Cloaca

is the posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts

Vagina

Is the tube that connects the uterus with the cloaca and is very complex in mallards

Pouches

Pouches are ‘‘dead end’’ side cavities in the vaginal lumen that cannot be eliminated by longitudinal elongation of the vagina. Pouches are located in the distal end of the vagina, close to the cloaca, and varied in number from 0–3 among species.

Uterus

In the uterus of birds the calcareous shell of the egg is formed and pigment is added.

Egg

It lays inside the uterus here to get its shell.

Isthmus

the shell membranes are deposited here.

Magnum

In a couple of hours the egg receives a coating of albumen here.

Infundibulum

Is the end of the fallopian tube where the ciliary currents carry the egg into the Magnum region

Ovary

Ovulation results in the release of an egg from a mature follicle on the surface of the ovary.The egg has extensive food reserves in the form of concentric layers of yolk.