Final answer:
Neurogenic shock is a form of vascular shock that occurs with cranial or spinal injuries that damage the cardiovascular centers in the medulla oblongata or the nervous fibers originating from this region. It is characterized by a decrease in systemic vascular resistance, leading to low blood pressure and poor tissue perfusion.
Step-by-step explanation:
Neurogenic shock is a form of vascular shock that occurs with cranial or spinal injuries that damage the cardiovascular centers in the medulla oblongata or the nervous fibers originating from this region. It is characterized by a decrease in systemic vascular resistance, leading to low blood pressure and poor tissue perfusion. In neurogenic shock, the injured nervous system fails to properly regulate blood vessel tone, resulting in vasodilation and decreased blood flow.
The pathophysiology of neurogenic shock involves disruption of the autonomic nervous system's control over the cardiovascular system. Normally, the sympathetic nervous system releases norepinephrine, which causes vasoconstriction and increased heart rate. However, in neurogenic shock, this response is impaired due to damage to the nerves controlling blood vessel tone and heart rate in the medulla oblongata.
As a result, the parasympathetic nervous system dominates, leading to vasodilation and bradycardia. This causes a decrease in systemic vascular resistance and cardiac output, resulting in low blood pressure. Additionally, the loss of sympathetic control over blood vessels can lead to pooling of blood in the veins, further decreasing venous return and cardiac output.