A 29-year-old female develops sepsis following a bacterial infection from a leg wound. As a consequence, she experiences profound vasodilation. For the prompt, explain in depth:
- What effect does vasodilation have on afterload and why?
- What effect does vasodilation have on blood pressure and why?
- How would her body compensate to bring her blood pressure back to homeostasis?
250 words- 2 references
A 29-year-old female develops sepsis following a bacterial infection from a leg wound. As a consequence, she experiences profound vasodilation. For the prompt, explain in depth:
- What effect does vasodilation have on afterload and why?
- What effect does vasodilation have on blood pressure and why?
- How would her body compensate to bring her blood pressure back to homeostasis?
250 words- 2 references
Vasodilation, the widening of blood vessels, has significant effects on hemodynamics, particularly afterload and blood pressure.
Effect on Afterload: Afterload refers to the resistance the heart must overcome to eject blood during systole. Vasodilation decreases vascular resistance, which consequently reduces afterload. When blood vessels dilate, the total peripheral resistance drops, allowing the heart to pump blood more easily, reducing the workload on the heart (Guyton & Hall, 2016).
Effect on Blood Pressure: Vasodilation typically leads to a decrease in blood pressure. Blood pressure is determined by cardiac output and systemic vascular resistance (SVR). As vasodilation lowers SVR, blood pressure decreases if cardiac output remains constant. This reduction can lead to hypotension, particularly in the context of sepsis, where vascular permeability increases and fluid may leak from the vasculature (Marik et al., 2017).
Compensatory Mechanisms: To restore blood pressure to homeostasis, the body initiates several compensatory mechanisms. The baroreceptors in the aorta and carotid arteries sense the drop in blood pressure and stimulate the sympathetic nervous system. This leads to increased heart rate (tachycardia) and myocardial contractility, enhancing cardiac output. Additionally, the kidneys may activate the renin-angiotensin-aldosterone system (RAAS), promoting vasoconstriction and sodium retention, which help to elevate blood pressure (Guyton & Hall, 2016).
References
- Guyton, A. C., & Hall, J. E. (2016). Textbook of Medical Physiology (13th ed.). Elsevier.
- Marik, P. E., Ramesh, M. K., & Phillips, G. (2017). Sepsis: A Review of Advances in Diagnosis, Management, and Treatment. Healthcare, 5(3), 4.