Lactation 2 Flashcards
What are the 3 key stages of breast development?
Pregnancy: Terminal lobes proliferate, and some milk production may occur.
Involution: Growth occurs with duct proliferation and fat deposition.
Lactation: Full development of ducts and lobes, enabling milk production.
What 4 structures are involved in milk production within the mammary gland?
Alveolus: Hollow structure where milk is produced.
Lactocytes: Milk-producing cells lining the alveolus.
Myoepithelial cells: Contract to push milk into ducts.
Capillaries: Provide nutrients from maternal blood supply.
What is the function of the nipple and areola in breastfeeding?
Nipple: Drains milk from ducts to infant.
Areola: Darker color helps baby locate nipple; contains erector muscles to enhance milk flow.
What 3 hormones prepare the breasts for lactation during pregnancy?
Estrogen: Stimulates ductal growth.
Progesterone: Supports lobular-alveolar development.
Placental lactogen: Prepares the breast for milk production.
What hormonal changes occur after birth to initiate lactation? What happens if the placenta is not fully delivered?
Prolactin and oxytocin levels increase.
If the placenta is not fully delivered, pregnancy hormones may persist, inhibiting milk production.
What is the function of prolactin in breastfeeding?
Stimulates milk production by targeting lactocytes in alveoli.
Levels increase with nipple stimulation and suckling.
What is the function of oxytocin in breastfeeding?
Triggers the let-down reflex, contracting myoepithelial cells to eject milk.
Released in response to baby’s suckling or hearing the baby cry.
What are the 4 steps of the let-down reflex?
Baby suckles, stimulating nipple nerves.
Signals are sent to the hypothalamus.
Hypothalamus signals the pituitary gland.
Pituitary releases prolactin (milk production) and oxytocin (milk ejection).
How does breastfeeding operate on a supply-and-demand basis?
Increased suckling = increased milk production.
Frequent feeding or pumping promotes consistent supply.
Lactation can be induced with hormone therapy and nipple stimulation.
What are the macronutrient proportions in mature human milk?
Fat: 51%
Carbohydrates (lactose): 42%
Protein: 7%
How does human milk’s mineral composition benefit infants?
Lower mineral concentrations reduce solute load on kidneys.
Minerals are in highly bioavailable forms.
What are the two main types of protein in human milk, and what are their functions?
Casein (20-30%): Helps absorb calcium, contributes to milk’s white appearance.
Whey (70-80%): Easily digestible proteins, including:
Immunoglobulins (IgA): Immune protection.
Lysozymes: Antibacterial properties.
Lactoferrin: Binds iron, prevents bacterial growth.
What are the key non-protein nitrogen compounds in human milk?
Carnitine: Supports fatty acid metabolism.
Taurine: Important for neural development.
What role do medium-chain fatty acids (MCFAs) play in human milk?
Synthesized in the mammary gland (6-14 carbons).
Easily digested and beneficial for gut health.
How does fat digestion in human milk differ from formula?
Contains lipases, aiding digestion.
Palmitate (16:0) positioned differently, improving fat and calcium absorption.
What is unique about human milk fat globules?
Encased in a membrane containing gangliosides and antibodies.
Supports brain development and immune function.
What are the 2 key carbohydrates in human milk, and their functions?
Lactose: Prevents glucose spikes, supports brain development.
Human milk oligosaccharides (HMOs):
Promote beneficial gut bacteria (e.g., bifidus factor).
Protect against pathogens.
What 5 immune components are found in breastmilk and what are their functions?
IgA antibodies: Provide passive immunity.
Lactoferrin, lysozymes: Antibacterial properties.
Prebiotics (HMOs) and probiotics (microbiota): Support gut health.
How does breastmilk transfer maternal immunity to the infant?
Entero-mammary pathway: Maternal gut bacteria move to the mammary gland.
Retrograde flow: Baby’s oral microbiota can enter the breast and influence milk composition.
What 6 factors influence breastmilk composition?
Stage of lactation (e.g., colostrum vs. mature milk).
Duration of feeding (fat content increases towards end of feeding).
Maternal diet, infections, medications, and alcohol use.
How does colostrum differ from mature milk?
Yellow, viscous, and secreted in small amounts.
Higher in protein and antibodies.
Helps establish gut microbiota and passage of meconium.
How does maternal diet influence breastmilk composition?
Protein and carbohydrates: Minimal effect.
Fats: Affects fatty acid profile (e.g., omega-3 content).
Vitamins: Dependent on maternal diet and stores.
Flavors: Can change milk taste (e.g., garlic, onion, mint).
What are the potential risks of drug use while breastfeeding?
Some prescription and OTC drugs are safe, but illicit drugs (e.g., cannabis, opioids) can cause lethargy, poor feeding, or seizures.
Best practice: Avoid drugs while breastfeeding.
What is the recommended caffeine intake while breastfeeding?
Up to 300 mg/day (2-3 cups of coffee).
Energy drinks should be avoided due to excessive caffeine and herbal ingredients.
How does alcohol affect breastmilk and infant health?
Freely diffuses into milk (same concentration as in blood).
Reduces milk production and can affect infant sleep and cognitive development.
Best practice: No alcohol while breastfeeding. If consumed, wait ~2 hours per drink before feeding.
What environmental toxins may be found in breastmilk?
Heavy metals: Lead, mercury, arsenic.
Persistent organic pollutants (POPs): Pesticides, microplastics (BPA, phthalates).
Why do benefits of breastfeeding outweigh contaminant risks?
Protective effects against environmental toxins (e.g., secondhand smoke).
Immune-boosting properties help mitigate exposure risks.
