic circulation through the aorta.

In the normal heart, the walls of the ventricles are thicker than those of the atria and the wall of the left ventricle is thicker than the wall of the right ventricle (the left ventricle must pump blood to the entire body).

There are four valves in the heart. The tricuspid valve separates the right atrium from the right ventricle. The pulmonary valve prevents backflow from the pulmonary artery into the right ventricle. The mitral valve (also known as the bicuspid valve) separates the left atrium from the left ventricle. Finally, the aortic valve prevents backflow of blood from the aorta into the left ventricle and therefore helps keep the systemic blood pressure up.

A continuous septum separates the left and right atria and the left and right ventricles.

Blood supply to the heart arises via two blood vessels that branch off early from the aorta, namely the left coronary artery and the right coronary artery. The left coronary artery branches into the left anterior descending artery and the left circumflex artery. The right coronary artery sends an important branch to the SA node in the right atrium. Occasionally, anatomical variants of the coronary arteries are found and these can vary quite widely in pattern.

The heart is innervated by autonomic fibres, both sympathetic and parasympathetic (from the vagus nerve) and is also affected by the volume of venous return to the heart and to hormones such as adrenaline.

Part of the human anatomy project.

(thing) by jafuser (9.3 mon) (print) ? 1 C! Mon Oct 09 2000 at 2:56:46

ASCII Art diagram of the human heart:

          |  \ \ | |/ /
          |  |\ `' ' /
          |  ;'aorta \      / , pulmonary arteries
          | ;    _,   |    / / ,
 superior | |   (  `-.;_,-' '-' ,
vena cava | `,   `-._       _,-'_
          |,-`.    `.)    ,<_,-'_, pulmonary veins
         ,'    `.   /   ,'  `;-' _,
        ;        `./   /`,    \-'
        | right   /   |  ;\   |\
        | atrium ;_,._|_,  `, ' \
        |        \    \ `       `,
        `      __ `    \   left  ;,
         \   ,'  `      \,  ventricle
          \_(            ;,      ;;
          |  \           `;,     ;;
 inferior |  |`.          `;;,   ;'
vena cava |  |  `-.        ;;;;,;'
          |  |    |`-.._  ,;;;;;'
          |  |    |   | ``';;;'  FL
                  aorta

Disclaimer: I was not the artist for this excellent ASCII drawing. This was found in an ASCII art archive along with several other scientific drawings.

(thing) by GoodKingNerdnor (1.6 mon) (print) ? Sat May 26 2001 at 19:42:15

A shape represented in mathematics as a "cardioid". It is expressed as this polar equation:
r = 2a(1 + cos(θ))

(person) by czeano (58 min) (print) ? 1 C! Sat Jul 21 2001 at 23:48:48

Heart was one of the leading hard rock bands of the 1970s and one of the few bands that survived the transition into 1980s pop. While the band may have been formed in the 1960s, it was the talents of sisters Ann and Nancy Wilson that made it famous.

Originally created in 1963 by Steve Fossen, Roger Fisher and Mike Flicker, the band eventually known as Heart went through several early name changes. Gigging under the names "The Army" and "White Heart," the three buddies-cum-musicians settled on Heart in the early 1970s. Shortly afterward, the Seattle based trio recruited the vocal talents of Ann Wilson, the daughter of a Marine Corps captain, and (later) her sister Nancy. The two had been raised in San Francisco and Taiwan before their family had settled in Washington.

With most of the songs based on early whimsical work by Ann, Dreamboat Annie was released. The album saw radio play through the popular singles "Crazy on You" and "Magic Man," but the rest of the record bore little resemblance to these rock anthems, resulting in poor sales and a niche audience.

Meanwhile, things were heating up inside the band as Mike Flicker and Ann became romantically involved. Not to be outdone by her sister, Nancy started a relationship with Roger. The dynamic later split up the founding members leaving the Wilsons with creative control of Heart.

In the early 1980s, the band had trouble staying on the charts and on the airwaves as band members turned over quickly. After a flopped 1983 album Passionworks, Heart was dropped from their contract with Portrait and signed by Capitol Records.

The new label brought about changes in the form of the self-titled record Heart, which finally brought the Wilson sisters to the spotlight. The band became known as a feminine vehicle and the videos that followed brought a romantic air to the band's music -- as opposed to the angry, heavy-hitting rock from earlier discs.

Heart struck gold (and platinum </joke>) with their singles "What About Love?," "These Dreams," "Alone" and "All I Want to Do Is Make Love to You." The end of the eighties was a lucrative time for the band as they rode their fame through four successful albums.

In the nineties, however, with the change to less flamboyant music, the band saw much less success as a whole and instead Ann and Nancy focused on their solo careers and their families. The two released several joint records under the name The Lovemongers.

Currently, Ann and Nancy are touring with John Paul Jones and several other classic rock giants performing Beatles covers mixed with their own Beatles-influenced music.

Discography

Dreamboat Annie (1976)
Little Queen (1977)
Magazine (1978)
Dog & Butterfly (1978)
Bebe Le Strange (1980)
Private Audition (1982)
Passionworks (1983)
Heart (1985)
Bad Animals (1987)
With Love From (1988)
Brigade (1990)
Desire Walks On (1993)

Heart is also the name of the band's 1985 album which re-introduced the Wilson sisters to a new audience of listeners: the MTV generation. After spending a year on sabbatical working on their image, Heart knew they were having trouble connecting with the current music scene. They came up with a plan to go "mainstream" with new looks, a revised sound, and formulaic videos to boot. Heart ended up as the band's best selling album, but it didn't add much to the band's repertoire. Several tracks (e.g. "What About Love?") became eighties pop mainstays, but these melodic anthems didn't mesh with the band's prior AOR approach.

Track listing:

I have a huge crush on Ann Wilson and got to see her perform live in the summer of 2001 at Music Midtown in Atlanta. It was great.

(thing) by sfc (1.5 y) (print) ? Wed Aug 07 2002 at 17:03:51

In Boxing, "heart" is used to describe the ability of a Boxer to overcome great adversity. To a large degree, heart is the most compelling aspect of the sport. A Boxing match is able to transcend many other sporting events when one (or both) of the fighters is pushed to their limits and continues to fight on. Heart is what makes a Boxer pick himself up after a devastating punch, continue fighting when they are being beaten and throw punches even when they keep getting hit by counters.

There are many great examples of fights that display heart. An excellent one is the recent match between Micky Ward and Arturo Gatti. In fact, the 9th round of that fight is probably best 3-minute display of heart you can find. Both fighters were completely exhausted going into the round. Early on Micky Ward landed his patented left hook to the body sending Gatti to the floor. A body blow like that is extremely painful and the pain lingers for a long time. Gatti managed to get to his feet. Ward then threw everything he could at Gatti. Gatti absorbed tremendous damage but refused to go down again. If this wasn't enough Gatti then showed tremendous heart and actually came back to win the middle of the round against the completely exhausted Ward. With still a minute left Micky Ward, well known as a "true warrior", again changed the direction of the round beating Arturo Gatti into the corner. This has to be one of the most amazing displays of skill and will power that I've ever witnessed in sports.

Heart is a very important factor in any fighter. Some fighters, like Micky Ward, have many fights where it was a major factor. Others, like Roy Jones, Jr., dominate their opponents so greatly that it never becomes a factor. Boxing fans always want to see their fighters get into tougher and tougher competitions. Many feel that you really can't judge a fighter completely until his heart has been tested. How will Roy Jones react when he finally gets knocked to the ground? That was certainly a question on people's minds about Mike Tyson when he fought Buster Douglas (of course, no one thought that Douglas would be Tyson's test).

There is a dark side to the concept of heart. A fighter with great heart will continue to fight on even when it is hopeless and they are getting injured. A perfect example of this is Evander Holyfield. He continues to fight even though it is dangerous at his age. If Holyfield were to fight someone like Lennox Lewis there is a good chance he would be dominated. Because of his great heart the fight would not end in a 6-round knockout. It would probably go the distance with Holyfield absorbing a great deal of damage. A fight like that would guarantee Holyfield being this generation's Mohammad Ali.

