during respiration our lungs work to help the body take in oxygen while removing carbon dioxide this cycle is referred to as gas exchange and for it to function properly the amount of ventilation must match the amount of perfusion in the alveoli of the lungs this means that there should be a balance in the ventilation to perfusion ratio this topic can be quite complex however we created this video to provide you with a quick overview of this topic so if you're ready let's get into it [Music] first and foremost what is ventilation ventilation refers to the amount of air that enters and leaves the alveoli for the body to be able to obtain oxygen there first must be sufficient amounts of air that reaches the alveolar region of the lungs then there is perfusion perfusion refers to the amount of blood that flows to the alveolar capillaries for the body to be able to obtain oxygen there also must be sufficient amounts of blood passing through the lungs to pick up oxygen molecules so that it can be transported to all of the organs and tissues of the body so what is the ventilation to perfusion ratio ventilation is abbreviated as v and perfusion is abbreviated as q the vq ratio refers to the amount of air that reaches the alveoli per minute compared to the amount of blood that reaches the alveoli per minute ideally the amount of oxygen and blood reaching the alveoli would be a perfect match this would result in a vq ratio of one however of course this isn't always the case especially for patients with cardiopulmonary conditions this is when a ventilation to perfusion imbalance comes into play a vq imbalance simply means that the amount of ventilation in the alveoli does not match the amount of perfusion there could either be a high or a low vq ratio a patient would have a high vq ratio if there is more ventilation or less perfusion for example this could occur when there is decreased blood flowing through the lungs but normal ventilation just to give an example this would be seen in a patient with a pulmonary embolism an area with ventilation but no perfusion is known as dead space alternatively a patient would have a low vq ratio if there is less ventilation or more perfusion for example this could occur during atelectasis because perfusion would be normal but there would be decreased ventilation an area with perfusion but no ventilation is referred to as a shunt you should know that a vq imbalance is typically the most common cause for hypoxemia in patients with respiratory diseases that is because any respiratory condition that causes decreased ventilation would result in a vq mismatch and eventually lead to low oxygen levels in the blood like i said before this topic can get pretty complex we made this video to try to simplify things and give you a quick overview of this topic we'll be breaking it down into much more detail in a future video real quick guys do me a huge favor and hit the like button it really helps support the channel and i greatly greatly appreciate it and while you're down there go ahead and click the subscribe button as well because we have a ton of other videos on our channel that i think you will enjoy just a quick reminder we are not doctors this video is for educational and informational purposes only and if you want to dive deeper and learn more about this topic you can go to respiratorytherapyzone.com where we have a ton of free study guides practice questions and other helpful resources i'll drop links to everything you need right below this video down in the description thank you so much for watching all the way to the end have a blessed day and as always real easy my friend [Music] you