Very few people know how their own respiratory and circulatory systems function. Because a spinal cord injury (Refers to damage to the spinal medulla. ) can affect these systems, it is important to understand how these less known parts of our anatomy interact.
The circulatory system, also known as the blood system, is in charge of “food distribution” and “collecting waste” in the organism. Blood carries the nutrients (Nutritional elements that the body requires like proteins, carbohydrates, lipids, vitamins and minerals. ) produced by digestion and oxygen to the cells. This system also carries cellular waste products to the kidneys and lungs where it is eliminated. When you inhale, the organism assimilates oxygen from the air. When you exhale, the organism expels carbon dioxide, which is a waste product from cellular activity.
Circulation and respiration are intimately related, and the body regulates these systems to maintain a balance between the level of oxygen and carbon dioxide in the blood flow.
A spinal cord injury (Refers to damage to the spinal medulla. ) can affect these vital functions. Blood vessels in paralyzed limbs lose the capacity to widen: “vasodilatation (Increased calibre of a vessel due to muscle release (antonym: vasoconstriction). )” is when a blood vessel dilates, and “vasoconstriction” is when a blood vessel constricts. These variations are necessary to regulate the body temperature and blood pressure. A spinal cord injury (Refers to damage to the spinal medulla. ) therefore affects the blood pressure, heart, and body temperature. When the respiratory muscles are affected by paralysis, pulmonary functions and the coughing capacity are limited.
These functions are more limited when the injury is in a higher area. Trauma (Any lesion or injury produced within a limited area of the body resulting from an external violent action of shock. ) in the cervical spinal cord can compromise breathing in different ways. For tetraplegics, residual muscles may compensate partially or fully for lost functions in certain respiratory muscles. At the time of the accident, these muscles maintain the injured person alive until the rescue services arrive. However, they can fatigue and might not be capable of doing the whole work on their own indefinitely. A respirator (Mechanism used for artificial respiration. ) may then be used. Just like any other muscle that is regularly trained, residual muscles strengthen over time. They generally become sufficient for the respiratory system to function.