Choose the ODD one out from the following terms given and name the CATEGORY to which the others belong:
Lumen, Muscular tissue, Connective tissue, Pericardium
Topic: Layers of blood vessels
Answer
Odd one out: PERICARDIUM. Category of the others: PARTS OF AN ARTERY AND VEIN (the layers of a blood vessel).
The lumen, muscular tissue and connective tissue are all parts of the wall and cavity of a BLOOD VESSEL: LUMEN — the central cavity through which blood flows MUSCULAR TISSUE — the middle layer, thick in arteries and thin in veins CONNECTIVE TISSUE — the outer layer giving strength
The PERICARDIUM is the double membrane enclosing the HEART — an organ, not a vessel.
THE CARE NEEDED: all four belong to the circulatory system, so "circulatory system" is not a category that separates three from one. The category must be narrower — the structure of a blood vessel. Whenever every term shares an obvious label, look for a finer one.