Whales are some of the most majestic and mysterious creatures in the animal kingdom. If you’ve ever wondered how many hearts these gentle giants of the sea have, you’re not alone.
If you’re short on time, here’s a quick answer to your question: whales have one heart, just like humans and most other mammals.
In this comprehensive guide, we’ll go over everything you ever wanted to know about whale hearts. We’ll explore whale heart anatomy, how their circulatory system works, heart rate and lifespan, how their hearts compare to human hearts, and much more.
By the end, you’ll be a whale heart expert!
Whale Heart Anatomy
Size and weight
A whale’s heart is an incredible organ, allowing these massive marine mammals to swim and dive at astounding depths. The heart of a blue whale, the largest animal on Earth, weighs around 400 pounds and is the size of a small car!
Other whale species have similarly gigantic hearts to match their enormous body size. The heart of a 60-foot fin whale can tip the scales at 1,300 pounds. That’s heavier than a grand piano! 🎹
To pump blood throughout their massive bodies, whale hearts beat at a much slower rate than human hearts. An average human heart beats around 60-100 times per minute. But a blue whale’s heart beats only 4-8 times per minute when diving and cruising.
When sprinting, it may beat up to 37 times per minute. Other whales like humpbacks and sperm whales have heart rates of 25-37 beats per minute. That slow, powerful rhythm allows them to dive for over 30 minutes and resurface without issue.
Chambers and valves
A whale’s heart has four chambers, just like humans and other mammals. The two upper chambers are the left and right atria. The two lower chambers are the sturdy left and right ventricles. Heart valves control blood flow between these chambers and arteries. 🩺
When oxygenated blood enters the heart through the left atrium, it passes through the bicuspid (mitral) valve into the left ventricle. The powerful left ventricle then pumps blood into the aorta and throughout the body.
From there, deoxygenated blood returns to the right atrium through the superior and inferior vena cava. It moves through the tricuspid valve into the right ventricle. Finally, blood is pumped from the right ventricle through the pulmonary valve and semilunar valves into the lungs to pick up fresh oxygen.
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The four valves play a critical role in regulating blood flow for the whale’s diving abilities. When diving deeply, the arteries constrict to limit blood loss to the extremities. At the same time, valves in the heart directing blood to the lungs constrict, sending oxygenated blood only to the brain, heart and essential organs.
Whale Circulatory System
Arteries and Veins
Whales have a closed circulatory system with a four-chambered heart that pumps blood through arteries and veins, much like land mammals. Their massive size requires an intricate network of blood vessels to circulate huge volumes of blood.
Some key arteries include the aorta, pulmonary arteries carrying blood to and from the lungs, coronary arteries supplying blood to the heart muscle, and carotid arteries to the brain and head. Veins return oxygen-depleted blood back to the heart and lungs.
The vena cava are especially large veins that return blood from the rear of the whale’s body.
Blood Flow
A whale heart beats at around 25-37 beats per minute on average, enabling tremendous blood flow compared to humans. At up to 300 gallons per minute, this allows oxygen and nutrients to reach their tissues efficiently despite high energy demands from swimming and body heat regulation.
Valves in veins prevent backflow given immense pressures. Studies show blood travels through arteries at up to 21 mph (9.4 m/s) as the heart constricts forcefully. Their blood also has a higher red blood cell concentration, improving oxygen transport.
This amazing circulatory system powers the world’s largest mammals.
Whale Heart Rate and Lifespan
A whale’s heart is an amazing organ. To pump blood throughout a whale’s large body, it beats at a much lower rate than a human heart, but moves huge volumes of blood with each beat. Let’s take a closer look at some key facts about whale hearts and lifespans:
Heart Rate
A blue whale’s heart beats just 4-8 times per minute at rest. This extremely slow pace allows time for the heart to fill with huge amounts of blood before contracting to pump it around the whale’s body. In comparison, the average resting human heart rate is 60-100 beats per minute.
During deep dives, a whale’s heart rate can drop as low as 2-4 beats per minute to conserve oxygen. Their flexible ribcage also collapses at depth, helping push more blood back to the heart.
Heart Size
The heart of a blue whale is about the size of a small car, weighing up to 180 kg. It needs to be incredibly muscular to pump blood throughout the massive body of the world’s largest animal.
The aorta that carries blood from the heart has a diameter of about 23 centimeters – you could easily fit a beach ball through it!
Lifespan
Many species of baleen whales like humpbacks and blue whales have long lifespans ranging from 80-90 years. Scientists believe bowhead whales live over 200 years on average based on analysis of amino acids in the lenses of their eyes.
These magnificent marine mammals achieve such great ages despite the huge demands placed on their heart to pump blood non-stop over timescales of centuries.
Their slow heart rate and tremendous stamina enable whales to live long lives spanning many human generations. We are only just beginning to unveil the mysteries of how these ocean giants can thrive for so long with a lifespan greater than any land mammal.
Comparison to Human Heart
Size difference
A whale’s heart is considerably larger than a human heart. The blue whale, the largest animal on Earth, has a heart that weighs about 400-700 pounds and is approximately the size of a small car. Comparatively, an adult human heart weighs less than 1 pound on average.
To pump blood throughout their massive bodies, a blue whale’s heart beats at only 8-10 beats per minute but pumps almost 220 gallons of blood with each beat. A human heart beats over 60 times per minute and pumps less than 1 gallon of blood per minute.
Lifespan difference
On average, whales live 30-80 years depending on the species. The bowhead whale has been known to live over 200 years. Humans in developed countries have an average life expectancy of around 80 years.
Due to their immense size, whales have adapted to have much longer lifespans than other mammals of comparable size. The whale’s sizable heart allows it to efficiently circulate oxygen and nutrients throughout its massive body over its long lifetime.
Environmental adaptations
A whale’s heart has adapted in incredible ways to pump blood efficiently through its large vascular system to help withstand cold ocean temperatures and high pressures when diving deeply for food.
For example, as a sperm whale dives 2000 feet underwater, its heart slows, and the whale’s blood vessels constrict to prevent blood loss to vital organs. This allows the whale to swim to ocean depths with extreme water pressure that would kill a human instantly.
| Whale Heart Adaptations | Human Heart Adaptations |
| 400-700 pound heart weight for largest whales | Under 1 pound heart weight on average |
| 8-10 beats per minute for largest whales | Over 60 beats per minute on average |
| Withstands extreme underwater pressures | Withstands only normal atmospheric pressure |
| Efficiently pumps blood at cold temperatures | Maintains consistent 98.6°F body temperature |
A whale’s hardy heart enables it to plunge to ocean depths of over 3000 feet in search of squid, copepods and fish to sustain its tremendous size. Without its highly adapted heart, a whale could not survive in Earth’s cold, pressurized marine environments.
To learn more, visit the American Cetacean Society’s whale anatomy page.
Conclusion
Now you know the answer to the question, “How many hearts does a whale have?”. As we learned, whales have just one heart that circulates blood throughout their bodies, even though they are much bigger than humans.
We covered whale heart anatomy, circulatory systems, heart rate and lifespan, and how whale hearts compare to our own. While whales have a single heart just like us, their hearts beat slower and last much longer.
Armed with this whale heart knowledge, you can impress your friends and family. The next time you see these magnificent marine mammals, you’ll have an even deeper appreciation for how their bodies work!
