The Hen -All Grown Up

It is always a good idea to learn some of the anatomy terms for your chickens. I have used these terms to describe my chickens if they are sick or hurt, or to distinguish from different breeds, etc.
A wonderful book for this is called The Field Guide to Chickens, by Pam Percy. She explains all the different combs, colors, patterns, breeds (and more) of chickens.
Here are some common terms to know of the chicken anatomy starting from head to feet:

-Comb: Located on top of the head. It is red and "meaty" looking. There are many different varieties of combs in shape and color. The comb plays a role in attracting a mate, it helps cool the body temperature in hot weather, and is an indicator of overall health.
-Wattles: Located under the beak. Red and meaty looking. Has same qualities as the comb. Visit this site for further information: http://communitychickens.blogspot.com/2011/01/chickens-comb-more-than-fashion.html
-Earlobes: Located behind the eyes. Generally, earlobe color indicates egg color. White earlobes for white eggs, and red earlobes for brown eggs.
-Primary feathers: These are the feathers on the very end of the wing. They are also called flight feathers. If you cut these, it will usually prevent a chicken from "flying".
-Hackle feathers: The hackles are the long pointy feathers around the neck.
-Saddle feathers: The longer feathers falling on the sides of the chicken just before the tail feathers.
-Crop: Is the part of their chest that bulges out slightly to the right. This is where they store their food before it is digested.
-Vent: The hen and rooster's reproductive organs are located inside the vent. (The egg of the hen comes out of this hole, but through a different tube than the poop would travel through, so the egg is sanitary). It should look pinkish/yellow and clean.
-Hock: The ankle, located in the middle of their leg that bends, this can get sprained or broken. 
-Shank: The shin, in human terms. The chicken leg has scales, and come in many different colors.
-Spur: Most prominently on roosters. Looks like a giant claw on the inside of the leg. Used as a defense mechanism. The hen usually just has a little knob for a spur.
-Toes: Chickens have between 4-5 toes.

"Healthy chickens…

Sugar, 5 months old

• When fully grown the chicken should sport a nice firm comb
• The comb will be bright red when the chicken is in lay.
• The eyes should be beady and bright.
• A healthy chicken will be perky, lean and active.
• Scales on the legs and feet should be smooth and not lifting.
• The colour of the legs is a good indicator of whether the chicken is laying. If they are very yellow then she is probably not laying eggs yet. If they are pale almost white then she probably is.
• When you pick your chicken up her body should be plump and firm, but with no flabbyness.
• You can examine your chickens eyes and nose to check there are no discharges.
• The vent (the chickens all-purpose exit point) should be moist and white, with no lumps, crustiness, bleeding etc." -http://www.keepchickens.info/health/