head; cranial region
Refers to the head as a body part, often in medical, anatomical, or formal contexts. More clinical than 頭 (あたま).
I injured my head in the accident.
We will take a CT scan of your head.
He fell and hit his head hard.
He sustained a head injury in the accident.
You protect your head with a helmet.
A falling rock hit him on the head.
頭部 (とうぶ) refers to the whole head region including skin and muscle, whereas 頭蓋骨 (ずがいこつ) refers specifically to the skull bone underneath.
Sino-Japanese compound of 頭 (head) and 部 (part, section).