MAMMO - MIDTERM 1

Midterm/ 1st quiz topic

Internal breast anatomy

• Encompasses a complex and intricate network of structures that constitute the functional framework of this vital organ.

• Comprising:

  • Mammary glands,

  • Lobes,

  • Lobules,

  • Ductal systems, and

  • Supporting connective tissues

• Plays a crucial role in its dual functions of milk production and nourishment during lactation.

Superficial fascia

• The breast tissue is encircled by a thin layer of connective tissue called ______________.

  • The deep layer sits immediately atop the pectoralis muscle,

  • And the superficial layer sits just under the skin.

Deep layer

Fascial Layer of the Breast

• The __________ of the fascial layer of the breast sits immediately atop the pectoralis muscle.

Superficial layer

Fascial Layer of the Breast

• The __________ of the fascial layer of the breast sits just under the skin.

Retromammary Space

• Or subglandular space

• A potential space between the breast tissue and the underlying pectoralis fascia;

• Allows for movement of the breast tissue.

• Lies between the fatty matrix and the glandular tissue.

1. Fibrous tissue

2. Glandular tissue

3. Adipose fatty tissue

Tissues of the breast include:

Fibrous tissue

Tissues of the Breast:

• Holds the breast tissue in place

Glandular tissue

Tissues of the Breast:

• Part of the breast that makes milk, called the lobes.

Fibroglandular tissue

Tissues of the Breast:

• Glandular tissue

  • Together, fibrous and glandular tissue are called _______________

Adipose Fatty tissue

Tissues of the Breast:

• Fills the space between the fibrous tissue, lobes, and ducts.

• It gives the breasts their size and shape.

Lobes and Lobules

Often feel like round lumps that are movable, although they may also be tender to the touch.

15-20

Adult women have __ - __ lobes in each breast.

20-40

Each lobe has __ - __ lobules.

Small milk ducts

Are attached to the lobules.

1. Lobules

2. Ductules

3. Lactiferous duct

4. Lactiferous sinus

5. Nipple

What is the correct order of structures through which milk flows, starting from it production site in the breast?

Lobes

• 15-20 in number

• Composed of glandular structures called lobules which empty via ductules into lactiferous ducts.

Lactiferous ducts

• Draining each lobe of the breast past through the nipple and open onto its tip as 16-20 orifices.

• Contains ampulla near its end

Ampulla

Lactiferous ducts contains ________ near its end

• Reservoir of milk or abnormal discharge

Terminal ductal lobular unit (TDLU)

• Comprising:

  • Terminal ducts,

  • Ductules,

  • Lobules, and

  • Associated stroma

• Serves as the site where breast tissue undergoes dynamic changes during hormonal fluctuations and is the origin of most breast cancers.

  • Ducts transport milk, while lobules are responsible for milk production.

• Terminal ducts,

• Ductules,

• Lobules, and

• Associated stroma

The Terminal ductal lobular unit (TDLU) comprises of:

Stroma (cell)

• The main function of _________ is:

  • To help support organs and act as connective tissue for particular organs.

• The connective tissue here connects to the parenchyma cells of things such as blood vessels and nerves.

Cooper Ligament

• Found under the skin of the breast, through and around the breast tissue.

• They connect to the tissue surrounding the chest muscles.

• These maintain the shape and structure of your breasts and help to prevent sagging.

Myoepithelial cells

• Form a semi-continuous protective sheet separating the human breast epithelium and the surrounding stroma.

• Have contractile functions

Basement membrane

• Located between the epithelium and mesenchymal tissues.

• Considered to form a protective barrier against the initial infiltration of tissue by tumor cells.

Ducts

• A thin tube in the breast that carries milk from the breast lobules to the nipple.

• Also called milk duct.

• There are about 10 ____ systems in each breast, each with its own opening at the nipple

Lymphatic System

• Our body's 'sewerage system'.

• It maintains fluid levels in our body tissues by removing all fluids that leak out of our blood vessels.

• Important for the optimal functioning of our general and specific immune responses.

  • ________ circulation in breast tissue helps regulate the local fluid balance as well as filter out harmful substances.

• But the breast's _________ can also spread diseases such as cancer through the body.

Lymphatic vessels

______________ provide a highway along which invasive cancerous cells move to other parts of the body.

Lymphatic flow of the breast

The _____________ is of great clinical significance because metastatic dissemination occurs principally by the lymphatic route.

85%

What percentage drains into the axillary nodes?

10%

What percentage drains into the Internal mammary/ Parasternal nodes?

5%

What percentage drains into “other” nodes?

• Anterior

• Posterior

• Central

• Lateral

• Apical

• Interpectoral

Axillary lymph nodes include:

• Supraclavicular

• Cephalic/ Deltopectoral

• Posterior intercostal

• Subdiaphragmatic

• Subperitoneal

"Other” lymph nodes include:

Axillary lymph nodes levels (Berg’s levels)

• These are defined according to the surgeon's approach to the axillary nodes during dissection.

• Anatomical landmark used: Pectoralis minor

• Clinical N-staging of breast cancer is done based on these.

Pectoralis minor

Anatomical landmark used for Berg’s levels?

Level 1

Axillary lymph nodes levels (Berg’s levels)

• Level that includes the nodes:

  • Lateral to lateral border of pectoralis minor (anterior, posterior & lateral group)

Level 2

Axillary lymph nodes levels (Berg’s levels)

• Level that includes the nodes:

  • Central axillary nodes located under pectoralis minor muscle

Level 3

Axillary lymph nodes levels (Berg’s levels)

• Level that includes the nodes:

  • Apical & infraclavicular nodes medial to pectoralis minor muscle

    • It is difficult to visualize & remove unless pectoralis muscles are sacrificed or divided.

• Axillary artery

• Internal thoracic

• The 2nd to 4th anterior intercostal arteries

The blood supply (main arterial sources) of the breast?

• Superior thoracic

• Thoracoacromial artery

• Lateral thoracic artery

• Subscapular artery

Branches of the axillary artery that supply the breast includes:

Anteromedial breast

The perforating branches of the internal thoracic artery supplies?

Second perforating artery

• Usually the largest

• Supplies the upper region of the breast, the nipple, areola and adjacent breast.

Venous Drainage

• Refers to the network of veins that transport deoxygenated blood away from the breast tissue, ultimately returning it to the heart for oxygenation and redistribution.

• The _______________ system in the breast is an essential component of its circulatory system.

Arteries

Veins follow the ________

Nipple

The venous drainage in the breast first converge around the ______ to form an anastomotic venous circle.

1. Superficial veins

2. Deep veins

The venous drainage in the breast first converge around the nipple to form an anastomotic venous circle and the form 2 sets of veins: ____________ & ____________.

Superficial veins

Drain into Internal thoracic vein & superficial veins of the lower part of the neck

Deep veins

Drain into Internal thoracic, Axillary & Posterior intercostal veins.

Intercostal veins

• Communicate with the vertebral veins.

• This route is responsible for metastasis of CA breast to vertebral bodies, sacrum and pelvic bones.

Nerve supply to the breast

• Essential for sensation, allowing individuals to perceive touch, pressure, temperature, and pain in the breast tissue.

• It's important to note that the degree of sensitivity varies among individuals and can be influenced by factors such as hormonal changes, surgeries (such as breast augmentation or reduction), and medical conditions.

4th to 6th intercostal nerves by their Anterior & Lateral cutaneous branches

Nerves that mainly supply the breast?

Anterior branch of the lateral cutaneous branch of T4

• Nerve that specifically supplies the nipple.

• Forms an extensive plexus within the nipple

• Its sensory fibres terminate close to the epithelium as free endings, Meissner corpuscles and Merkel disc endings.

• These are essential in signaling suckling to the central nervous system.

Ovarian and hypophyseal hormones

Secretory activities of the breast gland are largely controlled by __________________ rather than by efferent motor fibers.

Areola

The _______ has fewer sensory endings compared to the nipple.

Pectoral muscle

• Often referred to as the "pecs," are a pair of large muscles located in the chest area.

• They aren't a part of the breast tissue itself, they play a role in the overall appearance and support of the breasts.

• Provide foundational support to the breasts

• They lie beneath the breast tissue and help maintain the breast's position on the chest wall.

1. Support and Structure

2. Aesthetics

3. Posture

4. Exercise and Fitness

5. Recovery from Breast Surgeries

The pectoral muscle play a role in the overall appearance and support of the breasts by: