i am a research study scientist in ~ The university of Nottingham. My key area of research is cardiovascular biology and I aid teach college students to become veterinary surgeons and scientists. When I am not working, I carry out a most community and charity work and love spending time through my family, consisting of my 2 grandchildren. I have three children. The youngest has just perfect school and also the enlarge two have completed their degrees at university.

ns am a Manchester-based scientific research communicator and artist right now researching exactly how art and also games deserve to be provided as tools for science outreach, as component of a M.Sc. At the university of Hull. Ns have worked in participation with researchers everywhere the world, producing interdisciplinary projects that are offered to interact science to the public and to inspire people to get connected in STEM.

ns am a teacher and also have taught young human being for over 20 years. Ns am likewise a expert proofreader and copy-editor and an ext recently I have actually written my very first children’s novel. I have two children, Joshua and also Erin, who love learning around animals and also science. In mine spare time, I gain playing tennis to keep my heart fit and healthy and also my passion for the theater and also acting keeps my heart racing, specifically on opening night.


ns am an combine Professor the Anatomy and also Developmental genetics at The university of Nottingham and also a 2019 British science Association Media Fellow. I lead a group of research scientists investigating why people and also animals suffer from heart and also blood ship disorders, searching for techniques to detect, prevent, and cure. As soon as I am not working, i love come travel roughly the world, visit museums, and also write scientific research fiction. My boyfriend Andrew and I go to run to save our understanding healthy. *catrin.rutland

Young Reviewers

Age: 11

please boy that loves come play basketball and be with his family.

Age: 15

Hi, my surname is Bruna and I live in São Paulo.


We all take ours hearts for granted: the fascinating body organ inside everyone the beats continuously to store blood pumping with our bodies. Blood circulation ensures that oxygen, nutrients from food, hormones, and also waste products get to the correct cells. The heart is vital for maintaining humans and also most pets alive. Hearts are even much more interesting when we study what they do, how they look, how they work, and the similarities and differences in the hearts of types across the planet. Is a giraffe heart comparable to a human being heart? Which animal survives despite having no heart? can a heart yes, really beat over 1,500 time a minute? indigenous dinosaurs to insects, humans to dogs, this paper looks at what is yes, really happening on the inside, trying out the civilization of love anatomy.

You are watching: Animals with more than one heart

How countless Hearts do We Have?

You surely understand that humans and giraffes have just one heart, as most animals do—but not all. Octopuses and also squids (animals referred to as cephalopods) have actually three hearts. Two hearts pump blood come the gills to take up oxygen, and also the other pumps blood approximately the body (Figure 1). Worms are also unusual, with five structures called aortic arches acting as basic hearts. The hagfish, sometimes referred to as the slime eel, has one true heart plus three accessory pumps helping the blood come move. Just when you thought you had heard it all, some animals are heartless. Jellyfish, starfish, and also even corals manage really well there is no hearts. Starfish do not even have blood, for this reason this defines why no heart is required. Instead, castle use tiny hair-like structures referred to as cilia to press seawater with their bodies and they extract oxygen indigenous the water.

Figure 1 - The simple structures of pet hearts.Bird and also mammal hearts have 4 chambers (two atria and two ventricles). A frog, which is one amphibian, has a heart with 3 chambers (one ventricle and two atria), and fish hearts have two chambers (one atrium and also one ventricle). An octopus heart system contains three hearts—one key heart (H1) pumping blood to the body and two various other hearts (H2 and H3) pump blood come the gills. A, atrium; V, ventricle.

For Dr. That fans, the fictitious Time Lords have two hearts, but real humans an extremely rarely do. In exceptionally unusual cases, civilization with the an illness cardiomyopathy have actually a 2nd heart attached top top their own heart by doctors. The healthy and also damaged hearts job-related together come share the load. Also, pair that are born connected to each various other (conjoined twins) have the right to have 2 hearts naturally.

Mammal and also Bird Hearts

It is not simply the variety of hearts that can readjust between species. The an easy structure that this critical organ deserve to be extremely different from one species to the next. Hearts mostly consist that muscle the contracts and also relaxes, resulting in blood to move through blood ship to and also from the lungs and also around the human body (Figure 2)1. As mammals, we have 4 main components to the heart, a left and a ideal atrium and also a left and also a ideal ventricle. This is referred to as a four-chambered heart. Various other mammals and also birds all have four-chambered hearts. Other pet groups, such as reptiles, amphibians, fish, and insects, have actually hearts that look a tiny different (Figure 1).

