Use 'venous' when discussing anything related to veins in a health or medical situation.

Medical Context

'Venous' is often used by healthcare professionals and in academic texts, not in casual conversation.

Technical Term

'Venous' refers specifically to veins, not to arteries, so don't confuse it with 'arterial', which relates to arteries.

Not Arterial

 Here, venous blood warmed up by the shark's working muscles passes right next to arteries carrying cold, oxygen-rich blood from the gills. This arrangement transfers heat to the blood that gets cycled back to the body's vital organs. Warmer muscles enable faster, more powerful swimming, while warmer bellies aid digestion,

Why are sharks so...

 like a finger the gentleman up there had his finger chopped off by the it by an axe a guy on the bottom had his ear bit off by a dog you ever notice it's always a guy and leeches will remove the pooling blood to promote venous circulation there are other cases where leeches