Journal of Veterinary and Animal Sciences

Volume: 55 Issue: 1

  • Open Access
  • Research Article

Gross anatomy, topography and histology of murine mammary fat pads with study of ductal architecture using whole mount technique

J. Jayalakshmi1, Leena Chandrasekhar1*, N. Ashok1, K.M. Lucy1 and T.V. Aravindakshan2

1. Department of Veterinary Anatomy College of Veterinary and Animal Sciences, Mannuthy, Thrissur- 680 651

2. Centre for Advanced Studies in Animal Genetics and Breeding

Kerala Veterinary and Animal Sciences University Kerala, India

*Corresponding author: [email protected], Ph. 6238231353

Year: 2024, Page: 160-166, Doi:

Received: Oct. 13, 2023 Accepted: Dec. 13, 2023 Published: March 31, 2024


Mice are commonly used as a model organism in human breast cancer research. Understanding the normal histology of the mouse mammary gland is necessary to appreciate any abnormality in the tumour microenvironment. This study focuses on the morphological variations occurring in the mouse mammary gland in relation to their parity with special emphasis on orthotopic sites for tumour induction. The gross anatomy, topography and histology of the mammary gland has been described. The predominance of adipose tissue makes mice mammary fat pad unique. In nulliparous mice, ductal structures could be identified in all the five pairs of mammary fat pads. Adipose tissue was present in all the five mammary fat pads being the least in the cervical (first) mammary fat pad. Understanding the ductal architecture of murine mammary fat pads will be great importance to researchers for constructing mouse intra-ductal models (MIND) models. From the whole mount technique of the fourth mammary fat pad, it was observed that the mammary fat pad in mouse contained a single lactiferous duct, branched into four to five secondary ducts, which in turn branch into numerous tertiary ducts and ended in a bulbous structure called terminal end buds (TEBs). No division into separate lobules unlike in humans. The sub-iliac lymph node was located within the fourth mammary fat pad. In parous animals, the terminal end bud structures elongate and proliferate to form lobulo-alveolar units. Adipose tissue was scant as compared to the nulliparous gland. For the whole mount technique, an extended fixation time of 12 hours in Carnoy’s fixative was recommended for the parous mammary gland.

Keywords: Mammary gland, terminal end buds, whole mount, ductal structures


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Cite this article

Jayalakshmi, J., Leena, C., Ashok, N., Lucy, K.M. and Aravindakshan, T.V. 2024. Gross anatomy, topography and histology of murine mammary fat pads with study of ductal architecture using whole mount technique. J. Vet. Anim. Sci. 55(1):160-166