textbook chapter 6

what happens when the sperm meets the egg

• Egg is released from ovary into body cavity

• Picked up by fimbriae

• Enters the fallopian tube

• Goes to uterus 

• Womens cervix secretes mucus that flushes passageways to prepare for sperm

• Conception happens in outer third of fallopian tube

human sperm structure

• Acrosome: tip

• Head

• Nucleus containing chromosomes (inside head)

• Midpiece (contains mitochondria to provide energy for swimming)

• Tail

Conceptus

the fetus

Formations during the embryonic period (first 8 weeks)

• Inner part of the ball of cells differentiates into two layers: endoderm and ectoderm

• Later a third layer, the mesoderm forms between them

• Organs of the body differentiate themselves out of these layers

ectoderm

 nervous system and skin

endoderm

 digestive system (pharnyx to stomach and intestines to rectum and respitartory system)

mesoderm

muscles, skeleton, connective tissue, reproductive and circulatory systems 

• Development proceed in cephalocaudal order (head first, lower body last because head of embryo is way bigger than rest of body)

trophoblast

 another group of cells which will become placenta 

• Develps out of mass tissues that surround the conceptus early in development and nurture its growth by producing tendrils that penetrate the blood vessels in the wall of the uterus 

• Functions: site for exhange of subsances between the womens blood and fetuses blood 

  • Blood never circulates inside each others

  • Oxygen and nutrients can pass through the barrier 

  • Some viruses can pass through 

  • Colds and stuff cant pass

• Secretes hormones

  • Produces large quantities of estrogen and progesterone which cause the physical symptoms of pregnancy

  • Produces humuch chorionic gondaotropin (hCG) which is detected in pregnancy tests

umbilical cord

• Formed during fifth week of embryonic development

• Formed cord is 55cm

membranes

• Two membranes surround the fetus - the chorion, the amnion

• Amnion is innermost, filled with amniotic fluid where the fetus floats and moves and keeps it at constan temperature and projects from injury

emotional states

• Women who led very active lives before pregnancy may find pregnancy causes distress 

• Womens emotional state during prengnancy can have effect on developing fetus because cortisol crosses the placenta and increases risk of stillbirth and low birth weight

father infant bond

Likelihood depends partly on fathers responsiveness to the infant

nutrition during pregnancy

• Overweight and obese women are at increased risk of negative outcomes for themselves and the fetus such as hypertension, gestational diabetes, c section for the mother and congential abnormalities for the fetus

• Artificially sweetened soft drinks is linked to increased likelihood of preterm birth

viral infection during pregnancy

• Rubella: if women gets rubella during first month of prengnancy there is 50% chance that infant will be born deaf or have congenital deficits 

• Herpes: infant will contract the disease by contacting the sores, c section can prevent this

• HIV: can pass virus on during prengnacy, delivery or though breast milk

amniocentesis

• Inserting fine tube through womens abdomen and removing some amniotic fluid to diagnosis abnormalities 

• Performed between 13-16th week because abortion should be done early

chorionic villus sampling

• Can be done in first trimester 

• Catheter is inserted into uterus through cervix

• Needle is inserted through abdomen 

• Sample is taken from chrorionic villi and cells are analyzed

parturition

 whole process of childbirth

first stage labour stages

divided into 3 stages

• Early: contractions are spaced far apart, easy

• Late: dilation of cervix from 5-8 cm, shorter than early stage, contractions are closer

• Transition: short and difficult, most pain and exhaustion

coach

• Present during labour and delivery to tiem contractions and check on mother, help her

• Can be the partner and allows them to play active role in birth

midwives

• Midwives provide care from early pregnancy to 6 weeks after the baby is born

• Midwife visits are longer

• Midwives offer women a choice of birth place

• Midwife stays wit women through labour and birth

• Two midwives are usually present

anesthetics in childbirth

• Usually local and regional anesthetics which numb specific region of body

• Spinal block in first stage

• Epidural block numbs body from waist down

• Pudenal block is injection to vaginal wall which relives pain in lower vagina

• Local anestheic used to numb area that needs repair

• Tranquilizers will only be used if women is extremely anxious

home vs hospital birth

• No difference in maternal or fetal outcomes

• Only low risk pregnancies should do home births

• There must be access to a hospital incase an emergency arises

post partum blues

Symptoms begin few days after birth and most intense on week post partum and disappear two weeks later

post partum depression

• Severe

• Begins 2 to 3 weeks post partum

• Being in a hospital, low energy, lack of sleep, physical stresses contribute to this

• Genetic vulnerability, severe negative life events, poor quality relationship with partner or own mother are risk factors 

• Can happen to fathers too

Post partum psychos

• Most severe

• Rare

Breast milk

• Contains antibodies

• Prevents asthma and allergies

• Free from bacteria, always the right temperature 

• Reduced risk of obesity

• Shrinks uterus to normal size

• Reduces postpartum bleeding

• More rapid weight loss

• Reduces likelihood of pregnancy

• Reduces negative moods and perceived stress

• Reduces risk of breast cancer

• Can be arousing or lead to orgasm

ectopic pregnancy

• Egg implants in the fallopian tube

• Could occur if tubes are obstructed and aren't letting the egg go down

• Could rupture or abort

molar pregnancy

• Mass of abnormal tissue inside the uterus 

• Women think she's pregnant because of symptoms

pseudocyesis

• False pregnancy

• Symptoms of pregnancy but not pregnant

pregnancy induced hypertension

• Hypertension: elevated blood pressure

• Pre-eclampsia: elevated blood pressure, with fluid retention and swelling, and protein in urine

• Eclampsia: convulsions, could go into coma and die

D (Rh) Incompatibility 

• D antigen is a substance in the blood and if you have it, you are D positive and if you dont have it, you are D negative

• This is genetically transmitted, D+ is dominant over D-

• Problem when d- person receives blood transfusion or d- women is pregnant with d+ baby because if the bloods get mixed, it can build antibodies which can cause baby to be stillborn, anemic or developmentally delayed 

Combined factors for infertility

Immunologic response where women has allergic reaction to mans sperm causing her to produce antibodies for the sperm

Psychological aspects of infertility

• Feeling like ur masculinity or femininity is down

• Pressure on infertile couples is high 

• Stress is greater for infertile partner 

• Can lower sexual satisfaction 

Treatment of infertility

• Assessment of couples knowledge of sexua behaviour and conception and lifestyle factors such as regular drug use - can be treated easily

• Fertility drugs to produce LH and FSH to induce ovulation 

• Microsurgery for blocked fallopian tubes

• IVF

Assisted insemination

• Used by intertile couples, single people and same sex couples

• Aritifically placing semen in vagina, uterus or fallopian tubes

sperm banks

• Frozen human sperm banks 

embryo transfer

A fertilized egg is transferred from the uterus of one woman to the uterus of another woman

ifv

• Sperm and egg unite in a dish outside of the human body and then implanted in uterus 

• More likely to be low birth weight or have congenital abnormalities 

• Can freeze IFV eggs

gift and zift

GIFT: gamete intra-fallopian transfer

• Sperm and eggs are collected and then inserted into fallopian tube 

ZIFT: zygote intra-fallopian transfer

• Egg is fertilized with sperm in lab dish and developing egg is placed into fallopian tube

Prenatal genetic diagnosis

• Determining a fetuses genotype at a specific locus to detect marker for down syndrome