NEET PG DENTAL EXAM

Detailed explanation-1: -In biology, a lumen (plural lumina) is the inside space of a tubular structure, such as an artery or intestine. It comes from Latin lumen ‘an opening’.

Detailed explanation-2: -Resistance arteries are vessels with lumen diameters measuring <400 m when relaxed, and they constitute the major site of generation of vascular resistance. These vessels include small arteries, with relaxed passive lumens of more than ≈100 m (values vary between authors), and arterioles, which are smaller.