Janine recently had surgery on the neck, or narrow lower portion, of her uterus. janine's surgery was performed on the:

Cervix

Janine recently had surgery on the neck, or narrow lower portion, of her uterus. Janine's surgery was performed on the cervix.  

The cervix is the narrow neck-like passage that forms the lower portion of the uterus in the human female reproductive system. The cervix joins the vagina and uterus and it is mainly made up of fibromuscular tissue. The two major parts of the cervix are ectocervix and endocervix. During menstrual cycle, the cervix opens a bit to allow the passage of menstrual flow. The cervix also dilates largely to allow the passage of baby during childbirth.

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.