Thayerbirding is supported by its audience. When you buy through our links, we may earn an affiliate commission. Learn more

Which of the Following is the Correct Sequence of Blood Flow in Birds and Mammals

Written by Clinton Atkins / Fact Checked by George Dukes

which of the following is the correct-sequence-of-blood-flow in birds and mammals

Which of the following is the correct sequence of blood flow in birds and mammals? Mammals and avians have a four-chambered heart that pumps blood from the right ventricle to the lungs and the left ventricle to the rest of the body.

Birds and mammals have the same four-chambered heart with valves that play their own role in the circulatory system. Let’s learn more about the sequence of blood flow and more in this article.

Blood Flow in Birds and Mammals


The avian lung adapted to the metabolic demands of flight. Their efficient cardiovascular system is in charge of several things, such as transporting nutrients, oxygen and carbon dioxide, waste products, hormones, and maintaining heat.

The four-chambered heart structure of mammals and avians is designed to ensure that deoxygenated and oxygenated do not mix. The upper chambers are atria, while the lower two are ventricles. Deoxygenated blood is only present in the lungs and heart, while oxygenated blood flows throughout the body.

Furthermore, there are four valves that play a significant role in preventing the mix-up of oxygenated and deoxygenated blood.

  • Tricuspid Valve– stands between the right ventricle and right atrium
  • Pulmonary or Pulmonic Valve– separates the pulmonary artery and right ventricle
  • Mitral Valve– divides left ventricle and the left atrium and
  • Aortic Valve– which separates the aorta and the left ventricle

The aortic valve of the mammalian heart alongside these three other valves, closes after the chamber is full, preventing the blood from flowing backward. This process of pumping is called double circulation and is present in all mammals.

Moreover, the time when the left and right ventricles shrink and expel blood into the pulmonary artery and aorta is referred to as systole. During this time, it develops the greatest pressure on the blood in the mammalian aorta.

Frequently Asked Questions


What is the correct sequence for the cycle of blood flow?

The cycle of blood flow begins from the right side of the heart:

  1. Deoxygenated blood flows through the inferior and superior vena cava veins to enter the right atrium.
  2. Then, it will pass by the tricuspid valve and into the right ventricle.
  3. The pulmonic valve will open once the lower right chamber is full.
  4. From there, the blood is transported to the pulmonary artery and to the lungs.

The blood will go back to the heart, entering the left side:

  1. Oxygenated blood enters the upper left chamber after passing through the pulmonary veins.
  2. Then, the mitral valve will let the blood into the lower left chamber.
  3. The pressure from a full left ventricle will open the aortic valve and let the blood flow throughout the body.

Which of the following is the correct order of circulation?

In detail, the correct pathway for blood in a mammal and a bird is as follows:

  • Right atrium
  • Right ventricle
  • Pulmonary arteries
  • Left Atrium
  • Left ventricle
  • Aorta

What is an open circulatory system?

In an open circulatory system, the blood permeates the body. There are no vessels to lead the blood, so it flows freely through the cavities. The fluid in an open circulatory system is referred to as hemolymph. This system is mainly established in invertebrates, such as mollusks and arthropods.

What is the order of events in blood clotting?

Blood clotting or hemostasis happens when there is damage to a blood vessel. The rapid process goes as the following:

  • Blood vessel compression
  • Creation of a temporary platelet plug
  • The coagulation cascade is activated
  • Formation of the final clot or fibrin plug

The normal event in the process of blood clotting occurs between 60 to 90 seconds.

What is the difference between fish and mammal respiration?

Here we have a list that compares respiration in fish and in mammals:


  • Gas exchange happens in the gills
  • Can inhale oxygen dissolved in water
  • Gills only take a small portion of a fish’s body
  • A flap covers and protects the gills while letting the water in and out
  • Blood capillaries are close to the gill surface


  • Relies on the diaphragm to expand and contract the lungs
  • Oxygen and carbon dioxide are exchanged in the blood
  • Microscopic hair filters the air that passes through the airways
  • Have two lungs
  • The presence of liquid in the lungs can interrupt respiration

Read more: The respiratory system in birds and the mammalian respiratory system: what is the difference?


After knowing the answer to the question “Which of the following is the correct sequence of blood flow in birds and mammals?”, we hope all the information has been useful to you and that you learned something new.

Did you find everything you need to know about the sequence of blood flow in mammals and birds? Do you know anyone who would love to read this article? Share this article with them and comment on your thoughts below. We always love hearing from our readers!

5/5 - (2 votes)

Clinton Atkins


Hi, I'm Clinton. Rocky and I became friends after a birdwatching trip with our new group. And we have been enjoying every adventure together. When he told me the idea of establishing a site that shares our experiences and fun, I immediately agreed. After trials and errors, here we have Thayerbirding.

You May Also Like

how long before birds come to a new feeder

How Long Before Birds Come to a New Feeder?

Bird feeding is such a popular hobby that the US has declared every February its ...

how much weight can an eagle carry

How Much Weight Can an Eagle Carry? (Lifting Weights by Species)

The eagle is one of the largest winged animals in the world. These birds of ...

how much weight can a hawk carry

How Much Weight Can a Hawk Carry? Answer Will Surprise You!

Hawks are known to be fierce predators that swoop in on their prey, which are ...

where do cuckoo birds live

Where Do Cuckoo Birds Live in Real Life? Get Facts Here!

Cuckoos are medium-sized birds that range from half a foot to three feet long. They ...

how deep should a bird bath be

How Deep Should a Bird Bath Be? – The Right Water Level Depth

How deep should a bird bath be? The water bath for birds should be 1 ...

best bluebird feeder

The Best Bluebird Feeders (Perfect for Mealworms Suet & Fruits)

Bird feeders for bluebirds are a surefire way of attracting these gorgeous backyard birds. Even ...