M04.03.15 Cutaneous circulation

Cutaneous circulation refers to the blood flow in the skin, playing a vital role in thermoregulation, nutrient delivery, and waste removal. It involves a complex network of blood vessels regulated by neural and hormonal mechanisms to maintain homeostasis.

1. Anatomy of Cutaneous Circulation

• Superficial Plexus: Located just beneath the dermis.
• Deep Plexus: Found in the subcutaneous tissue.
• Arteriovenous Anastomoses (AVAs): Direct connections between arterioles and venules, bypassing the capillaries, crucial for temperature regulation.

2. Functions of Cutaneous Circulation

• Thermoregulation: Adjusts blood flow to the skin to regulate body temperature.
• Protection: Supplies immune cells and facilitates healing.
• Nutrient Supply and Waste Removal: Delivers oxygen and nutrients while removing metabolic wastes.

3. Regulation Mechanisms

• Neural Control
  • Sympathetic Nervous System: Vasoconstriction and vasodilation via norepinephrine and acetylcholine.
• Hormonal Control
  • Adrenaline: Causes vasoconstriction or vasodilation depending on receptor types.
• Local Factors
  • Nitric Oxide (NO): Vasodilation.
  • Endothelin: Vasoconstriction.

4. Clinical Relevance

• Raynaud’s Phenomenon: Excessive vasoconstriction leading to reduced blood flow to extremities.
• Hyperhidrosis: Excessive sweating due to overactive sweat glands.
• Peripheral Arterial Disease (PAD): Reduced blood flow causing ischemia.

Tables with Key Points to Remember

Table 1: Anatomy of Cutaneous Circulation

Table 2: Functions of Cutaneous Circulation

Table 3: Regulation Mechanisms

Bibliography

1. Johnson, J. M., & Kellogg, D. L. (2010). Thermoregulatory and thermal control in the human cutaneous circulation. Frontiers in Bioscience, 2, 825-853. doi:10.2741/s116
2. Charkoudian, N. (2003). Skin blood flow in adult human thermoregulation: how it works, when it does not, and why. Mayo Clinic Proceedings, 78(5), 603-612. doi:10.4065/78.5.603
3. Kellogg, D. L. (2006). In vivo mechanisms of cutaneous vasodilation and vasoconstriction in humans during thermoregulatory challenges. Journal of Applied Physiology, 100(5), 1709-1718. doi:10.1152/japplphysiol.01071.2005
4. Minson, C. T. (2010). Thermal provocation to evaluate microvascular reactivity in human skin. Journal of Applied Physiology, 109(4), 1239-1246. doi:10.1152/japplphysiol.00414.2010