The mammary gland of the weddell seal, Leptonychotes weddelli (Pinnipedia). I. Gross and microscopic anatomy

Abstract The Weddell seal cow possesses two subcutaneous, ellipsoidal, abdominal mammary glands with a volume of two to three liters when lactating. Corrosion casts reveal that approximately ten large ducts radiate from a gland cistern at the base of the nipple, and end in a complex system of termin...

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Bibliographic Details
Published in:The Anatomical Record
Main Authors: Tedman, R. A., Bryden, M. M.
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 1981
Subjects:
Online Access:http://dx.doi.org/10.1002/ar.1091990408
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Far.1091990408
https://onlinelibrary.wiley.com/doi/pdf/10.1002/ar.1091990408
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Summary:Abstract The Weddell seal cow possesses two subcutaneous, ellipsoidal, abdominal mammary glands with a volume of two to three liters when lactating. Corrosion casts reveal that approximately ten large ducts radiate from a gland cistern at the base of the nipple, and end in a complex system of terminal branches. Each gland has a separate arterial supply, mostly from the caudal deep epigastric with a minor contribution from the deep circumflex iliac. Histologically, lactating, nonlactating (resting), and immature glands resemble those of other eutherians. Sinusoidal blood vessels, not observed in the mammary glands of other mammals, are present within lactating but not in resting lobules in the seal. The terminal pouch and lactiferous sinuses possess circular smooth muscle and elastic fibers in the walls, and accumulations of lymphocytes immediately beneath the epithelium. Sebaceous and sweat glands open into the walls of the nipple and the apex of the terminal pouch. There are extensive networks of blood vessels and longitudinal smooth muscle and elastic fibers in the walls and base of the nipple. The possible functions of these morphological observations are discussed.