Lecture 7 Flashcards
Lactation and Human Milk
Lactation Physiology: Alveoli
Are the functional units of the mammary gland
Each alveolus has a cluster
of cells (secretory cells) with a duct in the centre to secrete milk
Ducts are arranged like
Branches of a tree with each smaller duct leading to 6-10 larger collecting ducts, leading to the nipple
…… surround the secretory cells and contract under the influence of …. and cause milk to be ejected into ducts
Myoepithelial cells
oxytocin
Within each lobes there are …
Within each lobes there are lobules within the lobules are the alveoli, there are a large number of blood cells surrounding to bring hormones to the cells
Mammary gland Development: Puberty
-Ovaries mature and increase in estrogen and progesterone initiates mammary lobular structures (lobes) complete 12-18 mo after menarche
What increases around the duct
Fibrous and fatty tissue
Ductal system matures and
Nipple grows with pigmentation change
Mammary Gland development: pregnancy
Human chrionic gonadotropin and ……
Human chrionic ganadotropin and placental lactogen allow further preparation
Mammary Gland development: pregnancy
Estrogen stimulates
Development of glands that will produce milk
Mammary Gland development: pregnancy
Progesterone allows
The tubules to elongate and epithelial cells that line the tubules to duplicate
Lactation hormones
Prolactin
Oxytocin
Prolactin stimulates
Milk production via suckling (baby)
Suppressed by prolactin inhibiting factors released by the hypothalamus during the last 3 mo pregnancy to allow for the body to prepare for milk productiomn
Oxytocin stimulates
Ejection of milk from the milk gland into ducts via suckling (baby)
also known as ‘Letdown’
feels like tingling, tightning or shooting pain 1min=contraction in milk ducts
also acts on the uterus during and after delivery, causing it to contract (shrink back to pre-pregnancy size)
Lactogenesis
Milk production
Lactogenesis 1
Colostrum
- Produced in 1st few days
- Low milk production
- High levels of white blood cells, immunoglobulin A, Vitamin A
- High protein, low fat
Lactogenesis 2
Transitional milk
- Produced after 1st couple of days up to - 10 days
- Increased milk production, stimulated by maternal hormones
-Higher protein and lower fat than mature milk
Lactogenesis 3
Mature Milk
-Begins around 10 days postpartum
-780ml consumed by infants on average during exclusive breastfeeding from 0-6months
-Milk composition is more stable
Breastfeeding initiation
within the first hour of birth
Healthy term infants with reflexes to feed
Suck and swallow
Oral search reflex
Rooting reflex
Suck and swallow in a coordinated pattern
Includes a gag reflex to prevent food and fluids into the lungs