OB Study Guide 1
Chapter 10
● Stages of fetal development
○ Preembryonic: fertilization through 2nd wk
■ Fertilization AKA conception
■ Zona pellucida: blocks all other semen from entering
➡️
■ Cleavage or mitosis occurs in ampulla of fallopian tube
■ Morula: formed within 3 days, 16 cells that float toward uterus blastocyst
■ Blastocyst: cells differentiate
➡️
● Inner: embryo + amnion
● Outer: trophoblast chorion
■ Implantation: process of attachment and placental formation
○ Embryonic AKA most critical of dev: 2nd - 8th wk
■ Basic structures of body organs and external features
■ Embryonic layers
● Ectoderm: CNS, special senses, skin, glands
● Mesoderm: skeletal, urinary, circulatory, reproductive organs
● Endoderm: respiratory system, liver, pancreas, digestive system
○ Fetal: 8th wk - birth
● Fertilization
○ Gender of zygote determined at fertilization
● Fetal circulation- structures/shunts and blood flow
○ Ductus venosus: connects umbilical vein to inferior vena cava; carries most O2 blood
○ Ductus arteriosus: connects main pulmonary artery to aorta
○ Foramen ovale: anatomic opening between right and left atrium bypassing pulmonary circulation
○
● Functions of amniotic fluid, placenta, & umbilical cord
○ Placenta AKA interface between mom and fetus & transfer organ
■ Makes hormones( hCG, hPL, hCS, estrogen, progesterone, relaxin) to control physiology
of mom + mature into fetal organs + induce mom to bring more food to placenta
■ Protects fetus from immune attack
■ Removes waste products
■ Layers: amnion (inner), chorion (outer)
■ Main purpose: replaces baby's lungs
○ Umbilical cord AKA lifeline to embryo that carries blood from mother to fetus and back to mom
■ Formed from amnion
■ 1 large vein, 2 small arteries (surrounded by wharton jelly to prevent compression) AVA
, ○ Amniotic fluid: essential for fetal lung development
■ Maintain body temp
■ Permits symmetric growth and dev
■ Cushion fetus from trauma
■ Allows umbilical cord to be free of compression
■ Promotes fetal mov to enhance musculoskeletal dev
■ Volume helps determine fetal wellbeing
● Oligohydraminos <500mL at term causes placental insufficiency
● Hydramnios or polyhydramnios >2L at term: nocturnal DI, neural tube defect
Chapter 11
● S/S of pregnancy: 3 P’s
○ Presumptive
■ Fatigue
■ Amenorrhea, NV
■ Breast tenderness/ enlargement + uterine enlargement
■ Urinary frequency
■ Hyperpigmentation
■ Fetal movement (quickening; could be just gas)
○ Probable
■ Braxton hicks
■ + pregnancy test
■ Abdominal enlargement
■ Ballottement
■ Goodell (cervix is softened), chadwick, hegar signs
○ Positive
■ Ultrasound
■ Fetal movement by clinician
■ Auscultation via doppler
● Reproductive system adaptations during pregnancy
⬆️ ➡️
○ Uterus
■ in size, weight; pear shape ovoid = hegar
■ Enhanced uterine contractility; braxton hicks
■ Ascent into abdomen by 20 weeks
■ Fundal height by 20 wk = 20 cm + 1cm/wk until 36 wks
○ Cervix
■ Softening = goodell; Increased vascularization = chadwick
■ Mucus plug formation
■ Ripening 4 wks before birth (soft and thinning)
○ Vagina
■ Increased vascularity w thickening + lengthening of vaginal vault
■ leukorrhea : white thick acidic secretion
○ Ovaries
■ No ovulation
■ Enlargement until 12-14 wk of gestation
○ Breast
■ Increase in size + nodularity + nipple size; more erect & pigmented
Chapter 10
● Stages of fetal development
○ Preembryonic: fertilization through 2nd wk
■ Fertilization AKA conception
■ Zona pellucida: blocks all other semen from entering
➡️
■ Cleavage or mitosis occurs in ampulla of fallopian tube
■ Morula: formed within 3 days, 16 cells that float toward uterus blastocyst
■ Blastocyst: cells differentiate
➡️
● Inner: embryo + amnion
● Outer: trophoblast chorion
■ Implantation: process of attachment and placental formation
○ Embryonic AKA most critical of dev: 2nd - 8th wk
■ Basic structures of body organs and external features
■ Embryonic layers
● Ectoderm: CNS, special senses, skin, glands
● Mesoderm: skeletal, urinary, circulatory, reproductive organs
● Endoderm: respiratory system, liver, pancreas, digestive system
○ Fetal: 8th wk - birth
● Fertilization
○ Gender of zygote determined at fertilization
● Fetal circulation- structures/shunts and blood flow
○ Ductus venosus: connects umbilical vein to inferior vena cava; carries most O2 blood
○ Ductus arteriosus: connects main pulmonary artery to aorta
○ Foramen ovale: anatomic opening between right and left atrium bypassing pulmonary circulation
○
● Functions of amniotic fluid, placenta, & umbilical cord
○ Placenta AKA interface between mom and fetus & transfer organ
■ Makes hormones( hCG, hPL, hCS, estrogen, progesterone, relaxin) to control physiology
of mom + mature into fetal organs + induce mom to bring more food to placenta
■ Protects fetus from immune attack
■ Removes waste products
■ Layers: amnion (inner), chorion (outer)
■ Main purpose: replaces baby's lungs
○ Umbilical cord AKA lifeline to embryo that carries blood from mother to fetus and back to mom
■ Formed from amnion
■ 1 large vein, 2 small arteries (surrounded by wharton jelly to prevent compression) AVA
, ○ Amniotic fluid: essential for fetal lung development
■ Maintain body temp
■ Permits symmetric growth and dev
■ Cushion fetus from trauma
■ Allows umbilical cord to be free of compression
■ Promotes fetal mov to enhance musculoskeletal dev
■ Volume helps determine fetal wellbeing
● Oligohydraminos <500mL at term causes placental insufficiency
● Hydramnios or polyhydramnios >2L at term: nocturnal DI, neural tube defect
Chapter 11
● S/S of pregnancy: 3 P’s
○ Presumptive
■ Fatigue
■ Amenorrhea, NV
■ Breast tenderness/ enlargement + uterine enlargement
■ Urinary frequency
■ Hyperpigmentation
■ Fetal movement (quickening; could be just gas)
○ Probable
■ Braxton hicks
■ + pregnancy test
■ Abdominal enlargement
■ Ballottement
■ Goodell (cervix is softened), chadwick, hegar signs
○ Positive
■ Ultrasound
■ Fetal movement by clinician
■ Auscultation via doppler
● Reproductive system adaptations during pregnancy
⬆️ ➡️
○ Uterus
■ in size, weight; pear shape ovoid = hegar
■ Enhanced uterine contractility; braxton hicks
■ Ascent into abdomen by 20 weeks
■ Fundal height by 20 wk = 20 cm + 1cm/wk until 36 wks
○ Cervix
■ Softening = goodell; Increased vascularization = chadwick
■ Mucus plug formation
■ Ripening 4 wks before birth (soft and thinning)
○ Vagina
■ Increased vascularity w thickening + lengthening of vaginal vault
■ leukorrhea : white thick acidic secretion
○ Ovaries
■ No ovulation
■ Enlargement until 12-14 wk of gestation
○ Breast
■ Increase in size + nodularity + nipple size; more erect & pigmented
