Word Count : 1104

---

The transportation of oxygen and carbon dioxide by the blood is essential for maintaining the physiological processes necessary for cellular metabolism. Oxygen is required by cells for aerobic respiration, while carbon dioxide is a waste product of this process that must be expelled from the body. The mechanisms by which these gases are transported involve complex interactions between the respiratory and circulatory systems, specifically the lungs, red blood cells, plasma, and various proteins such as hemoglobin. ### Oxygen Transport in Blood The majority of oxygen transport occurs via red blood cells (RBCs), specifically through the protein hemoglobin. Oxygen is relatively insoluble in plasma, so the body relies on hemoglobin for efficient transport. #### 1. Oxygen Transport Mechanisms Oxygen is transported in two primary forms: * Dissolved in plasma: About 1.5–2% of oxygen is transported in dissolved form. This small fraction exerts the partial pressure of oxygen (PaO₂) and plays a critical role in the diffusion of oxygen across alveolar membranes. * Bound to hemoglobin: Approximately 98–98.5% of oxygen binds to hemoglobin in RBCs to form oxyhemoglobin (HbO₂). Each hemoglobin molecule can bind up to four oxygen molecules due to its four heme groups, each containing an iron atom. #### 2. Oxygen-Hemoglobin Dissociation Curve The oxygen-hemoglobin dissociation curve represents the relationship between PaO₂ and hemoglobin saturation (SaO₂). It is sigmoid in shape due to cooperative binding. At high PaO₂ (e.g., in pulmonary capillaries), hemoglobin binds oxygen readily. In systemic capillaries, where PaO₂ is lower, hemoglobin releases oxygen to the tissues. Several factors can shift this curve: * Right shift (facilitates oxygen release): increased CO₂ (Bohr effect), increased temperature, decreased pH, and increased 2,3-bisphosphoglycerate (2,3-BPG). * Left shift __________ __________ ____ _____ ____ _________ ___ ___.
