hosa human growth and development

2 factors that have a large influence on the health of the fetus

heredity (genetic traits) and environment

how many chromosomes do each sperm and ovum contribute?

23 each

zygote

cell formed when sperm and ovum fertilize

how is the sex of the zygote determined?

• combination of x and y chromosomes

• ovum always has x, the chromosome that the sperm donates ultimately decides the sex

• xx - female

• xy - male

dominant vs recessive genes

• dominant: can express their traits over other genes

• recessive: can only express in pairs

examples of diseases from recessive traits

sickle cell disease (african americans), tay-sachs disease (european jewish), hemophilia, etc.

karyotype

chromosomal structure of an organism

healthy people 2030

• decrease deaths of mothers due to disparities like race and ethnicity

• improving medical care during pregnancy

leading cause of maternal and perinatal deaths

hypertension

teratogens

• chemical or physical substances that can negatively affect the unborn

• e.g. tobacco, alcohol, and other drugs

postpartum depression

feeling alone, sad, and overwhelmed after the baby is born

prenatal period

period from fertilization to birth

ovulation

• every ~28 days, ovum matures and is released in this process

• happens from menarche to menopause

fertilization

• when sperm and ovum unite; all genetic traits are determined

• takes place in the fallopian tube

• aka. conception

morula

after the zygote performs a series of cell divisions

blastocyst

when the morula travels down the fallopian tube to the uterus and implants into the uterine wall (5-6 days after fertilization)

how long does fertilization to implantation take?

about 7 days

embryo

after implantation (7-8 days after fertilization)

fetus

at the end of the 8th week, when all the essential structures are formed

length of pregnancy

40 weeks

3 stages of prenatal development

• preembryonic: fertilization (2 weeks)

• embryonic: 2 weeks after fertilization to the end of the 8th week

• fetal: 9th week to birth

hormones involved in labor

• progesterone: from ovaries; maintains pregnancy and stimulates uterine contractions

• oxytocin: from the hypophysis of the pituitary gland; stimulates uterine contractions and prepares the breasts for breastfeeding

• prostaglandins: from various tissues; stimulates uterine contractions

• like POP the baby’s out

3 stages of labor

• stage 1 (dilation): longest (12-24 hours); onset of regular contractions to complete dilation of the cervix; effacement (shortening and thinning of the cervix) also occurs

• stage 2 (expulsion): most difficult (1½ hours); dilation of cervix to birth

• stage 3: shortest (5-30 mins); birth of baby to delivery of the placenta

• duration is affected by factors like # of previous pregnancies

amniotic sac

• protective sac full of amniotic fluid of fetal membranes that surrounds the fetus

• amniotic fluid: cushions, maintains even temp, and provides fluid source

placenta

• link btwn mother and fetus 

• purpose: producing hormones, trasnporting nutrients and waste, protecting baby from harm

umbilical cord

• link btwn the fetus and placenta; whitish blue and covered by a glistening membrane at birth

• must be assesed for 2 arteries and 1 vein at birth

when is the neonate given an apgar score?

1 minute and 5 minutes after birth

apgar score

• assessment on color, reflex, irritability, heart rate, respiratory rate, and muscle tone

• can rats in houses run more?

• appearance, pulse, grimace, activity, respiration

infant’s head in proportion to body

¼ of total length (big in proportion)

infant’s head circumferance

• 13-14 inches, 1 inch larger than chest

• increases 3 inches during first 8 months

how many soft bones in a skull of a infant?

6 in total; 1 occipital, 1 frontal, 2 parietal, 2 temporal

sutures

bands of cartilage that separate skull bones in infants

anterior fontanel

larger, diamond shaped; should close by 12-18th month

posterior fontanel

smaller, triangular shaped; should close by 4th month

molding

• deformity of the infant’s skull due to it having to pass through the narrow birth canal

• disappears naturally within a few days

length of infant

19-21 in. (48-53 cm)

how much do infants grow in the first year?

