904
UNIT SIX
matures by a week to ten days, it has antibodies,
enzymes, and white blood cells from the mother
that continue infection protection. A milk protein
called lactoferrin binds iron, making it unavailable
to microorganisms that might use it to thrive in
the newborn’s digestive tract. Another biochemi-
cal in human milk, biF
dus factor, encourages the
growth of the bacteria
Lactobacillus bif
dus,
which
manufacture acids in the baby’s digestive system
that kill harmful bacteria.
A breastfed baby typically nurses until he or
she is full, not until a certain number of ounces
have been drunk, which may explain why breast-
fed babies are less likely to be obese than bot-
tlefed infants. Babies nurtured on human milk are
also less likely to develop allergies to cow’s milk.
A nursing mother must eat about 500 calories per
day more than usual to meet the energy require-
ments of milk production—but she also loses
T
he female human body manufactures
milk that is a perfect food for a human
newborn in several ways. Human milk is
rich in the lipids required for rapid brain growth,
and it is low in protein. Cow milk is the reverse,
with three times as much protein as human milk.
Much of cow milk protein is casein, which spurs
a calf’s rapid muscle growth, but forms hard-to-
digest curds in a human baby’s stomach. The
protein in human milk has a balance of essential
amino acids more suited to human growth and
development than does the protein in cow’s milk.
Human milk protects a newborn from many
infections. ±or the first few days after giving
birth, a new mother’s breasts produce colostrum,
which has less sugar and fat than mature milk but
more protein, and is rich in antibodies. The anti-
bodies protect the baby from such infections as
Salmonella
poisoning and polio. When the milk
weight faster than a mother who bottlefeeds,
because the fat reserves set aside during preg-
nancy are used to manufacture milk.
Breastfeeding is not the best choice for all
women. It may be impossible to be present for
each feeding or to provide milk. Also, many drugs
a mother takes may enter breast milk and can
ect the baby. Another disadvantage of breast-
feeding is that the father cannot do it.
An alternative to breastfeeding is infant for-
mula, which is usually cow milk plus fats, proteins,
carbohydrates, vitamins, and minerals added
to make it as much like human milk as possible.
Although infant formula is nutritionally sound,
the foul-smelling and bulkier bowel movements
of the bottlefed baby compared to the odorless,
loose, more frequent and less abundant feces of a
breastfed baby indicate that breast milk is a more
digestible F
rst food than infant formula.
23.3
CLINICAL APPLICATION
Human Milk—The Perfect Food for Human Babies
Neonatal Period
The
neonatal
(ne
o-na
tal)
period,
which extends from birth
to the end of the first four weeks, begins very abruptly at
birth. At that moment, physiological adjustments must occur
quickly because the newborn (neonate) must suddenly do for
itself what the mother’s body had been doing for it. The new-
born must respire, obtain and digest nutrients, excrete wastes,
and regulate body temperature. However, a newborn’s most
23.4
POSTNATAL PERIOD
Following birth, both mother and newborn experience
physiological and anatomical changes. The postnatal
period of development lasts from birth until death. It can
be divided into the neonatal period, infancy, childhood,
adolescence, adulthood, and senescence. Dying is also part
of the life cycle.
TABLE
23.7
|
Agents Contraindicated During Breastfeeding
Agent
Use
EF
ect on Lactation or Baby
Doxorubicin, methotrexate
Cancer chemotherapy, psoriasis, rheumatoid arthritis
Immune suppression
Cyclosporine
Immune suppression in transplant patients
Immune suppression
Radioactive isotopes
Cancer diagnosis and therapy
Radioactivity in milk
Phenobarbitol
Anticonvulsant
Sedation, spasms on weaning
Oral contraceptives
Birth control
Decreased milk production
Ca²
eine (large amounts)
±ood additive
Irritability, poor sleeping
Cocaine
Drug of abuse
Intoxication, seizures, vomiting, diarrhea
Ethanol (alcohol) (large amounts)
Drug of abuse
Weak, drowsy; infant decreases in length but gains weight;
decreased milk ejection re³
ex
Heroin
Drug of abuse
Tremors, restlessness, vomiting, poor feeding
Nicotine
Drug of abuse
Diarrhea, shock, increased heart rate; lowered milk production
Phencyclidine
Drug of abuse
Hallucinations
previous page 934 David Shier Hole's Human Anatomy and Physiology 2010 read online next page 936 David Shier Hole's Human Anatomy and Physiology 2010 read online Home Toggle text on/off