Cardiovascular: Blood Flow Through the Heart

Blood Flow Through the Heart: A Clear, Step by Step Guide for Veterinary Nurses ✨

Understanding how the blood flows through the heart is important for us as veterinary nurses + this blog aims to break it down simply, clearly, and in a way that actually sticks (hopefully!).

✨ Why This Matters

The heart isn't just a pump - I think of it as a coordinated system? Kind of. It makes sure that oxygen is delivered + carbon dioxide is removed - which in turn ensures tissue perfusion.

✨ The Big Picture

Let's think of the heart as 2 halves:

  • right side: sends blood to the lungs (deoxygenated)
  • left side: sends blood to the body (oxygenated)

Each side has:

  • an atrium: receives blood
  • a ventricle: pumps blood out

Valves sit between these chambers! This makes sure there is a one-way flow.

✨ Step-by-Step Blood Flow

  1. Blood returns to the heart (deoxygenated): blood that is low in oxygen travels via the cranial vena cava or caudal vena cava into the right atrium

  2. Right atrium → right ventricle: blood passes through the tricuspid valve into the right ventricle

  3. Right ventricle → lungs: blood is pumped through the pulmonary valve into the pulmonary arteries, which then travels to the lungs

  4. Gas exhange occurs in the lungs: carbon dioxide (CO2) is removed + oxygen (O2) is absorbed, where blood becomes oxygenated

  5. Blood returns to the heart (oxygenated): this happens via the pulmonary veins, into the left atrium

  6. Left atrium → left ventricle: blood flows through the mitral (bicuspid) valve, into the left ventricle 

  7. Left ventricle → body: blood is pumped through the aortic valve, into the aorta + is then distributed to the systemic circulation by the arteries

✨ Nursing Insight

Understanding this flow, allows us to:

  • interpret heart sounds (e.g., the "lub" is the atrioventricular (AV) valves closing + the "dub" sound is the pulmonary valves closing)
  • understand ECG changes
  • recognise complications
  • monitor anaesthetised patients effectively

I really hope this helps! For a quick-reference version of the blood flow or more in-depth information, you can purchase my 'the heart: blood flow + anatomy' poster + my 'blood vascular system' guide here: 

https://thatvetnurselife.co.uk/products/digital-product

https://thatvetnurselife.co.uk/products/a6-blood-vascular-system-guide-for-student-veterinary-nurses-32-page-anatomy-physiology-booklet

Thank you so much for reading, Jade 🤍

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