the.com/tectum

means The tectum is the roof-like region of the midbrain that processes sensory input — especially visual and auditory signals — and triggers quick, reflexive orienting movements like turning your head toward a sudden sound.

from Straight from Latin 'tectum,' meaning 'roof' — the past participle of 'tegere,' 'to cover,' the same root that gives us 'protect' and 'detective' (those who uncover). Anatomists borrowed the word because the structure sits atop the midbrain like a covering, forming the dorsal 'roof' over the brainstem's plumbing below.