Chapter 12 Flashcards
Ovulation occurs…
14 days into the menstrual cycle
Pre-Embryonic Period
12-14 days after fertilization
Embryonic Period
15 days-8 weeks after fertilization
Most critical stage of development
Most vulnerable to teratogens
Fetus
9-38 weeks
Less vulnerable to teratogens
Umbilical Cord
Consists of Wharton’s Jelly (to prevent cord compression) and 2 arteries and 1 vein
Placenta
Endocrine gland functions (HcG, HcS, estrogen, and progesterone)
Adequate circulation necessary for placental function
Viability
Infant supposedly viable at > 20 weeks
Amniotic Fluid
Cushions against impacts to maternal abdomen
Maintains stable temperature
Allows symmetric development
Prevents the membranes from adhering to developing fetal parts
Allows room and buoyancy for fetal movement
4 Weeks
Heart develops and begins to beat
Genital ridge appears
8 Weeks
Cerebral cortex begins to acquire atypical cells
12 Weeks
Lungs acquire definite shape
Kidney able to secrete urine
Earliest tastebuds indicated
Sex recognizable
Lanugo first appears
16 Weeks
Most bones distinctly indicated throughout the body
Kidneys in position
General sense organs differentiate
20 Weeks
Enamel depositing nose and ears ossify
24 Weeks
Able to hear
28 Weeks
Lecithin is forming on alveolar surfaces
Receptive to lights
30-31 Weeks
Can turn head from side to side
Aware of sounds outside of the mother’s body
40 Weeks
Scant vernix caseosa
Moderate to profuse hair
Myelination of brain begins
Sleep-wake cycle
First System to Function
Cardiovascular
Progesterone
Suppresses secretion of FSH and LH by the anterior pituitary
Maintains pregnancy by relaxing smooth muscles
Causes fat to deposit in subcutaneous tissues over the maternal abdomen, back, and upper thighs
Decreases mother’s ability to use insulin
Estrogen
Relaxes pelvic muscles and joints
Interferes with folic acid metabolism
Prolactin
Prepares breasts for lactation
Oxytocin
Stimulates uterine contraction
Stimulates milk ejection from breasts
Cortisol
Stimulates production of insulin
Increases peripheral resistance to insulin
Aldosterone
Stimulates reabsorption of excess sodium from the renal tubules
