MSK-2- ANATOMY- Mammary Glands

Question 1

What is the primary function of modified sweat glands in the breast?

Answer 1

Modified sweat glands secrete milk, and they are fully developed in adult females as an accessory sex organ.

Question 2

What is the condition of the breast in males and prepubertal females?

Answer 2

The breast is rudimentary in males and females before puberty.

Question 3

Where is the nipple in males and nulligravida females?

Answer 3

The nipple is located opposite the 4th intercostal space.

Question 4

What is the areola?

Answer 4

The areola is the central pigmented area surrounding the nipple.

Question 5

Where is the breast located anatomically?

Answer 5

The breast is located in the superficial fascia of the pectoral region.

Question 6

What are the horizontal and vertical extents of the breast?

Answer 6

Horizontally, it extends from the lateral border of the sternum to the mid-axillary line (including the axillary tail). Vertically, it extends from ribs 2 to 6 in the midclavicular line.

Question 7

What structures does the breast rest on?

Answer 7

The breast rests on the pectoral fascia (covering pectoralis major muscle), serratus anterior muscle, and external oblique muscle.

Question 8

What is the axillary tail of the breast?

Answer 8

The axillary tail is the lateral extension of the upper lateral quadrant of the breast that pierces deep pectoral fascia and communicates with anterior axillary lymph nodes.

Question 9

What are the three main components of the breast structure?

Answer 9

1. Skin with nipple and areola 2. Parenchyma (lobes, lobules, alveoli, and duct system) 3. Stroma (adipose tissue, connective tissue, Cooper’s ligaments).

Question 10

What is the parenchyma of the breast?

Answer 10

The parenchyma consists of 15-20 lobes containing lobules and alveoli. The ducts converge to form lactiferous ducts that open into the nipple.

Question 11

What is the stroma of the breast?

Answer 11

The stroma includes adipose tissue, connective tissue, and Cooper’s ligaments, which anchor the breast to the pectoral fascia.

Question 12

What are Cooper’s ligaments?

Answer 12

Cooper’s ligaments are connective tissue bands that support the breast by anchoring it to the pectoral fascia.

Question 13

What histological features are seen in the inactive state of the breast?

Answer 13

Less lactiferous ducts and no alveoli. Sparse glandular tissue with dense connective tissue, ducts lined by cuboidal epithelium and myoepithelial cells, and fat tissue between lobes and lobules.

Question 14

What histological features are seen in the active state of the breast?

Answer 14

Increased glandular tissue with alveoli, ducts lined by columnar or cuboidal cells, and plasma cells in connective tissue for IgA secretion.

Question 15

What is the secretory mechanism of the breast during lactation?

Answer 15

Lipids are secreted via apocrine secretion, while proteins are secreted by exocytosis.

Question 16

From which embryological tissues does the breast develop?

Answer 16

The breast develops from ectodermal and mesenchymal tissues around the 5th week of gestation.

Question 17

What is the milk ridge?

Answer 17

The milk ridge is a line of mammary gland tissue along which the pectoral part develops into the breasts.

Question 18

What hormones regulate breast development and function?

Answer 18

Estrogen, progesterone, prolactin, and oxytocin are key hormones involved in breast development and function.

Question 19

What arteries supply blood to the breast?

Answer 19

Axillary artery (Superior thoracic, Thoraco-acromial, Lateral thoracic, Subscapular), Internal thoracic artery, and Intercostal arteries (2nd-4th).

Question 20

What veins drain blood from the breast?

Answer 20

Superficial veins drain into the internal thoracic vein and superficial veins of the lower neck. Deep veins drain into internal thoracic, axillary, and posterior intercostal veins.

Question 21

What is the significance of intercostal veins in breast pathology?

Answer 21

Intercostal veins communicate with vertebral veins, providing a route for metastasis of breast cancer to vertebral bodies, sacrum, and pelvic bones.

Question 22

What is the nerve supply to the breast?

Answer 22

The 4th to 6th intercostal nerves (anterior and lateral cutaneous branches) supply the breast. The nipple is innervated by the anterior branch of the lateral cutaneous branch of T4.

Question 23

What sensory endings are found in the nipple?

Answer 23

Sensory endings include free nerve endings, Meissner corpuscles, and Merkel disc endings, essential for signaling suckling.

Question 24

How is lymph drained from the breast?

Answer 24

Lateral quadrants drain into anterior axillary lymph nodes, medial quadrants into internal thoracic lymph nodes, with some drainage to posterior intercostal and anterior abdominal lymph nodes as well as opposite side breast lymph nodes.

Question 25

What are common breast pathologies?

Answer 25

Supernumerary nipples, retracted nipples, breast abscess, fibrocystic adenoma, breast carcinoma, and gynecomastia.

Question 26

What is gynecomastia?

Answer 26

Gynecomastia is unilateral or bilateral enlargement of the male breast, often occurring at puberty.

