BIOH 370 1st editionLecture 36 Outline of Last Lecture Reproductive System Day 5 & Development and InheritanceI. STIs:a. Bacteriali. Gonorrheaii. Syphilisiii. Chlamydiab. Virali. Genital Wartsii. Genital HerpesII. Reproductive System Developmental Aspects- Sex DeterminationIII. Male/Female Homologous Reproductive OrgansIV. MenopauseV. Development and Inheritancea. From Egg to Zygoteb. Fertilizationc. Embryonic Developmentd. Formation of PlacentaVI. Changes During PregnancyThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.a. Maternal Changesb. Hormonal ChangesVII. Embryonic PeriodOutline of Current Lecture Development and Inheritance Day 2I. Embryonic Perioda. 4th Weekb. 5th Weekc. 7th Weekd. 8th WeekII. Fetal PeriodIII. Invasive Prenatal Diagnostic TestsIV. Non-invasive Prenatal TestsV. Effects of Pregnancya. Anatomical Changesb. Physiological ChangesVI. Initaition of Labor (Parturition)VII. Stages of Labora. Dilation Stageb. Expulsion Stagec. Placental StageCurrent LectureDevelopment and Inheritance Day 2I. Embryonic Perioda. 4th Week:- By the middle of the 4th week, upper limb buds begin to develop.- By the end of the 4th week, lower limb buds and the heart prominence form.- At the end of the 4th week, the embryo has a tail.b. 5th Week:- During the 5th week, the brain and head develop rapidly and the limbs develop further.c. 7th Week:- By the 7th week, the regions of the limbs become distinct and digits appear.d. 8th Week:- By the end of the 8th week, eyelids come together, the tail disappears, external genitals begin to differentiate and digits are distinct and are nolonger webbed.II. Fetal Period:- At 17-20 weeks can test for gestational diabetesIII. Invasive Prenatal Diagnostic Testsa. Chorionic Villi Testing (CVS): test the fetal portion- ultrasound guided- can also do trans vaginally depending on fetus’ position in mother’s uterusb. Amniocentesis- can be done around 14-16 weeks- take amniotic fluid to look at genetic componentsUltrasoundtransducerNeedleCatheterUrinary bladderVaginaFetus(8–10 weeks)Amniotic fluidUterine cavityChorionic villi(b) Chorionic villi sampling (CVS) NeedleUltrasound transducerAmnionAmniotic fluidUterusFetus(14–16 weeks)Placenta(a) AmniocentesisIV. Non-invasive Prenatal Testsa. Ultrasound and triple/quad screen- Blood tests- Quality has improved over the last few years significantly - Assesses relative likelihood of defects but not a positive yes or nob. MaterniT21 blood test:- Takes blood from mother- Amplificaiton of fetal DNA found in maternal blood to determine whether trisomies are presento Trisomy 21 (Down’s Syndrome), Trisomy 18, Trisomy 13o Only test for these three trisomies because these are the only trisomies that would allow a fetus to develop as far as if has- pregnancy lost if other trisomies- 99% accurateV. Effects of Pregnancya. Anatomical Changes:- Reproductive organs become engorged with bloodo Chadwick’s sign: the vagina develops a purplish hueo Breasts enlarge and areolae darkeno Pigmentation of facial skin many increase (chloasma)- The uterus expands, occupying most of the abdominal cavity- Lordosis occurs with the change in the center of gravity- Weight gain of ~13 kg (28 lb)- between 25-35 pounds= 7-8 pounds in blood weight, lactation, etc, some in water weight- Relaxin causes pelvic ligaments and the pubic symphysis to relax to ease birth passage(a) Before conception (Uterus the size of a fst and resides in the pelvis.) (b) 4 months (Fundus of the uterus is halfway between the pubic symphysis and the umbilicus.) (c) 7 months (Fundus is well above the umbilicus.) (d) 9 months (Fundus reaches the xiphoid process.) b. Physiological Changes:- GI tracto Morning sickness due to elevated levels of estrogen and progesteroneo Heartburn and constipation are common- Urinary systemo Urine production due to metabolism and fetal wasteso Stress incontinence may occur as bladder is compressed- Respiratory systemo Estrogens may cause nasal edema and congestiono Tidal volume increaseso Dyspnea (difficult breathing) may occur later in pregnancy- Cardiovascular system o Blood volume increases 25–40%o Blood pressure and pulse riseo Venous return from lower limbs may be impaired, resulting in varicose veinsVI. Initaition of Labor (Parturition)- Head placed downward in uterus= vertex (what is wanted for birth)- Feet first- downward in uterus= breech= not good- During the last few weeks of pregnancyo Fetal secretion of cortisol stimulates the placenta to secrete more estrogen Causes production of oxytocin receptors by myometrium Antagonizes calming effects of progesterone, leading to Braxton Hicks contractions in uterus- Surfactant protein A (SP-A) from fetal lungs causes softening of the cervix- Fetal oxytocin causes the placenta to produce prostaglandins- Oxytocin and prostaglandins: powerful uterine muscle stimulants- Maternal emotional and physical stresso Activates the hypothalamus, causing oxytocin release from posterior pituitary o Positive feedback mechanism occursEstrogen from placenta Induces oxytocin receptors on uterus Oxytocin from fetus and mother’s posterior pituitary Stimulates uterus to contract Stimulates placenta to make Stimulate more vigorous contractions of uterus Prostaglandins (+) (+) VII. Stages of Labora. Dilation Stage:- Longest stage of labor: 6–12 hours or more- Initial weak contractions:o 15–30 minutes apart, 10–30 seconds longo Become more vigorous and rapid- Cervix effaces and dilates fully to 10 cm- Amnion ruptures, releasing amniotic fluid - Engagement occurs: head enters the true pelvisb. Expulsion Stage:- Strong contractions every 2–3 minutes, about 1 minute long- Urge to push increases (in absence of local anesthesia)- Crowning occurs when the largest dimension of the head distends vulva- Delivery of infantc. Placental Stage:- Strong contractions continue, causing detachment of the placenta and compression of uterine blood vessels- Delivery of the afterbirth (placenta and membranes) occurs ~30 minutesafter birth- All placenta fragments must be removed to prevent postpartum