True Circulatory Systems: Blood Veins

STORY

True Circulatory Systems: Blood Veins

By Michael Alan Prestwood

Tue 9 Jul 2024

Published 2 years ago.

Updated 4 weeks ago.

True Circulatory Systems: Blood Veins

545 Million Years Ago (after through-gut digestion: mouth/anus)

Circulatory fluid transport (veins)

Open and closed vascular systems: As animals increased in size and complexity during the Cambrian, specialized circulatory systems evolved. Open systems allowed fluid to bathe tissues directly, while closed systems developed vessels and true blood, enabling efficient long-distance transport of oxygen and nutrients.

Blood, a specialized fluid carrying nutrients and waste, evolved around 520 million years ago in multicellular organisms. It evolved to feed internal cells and carry away waste. As oxygen levels rose and multicellular life emerged, blood evolved to transport oxygen and nutrients to cells.

— map / TST —

Michael Alan Prestwood
Author & Natural Philosopher

Prestwood writes on science-first philosophy, with particular attention to the convergence of disciplines. Drawing on his TST Framework, his work emphasizes rational inquiry grounded in empirical observation while engaging questions at the edges of established knowledge. With TouchstoneTruth positioned as a living touchstone, this work aims to contribute reliable, evolving analysis in an emerging AI era where the credibility of information is increasingly contested.