Download - Conception and Pregnancy
Conception and Pregnancy
http://www.youtube.com/watch?v=Cr45f2OjC5U&list=PL676C9F52251404E4
Fertilization
Sperm + ova = zygoteOvum can be fertilized over a
maximum range of 72 hours each menstrual cycle.
Estimated that 30% of all fertilized oval naturally do not survive.
Fertilization begins when:The head of one sperm enters
ovum.Occurs in outer 1/3 of fall. Tube.Fertilized ovum is called a zygote.
One cell, one nucleus, all the necessary ingredients for its development.
In Vitro Fertilization
1st attempted in 1978Ovum retrieved by laparoscope,
mixed with semen in a test tube.Returned to uterus after 2 ½ days50% success rate of fertilization20-30% implant rate of those
fertilized.
http://www.youtube.com/watch?v=7FHLPi5YCz0
Cell Division
It is called cleavage.Bulk of cell does not change.Rapidly dividing cell ball
develops: blastocystPassage to uterus takes 7-9 days.
Embryo Stage: Begins the 2nd week and extends
through the 8th week.
Fetal Stage:After the 8th week, until birth.
BlastocystFluid filled hollow ball of cellsBurrows little finger-like projections
called villi into the blood supply of the endometrium.
Outer rim becomes the chorion (fetal membrane).
Cells near the outer rim become the embryo.
Placenta
Develops by 3 monthsTakes over job of providing
nourishment for the fetus and carrying fetal waste to the maternal blood.
Joined to fetus by umbilical cordBegins to secrete estrogen and
progesterone.
Approximately 8 in. in diameter, 1 in. thick, and about 1/6 of fetal wt.
Transfer of nourishment and waste occurs by osmosis
Calcium, phosphorous, amino acids, glucose, fats, bacteria, viruses, antibodies pass from maternal side to fetal side.
NO intermixing of maternal blood and fetal blood.
O2 and CO2 pass through by diffusion
Prevents passage of some but not all harmful substances into fetus.
Nicotine, alcohol, most drugs pass through placental barrier and harm the fetus.
Umbilical cord: 1 umbilical vein, 2 umbilical arteries, Wharton’s jelly enclosed in a membrane.
Cords are examined at birth for completeness.
Birth
At birth, lung function is established.
Umbilical vein and arteries become fibrous cords.
Once cord is cut, large amount of blood returns to the heart from the lungs.
Also at birth, the foramen ovale closes due to equalization of pressure in the atria, and normal circulation begins.
Gestation is the period of development of the child in the mother’s uterus. Lasts approximately 280 days.
Pregnancy is described in terms of the number of weeks of gestation (40 total), or it may be divided into three trimesters of 3 months each.
The due date, or estimated date of confinement (EDC), is calculated from the first day of the last menstrual period (LMP).
A fetus is viable when it is capable of living outside of the mother. It depends on the developmental age, birth wt, and developmental stage of the lungs.
The amnion, also known as the amniotic sac, is the innermost of the membranes that surround the embryo in the uterus and form the amniotic cavity.
Amniotic fluid is the liquid in which the fetus floats and is protected.
Amniocentesis is a surgical procedure in which a needle is inserted through the abdominal and uterine walls to obtain a specimen of amniotic fluid.
Done after 16th week of pregnancy, is used to evaluate fetal health and diagnose certain congenital disorders.
Abruptio Placentae:An abnormal condition in
which the placenta separates from the uterine wall prematurely before the birth of the infant.
Placenta previa:The abnormal implantation of the
placenta in the lower portion of the uterus. Symptoms include painless sudden-onset bleeding during the third trimester. Treatment ranges from bed rest to immediate delivery by C-section.
Pregnancy:Physiological Changes
Hegar’s sign: softening of the lower part of the uterus; about the 6th week.
Goodell’s sign: cervix softening
Chadwick’s sign: tissue around the vagina becomes thicker, softer, and takes on a bluish, purple color.
Braxton-Hicks contractions: painless, intermittent contractions of the uterus, caused by enlargement.
Ballottement: rebounding of the floating fetus in the uterus when the fetus is lightly tapped during a vaginal exam; after the 4th month.
Signs and Symptoms
Skin:Linea nigra; dark line from
umbilicus to mons pubisChloasma: a dark freckle-like
pigmentation of the faceStriae gravidarum: white streaks
on breasts, abdomen, thighs.
Cessation of mensesUrinary frequencyMorning sicknessQuickening: 1st sensation of fetal
movement, around 4th monthBreasts: fuller, larger, tender.Fetal heartbeat: heard 3rd month
with fetone
Ultrasound: sound waves that scan the abdomen to identify outline of baby and placenta.
