• Pectoralis muscle lies underneath the tissue. • is the main structure of the breast. • There is lots of collagen and elastin between the mammary glands • pores are microscopic. • Within each lobe are smaller chambers called lobules, which contend clusters of alveolar glands that produce milk when a woman is lactating. • 1 in 8 women will develop . https://www.khanacademy.org/partner-content/stanford-medicine/ /v/breast-anatomy

• Mammary glands- secrete milk • Lactiferous - drains milk to the nipple • There is not a single hole in the nipple. There are many holes called nipple pores. • - darker area of skin. Its to help newborns see them better • Myo- muscles/ contracts • Epithelial cells- cells that line things • Myoepithelial cells line mammary glands and contract to eject milk through the lactiferous ducts • All of the structures are supported by connective tissue. In the breast it is collagen and elastin. Which then come together in strong ligaments that anchor to the chest wall. (Coopers ligaments) • Adipose tissue- forms part of the framework or the structure and supports all of these glands, along with the connective tissue, collagen and elastin. https://www.khanacademy.org/science/health-and-medicine/human-anatomy- and-physiology/reproductive-system-introduction/v/breast-anatomy-and-

• Milk can boost a newborns immune system because it contains antibodies that the baby can't make on its own yet and all the nutrients a growing infant needs for the first 6 months of life. • Mammary glands expand during pregnancy in response to hormones such as estrogen and . • contain bumps called areola glands or Montgomery glands. They secret an oily substance called lipid fluid. Which moisturizes the nipple so it doesn't get dry or cracked during breastfeeding. The oil has a certain smell that attracts the baby to the nipple as well. • Suspensory ligaments/cooper's ligaments help support the breast. • Lactation begins when an infant begins to suckle on the moms breast. When the baby suckles special receptors called mechanoreceptors in the nipple get activated and start to send messages up the spinal cord and into the moms brain to the hypothalamus. When the hypothalamus receives these messages 2 things happen. It sends on signals to neurons in the posterior pituitary gland telling them to make oxytocin. The hypothalamus also sends an off signal to a special type of neuron in the anterior pituitary that releases a hormone called prolactin inhibiting hormone. • Oxytocin stimulates the myoepithelial cells to eject milk. • Any baby that cries can help stimulate will trigger to the hypothalamus to start the cascade of events.

B. Using the on-line medical dictionary thoroughly define the following:

- Adipose Tissue: Is specialized connective tissue composed of fat cells (Adipocytes.) The female breast is mostly made of adipose tissue. The tissue extends from the collarbone, down to the underarm, and across to the middle of the rib cage. In the breast the adipose tissue surrounds and supports the glands. - Pectoralis muscle: The pectorals major and minor muscles that make up the upper and front part of the chest and in front of the armpit. - Lobe: A healthy female breast contains between 12-20 sections called lobes. Each of the lobes is made up of many smaller lobules which is the gland that produces milk for mother and newborn. The lobes and lobules are connected by milk ducts which act as tubes to carry the milk to the nipple. They are made up of mammary glands. - Areola: The darkened area surrounding the nipple of the . IN pregnancy it gets darker. For women who are not pregnant it will be an almost reddish color in caucasians but for pregnant brunettes they will turn almost black. - Nipple: Is a small projection near the center of the areola of the mammary gland. They contain dense fibrous connective tissue and some erectile tissue surrounding the openings of the lactiferous ducts. - Opening of the lactiferous duct: Is where the opening of the nipple pores are. Which is how the baby gets its milk. - Lactiferous sinus: (ampulla) The short oval enlarges dilation of each lactiferous duct in the breast just beneath the nipple. It is a storage of milk which is gradually produced by the alveoli. When the infant begins to nurse the milk will be let down. - Lactiferous duct: There are about 15-20 tubular drains for the lobes of the mammary glands which then open at the top of the nipple. The ducts open at the lactiferous sinus which is a small storage for the milk. - Lobule: Are the glands that produce milk. - Mammary glands: Are modified sweat glands. It is made up of connective tissues, fats and tissues that hold the glands that contain milk. They are inside of the Lobes and make the milk. They are connected to lactiferous ducts which help to bring the milk to the opening of the nipple. - Myoepithelial cells: Help to squeeze the milk of the secretory cells into the duct. - Connective tissues: Is a tissue that connects everything in the body in one way or another. There are a couple types of connective tissue, the most common type in the breast are the adipose tissue. - Cooper’s ligaments: Bands of tough, fibrous, connective tissue that shape and support the . - Pectoralis major: Are also known as “pecs” and lie underneath the breast tissue in females and cover majority of the chest. - Nipple pores: Are the openings to the nipple ducts that allow to come through. - Montgomery glands: Are bumps on the areola that secrete oil. They provide lubrication and protects the breast from bacteria. - Lipoid fluid: Is the oily secretion released from the Montgomery glands. - Mechanoreceptors: Detect stimuli such as touch, pressure, vibration and sound. In breastfeeding this is done by the infant suckling on the mothers breast which sends a signal to the mothers brain to start releasing prolactin and that brings the milk. - Hypothalamus: Is located at the base of the brain near the pituitary gland. It is very small but plays a major role in producing/releasing hormones and regulating body temperature. - Oxytocin: Is mainly produced in the hypothalamus and is released by the pituitary gland. Oxytocin is known as the love hormone and helps with labor along with lactation. When the baby sucks on the mothers nipple it sends signals to the mothers brain to release oxytocin and prolactin. - Pituitary: Prolactin and oxytocin is released through the pituitary gland. - Prolactin: Is the hormone that produces lactation and is developed in the pituitary gland.

Part 2 Refer to the following link and review the breast anatomy: Breast Anatomy Using pencils, pens, colored pencils and/or markers draw: 1.) the side view of the breast, including all structures reviewed and label appropriately 2.) the front view of the breast with the skin cut away to view the internal structures of the the a anatomy of the breast and label appropriately. All words from the definition list should be drawn and labeled appropriately. You may submit your drawing via email or here in the forum.