Final answer:
The cecum is the part of the large intestine that attaches to the appendix. It serves as a sac-like structure that continues the absorption of water and salts. The appendix, although vestigial, may have an immunologic function and serve as a bacterial reservoir.
Step-by-step explanation:
The part of the large intestine that attaches to the appendix is the cecum. It is a sac-like structure that receives the contents of the ileum and continues the absorption of water and salts. The appendix is a winding tube that attaches to the cecum, and although it is considered vestigial, it may have an immunologic function and serve as a bacterial reservoir.