It includes the complete tubular genitalia of the female and has 5 parts – infundibulum, magnum, isthmus, uterus (shell gland) and vagina. The vagina is attached to cloaca.
The anterior end of the infundibulum is a thin membranous tissue with no smooth muscles; in the posterior part it is highly muscular and glandular. It is highly motile at the time of ovulation, engulfs a follicle before ovulation and pick-up the released ovum. The infundibulum is the site of fertilization.
The magnum secretes the albumen (egg white) and is the longest portion of the oviduct. Mucosa contains tubular glands. Albumen is made up of many proteins and serves as a reserve for embryonic growth. The magnum secretion is regulated by estrogen, androgen and progesterone
The isthmus, separated from the magnum by a nonglandular band secretes shell membrane that forms an enclosing sac to hold the egg contents and provides support for the deposition of hard shell.
The shell gland (uterus) adds fluid to the developing egg, secretes hard shell, adds a proteinaceous cuticle over the hard shell and in some birds adds shell pigments. It is thick walled muscular organ, has mucosal folds covered with ciliated and non-ciliated epithelial cells. Tubular glands underlie the epithelium.
The uterus is separated from the vagina by uterovaginal sphincter. The vagina contains tubular glands (Sperm storage tubules) that are capable of prolonged storage of spermatozoa. It functions in transport of spermatozoa and transport of eggs. Sperm is stored for up to 32 days in chicken and 70 days in turkeys.