Souffle: soft murmur produced by blood flow in the placenta and umbilical arteries.
Labor and Delivery:Engagement and Lightening
Final 2 – 4 weeks of gestationFetal head sinks into pelvis
(engagement)Effects on mother (lightening):Fundus lowers, upper abdomen
flattens, breathing easier; walking more difficult.
Onset of Labor
The “Show” – mucus streaked with blood from cervix
Rupture of waters: amniotic sac tears and releases amniotic fluid
Labor pains: regular contractions of the uterus.
True Labor
Characterized by rhythmic, increasingly intense uterine contractions
Cervix changes shape:Effacement: shorteningDilation: widening
Crowning: fetal head presents and can be seen
Presentation: manner in which the fetus presents itself in the vagina
Cephalic presentation: head firstBreech presentation: buttocks or
legs first
Discussion
Suctioning of infant immediately upon delivery
Cry: present or absent; weak or strong
Apgar Score
An evaluation of a newborn infant’s physical status by assigning numerical values (0 to 2) to each of five criteria:
Heart rateRespiratory effortMuscle toneResponse stimulationSkin colorThe newborn is evaluated at 1
and 5 minutes after birth.
A total Apgar score of 8 to 10 indicates the best possible condition.
http://www.youtube.com/watch?v=7U2z7WMthZ0
Diseases and Disorders
Dysmenorrhea:Painful spasms of uterine
muscles.Amenorrhea:Absence of normal menstruation
due to hormone imbalance, pregnancy, wt. loss, menopause.
PMS:Premenstrual Syndrome;
irritability, fatigue, nervousness, depression, cause unknown.
PID:Pelvic Inflammatory Disease; can
cause salpingitis, oophoritis.
Vaginitis:Usually yeast infections (Candida)Causes leukorrhea (white
discharge); can be viral, bacterial, fungal, protozoan;
Causes thick discharge, mild pain on urination, itching.
Treatment: metronidazole
Myoma:Fibroma / fibroids; benign tumors
of the smooth muscleOvarian cysts:Fluid filled sac that develops from
a follicle that fails to rupture completely
Endometriosis:Displaced endometrial tissue,
usually on the peritoneum of the abdomen
Cancer:Ovaries, breast, uterus, cervix
(Pap smear).Testicular, prostate (PSA test)
Hermaphrodite:Has both testicular and ovarian
tissue; rare in humans, more common in other species.
Klinefelter’s Syndrome:XXY (47); male with small testes,
gynecomastia, subnormal intelligence; occurs in 1:700 live births.
Turner’s Syndrome:XO (45); female, poorly
developed gonads, short stature, impaired intelligence, ovaries fail to respond to FSH, LH stimulation.
STD’s http://
www.youtube.com/watch?v=ARe5tEpb99s
Fact or Myth?
Gonorrhea
Bacteria spread by genital contact as well as contact with anal and pharyngeal mucosal surfaces.
Males: painful urination & discharge of pus.
Females: lower abdominal discomfort, vaginal discharge, abnormal bleeding.
Gonorrhea
Treated with antibiotics.
Syphilis
Caused by bacteriaCauses ulcers (chancres) on
penis and in vagina.Secondary signs: pink rash over
body, fever, joint pain.
Syphilis
Tertiary signs: destructive lesions of CNS; blood vessels, bones, skin.
Treated with penicillin (PCN).
Chlamydia
Most common STDVaginal discharge or burning
abdominal, rectal, or testicular pain
Painful intercourse and irregular menses.
Genital Herpes
May remain silent for weeks or years.
Blister-like lesionsCongenital herpes can cause
severe malformation of fetusCan lead to cervical cancerIncurable!!!!
Genital Warts
Viral; common skin wart on genitals.
Caused by papilloma virusTreatment: chemical or physical
removalCan lead to cervical cancerIncurable!!!!
Hepatitis B
ViralIncurableImmunization available
AIDS
Acquired Immunodeficiency Syndrome
Viral; caused by HIV Early: wt. loss, frequent fevers,
mild infections, weakness, enlarged lymph glands
AIDS
Later: susceptibility to common infections, pneumonia, cancer.
Treatment: antivirals, immunostimulants to slow progress of virus
Incurable!!!!
Non-gonococcal Urethritis
Bacterial infectionThin, clear discharge from penis
or vagina, mild pain during urination
Pubic Lice
Cause: louseItching in region of pubic hairTreatment: creams, lotions, or
shampoos containing gamma benzene hexachloride