Infundibulum

An infundibulum (Latin for funnel; plural, infundibula) is a funnel-shaped cavity or organ.

• Lungs: The alveolar sacs of the lungs from which the air chambers (alveoli) open are called infundibula
• Heart: The outflow portion of the right ventricle, the infundibulum of the heart, is another name for the conus arteriosus
• Ovary: The end of the mammal oviduct nearest to the ovary is the infundibulum of uterine tube
• Brain: A small outgrowth of the ventral wall of the embryo brain from which the pars nervosa (the posterior lobe) of the pituitary gland develops is also called the infundibulum. (Another name for this structure is the pituitary stalk.)
• Kidney: Part of the collecting system in the kidneys; urine flows from the calyces, through the infundibula into the renal pelves
• Ethmoid bone: Ethmoidal infundibulum
• In plant morphology, infundibular means funnel-shaped, for example in the corolla of a flower.

Other uses

• In the science fiction novel The Sirens of Titan by Kurt Vonnegut, a "chronosynclastic infundibulum" is a kind of wormhole through time and space, defined as "where all the different kinds of truths fit together".
• In the fantasy novel Little, Big by John Crowley, the character Theodore Bramble considers "a peculiar geography I can only describe as infundibular ... I mean by this that the other world is composed of a series of concentric rings, which as one penetrates deeper into the other world, grow larger. The further in you go, the bigger it gets."
• In geometry, infundibular refers to the arc of a sphere or any portion of a circle.