Those letters can be rearranged to spell knuckle.
Heart
Any chance it is something to do with part of one's attitude or mindset? In that case it could be angst.
Your head is heaviest part of your body.
Hormones
Sensitivity of the body part
The letters 'leukkcn' can be rearranged to spell the body part knuckle.
It is knuckle
toenail
You can spell either bowel (internal) or elbow (external).
The letters spell the word thorax. It is a body part.
The letters spell the word liver. The liver is a body part.
traches
The fallopian tubes is a body part that begins with the letter F and has 8 letters.
Heart
armpit
Unscramble the letters and it is- and you have two of them.
tummy!