The Head of each local body is Jesus Christ. He is also the Great Shepherd; serving under Him as spiritual shepherds of each church are elders, chosen by the church from among its male members who meet all scriptural qualifications.  1 Timothy 3:2-7 ;  Titus 1:6-9 ;  Titus 1:5  suggests that a plurality of elders is warranted for church oversight. Each elder is then to function as one of that plurality in each church.
New Testament scriptures expressly assign the below functions to elders: