BREAST+ANATOMY+&+PHYSIOLOGY

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 * __Breast Anatomy __**

 **__Breast Layers: __** 1. Subcutaneous Layer 2. Mammary (glandular) layer 3. Retromammary layer 1st Layer is ** Subcutaneous Layer ** : · Very thin consisting of fat & connective tissue · Cooper’s Ligaments

2nd Layer – ** Mammary (Glandular) Layer: ** · Functional layer of the breast · 15-20 lobules radiate from nipple · Lactiferous ducts - carry milk from acini to nipple · Fatty tissue · Cooper’s Ligaments 3rd Layer - ** Retromammary Layer ** · Thin Layer · <span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">Cooper’s Ligaments <span style="font-family: Symbol; font-size: 14pt; line-height: 115%; margin: 0in 0in 0pt 0.5in; text-indent: -0.25in;">· <span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">Fatty Tissue

<span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%; margin: 0in 0in 10pt;">Lobes are the functional portion of the breast. Each lobe contain milk-producing glands called <span style="color: #00b050; font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">**acinus (ancini).** The breast contain literally hundreds of acinus, which resemble the grapes on a vine.

<span style="color: #00b050; font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">**Terminal Ductal Lobular Units (TDLU)** are terminal ends of the duct and the acini and are surrounded by loose, dense connective tissue. TDLU’s are usually 1-2 mm in size, not visible on ultrasound.

<span style="color: #00b050; font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">**Cooper’s Ligaments** contain connective tissue septa (which form the “skeleton” structure of the breast).

__<span style="font-family: 'Stylus BT','sans-serif'; font-size: 20pt; line-height: 115%;">Sonographic Appearance __

<span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%; margin: 0in 0in 10pt;">Boundaries = strong, bright echo reflection · <span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">Skin line · <span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">Nipple · <span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">Retromammary Layer <span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%; margin: 0in 0in 10pt;">Subcutaneous fat = hypoechoic Cooper’s Ligaments = echogenic Pectoral muscle = low level echoes Ribs = hyperechoic

**__<span style="color: #444444; font-family: 'Stylus BT','sans-serif'; font-size: 20pt; line-height: 115%;">Vascular Supply __** <span style="color: #444444; font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%; margin: 0in 0in 10pt;">Main vascular supply = internal mammary and lateral thoracic artery Venous Drainage = superficial veins that are just under the skin (these veins can be seen on ultrasound)

**__<span style="color: #444444; font-family: 'Stylus BT','sans-serif'; font-size: 20pt; line-height: 115%;">Lymphatic System __**

Importance of evaluating axillary lymph nodes when malignancy is present



__<span style="color: #444444; font-family: 'Stylus BT','sans-serif'; font-size: 20pt; line-height: 115%;">The Male Breast __ <span style="color: #e36c0a; font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">Gynecomastia <span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">– condition in which the ductal elements fluctuations, disease processes or medications //__<span style="color: #00b050; font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">Increased risk for male patients for breast cancer: __//** · <span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">Klinefelter’s Syndrome · <span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">Male-to-Female Transsexual · <span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">History of prior chest wall irradiation <span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%; margin: 0in 0in 0pt 0.5in; text-indent: -0.25in;">(especially for Hodgkin’s lymphoma) · <span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">History of orchitis or testicular tumor · <span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">Liver disease · <span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">Genetic predisposition for gene mutation
 * <span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%; margin: 0in 0in 10pt;">hypertrophy during puberty or later in life due to hormonal

__<span style="color: #444444; font-family: 'Stylus BT','sans-serif'; font-size: 20pt; line-height: 115%;">Physiology of the Breast __

<span style="color: #444444; font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%; margin: 0in 0in 10pt;">Primary function is fluid transportation, secondary to milk production. Milk is produced within the ancini and carried to the nipple by the ducts. Breasts are affected by changing hormone levels with menstrual cycle, pregnancy and lactation. Development begins prior to menarch at approximately 16 years old. <span style="color: #444444; font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">During pregnancy, <span style="color: #00b050; font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">Prolactin **<span style="color: #444444; font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;"> is produced by the pituitary gland enables the **<span style="color: #e36c0a; font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">acini **<span style="color: #444444; font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">to produce milk. The delivery of the placenta after birth initiates milk production and the sucking stimulation of the baby initiates the release of ** <span style="color: #00b050; font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;">oxytocin **<span style="color: #444444; font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%;"> which stimulates additional milk production. ** <span style="color: #444444; font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%; margin: 0in 0in 10pt;">At the end of lactation, the breast tissue parenchyma involutes (meaning closely coils); therefore breast screening should not be performed until at least 6 months after breastfeeding. <span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%; margin: 0in 0in 10pt;">The “//milk line”// is the anatomic line along which breast tissue. In many women, the breast tissue extends deep into the axilla, which is referred to as the axillary tail of the breast or the

Tail of Spence. **

<span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 115%; margin: 0in 0in 10pt; overflow: hidden;"> <span style="font-family: 'Stylus BT','sans-serif'; font-size: 14pt; line-height: 0px; margin: 0in 0in 10pt; overflow: hidden;">