Advanced Mammary Lobules and Ducts Quiz

Q1. Which portion of the mammary ductal system is directly associated with the lobule in a terminal duct lobular unit?

• Cystic duct
• Thoracic duct
• Terminal duct
• Common bile duct

Q2. Why is the terminal duct lobular unit especially important in breast pathology?

• It contains the principal motor nerve of pectoralis major
• It forms the axillary artery
• It separates the lung from the pleura
• Many common proliferative and neoplastic breast processes arise within or involve it

Q3. Which cell population provides a contractile layer around many mammary ducts and alveoli?

• Purkinje cells
• Fibrocartilage cells
• Myoepithelial cells
• Osteoclasts

Q4. What is the principal functional consequence of oxytocin acting on mammary myoepithelial cells?

• Milk ejection into and through the ductal system
• Closure of all lactiferous ducts
• Formation of axillary lymph nodes
• Production of breast adipose tissue

Q5. Which structural change occurs in mammary lobules after lactation ceases?

• Permanent ossification of the lobules
• Complete disappearance of all mammary ducts
• Regression of the expanded secretory apparatus
• Transformation of lobules into skeletal muscle

Q6. Which description best characterizes the resting adult mammary gland compared with the lactating gland?

• The resting gland has less-developed secretory alveoli and relatively prominent ducts
• The resting gland contains more active secretory alveoli than the lactating gland
• The resting gland is composed entirely of smooth muscle
• The resting gland has no ductal structures

Q7. Which statement best describes the epithelial organization of the terminal mammary ductal system?

• Luminal epithelial cells are accompanied externally by myoepithelial cells and a basement membrane
• The duct wall is composed primarily of hyaline cartilage
• The ducts are lined exclusively by skeletal muscle fibers
• The ducts lack epithelial lining

Q8. Which statement best describes the older concept of a lactiferous sinus near the nipple?

• The lactiferous sinus is another name for the retromammary space
• The lactiferous sinus is a lymph node within the nipple
• Every lactiferous duct forms a large permanent chamber filled with milk
• A large reservoir-like lactiferous sinus is not consistently present as traditionally depicted

Q9. How are the mammary lobules and major lactiferous ducts functionally connected?

• Lobules and lactiferous ducts have no anatomical continuity
• Small ducts from lobules merge into progressively larger ducts that lead to the nipple
• Each lobule empties directly into the bloodstream
• Each lobule connects directly to an axillary lymph node instead of a duct

Q10. Which statement best integrates the anatomy of mammary lobules and ducts?

• Lobules are isolated structures without ducts or epithelial cells
• Mammary ducts primarily transport lymph from the breast
• Lobules contain terminal glandular units connected to a branching ductal system that conveys milk toward the nipple
• The mammary ductal system is formed from skeletal muscle and cartilage