_____ _________ _________ _________ _____ __________ ___ _____.
__________ ________ ___ ___ __________ __________ ______.
__________ _________ _________ ______ ___ ____ _______ ____ _____.
____ _______ ___ ________ _________ __________ __________ _________ ___ ____ _________ ____.
_____ _______ ____ _____ _____.
___ ____ _________ _____ ___ _______ ______ ______ ______.
___ __________ ____ _____ __________ __________.
_______ ______ _______ __________ _________ ______ ____.
______ ______ ______ _________ ______ ______.
________ ______ ___ _____ ______ _____ ______.
_______ _____ ______ ________ _______ ________ _______ ___.
____ _____ _______ ____ ____ _____ ___ _____ ____ ___.
______ ______ __________ __________ _________.
________ ___ ______ _____ _________ ______ _______.
____ __________ _________ _________ _______ _______ ______ __________.
________ __________ __________ ___ ________ _______ _______ ____ _____ ___ ________.
___ ____ ______ ____ _________ ___ ____.
___ ______ ___ ___ ___ _______ _________ __________ ___ ___.
________ _______ ____ ______ ____ ______ _________ _________.
____ ___ __________ _____ __________.
___ _________ _____ _________ _________ _________.
______ _______ ________ ____ ____ ___ __________ _____.
______ ______ ____ _____ _______ _______ _______ _____.
___ _________ ______ ___ ____ ________ _____ ______ __________ __________.
____ ___ _________ _____ ________ _____ ________ ______.
______ ________ ______ _________ ___ _______ ___ ___ _________ ____.
_________ ________ ____ _____ _________ ___ ___ ______ _____.
________ _____ ____ ___ __________ _______ ______ ______.
______ _________ ____ __________ ____ ____ __________ _______ __________ ______ ________.
_______ _____ ___ _________ _______ ________ ______ ____ __________ ___ _________.
_________ ______ _____ _______ _______ __________ _______ ________.
_______ _______ ___ __________ ___.
_____ _________ _________ ____ _____ _________ ________ ________ _____ __________ ___.
_________ __________ ___ _____ ___ ___.
__________ ________ _______ ______ _______ _____.
____ ________ ____ _______ ___ _____ ___ ________.
____ __________ _____ _______ ___ ___ _________ ______ __________ ________ ________ __________.
_________ ____ ___ ______ ______ ___.
_________ _____ ______ _____ __________ ___.
____ _____ ______ _______ __________ _____ _________ ________ ________ _________ ____.
________ __________ _____ _____ ____ ___ ______ ________ _____ _______ _______ ____.
_________ ________ ______ ____ _______ __________ ___ _____ ___ ____ ____.
______ __________ __________ __________ _________ ________ ___ _________ ____ _______ _______.
_________ ________ _______ __________ _________ ________ ______ _____.
__________ _____ _________ ______ ________ ________ __________ _______ ____ ___ __________.
_______ _____ ______ ____ ___ ______.
_______ ______ ______ _________ ____ ________ ___ _________ ________ ____.
_____ ___ ____ ______ ______ _________ ____ _______ ____ _______ _______ ________.
___ _________ __________ _________ ___ ______ _____ __________.
____ ______ ____ _________ _______ _____ _____ __________.
__________ __________ ____ __________ ___ __________ ____.
______ _____ _______ ____ _________ ___ __________ __________.
__________ _________ _______ __________ ________ ______ _____ _________ _________ ______ ________ ______.
________ ________ ____ _____ ____ ______ ______.
___ ____ ___ _____ ___ ____ _____ ___ _______ _______.
___ ______ ________ _____ _________ ________ __________ _________.
______ ______ __________ _______ __________ _________ _________ _______ ______ _____.
_____ ________ ________ ________ _______ ______ _______ ____ _________ _________ ___ _____.
______ __________ ______ ______ ___ ________ _____ ____ ___.
___ ___ ________ ________ ___ _______ ______.
_______ _____ ___ _________ ______.
________ _______ ___ _________ __________ ________ _______ ______ ______ ______ _____.
____ __________ _________ _________ _____ _______ ________.
___ ___ _____ ________ ______ ____ ___.
_____ _______ _____ ___ ___ ______.
_________ ____ _____ __________ ___.
____ _______ _________ ___ __________.
___ _______ _______ ________ _________ _______.
______ ___ __________ _____ __________ _____ ________ __________ ____ ________ ________.
______ _________ ________ ___ __________ _______ _____.
________ ______ _______ ________ ____ __________ ___.
________ ________ __________ ___ _____ __________ _____.
__________ _________ _________ ____ _____ ______.
___ _______ ______ _________ __________ ______.
_______ ______ ___ _________ _________ ____ ___ __________ ______.
________ _________ _______ _________ _______ ____ ____ ________ __________ ___ ___.
______ ____ _____ _____ ____ _____.
______ ________ _____ ______ _________.
___ _____ _____ _______ _________ ____ ________ _________ _______ _______.
_______ ________ _____ _______ ______ _____ ________ ____ _____ ____ ____.
_________ ________ ______ ___ ______ _____ __________ __________ ____ _____ __________ ______.
__________ ____ ____ ________ _______.
__________ ____ ____ ____ ________ _______ ______ ______ ___ ________ ______.
__________ ______ ________ _______ ____ ___ _________ _______ _____ _______ ________ _______.
_____ ___ ______ ________ _________ _____ _____ ___.
________ _______ ____ ______ ______ ______ ______ ___ ______ ________ __________ ___.
___ ____ ___ ___ ____ ___ ____ ______ ___ ___ ________.
_________ _____ _____ ____ ____ __________ ________ ________ __________ _________ ___.
___ ___ ________ __________ ____.
_______ __________ ______ ______ ______.
___ _____ ________ ________ _________ __________.
_______ __________ __________ _________ _______ __________ _________ _________ ___ ___ ________ ___.
____ ________ ________ _____ __________ _______ _____.
______ ________ _______ ___ _______ __________ _________ ___.
___ ______ ________ _______ _________ ___ ______.
_______ __________ ______ ________ ___ _________ _____ _______ ______ _______ _____ ______.
________ __________ ____ ______ ______ ___ _________ _______ ________ __________ ________ _________.
____ ______ ________ __________ ____ ________.
Get Full Answer on WhatsApp