nipple

note: all information in this writeup is with regards to human anatomy

In case anyone was not entirely clear about it, the nipple is the thing that sticks out from the breast. The areola is the coloured area around the nipple.

Also known as the mammary papilla, the nipple is the outlet for 15-20 lactiferous ducts which are arranged cylindrically around the tip of this projection of the breast.

Small non-striated muscle cells (myocytes) arranged cylindrically within the nipple are responsible for the nipple becoming erect when they are stimulated (for example, by suckling).

Embryologically, nipples develop along the 'milk lines' which extend from mid-clavicle down to the pubis on either side in humans. Most people develop two (one on each side) but some have supernumerary nipples. Occasionally, the extra nipples have lactiferous glands attached.

The physiological purpose of nipples in humans is to express milk during lactation. Sometimes, babies (male or female) are born expressing milk. This is called "witches' milk", is caused by maternal oestrogens acting on the baby and is quite normal. Witches' milk disappears after several days.

Foreigners may notice the unusual obsession Americans have with nipples. What is merely a feeding duct in most of the Communist world and some primitive collonies is a one of life's great questions in the USA, perhaps only surpassed by paint chips. In no other country, you'll be reminded so constantly of the fact nipples get erect in cold weather, can poke through superheroes' steel costumes, are frequently chased by horny teenagers and so many other lifesaving subjects.

Of course, we here slave over buttocks, so what can I say.

Nip"ple (?), n. [Formerly neble, a dim. of neb. See Neb, Nib.]

1. Anat.

The protuberance through which milk is drawn from the breast or mamma; the mammilla; a teat; a pap.

2.

The orifice at which any animal liquid, as the oil from an oil bag, is discharged.

Derham.

3.

Any small projection or article in which there is an orifice for discharging a fluid, or for other purposes; as, the nipple of a nursing bottle; the nipple of a percussion lock, or that part on which the cap is put and through which the fire passes to the charge.

4. Mech.

A pipe fitting, consisting of a short piece of pipe, usually provided with a screw thread at each end, for connecting two other fittings.

Solder nipple, a short pipe, usually of brass, one end of which is tapered and adapted for attachment to the end of a lead pipe by soldering.

© Webster 1913.