Doctor heads first for part of the Midlands (13)
I believe the answer is:
staffordshire
'part of the midlands' is the definition.
The definition suggests a singular noun which matches the answer.
'doctor heads first for' is the wordplay.
'doctor' is an anagram indicator.
'heads'+'first'+'for'='headsfirstfor'
'headsfirstfor' with letters rearranged gives 'STAFFORDSHIRE'.
Can you help me to learn more?
(Other definitions for staffordshire that I've seen before include "County E. of Shropshire" , "English county" .)