EssaysForStudent.com - Free Essays, Term Papers & Book Notes
Search

Structure of the Heart; Function of the Heart; Diseases of the Heart ; History of Heart Research; Hearts in Other Animals

By:   •  Essay  •  877 Words  •  November 24, 2009  •  1,152 Views

Page 1 of 4

Essay title: Structure of the Heart; Function of the Heart; Diseases of the Heart ; History of Heart Research; Hearts in Other Animals

Editors' Picks

Great books about your topic, Heart, selected by Encarta editors

Related Items

* Aorta

* Artery

more...

Encarta Search

Search Encarta about Heart

Also on Encarta

• 7 tips for funding an online degree

• How to succeed in the fashion industry without being a top designer

• Presidential Myths Quiz

Advertisement

Click Here!

Heart

Encyclopedia Article

Find | Print | E-mail | Blog It

Multimedia

House MiceHouse Mice

29 items

Article Outline

Introduction; Structure of the Heart; Function of the Heart; Diseases of the Heart ; History of Heart Research; Hearts in Other Animals

I

Introduction

Print this section

Heart, in anatomy, hollow muscular organ that pumps blood through the body. The heart, blood, and blood vessels make up the circulatory system, which is responsible for distributing oxygen and nutrients to the body and carrying away carbon dioxide and other waste products. The heart is the circulatory system’s power supply. It must beat ceaselessly because the body’s tissues—especially the brain and the heart itself—depend on a constant supply of oxygen and nutrients delivered by the flowing blood. If the heart stops pumping blood for more than a few minutes, death will result.

The human heart is shaped like an upside-down pear and is located slightly to the left of center inside the chest cavity. About the size of a closed fist, the heart is made primarily of muscle tissue that contracts rhythmically to propel blood to all parts of the body. This rhythmic contraction begins in the developing embryo about three weeks after conception and continues throughout an individual’s life. The muscle rests only for a fraction of a second between beats. Over a typical life span of 76 years, the heart will beat nearly 2.8 billion times and move 169 million liters (179 million quarts) of blood.

Since prehistoric times people have had a sense of the heart’s vital importance. Cave paintings from 20,000 years ago depict a stylized heart inside the outline of hunted animals such as bison and elephant. The ancient Greeks believed the heart was the seat of intelligence. Others believed the heart to be the source of the soul or of the emotions—an idea that persists in popular culture and various verbal expressions, such as heartbreak, to the present day.

II

Structure of the Heart

Print this section

The human heart has four chambers. The upper two chambers, the right and left atria, are receiving chambers for blood. The atria are sometimes known as auricles. They collect blood that pours in from veins, blood vessels that return blood to the heart. The heart’s lower two chambers, the right and left ventricles, are the powerful pumping chambers. The ventricles propel blood into arteries, blood vessels that carry blood away from the heart.

More from Encarta

Offer: Live online homework help

Math, Science, History and English

Try Tutor.com for free!

Educating mom

Colleges reach out to single parents.

Find out how.

Cats Quiz

Continue for 3 more pages »  •  Join now to read essay Structure of the Heart; Function of the Heart; Diseases of the Heart ; History of Heart Research; Hearts in Other Animals and other term papers or research documents
Download as (for upgraded members)
txt
pdf
Citation Generator

(2009, 11). Structure of the Heart; Function of the Heart; Diseases of the Heart ; History of Heart Research; Hearts in Other Animals. EssaysForStudent.com. Retrieved 11, 2009, from https://www.essaysforstudent.com/essays/Structure-of-the-Heart-Function-of-the-Heart/13355.html

"Structure of the Heart; Function of the Heart; Diseases of the Heart ; History of Heart Research; Hearts in Other Animals" EssaysForStudent.com. 11 2009. 2009. 11 2009 <https://www.essaysforstudent.com/essays/Structure-of-the-Heart-Function-of-the-Heart/13355.html>.

"Structure of the Heart; Function of the Heart; Diseases of the Heart ; History of Heart Research; Hearts in Other Animals." EssaysForStudent.com. EssaysForStudent.com, 11 2009. Web. 11 2009. <https://www.essaysforstudent.com/essays/Structure-of-the-Heart-Function-of-the-Heart/13355.html>.

"Structure of the Heart; Function of the Heart; Diseases of the Heart ; History of Heart Research; Hearts in Other Animals." EssaysForStudent.com. 11, 2009. Accessed 11, 2009. https://www.essaysforstudent.com/essays/Structure-of-the-Heart-Function-of-the-Heart/13355.html.