M04.03.015 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
| Component | Description |
|---|---|
| Superficial Plexus | Beneath the dermis, involved in thermoregulation. |
| Deep Plexus | Located in subcutaneous tissue, supports skin nutrition. |
| Arteriovenous Anastomoses | Direct connections between arterioles and venules, crucial for heat exchange. |
Table 2: Functions of Cutaneous Circulation
| Function | Description |
|---|---|
| Thermoregulation | Adjusts blood flow to regulate body temperature. |
| Protection | Delivers immune cells and aids in wound healing. |
| Nutrient Supply | Provides oxygen and nutrients to the skin. |
| Waste Removal | Removes metabolic byproducts from the skin. |
Table 3: Regulation Mechanisms
| Mechanism | Effect on Blood Vessels | Key Mediators |
|---|---|---|
| Neural Control | Vasoconstriction/Vasodilation | Norepinephrine, Acetylcholine |
| Hormonal Control | Vasoconstriction/Vasodilation | Adrenaline |
| Local Factors | Vasodilation/Vasoconstriction | Nitric Oxide, Endothelin |
Bibliography
- 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
- 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
- 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
- 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