MAMMO 1 - Breast Anatomy

Male vs. Female Breast

• Structurally identical until puberty

• Male breast lacks lobules (no milk production)

• Composed of: fibrofatty tissue, ducts lined by epithelial & myoepithelial cells

Epithelial Cells

• Functions: Protection, secretion, absorption, filtration, diffusion, sensory reception

• Found in: Skin, intestines, respiratory & abdominal lining, glands

Male Breast Imaging

• Mammography: Radiolucent, prominent pectoralis muscle

• Ultrasound: Mostly fat & skin

• After puberty (due to testosterone):

  • Atrophy of ducts

  • Contains: subcutaneous fat, stromal elements, small nipple-areolar complex, poorly developed ductal system

1. Fetal

2. Puberty

3. Menstruation

4. Pregnancy

5. Lactation

6. Menopause

7. Post-menopause

Developmental Stages

• Germinal (Weeks 1–2)

• Embryonic (Weeks 3–8)

• Fetal (Weeks 9–40)

Fetal Development Stages

Germinal (Weeks 1–2)

Fertilization → Zygote → Blastocyst → Implantation

Embryonic (Weeks 3–8)

Formation of: neural tube, organs, limb buds, body structures

Fetal (Weeks 9–40)

Maturation of organs, growth, reflexes, brain activity, lung surfactant

Puberty

• Ages: Girls (8–14), Boys (9–16)

• Controlled by hypothalamus → GnRH → pituitary → LH & FSH → sex hormones

Tanner Stages for Male

1. Brain signals begin

2. Testicle/scrotum growth, early pubic hair

3. Penis/testicle growth, voice cracks, muscle/height growth

4. Penis/testicle enlargement, armpit hair, permanent voice

5. Adult-size genitals, facial hair, growth ends

Tanner Stages for Female

1. No visible changes yet

2. Breast buds, areola expands

3. Buds expand, pubic/underarm hair, acne

4. Fuller breasts, menarche, slowed height growth

5. Adult breasts, regular periods, full pubic hair

Menstruation

• Normal vaginal bleeding, ~3–7 days, starts ~age 11, ends ~51 (menopause)

• Symptoms: cramps, back pain, bloating, cravings, mood swings

Premenstrual Syndrome

• 1–2 weeks before period

• Includes: breast tenderness, acne, bloating, headaches, cravings, mood changes

• Follicular

• Ovulation

• Luteal

Menstrual Cycle Phases

Follicular

FSH stimulates follicle growth & uterine lining thickens

Ovulation

Egg released (~day 14), survives ~24 hrs

Luteal

Corpus luteum → progesterone → thickens lining; if no pregnancy → menstruation

• PMS

• Dysmenorrhea (painful periods)

• Menorrhagia (heavy bleeding)

• Amenorrhea (no periods)

Common Menstrual Problems

Pregnancy

• Gestation = 40 weeks (counted from last period)

• Conception = sperm + ovum = fertilized egg

• 1–4

• 5–8

• 9–12

• 13–16

• 17–24

• 25–36

• 37–40

Fetal Development Milestones

Week 1–4

Fetal Development

• Fertilization, implantation

Week 5–8

Fetal Development

• Heartbeat, limb buds, organ formation

Week 9–12

Fetal Development

• Genital differentiation, facial features

Week 13–16

Fetal Development

• Rapid growth, bone formation

Week 17–24

Fetal Development

• Vernix forms, movements, eye opening

Week 25–36

Fetal Development

• Brain development, weight gain

Week 37–40

Full-term, organ readiness for birth

Lactation

• Breast changes: Areola darkens, Montgomery glands enlarge

• Prolactin Reflex:

  • Suckling → brain → pituitary → prolactin → alveoli secrete milk

• Milk Ejection (Letdown) Reflex:

  • Suckling → brain → pituitary → oxytocin → alveoli muscles contract

• Water

• Lactose

• Whey/Casein Proteins

• Fats

• Vitamins/Minerals

• Immunoglobulins (IgA)

• Enzymes

• Hormones

• WBCs, Stem Cells, Cytokines

• Oligosaccharides

• Nucleotides

• Growth Factors

Breast Milk Composition

Hydration

Function of Water

Energy

Function of Lactose

Growth, enzymes, immune support

Function of Whey/Casein Proteins

Brain & nerve development

Function of Fats

Body function, growth

Function of Vitamins/Minerals

Immunity

Function of Immunoglobulins (IgA)

Digestion

Function of Enzymes

Body processes

Function of Hormones

Immunity, tissue repair

Function of WBCs, Stem Cells, Cytokines

Gut bacteria growth

Function of Oligosaccharides

DNA/RNA synthesis

Function of Nucleotides

Tissue development

Function of Growth Factors

Menopause

Natural end of menstruation, ovaries stop producing estrogen/progesterone

• Pre-menopause

• Peri-menopause

• Menopausal Phase

• Post-menopausal

Categories of Menopause

Pre-menopause

Time before menopause

Peri-menopause

Transition period (climacteric)

Menopausal Phase

End of menstruation (age 44–55)

Post-menopausal

No periods for 12 months

• Physiologic

• Pathologic

Menopause Types

Physiologic

Natural, age-related decline (avg ~51 yrs)

Pathologic

Occurs before 40 (about 5% of women)

• Upper Outer

• Upper Inner

• Lower Outer

• Lower Inner

Divisions of the Breast

Upper Outer

Above & lateral to nipple (10 o’clock)

Upper Inner

Above & medial to nipple (2 o’clock)

Lower Outer

Below & lateral to nipple (4 o’clock)

Lower Inner

Below & medial to nipple (8 o’clock)