Heart is very often the most compelling aspect of Boxing. Even though the "fight choreography" in Rocky is ridiculous it is still a great Boxing movie. Rocky capture's the very important concept of heart by Balboa's drive and refusal to quit in his brutal match. Even though he loses the fight, the audience is moved by Rocky's tremendous heart. Fights that display this are rare and happen somewhat randomly. But when you can manage to witness a great display of heart you will rembember it forever.

(idea) by Sp8472 (2.4 y) (print) ? Tue Jan 07 2003 at 17:49:32

The heart beats when the cardiac muscles around the outside of the organ contract. The heart contracts in two phases, first squeasing the blood that is in the two atria into the ventricles, and then squeasing the blood from the ventricles out of the heart, either to the lungs or to the rest of the body. When the cardiac muscles are contracting the heart is described as being in systole, and when it is relaxed it is described as being at diastole.

The heart muscle is made up of many cells, bound to each other my "intercolated discs". These intercolated discs spread electrical signals over the whole muscle very quickly, so when a message is sent to the muscle, it all acts as once, which is very important when trying to move large volumes of blood around. When the atria contract, the "sino-atrial node" sends a signal out, which spreads across all of the muscle. This signal is stopped by a non-conductive layer between the muscle surrounding the atria and the muscle surrounding the ventricles, so the whole of the heart doesn't contract at once. The atrial muscles contract, squeasing blood into the ventricles of the heart.

The signal from the sino-atrial node activates another node, the "atrioventricular node". Once the atrial muscles have contracted, the atrioventricular node sends another electrical signal down the "bundle of Hes", a clump of nerve cells bridging the non-conductive material between the atrial and the ventricular muscles. The signal travels down this, which half way down splits into two. At the bottom, or "apex" of the heart, the electrical signal is released from the nerve cells out into the muscles, and then spreads throughout the ventricular muscles making the ventricles contract.

The reason for the electrical signal travelling to the bottom of the heart before the ventricular muscles contract is two fold:

To provide a short delay between atrial and ventricular contractions
To make the ventricles contract from the bottom upwards if there is any delay at all in the signal spreading, ensuring that all the blood is squeased out of the heart

Systole lasts around 0.6 seconds when at rest (this will be shorter when the heart is beating fast). The heart then goes through diastole, a period of resting, which lasts around 0.3 seconds when at rest. During this time all the changes which have occured during systole are reset, and the heart prepares to contract again. Although the two sides of the heart pump to different places in the body (the right side pumps blood to the lungs for oxygenation, and the left side pumps oxygenated blood to the rest of the body), both sides contract at the same time as it is simply easier to make all the muscle contract at once.

All this makes the cardiac muscles surrounding the heart very active, so they use up a lot of oxygen and glucose respiring in order to keep up enough energy. As a result, 5% of the oxygenated blood pumped out by the heart is fed straight back in to the heart muscles to power them.

An interesting note is that the heart muscles are "Myogenic". This means that even when taken out of the body, the signals will still be send by the sino-atrial node for the heart to beat, and, as long as it has sufficient levels of glucose and oxygen, the heart will continue to beat. This is what makes heart transplants possible, as by cooling them the usage of oxygen and glucose can be kept to a minimum, and so the heart can be kept beating for up to a day (although it is usually no longer than 4 hours).

(poetry) by seagulltheme (1.8 hr) (print) ? Wed Apr 04 2007 at 2:23:00

All journeys must have a some start,
today it's blood entering your heart:
Two pipes join at the top
of your blood's first pit-stop;
your atrium is where it'll fast dart.

So through the tricuspid valve blood seeps,
and then to a ventricle it ekes.
That cavity then squeezes,
with the force of ten sneezes
like a wound balista releases!

Past the big pulmonic valve blood's bumped,
and into another tube it's dumped.
The blood goes in a lung,
and with air it is wrung,
and back to the heart it is pumped.