An infundibulum is a funnel-shaped cavity or organ.

Lungs

The alveolar sacs of the lungs from which the air chambers (alveoli) open are called infundibula

Ovaries

The end of the mammalian oviduct nearest to the ovary also bears this name.

Brain

A small outgrowth of the ventral wall of the embryonic brain from which the pars nervosa of the posterior lobe of the pituitary gland develops is also called the infundibulum.