Causes of Depolarization

Depolarization of muscles refers to the muscle when it is in the contracted state. Negative effects can occur if a muscle is depolarized due to an unexplained change in chemical actions. This causes a change to the smooth muscles. Depolarization can cause the pulmonary artery to be out of rhythm. Some muscles can become permanently and painfully drawn due to prolonged depolarization. There are known factors that occur to cause depolarization.

Acute Hypoxia

Acute hypoxia is the rapid reduction of oxygen available for use by the body's tissues. This can be caused by airway obstruction, asphyxia, hemorrhage or sudden cardio-respiratory failure. Changes in oxygen tension can cause high pulmonary vascular tone and create arrhythmic contracts or depolarization. Acute hypoxia can be experienced by anyone in any age group. Infants in a neonatal unit experience oxygen reduction as well as people who are elderly. Some indicators of acute hypoxia are hypoventilation or hyperventilation that cause headaches, confusion and loss of consciousness.

Hyperkalemia

Hyperkalemia refers to the concentration of levels of potassium in blood plasma or serum. When potassium levels increase, this can cause a change in the membranes of smooth muscles, which causes depolarization to occur. The increase in potassium in the body causes excesses to build up. These excesses can cause the body to release more potassium ions than the body can handle. A typical person has the ability to regulate the flow of potassium by preventing the release through cellular activity. When this fails, a person's body will force him to get rid of the extra potassium through urination or vomiting. When all three self-protection mechanisms fail, depolarization occurs in smooth muscles such as the heart.

Voltage

Artificial depolarization of a muscle can occur with a low voltage placed on a nerve that sends the current to the muscle. The electrical current will trigger the muscle to contract. This is the basis of physical therapy stimulation treatments for people who have weakened muscles due to stroke or injury. The low voltage stimulation is also used for vital stimulation therapy to train the muscles of people with dysphasia (weakened swallow muscles) to swallow. The probes are placed on the targeted muscles and a trained therapist adjusts the voltage and rhythm of the electrical stimulation. The voltage causes the muscle to depolarize, which sends a signal to the brain and other nerve endings. The goal is to train or retrain the patient to learn the movements as well as strengthen the muscle.