Why does a vasoconstrictor drug, like phenylephrine, increase blood pressure in patients experiencing septic shock?

💡 Explanation

Vasoconstrictors increase blood pressure by narrowing blood vessels. This is because the mechanism of increased systemic vascular resistance directly elevates arterial pressure. Therefore, blood pressure rises rather than venous return decreasing or stroke volume changing directly.

• What distinguishes proteasomal degradation from chaperone-mediated autophagy in intracellular protein clearance?
• A 75-year-old patient with decreased lung compliance demonstrates reduced forced expiratory volume (FEV1). Which mechanism explains this decline in pulmonary function, given age-related tissue changes?
• If an athlete restricts water intake before prolonged exercise, why does plasma osmolality increase despite vasopressin release affecting the collecting ducts?
• An individual with hypertension starts taking a medication that blocks angiotensin II receptors. Which outcome is most likely regarding cardiovascular hemodynamics?
• Why does severe dehydration impair thermoregulation more significantly in elderly individuals compared to younger adults during prolonged exposure to high ambient temperatures?
• Following a bout of streptococcal pharyngitis, what explains the development of acute rheumatic fever despite antibiotic treatment that eradicated the bacteria?