Summary of Fisiología -Transporte de O2 y CO2 en sangre y líquidos tisulares | Parte 1

00:00:00 - 00:10:00

In the first part of the video titled "Fisiologia - Transporte de O2 y CO2 en sangre y líquidos tisulares | Parte 1," the speaker discusses the transport of oxygen and carbon dioxide in the blood and tissues. Oxygen is transported from the lungs to the bloodstream, where it is used for cellular respiration. In contrast, carbon dioxide released during cellular respiration moves from the bloodstream to the tissues. These processes occur due to the pressure gradient, with the difference in pressure between the alveoli and the bloodstream leading to the diffusion of oxygen and carbon dioxide, respectively. The speaker also discusses the binding of oxygen to hemoglobin, which enhances its transport capacity. In addition, the speaker explains the maximum amount of oxygen that can be transported by the blood and tissues and how it decreases with the presence of oxygen impurities such as methemoglobin.

• 00:00:00 In this section, the speaker discusses the transport of oxygen and carbon dioxide in the blood and tissues. Oxygen is transported from the lungs to the bloodstream through the alveolar walls and the pulmonary capillaries, which eventually form the venas pulmonales that carry the oxygenated blood to the heart. The heart pumps the oxygenated blood through the arteries, arterioles, and capillaries to the tissues of the body where it is used for cellular respiration and oxygen is consumed. This process is reverse due to the pressure gradient. In the presence of oxygen, the pressure gradient between the alveoli and the bloodstream is such that oxygen moves from the alveoli to the blood. In the presence of carbon dioxide, the pressure gradient between the bloodstream and the tissues with the accumulate of carbon dioxide is such that carbon dioxide moves from the bloodstream to the tissues. The exchange of gases between the blood and the tissues can be done through diffusion, which is the flow and exchange of substances between a region of higher concentration to a region of lower concentration. In this case, the oxygen moves from the lungs, where the concentration is high to the bloodstream where the concentration is low, due to the difference in pressure. The same process happens with carbon dioxide moving from the tissues where the concentration is high to the bloodstream where the concentration is low. This process ensures that the body receives a sufficient amount of oxygen and gets rid of carbon dioxide.
• 00:05:00 In this section of the video, the speaker discusses the transport of oxygen and carbon dioxide in blood and interstitial fluid. The speaker explains that the pressure difference between the mercury in the capillary beds of the lungs and the interstitial fluid results in the diffusion of oxygen and carbon dioxide towards and away from the lung capillaries, respectively. The speaker notes that the flow of blood and metabolism in tissue can impact the pressure of carbon dioxide in blood, with an increase in flow and metabolism resulting in an elevated pressure. The speaker also discusses the binding of oxygen to hemoglobin in blood, which enhances its transport capacity.
• 00:10:00 In this section of the YouTube video, the speaker explains the maximum amount of oxygen that can be transported by the blood and tissues. According to the speaker, when the hemoglobin is chemically pure, it can transport approximately 20 milliliters of oxygen for every 100 milliliters of blood. However, when oxygen impurities such as methemoglobin are present, this amount decreases. In a normal person, the total amount of oxygen that is transported by the hemoglobin in the arterial blood is 19.4 milliliters when it has a saturation of 97%. However, when the pressure of oxigena arterial dips to 40 millimeters of mercury and the hemoglobin is saturated at 75%, the amount transported decreases to 14.4 milliliters. In these conditions, approximately 0.29 milliliters of oxygen are transported in every 100 milliliters of blood. However, when the pressure of oxigena de the blood decreases, only 0.12 milliliters of oxygen remain dissolved in the blood in the capilaries. Therefore, the percentage of oxygen that is transported in a dissolved state is small, usually less than 3% of the total in comparison to the 97% transported by hemoglobin during intense exercise.