Figure 2 - mind have adapted differently to ideal suit every animal.(A) The giraffe has actually a very huge left ventricle so that the love muscle can pump blood to the body and all the way up the long neck come the head. The giraffe’s ideal ventricle is smaller, as it just pumps blood come the lungs. Microscope pictures of the heart muscle that a chick (B) and a dog (C) are also shown. The chick is young and also therefore only has one ventricle and one atrium. Later, the chick heart will end up being four-chambered, through two atria and also two ventricles.

Reptile and also Dinosaur Hearts

Reptile hearts have three chambers, two atria and one ventricle (Figure 1). The exception is crocodilians, which have actually four-chambered hearts, as with mammals and birds. However, over there is a hole in the crocodile chamber wall, so whether there are three or four heart chambers is up because that debate. Civilization often wonder even if it is dinosaurs evolved from bird or reptiles. Recognize a dinosaur love is very rare because, unequal bone, the heart is a soft tissue, so that is not regularly preserved. One perhaps fossilized heart appeared to show that dinosaurs had four heart chambers, an ext like birds 보다 reptiles. Sadly, together this specimen to be investigated more using an ext advanced clinical technology, it was found not to be dinosaur tissue, so us still perform not know enough around dinosaur hearts come predict which animals dinosaurs evolved from <2>.

Amphibian Hearts

Amphibians are an interesting group, together their hearts vary greatly. Living on land and also in water, many get oxygen using their lungs, but likewise take it up via their skin. Many amphibians, consisting of frogs and toads, have three-chambered hearts, with two atria and also one ventricle (Figure 1). However, lungless salamanders do not have a structure dubbed a septum to divide the atrium into two separate parts, therefore this pet has simply one atrium and one ventricle. Some lesser known amphibians seem to have actually a septum in in between their ventricles, for this reason perhaps ancient amphibians had four-chambered hearts, like mammals and also birds.

Fish and also Insect Hearts

Fish hearts have just two chambers, an atrium and also a ventricle (Figure 1). Insects often have just a tube the pumps hemolymph (the name for the insect indistinguishable of blood) freely approximately the whole body, through a ship to aid it move. Cockroaches, however, have actually 13 heart chambers!

How big is your Heart?

It goes without saying the heart size varies in various animals. After all, a whale can not endure with a mouse-sized heart. An adult human being heart weighs around 0.6 lbs. If you do a fist, that is around the dimension of her heart. The giraffe love is a hefty 26 lbs, however the blue whale really tips the scales at 400 lbs. The world’s smallest heart belongs to the fairyfly. This tiny pet is just 0.2 mm long, and a microscope is necessary to watch its heart.

Hearts room normally around 0.6% of an animal’s body mass. Dogs and also wolves have relatively large hearts in comparison through their weight, at 0.8%. Meanwhile, the cat love is just 0.35% the a cat’s human body weight. Hopefully, family member heart size and the amount of love pets feel room not related. If they were, the world’s smallest mammal, the Etruscan shrew, would have actually a most love to give! The mouse-like shrew weighs a tiny 2 g and is approximately 4 centimeter long, but its heart makes up 1.2% the its body weight <3>. Scientists likewise found the the shrew heart have the right to shrink in cold weather. This shrinkage helps shrews make it through harsh climates, by reducing the lot of food that needs. This tiny mammal eats double its body load in food every day, for this reason hibernation is not an option. They rarely also sleep.

Swift and also Sluggish love Rates

The way animals’ hearts work varies between species, too. The heart rate, measured in beats every minute (bpm), different in various species. Generally, larger animals have slow heart rates. A huge slug has a heart rate of roughly 55 bpm, while smaller sized slug varieties are in the 90s. Plenty of whales have heart rates of 10–30 bpm, giraffes room 40–90, and also cats are about 150. In also smaller animals, the number increases: an adult chicken has a heart rate of 259 bpm, a chick is 400 (Video 1), and the hamster heart beats far at 450 bpm. The little Etruscan shrew clocks 835 bpm, more than 12 times higher than a person. The greatest recorded shrew rate was 1,511 bpm, a civilization record for a warm-blooded animal <3>.

People have actually heart rates of about 60–100 bpm, yet children often have slightly higher rates. At 1 month old, 70–190 is fairly normal, 80–120 because that 3–4-years-olds, and 60–100 by the time a boy is 10 years old. A cultivation baby inside its mother starts at 80 bpm in mainly 5, 155–195 at 9 mainly old, and also around 130 just before it is born. Interestingly, the human being heart starts together a tube in the 19–20-days-old embryo, rather prefer a fish, yet gradually rotates, develops, and also separates into four chambers over the next 6 weeks.

