FM 15 Pregnancy & Foetal

PL1401

Oocyte must be fertilize within ? hours

24h

Sperm survive for ? hours

48

Fertilized egg is called

zygote

Genetic material is passed onto which cells?

Daughter cells

How many cells are present 2 days after fertilization?

4 cells

How many cells are present 3 days after fertilization?

16 cells (morula)

How many cells are present 4 days after fertilization?

\~100 cells

When does the fertilized oocyte reach the uterus?

Day 4

When the fertilized oocyte reaches uterus, the fluid filled space formed is called

blastocyst

Which cells becomes the embryo in cleavage?

Inner cells

Which cells is needed for placenta formation in cleavage?

Trophoblast cells

What is cleavave?

Single cell becomes subdivided into smaller cells

6-7 days after ovulation, ___ attaches to ___

Blastocyst/Endometrium

Implantation is usually low in the uterus T/F

False. High

Endometrium ___ at point of contact with blastocyst

thickens

What happens to trophoblast cells in implantation?

Devide, form layers, extend into endometrium

Implantation complete by day ? after ovulation?

\~ 12

Role of progesteron and oestrogen after fertilization?

Prevent break down of endometrium

Trophoblast cells secret which hormone?

Human chorionic gonadotropin (hCG)

hCG role?

Maintain CL

When does hCG level peak?

\~ 2 months

What hormone is tested in pregnancy test?

hCG duh

What happens to hCG level after placenta is able to produce hormone?

Drop gradually

What is implantation?

When a fertilized egg attaches to endometrium

First signal to produce hCG?

Implantation

What is placentation?

Embryo & endometrium tissues form **placenta**

Are you tired?

Take a rest then come back. It’s ok

What is chorion?

Inner mass cells divide & line inner surface of trophoblast

(one of the membranes between fetus & mother, exchange nutrition)

Chorion function?

Contact mother’s blood supply and form new blood vessels

When is the placenta fully functional?

3rd month

What carries oxygen and nutrients from the placenta into fetus's blood

Umbilical cord - correct

Umbilical vein/Ductus venosus - acceptable

When does the fetus have a basic heart and blood vessel?

3rd week - and you took longer than that to study a single module

What carries oxygenated blood from placeta?

Umbilical vein correct

Umbilical cord acceptable

Oxygenated blood is carried from placeta via ___

ductus veno**sus**

Oxygenated blood is emptied into ? of the fetus

inferior vena cava (right heart)

**Liver is bypassed** when deoxygenated blood is carried to the fetus T/F

False. Liver & lung are bypassed but it’s oxygenated blood

Liver & lung does not work fully until after birth

What empties deoxygenated blood and waste into placenta?

Aorta

What is the hole inbetween left and right atria of fetus?

Foramen ovale

What transfer most venous blood into the aorta?

ductus arteriosus

Fetus length at 8 weeks

22mm

Fetal characteristic at 8 weeks

Very large head

All major organs present

Fetus length at 9-12 weeks

90mm

Fetus length at 13-16 weeks

150mm

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Fetal characteristic at 13-16 weeks

Sensory organs in correct position

Increase in body size (this is so obvious???)

Fetus length at 17-20 weeks

190mm

When is fetal position assume?

17-20 weeks

eg head should face down, facing mother’s back ect

Fetus length at 21-30 weeks

280mm

Lung is fully developed at week 28 T/F

False

Fetus length & weight at 30-40 weeks

360mm, 3.2kg

What the hell is Parturition

Childbirth

Oestrogen level near the end of pregnancy?

Increase

What does increased level of oestrogen near childbirth cause?

Cause oxytocin receptors on myometrium

Oxytocin induces contraction

It’s not on the lecture note just random information

Prostaglandins is produced by

Placenta and fetal cells

Prostaglandins role in childbirth (not on test hopefully)

Induces unimaginable amounts of pain to discourage young women from starting families

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Also helps dilate cervix and cause uterine contractions to push the baby out but that’s a minor role ig

Oxytocin & prostaglandins level is increased in a positive feedback loop T/F

True. When will this pain end

List some physiological changes in mothers during pregnancy

Nausea

Heartburn (acid reflux)

Constipation

Incontinence (bladder muscles don’t work as usual)

Dyspnoea (diff breathing)

Cardiovascular effects (separate question)

Cardiovascular effects of pregnancy

↑ blood volume

↑ blood pressure (hypertension or preeclampsia in 10%)

↓ venous return