The Importance of Breasts - A Lecture by Jonathan Benan

Introduction

Estrogen During Puberty
- Released from ovaries, promotes secondary sex characteristics.
- Development of breast tissue.
Structure
- Made up of mammary glands, connective tissue, adipose (fat) tissue.
- Supported by Cooper’s ligaments (suspensory ligaments).
- Changes with Age: Ligaments become looser, causing sagging.
Mammary Glands
- Modified sweat glands producing milk
- Made of 15-20 lobes, separated by adipose tissue.
- Each lobe has lobules, which contain alveoli with milk-secreting epithelial cells.

During Pregnancy
- Pituitary gland releases prolactin to stimulate lactation.
- Placenta releases estrogen and progesterone, inhibiting milk secretion until birth.
Post-Birth
- Prolactin levels remain high after placenta is birthed, enabling milk secretion.
- Colostrum: Initial fluid produced, rich in antibodies and nutrients.
- Typical breast milk produced after a week.
Milk Ejection (Let Down)
- Sensory input from suckling stimulates the hypothalamus, leading to oxytocin release from the posterior pituitary gland.
- Oxytocin causes myoepithelial cells around alveoli to contract, enabling milk flow.
- Emotional stimuli (fondling, baby crying) can trigger milk let down.

Components:
- 88.5% water, 3.3% fat, 6.8% lactose, 0.9% casein (main protein), 0.4% lactalbumin and other proteins, 0.2% minerals (ash).
Comparison with Cow’s Milk
- Human milk has more lactose but less protein compared to cow's milk.
Immune Support
- Contains antibodies and several types of white blood cells beneficial to the newborn’s immune system.
Caloric Expenditure for Moms
- 600-750 calories burned/day producing milk, potentially higher for greater milk production.

Factors Influencing Breast Shape and Size
- Size of mammary glands and amount of adipose tissue.
- Strain on suspensory ligaments, age, and pregnancy changes.
Breast Augmentation
- Placement Options:
  - Over the muscle (subglandular): Implant placed below natural breast tissue but above pectoralis major muscle.
  - Under the muscle (submuscular): Implant placed deep to the pectoralis major.
- Considerations
  - Amount of natural breast tissue affects placement option.
  - Recovery, potential rippling, and appearance considerations.

Interactive learning in anatomy through hands-on experience in the anatomy lab.
Introduction of the sponsor: Brilliant, an interactive online learning platform.
Reminder to visit Brilliant for free trials and premium subscriptions.

Thank You for Watching!