Tenn. Code Ann. § 49-6-401: "Junior high schools" and "senior high schools" defined

(a) "Junior high schools" are schools in which are taught any combination of grades corresponding to grade seven through grade ten (7-10); however, the school must include grade nine (9).

(b) "Senior high schools" are schools in which are taught any combination of grades corresponding to grade nine through grade twelve (9-12); however, the school must include grade twelve (12).