Exercise, Temperature and Hibernation All change Heart Rate

Heart rate changes in most exercising animals. Running giraffes can reach 170 bpm and humans have the right to hit 220, but ideally it have to be a little less. A crocodile heart rate at 10° C is 1–8 bpm, in ~ 28° C it hits 24–40, and also once it reaches end 40° C, the heart can become damaged. Young swifts (birds) reduced their heart rates as soon as in the nest, to avoid starvation. Hibernating pets can likewise lower their heart rates. Grizzly bears generally clock 84 bpm, i m sorry lowers to 19 bpm throughout hibernation; a human heart would certainly usually avoid working if the went the low. Emotions, such as fear, love, and excitement, as well as hormone levels, sickness, oxygen levels, and also other determinants both inside and also outside the the human body can readjust the love rate.

Mending a broken Heart

In ours previous Frontiers because that Young Minds document “Mending a damaged Heart,” we looked at resolving failing mind <4, 5>. The zebrafish has actually a really important ability: it deserve to regenerate (regrow), therefore if that gets hurt or that is heart has a problem, it can regularly repair itself. Human bodies room fantastic, and they continuously shot to change heart cells and also repair heart tissue, but the zebrafish is a real skilled at repair a broken heart.


In this article, us looked at some of the similarities and also differences in between the mind of miscellaneous species. Mammals and also birds have actually very similar hearts because of evolution, if reptiles, fish, insects, and other animals evolved mind that are slightly in different way from those of mammals. The setting both inside and outside the each pet helps manage the heart’s structure and also function, yet lifestyle choices, such as exercise and also food, can have huge impacts on your heart’s health. Your friends’ mind are much more similar to yours 보다 to a giraffe’s for example, and also even more similar than to a frog or spider heart, yet every person’s love is unique. Her heart is continually adapting to the situations you are in, reacting to food, exercise, emotions, and also illness. Uneven a squid, friend only have one heart, and also it will certainly beat approximately 2.21 billion time in her life, so that is worth keeping it healthy.


Cephalopods: animals without backbones, consisting of squids, octopi, and also nautiluses. Cephalopods have symmetrical bodies, prominent heads, and also tentacles.

Atrium: The upper chamber or chambers of the heart. The many is atria: for example, you deserve to have one atrium or 2 atria.

Ventricle: The lower chamber or chambers the the heart.

Amphibian: pets with backbones that need water or wet settings to survive. Amphibians include toads, frogs, salamanders, and caecilians (amphibians without legs or limbs).

Hemolymph: Fluid, comparable to blood, that some straightforward animals have to move nutrients and also oxygen about their bodies.

Heart Rate: The number of times every minute that a love beats.

Video 1: early on, once a chick is farming in an egg, the heart can be viewed on the external of the body. End time, the love will relocate inside the body. This video shows a chick’s love beating as soon as it is simply a couple of days old. The heart is still a tube containing 2 chambers, a ventricle and an atrium, yet as it grow it will eventually have four chambers. You can see the blood pumping v the heart chambers.

Conflict that Interest

The writer declare the the study was conducted in the absence of any type of commercial or financial relationships that could be interpreted as a potential conflict of interest.


The authors would choose to thank our young reviewers, Erin and also Joshua Rutland. Part of this work was made feasible due to capital from the Anatomical society with a public Engagement and Outreach grant to Catrin title Anatomy for ALL—Making Anatomy Accessible. We would additionally like to thank the British scientific research Association and also University of Nottingham for awarding Catrin v a BSA Media Fellowship 2019.


1. watch the file “Blood ship Under the Microscope” because that information around blood <1>.

See more: I Don T Want To Touch You Just Want My Touch You Dont Want My Heart Lyrics


<1> Machado, M., Mitchell, C., Franklin, J., Thorpe, A., and Rutland, C. S. 2020. Blood ship under the microscope. Front. Young psychic 8:151. Doi: 10.3389/frym.2019.00151

<2> Cleland, T., Stoskopf, M., and Schweitzer, M. 2011. Histological, chemical, and also morphological reexamination that the “heart” the a small Late Cretaceous Thescelosaurus. Naturwissenschaften. 98, 203–211. Doi: 10.1007/s00114-010-0760-1

<3> Jurgens, K. D., Fons, R., Peters, T., and Sender, S. 1996. Heart and also respiratory rates and also their meaning for convective oxygen transport prices in the smallest mammal, the Etruscan shrew Suncus etruscus. J. Exp. Biol. 199:2579–84.

<4> Clark, N., Alibhai, A., and also Rutland, C. S. 2018. Repair a damaged heart—the genetics of heart disease. Front. Young mental 6:19. Doi: 10.3389/frym.2018.00019

<5> Simpson, S., Rutland, P., and also Rutland, C. S. 2017. Genomic insights right into cardiomyopathies: a comparative cross-species review. Vet. Sci. 4:19. Doi: 10.3390/vetsci4010019