2. Explore anatomy of the breast
Describe the physiology of lctation
3. The breast are also known as mammary
glands and they are glandular tissues
stimulated by increase in female
hormones at puberty and during
pregnancy and lactation.
They are regarded as accessory glands of
the female reproductive system.
The external shape or size of the breast
is not predictive of its internal anatomy
nor of its lactation potential.
4. Skin: the breast is covered with skin
and subcutaneous tissue, at the
centre around the nipple the
covering consist of primary areola
which is specialized form of skin.
Adipose tissue: forms the bulk of the
breast tissue but there is no fat
immediately below the nipple and
areola
5. Fibrous tissue: fascia of which the breast
rest and send out extensions in the form
of fibrous processes called suspensory
ligaments of cooper; from the back of the
breast forwards to the subcutaneous
tissue underlying the skin and nipple.
This supports the breast.
Glandular tisue: 15 to 20 lobes in each
breast. Each lobe is made up of 40 tiny
lobules which are connected together to
form ducts by loose connective tissues
and blood vessels
6. ◦ Each lobule consist of a
rounded cluster of between
10 and 100 specialised
alveoli called acini cells
which are secretory units of
the glands
◦ The alveoli have epithelial
cells which manufacture
colostrum during pregnancy
up to 3rd day postpartum
◦ The alveoli open up to tiny
ducts which unite to form
larger ducts known as
lactiferous ducts
7. ◦ Lactiferous ducts vary in number according to
number of lobes and they converge towards
the areola where they become slightly
distended forming the lactiferous sinuses
(ampullae).
◦ Lactiferous sinuses serve as reservoirs for
milk during lactation then continue as
lactiferous ducts which pass through the
nipple and lead to 15 to 20 tiny openings at
the end of the nipple
The nipple: composed of erectile tissue and is
surrounded by epithelium and smooth muscle
fibres and nerve endings which cause erection
of the nipple on contraction of the muscle
fibres
8.
9. Breast profile:
◦ A ducts
◦ B lobules
◦ C dilated section of duct
to hold milk
◦ D nipple
◦ E fat
◦ F pectoralis major muscle
◦ G chest wall/rib cage
Enlargement:
◦ A normal duct cells
◦ B basement membrane
◦ C lumen (center of duct)
10. Alveoli: hollow cavities, a few
millimeters large) lined with milk-
secreting cuboidal cells (acini cells)
and surrounded by myoepithelial
cells. These alveoli join up to form
groups known as lobules. The
myoepithelial cells can contract
under the stimulation of oxytocin
thereby excreting the milk from
glands through the lactiferous ducts
toward the nipple,
11. During pregnancy several hormones
develop the breast and stimulate
secretion of colostrum
◦Oestrogen
◦Progesterone
◦Prolactin is a hormone which initiate
milk production and it also
suppresses ovulation. Continued
production is associates with
neonate feeding with high levels
during night feeds.
12. The hormone prolactin is very
important in the initiation and
maintenance of lactation.
Prolactin is produced in the anterior
pituitary gland and it stimulates the
acini cells. Acini cells in the alveoli
are responsible for milk production.
Milk production begins in fist week
post delivery about the 3rd day.
13. When placenta is delivered HPL levels drop
which results in drop in oestrogen and
progesterone levels. This allows the
release of prolactin.
Milk is formed as tiny fat globules within
the cytoplasm of the acini cells and the
golgi apparatus is responsible for
secretion of milk proteins.
The globules unite to form small droplets
and the new globules produced pushes the
droplets forward bursting the surface so
that milk flows into lactiferous tubules
14. Milk is pushed forward along the
lactiferous tubules mechanical effect
of suckling and hormonal effects of
oxytocin in a reflex called
neurohormonal or let-down reflex.
Oxytocin is released in posterior
pituitary gland and it stimulates
myoepithelial cells surrounding the
alveoli to contract and force milk
towards the nipple.
15. Oxytocin acts on smooth muscles
and this causes
◦Flow of milk
◦Nipple erection
◦Contraction of uterine muscle-
after pains.
16. The neonate grasps the whole nipple
and the primary areola are drawn into
the babys mouth
The neonate closes its jaws onto the
areola tissue situated over the
lactiferous sinuses.
This expresses milk from the sinuses
into the babys mouth who then
swallowed.
17. A vacuum is created in the baby's
mouth which helps draw more milk
from the lactiferous sinuses.
As milk is drawn from the sinuses
and the lower ducts more milk flow
down from the upper lactiferous
ducts, tubules and alveoli to take its
place. This continues until the breast
is emptied
18. Suckling of the neonate and
nipple stimulation.
Mothers emotional status
Rest: increases prolactin
production. Concentration is
usually high at night.
Diet
Fluid intake
19. Do not allow neonate to suckle
Do not express
Limit fluid intake
Contain the breast in a firm bra
Medications may also be given
such as pyridoxine
200mg(vitamin B6)
