Capillaries are like the super-thin, twisty highways of our body! With a width similar to the tenth part of a human hair (about 10μm), they're the tiniest blood vessels around. 🌌

Your eye's lens and cornea are the clear windows to your soul. They don’t have these capillary highways because they need to be transparent! So, no traffic in these parts!

• Huge Network: Capillaries aren’t lone rangers; they branch and rejoin, creating a humongous network. It's like the internet, but for your blood!
• Why So Many?: Ever wondered why there are so many tiny roads instead of a few big ones? Many capillaries increase the chance for blood and tissue to "chat" through diffusion. 🗣️💬
• Location, Location, Location: If a cell in your body is active and bustling, you bet it’s got a capillary nearby! Just like having a coffee shop close to work. ☕️

• Single Layer Avenue: The capillary wall is a one-lane street made of endothelium cells. Check out "Figure 3" for a closer look!
• Basement Membrane - The Security Guard: This gel layer, formed from crosslinked proteins, acts like a bouncer at a club. It lets in small or medium-sized "guests" (particles) but stops big ones (macromolecules) at the door.
• Porous Personality: The capillary walls have many pores, making them super permeable. Imagine a sieve, letting through part of the blood plasma but keeping the red blood cells in.