• 1 inch per month

• will be 1.5 times longer and brain will be 2.5 times larger

posture of infants

• head rests on chest due to short and deeply creased neck

• arms and legs are tighly flexed

weight of infants

• 5.5-10 ibs

• boys are slightly larger

normal physiological weight loss

• loses 5-10% of the birth weight in the first days of life

• outtake > intake

• recovers in 10 days

at what rate does the infant gain weight in the first year?

• 5-6 oz. per week for first month

• double birth weight in 5-6 months

• triple birth weight in 12 months

what % of the infant is water?

75%

acrocyanosis

• blueness of hands and feet due to lack of peripheral circulation

• disappears few hours later

where is the skin more pigmented in infants?

earlobes, scrotum, and back of the neck

slate gray nevus (mongolian spot)

• a pigmented area in the lumbar-sacral region

• fades by age 4

• in infants with more melanin

lanugo

• covering of fine hair around the body

• gone in a few days

vernix caseosa

• white, creamy covering

• protects fetus’s skin during pregnancy

milia

• small clusters of spots on nose, chin, and forehead

• retention of sebaceous material

• will disappear without treatment

physiological jaundice (icterus neonatorum)

• yellow tinge

• occurs within 48-72 hours

• higher RBC at birth; as RBC decreases, excessive bilirubin is produced

what do the breasts of newborns look like?

• swollen for both sexes

• due to maternal hormones

• will disappear without treatment

what does the scrotum look like in newborns?

• large and edematous

• should be palpated for the presence of testicles (usually descend from abdominal cavity to scrotal sac by 7th month)

• undescended testicles are treated with surgery or hormone therapy

what is the newborn’s penis inspected for?

• urethral opening

• tip of the head of the penis under the foreskin

circumcision

surgical removal of foreskin for hygienic or religious reasons

pseudomenstruation

• blood-tinged vaginal discharge

• due to maternal hormones

• will disappear without treatment

how often does a infants urinate?

• first urination within 24 hours

  • may be rust-colored due to uric acid crystals

• 8-10 times per day after

what are the eyes of a newborn treated with and why?

• erythromycin is applied

• to prevent infections from gonorrhea or chlamydia

when is eye color determined?

3-6 months

when do tears appear?

4 weeks, when lacrimal ducts develop

cleft palate

• incomplete formation and nonunion of the hard palate

• corrected through surgery

when do the first teeth appear?

• 6-7 months

• by 12 months, 6-8 teeth will have developed

first types of deciduous teeth

2 lower central incisors, then the 2 upper central incisors

appearance of newborn’s abdomen

large and flabby

what happens to the umbilical cord after birth?

• is clamped and cut

• after a few days, blood vessels become dry

• yellow to brown to black

• by day 10, the cord falls off

what can the newborn eat?

• simple carbs

• whole milk cannot be digested

how much can the infant’s stomach hold?

• 1-3 oz at birth

• 10 oz by 10 months

why is burping so important in infants?

• underdeveloped cardiac sphincter

• to release swallowed air

infant’s stool appearance

• breastfed: light, mustard seed colored

• formula-fed: semi-solid, tan or yellowish

meconium

• first stool

• thick, black, tarry, and odorless

• within 10 hours

how often do infants have bowel movements?

4-6 per day

congenital hip dysplasia

due to an extra gluteal fold

creases on feet and palms of infants

• full-term: soles are deeply creased

• pre-term: fine lines

examples of protective reflexes

blinking, sneezing, swallowing, and gag reflex

newborn’s vision at birth

• can track objects

• prefer bright lights

• react to light by dilating and contracting pupils

• 10-30 times less sharp than 20/20

strabismus

• when eyes aren’t lined up properly

• immature ciliary muscles cause unequal eye movement

timeline of infant’s vision

• 3-4 months: able to focus on objects and be well-aligned

• 4 months: binocular vision; able to focus both eyes at the same time to make one image

