Health Library Explorer
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A-Z Listings Contact Us

Basic Anatomy of the Heart

About the heart

The heart is the hardest working muscle in the human body. It's located almost in the center of the chest. The adult human heart is about the size of a fist.

At rest, a normal heart rate for adults is 60 to 100 beats per minute. In a well-trained athlete, the resting heart rate can be healthy at a rate of 40 to 60 beats per minute. With exercise, the heart beats faster and the heart rate increases to get more oxygen to the muscles.

How the heart works

  • Front view of female body showing arteries, veins, heart, and lungs with closed circulation system.

    The cardiovascular system is made up of the heart and blood vessels. Its job is to circulate blood throughout your body. The blood brings oxygen and nutrients to the tissues.

  • Cross section of heart showing blood flow and conduction system.

    The heart is made up of:

  • 4 chambers (2 atria and 2 ventricles) that get blue (deoxygenated) blood from the body. They pump out red (oxygen-rich) blood back to it:
    • The atria get blood coming back to the heart.
    • The ventricles pump the blood out of the heart.
  • Blood vessels that include a network of arteries and veins that carry blood throughout the body:
    • Arteries carry blood from the heart to the body tissues.
    • Veins carry blood back to the heart.
  • 4 valves to prevent backward flow of blood:
    • Each valve is meant to allow the forward flow of blood. It prevents backward flow.
  • An electrical system that serves as a natural pacemaker. It also conducts electricity to stimulate the heart muscles to contract. This controls the rate and rhythm of the heartbeat.
Online Medical Reviewer: Daphne Pierce-Smith RN MSN
Online Medical Reviewer: Janet Campbell RN BSN
Online Medical Reviewer: Tara Novick BSN MSN
Date Last Reviewed: 5/1/2023
© 2000-2026 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.
Contact Our Health Professionals
Follow Us
Powered by StayWell
About StayWell | Disclaimer | Terms of Use

Our web site is designed to provide general information to educate users about programs and services, which may be available through our hospitals. The web site is not intended to provide medical advice nor should the information be used to attempt to determine the presence, absence or severity of any illness or medical condition which may be perceived or experienced by the user of this site. If you have or suspect you may have an illness or condition which you believe requires medical attention, we recommend you call your primary care physician. If you believe you are experiencing a medical emergency please call "911" (or your local medical emergency number) or seek immediate care from the nearest hospital Emergency Department. The provision of information to users of this web site is not intended as an inducement or to otherwise influence a person's decision to order or receive any item or service from a particular provider, practitioner or supplier that is reimbursable under Medicare, a state healthcare program (e.g., AHCCS) or any other healthcare plan.

Physicians are members of the medical staff at each facility, but are independent contractors who are neither employees nor agents of Tenet Florida Coastal Division; and, as a result, Tenet Florida Coastal Division is not responsible for the actions of any of these physicians in their medical practices.