breast anatomy board Flashcards

1
Q

When do the mammary ridges develop in an embryo?

A

Fifth or sixth week of gestation.

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2
Q

What is the path of the mammary ridge along the ventral aspect of an embryo?

A

Base of the forelimb (future axilla) to the base of the hindlimb (inguinal area).

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3
Q

What is the result of incomplete involution of the mammary ridge?

A

Accessory breast tissue and supernumerary nipples.

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4
Q

Is amastia more commonly unilateral or bilateral?

A

unilateral

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5
Q

What is the cause of unilateral amastia?

A

Arrested mammary ridge development during the sixth week of fetal development.

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6
Q

Where is the most common site of aberrant breast tissue?

A

axilla

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7
Q

Where is the most common site of a supernumerary nipple?

A

inframammary area

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8
Q

Each cluster of alveoli leads to a milk duct that empties into a lactiferous sinus. Each lactiferous sinus drains one lobe of the breast. How many lobes are in the breast?

A

15 to 25 lobes per breast.

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8
Q

The breast overlies which ribs?

A

Second to sixth.

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9
Q

What is the most common bacteria cultured from breast tissue?

A

Staphylococcus epidermidis.

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10
Q

Which vessel provides the dominant blood supply to the breast?

A

Internal mammary artery

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11
Q

The internal mammary artery is a branch of which artery?

A

Subclavian artery (left)/brachiocephalic artery (right)

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12
Q

Usually, what vessel is the largest artery entering the pectoralis major muscle and overlying breast parenchyma?

A

The second intercostal internal mammary perforator

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13
Q

Name three branches of the axillary artery (from medial to lateral) that serve as blood supply to the breast.

A

Thoracoacromial, lateral thoracic, and thoracodorsal arteries

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14
Q

When dissecting the axilla, if you clip the intercostobrachial nerve, where will you lose sensation?

A

Upper medial aspect of arm and axilla

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15
Q

The intercostobrachial nerve is a branch of what nerve?

A

Lateral branch of the second intercostal nerve

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16
Q

Axillary nodes are noted as level I, level II, or level III. What anatomic structure determines their “level”?

A

Pectoralis minor muscle

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17
Q

Where are level I axillary lymph nodes located?

A

Lateral/below the lower border of pectoralis minor

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18
Q

Where are level II axillary lymph nodes located?

A

Behind pectoralis minor

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19
Q

Where are level III axillary lymph nodes located?

A

Medial/above the upper border of pectoralis minor

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20
Q

What is the primary innervation to the nipple–areola complex?

A

Lateral branch of the fourth intercostal nerve

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21
Q

What is the course of the lateral branch of the fourth intercostal nerve?

A

It pierces the deep fascia in the midaxillary line and takes an inferomedial course within the pectoral fascia. On reaching the midclavicular line, it turns 90◦ and continues through the glandular tissue toward the posterior surface of the nipple

22
Q

What is the normal diameter of the areola complex?

A

35 to 45 mm

23
Q

What is the function of the Montgomery glands?

A

They are sebaceous glands that produce a waxy substance to assist with lubrication and protection of the
nipple–areola complex

24
Q

The suspensory ligaments of Cooper attach which structures?

A

Deep pectoralis fascia to the dermis of the breast

25
Q

What is the lateral margin of the breast parenchyma?

A

Lateral margin of the latissimus dorsi

26
Q

What is the superior margin of the breast parenchyma?

A

The clavicle

27
Q

What is the medial margin of the breast parenchyma?

A

Lateral sternum

28
Q

What is the major component of the anterior axillary fold?

A

Pectoralis major

29
Q

What is the origin of the pectoralis major muscle?

A

Medial sternal half of the clavicle and lateral aspect of the sternum/costochondral region, from the sternal notch
down to the sixth or seventh costal cartilages

30
Q

The insertion of the pectoralis major tendon lies between which two muscles?

A

Coracobrachialis (posterior) and deltoid (anterior)

31
Q

Which nerve provides motor innervation to the lateral and inferior pectoralis major muscle?

A

Medial pectoral nerve

32
Q

The serratus anterior originates from costal attachments of the anterolateral aspects of the first through the eighth ribs. Where does this muscle insert?

A

Deep medial surface of the scapula

33
Q

What is the innervation to the serratus anterior muscle?

A

Long thoracic nerve

34
Q

What is the clinical manifestation of injury to the long thoracic nerve?

A

Winged scapula

35
Q

How can one locate the long thoracic nerve?

A

Positioned laterally, superficial to the external surface of the serratus anterior muscle in the midaxillary line

36
Q

If the thoracodorsal artery is proximally occluded/ligated, which vessel is capable of providing a significant portion of blood supply to the latissimus dorsi?

A

Serratus branch of the thoracodorsal artery

37
Q

Which nerves supply innervation to the medial breast?

A

The second to sixth medial intercostal nerves

38
Q

Which condition is associated with a congenital absence of the pectoralis major muscle, usually the sternal component, as well as breast and areolar hypoplasia?

A

Poland syndrome

39
Q

Following efferent lymphatic drainage into the deep pectoral nodes and subscapular nodes, which nodes are next in the lymphatic drainage pathway of the breast?

A

Central axillary nodes and apical axillary nodes

40
Q

Following efferent drainage into the axillary nodes, which nodes are next in the lymphatic drainage pathway of the breast?

A

Supraclavicular nodes

41
Q

If lymphatic drainage takes a medial pathway (vs. draining into the axilla), which nodes are the primary drainage basin?

A

Internal mammary nodes/parasternal nodes

42
Q

True/False: Axillary nodes primarily drain the lateral half of the breast, while parasternal nodes drain medial quadrants

A

False: Dye flow studies report that both the axillary and the parasternal lymphatic groups receive lymph from all quadrants of the breast

43
Q

What aspect of the breast parenchyma supplies lymph to the internal mammary/parasternal nodes?

A

The entire gland

44
Q

Which hormone is principally responsible for ductal development and maintenance of glandular elements during the reproductive years?

A

Estrogen

45
Q

Which hormone is principally responsible for lobular development and differentiation of epithelial cells?

A

Progesterone

46
Q

Which hormone stimulates the differentiation of milk-producing cells and initiates the synthesis of milk components

A

prolactin

47
Q

In the youthful, non-ptotic breast, where should the NAC be located?

A

Above the inframammary fold (IMF)

48
Q

In the youthful, nonptotic breast, what is the normal distance between the sternal notch and the nipple?

A

17 to 21 cm

49
Q

In the youthful, nonptotic breast what is the normal distance between the nipple and the IMF?

A

7 to 8 cm

50
Q

What is the etiology of a congenital inverted nipple? What is its incidence?

A

Failure of the mammary pit to elevate above skin level during infancy; 2% to 4%

51
Q

What is Poland syndrome?

A

Hypoplasia or absence of the ipsilateral breast, absence of the sternal head of the pectoralis major muscle, costal
cartilage and rib defects, hypoplasia of subcutaneous tissues of the chest wall, and brachysyndactyly.

52
Q

What is the anatomic abnormality with the tuberous breast deformity?

A

NAC hypertrophy, constricted breast/lower pole, herniation of breast tissue into NAC

53
Q

What is the difference between skin sparing mastectomy and total skin sparing mastectomy?

A

The NAC is preserved with total skin-sparing mastectomy