The tiny blood vessels that the meta arteries end up in are called capillaries.
What are Capillaries?
Capillaries are the smallest blood vessels in the body, connecting the arterioles (small arteries) to venules (small veins). They form an intricate network throughout tissues and organs, facilitating the exchange of substances.
Structure of Capillaries
- Thin Walls:
Capillaries have extremely thin walls, composed of a single layer of endothelial cells. This allows for easy diffusion of gases, nutrients, and waste products.
- Diameter:
The diameter of capillaries is about 5-10 micrometers, just wide enough for red blood cells to pass through in single file.
Function of Capillaries
- Exchange of Materials:
Capillaries are crucial for the exchange of oxygen and carbon dioxide between blood and tissues. Oxygen is delivered to cells, while carbon dioxide is removed for exhalation.
- Nutrient Delivery:
They transport essential nutrients, such as glucose and amino acids, from the bloodstream to individual cells.
- Waste Removal:
Capillaries also assist in removing metabolic waste from cells, transporting it to larger blood vessels for excretion.
Importance in Circulatory System
- Regulating Blood Flow:
Capillaries help regulate blood flow and pressure within the circulatory system, ensuring that blood reaches all parts of the body efficiently.
- Connection to Veins and Arteries:
Their connection to both arteries and veins allows for a complete circuit of blood flow, essential for maintaining homeostasis and overall body function.
Understanding capillaries is vital as they play a pivotal role in the circulatory system, ensuring that all bodily functions are supported efficiently.