You don't need an in-depth knowledge of anatomy, physiology, mechanobiology, or histology to provide evidence-based, state-of-the-art clinical care for breastfeeding and lactating women.

But there is some foundational knowledge which helps make sense of what is likely to be most effective in clinical breastfeeding and lactation support (when we lack proof of efficacy, which is the case for so much of what we offer when helping lactating women). For instance, if you want to understand why the NDC management of milk production concerns or breast inflammation are different to current models, and why NDC lactation clinical practice seems different overall to standard clinical approaches, then you need a solid understanding of functional anatomy and mechanobiology.

The principles of mechanobiology and biomechanics are explored elsewhere in the Lactation Fellowship.

Here we'll look at five other fields of study in the life sciences, which help build the knowledge base of clinicians who offer specialised services in breastfeeding and lactation support. You'll see that they overlap. This article is a quick revision and refresh which aims to get you oriented before we do deeper dives.

Anatomy

Definition: The study of the structure of the body and its parts e.g. of the breast and related organs.

Focus: What the body looks like and where things are located e.g. the physical features of the mammary system.

Types:

• Gross or macroscopic anatomy: study of visible structures (e.g. breasts, nipples, infant frenula).

• Microscopic anatomy: study of structures which are too small to be seen with the naked eye, and are seen only with a microscope (e.g., lactocytes, keratinocytes, milk ducts). Microscopic anatomy includes histology (tissues) and cytology (individual cells).

Functional Anatomy

Definition: A branch of anatomy that emphasizes how structures or body parts contribute to movement and function e.g. how structures support the action of breastfeeding.

Focus: Not just "what is where," but "what does it do in action", or "how does this structure help the body work?" e.g. how anatomy is organised to allow fit between mother and baby, infant sucking, and milk transfer.

Application: Biomechanics

Example: Explaining how the infant's intra-oral vacuum affects the maternal nipple.

Physiology

Definition: The study of how the body and its systems work (their functions).

Focus: Biological processes and mechanisms that keep the body alive and functioning.

Levels: Can be studied at cellular, organ, or whole system levels (e.g., mammary endocrine system, or how lactocytes secrete milk).

Example: Understanding how myoepithelial cell contraction happens, how the milk ejection reflex works.

Histology

Definition: The study of tissues at the microscopic level.

Focus: Cellular and tissue structure, organization, and how this relates to function e.g. cellular and tissue architecture of the breast.

Application: Pathology, medical diagnostics, research.

Example: Using microscopy of biopsied tissue to view the structure of alveoli lined with secretory epithelial cells or lactocytes, or the changes in breast tissue across lactation stages.

Cytology

Cytology is the branch of biology concerned with the study of cells, including their structure, function, and behavior. It falls under the umbrella of microscopic anatomy. When applied to lactation, cytology focuses on the specific cells in the mammary gland and how their structure and function enables milk production and secretion. For example

• Secretory epithelial cells (lactocytes): Line the alveoli; synthesize and secrete milk components (proteins, fats, lactose)

• Myoepithelial cells: Surround the alveoli; contract in response to oxytocin to push milk into ducts.

Here are some processes studied in the cytology of lactation:

• Cellular changes in the breast from pregnancy → lactation → involution.

• How milk components are packaged inside lactocytes (Golgi apparatus, secretory vesicles).

How these fields of study work together in human lactation

Anatomy → The breast’s structural 'map'.

Functional Anatomy → How those structures enable effective fit and hold and feeding.

Mechanobiology → How forces (suckling, pressure, stretching) regulate tissue responses and milk flow.

Physiology → The hormonal and systemic processes driving milk production and ejection.

Histology → The microscopic tissue-level changes that underlie these functions.

Here is an example of how these fields of the life sciences apply to an infant suckling at the breast.

• Anatomy: Milk ducts carry milk from alveoli to nipple.

• Functional Anatomy: Nipple shape and duct arrangement and how external pressure on these affects milk removal.

• Physiology: Oxytocin triggers contraction of myoepithelial cells → milk let-down.

• Histology: Microscopic view shows secretory epithelial cells surrounded by contractile myoepithelial cells.

• Mechanobiology: Negative pressure from infant suckling removes milk from alveoli; lack of milk removal may result in a build up of hydrostatic pressure in the alveoli, which stretches the lactocytes and their tight junctions, triggering inflammatory feedback loops.