Question 27

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Answer 27

Options

Question 28

A 40-year-old female presents with a firm, non-tender lump in the upper outer quadrant of her breast. Examination reveals no skin changes, but there is a palpable lymph node in the axilla. What is the most likely diagnosis?" "A) Breast abscess, B) Fibroadenoma, C) Breast carcinoma, D) Ductal ectasia

Answer 28

C) Breast carcinoma" "The firm, non-tender lump in the upper outer quadrant with axillary lymph node involvement is highly suggestive of breast carcinoma. The upper outer quadrant is the most common site of breast cancer.

Question 29

A 25-year-old lactating mother presents with fever, redness, and swelling in her left breast. The affected area is warm and tender. What is the most likely diagnosis?" "A) Fibroadenoma, B) Ductal ectasia, C) Mastitis, D) Gynecomastia

Answer 29

C) Mastitis" "Mastitis is a common infection in lactating women. The clinical features of fever, redness, and tenderness in the breast are characteristic.

Question 30

A 60-year-old male presents with back pain and lytic lesions in the vertebral bodies. Imaging shows no primary lesion in the spine. Which mechanism explains how breast cancer could cause these findings?" "A) Direct invasion, B) Hematogenous spread via vertebral veins, C) Lymphatic spread, D) Extension through the diaphragm

Answer 30

B) Hematogenous spread via vertebral veins" "Breast cancer can metastasize to the spine through the Batson venous plexus, which connects the intercostal veins with the vertebral veins.

Question 31

A 32-year-old pregnant woman complains of breast tenderness and increased size. What histological changes are most likely occurring in her breast?" "A) Increased development of glandular tissue and alveoli, B) Decrease in adipose tissue, C) Formation of Cooper’s ligaments, D) Apoptosis of ductal cells

Answer 31

A) Increased development of glandular tissue and alveoli" "During pregnancy, estrogen and progesterone stimulate glandular tissue and alveoli development, preparing the breast for lactation.

Question 32

A 45-year-old female has a lump in the medial quadrant of her breast. Biopsy confirms malignancy. Which lymph nodes are most likely to harbor metastasis?" "A) Axillary lymph nodes, B) Internal thoracic lymph nodes, C) Supraclavicular lymph nodes, D) Posterior intercostal lymph nodes

Answer 32

B) Internal thoracic lymph nodes" "The medial quadrant of the breast drains primarily into the internal thoracic lymph nodes.

Question 33

A 22-year-old male presents with unilateral breast enlargement that is firm and tender. What is the most likely diagnosis?" "A) Fibroadenoma, B) Ductal ectasia, C) Gynecomastia, D) Breast carcinoma

Answer 33

C) Gynecomastia" "Gynecomastia is common in males, particularly during puberty, due to hormonal imbalances between estrogen and testosterone.

Question 34

A 50-year-old female presents with nipple retraction and a hard, irregular lump in the breast. Which structure is responsible for the nipple retraction?" "A) Lactiferous ducts, B) Cooper's ligaments, C) Axillary tail, D) Pectoral fascia

Answer 34

B) Cooper's ligaments" "Nipple retraction occurs when Cooper's ligaments are tethered or pulled by a tumor.

Question 35

A newborn presents with a small, palpable mass under the nipple bilaterally. Parents are concerned. What is the most likely explanation for this finding?" "A) Breast abscess, B) Gynecomastia, C) Maternal hormone effect, D) Fibrocystic changes

Answer 35

C) Maternal hormone effect" "The palpable mass is due to maternal estrogen crossing the placenta, which stimulates temporary breast tissue development in the newborn.

Question 36

A 28-year-old female presents with a mobile, well-defined lump in the breast. There are no associated skin changes or tenderness. What is the most likely diagnosis?" "A) Breast carcinoma, B) Fibroadenoma, C) Mastitis, D) Ductal ectasia

Answer 36

B) Fibroadenoma" "Fibroadenoma is a common benign breast tumor in young women. It is characterized by a mobile, well-defined lump.

Question 37

A 45-year-old female with breast cancer complains of persistent back pain. Imaging reveals metastatic lesions in the lumbar spine. What venous system is most likely responsible for the spread?" "A) Superior vena cava, B) Batson venous plexus, C) Portal vein, D) Axillary vein

Answer 37

B) Batson venous plexus" "The Batson venous plexus connects the intercostal veins to the vertebral veins, allowing for hematogenous spread of cancer to the spine.

Question 38

A 29-year-old female reports nipple discharge. Imaging reveals dilated ducts without masses. What is the most likely diagnosis?" "A) Fibroadenoma, B) Mastitis, C) Ductal ectasia, D) Breast abscess

Answer 38

C) Ductal ectasia" "Ductal ectasia involves dilation of the lactiferous ducts, often presenting with nipple discharge without a palpable mass.

Question 39

A 34-year-old female complains of difficulty with milk ejection while breastfeeding. What hormone and sensory pathway are primarily involved?" "A) Estrogen and spinal nerves, B) Progesterone and cranial nerves, C) Oxytocin and sensory pathways from the nipple, D) Prolactin and autonomic pathways

Answer 39

C) Oxytocin and sensory pathways from the nipple" "Oxytocin causes contraction of myoepithelial cells for milk ejection, and sensory stimulation from the nipple during suckling triggers its release.