Skill:
• Identification of blood vessels as arteries, capillaries or veins from the structure of their walls
The difference in the structural characteristics of arteries, capillaries and veins is attributable to their respective functions
- Arteries have thick walls and narrow lumens because they transport blood at high pressure
- Capillaries have walls that are only a single cell thick because they exchange materials between blood and tissue
- Veins have thin walls with wide lumens and valves because they transport blood at low pressure
Comparison of Blood Vessel Structure
Identification of Blood Vessels
Blood vessels can be identified from histological slides or images according to the thickness of their walls:
- Arteries have thick walls composed of three distinct layers (tunica)
- Veins have thin walls but typically have wider lumen (lumen size may vary depending on specific artery or vein)
- Capillaries are very small and will not be easily detected under the same magnification as arteries and veins
Identify the Blood Vessel
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