• 6 months: 20/100 or better

• 7-9 months: more precise depth perception

moro reflex

• sudden movement causes extension of extremities

• gone by 3-4 months

tonic neck reflex

• if head of back-lying infant is turned a side, the arm and leg of that side will extend

• gone by 5 months

rooting reflex

• gently stroking a infant’s cheek causes it to turn toward that side and open its mouth

• gone by 4-6 months

sucking reflex

• makes sucking movements when anything touches lips or tongue

• gone by 6 months

babinski reflex

• stroking of sole causes the toes to hyperextend and fan outward; the big toe turns up

• gone by 3 months

palmar grasp reflex

• briefly grasps any object placed in hands

• gone by 3 months (starts from 6 weeks)

infant’s hearing timeline

• birth: filled with vernix, which is gone within a few days; reacts to loud and low-frequency sounds

• 6-8 months: recognition of mother’s voice

• 12 months: can distinguish btwn different sounds and recognize the source

infant’s sense of taste

• can distinguish btwn different tastes

  • sweet: sucking movements

  • sour: grimace and pout

• 12 months: preference for certain flavors

infant’s sense of touch

• birth: face, hands, and soles of feet are sensitive; pain perception is present (reaction is cryin gnad thrusting whole body, arms, and legs)

• 12 months: withdrawal from pain but cannot recognize source

infant’s sense of smell

• strong odors: turns away

• can recognize the smell of breastmilk, even distinguishing btwn mother’s and others’

temperature right after birth

• slightly below normal due to the cooler environment in the delivery room

• skin-to-skin contact to warm the infant (placing naked infant onto mother’s bare chest)

• head should be covered to prevent more heat loss

temperature of infants

• taken by axillary route (armpit)

• 97.7-99.5 F

infant’s heart rate

• listening for 1 full minute

• 120-160 bpm (higher due to inefficiency of the heart)

• 20 bpm variations due to crying and rest

• will decrease

infant’s blood pressure

• 65/40 mm Hg

• will increase

infant’s respiratory rate

• counted for 1 full minute by watching the abdomen rise and fall

• irregular, shallow, and diaphragmatic

• apnea: absence of breathing; brief periods occur

• 30-60 breaths per minute

gross motor skills

movements of large muscles of the arms and legs

fine motor skills

movements of hands and fingers

infant’s timeline of gross motor skill development

• follows a cephalocaudal pattern (head down)

• 2 months: head control

• 3 months: can hold head up briefly

• 4 months: can raise head to 90 degree position from prone position (face down); can roll over from abdomen to back

• 6 months: can roll both ways, sit with support, and hold head straight

• 7 months: sitting alone

• 8 months: can pull up to standing position

• 9 months: crawling (abdomen on floor)

• 10 months: can change from prone to sitting

• 11 months: creeping (all 4 limbs are raised)

• 12-15 months: walking unassisted

infant’s timeline of fine motor skill development

• follows a proximodistal development (center of body to outward)

• 5 months: purposeful reaching and grasping with whole hand

• 6 months: holding bottle, bringing something to mouth

• 7 months: hand preference; pincer grasp (thumb and index finger)

• 9 months: able to drink from a cup and attempt to use a spoon

• 12 months: can hold pencil and scribble; can build tower of 2 blocks

task of infant (erikson’s theory)

• trust

• when environment consistently satisfies basic needs

attachment of infants

• emotional bond btwn mother and child

• to strengthen sense of security and self

• degree of attachment can affect the social and psychological development for the rest of the life

maternal deprivation

due to lack of attachment; leads to decreased intelligence, more aggression, depression, and deliquency

engrossment

process of bonding

temperament of infants

• biologically determined

• 3 basic types:

  • easy: readily adjusts to changes

  • difficult: adjusts slowly and negatively to changes

  • slow to warm up: adjusts slowly to changes

• personality is shaped by temperament and environment

parental guidance of infants timeline

• 6 months: using distraction

• 7-12 months: more direct training, “no.”

  • both verbal and physical action