Fetal development

uterine (mentrual) cycle

menstrual phase, proliferative phase, (ovulation), secretory phase

ovarian cycle

follicular phase, ovulation, luteal phase

Capacitation

when sperm reach the ovum and prepare for fertilization --> change in shape to allow them to release enzymes to break down the ovum membrane

gamete

sex cell

ovum

mature female gamete

sperm

mature male gamete

gametogenesis

the process in which cells undergo meiosis to form gametes

cleavage

rapid cell division

morula

a solid ball of cells resulting from division of a fertilized ovum

blastocyst

a hollow ball of cells --> implants in uterus

embryoblast

The inner cell mass of the blastocyst, which is the developing human

trophoblast

The outer cell mass of the blastocyst, which is the placenta

how is the zygote propelled

cilia + peristalsis --> reaches uterine cavity in 3-4 days

When does implantation occur?

6-10 days after fertilization --> bleeding/spotting

chorionic villus

fingerlike projections of the chorion that extend into the uterine lining

intervillous space

The space in the placenta in which maternal blood bathes chorionic villi, allowing the exchange of materials between the fetal and maternal circulations.

functions of the placenta

nutrients, oxygen, hormones, waste transfer

human chorionic gonadotropin (hCG)

hormone produced by an embryo following implantation--> stimulates corpus luteum to produce progesterone until placenta takes over

human placental lactogen hPL

Hormone produced by the placenta that stimulates the mammary glands to produce milk

progesterone

hormone produced in ovaries --> maintains pregnancy

estrogen

hormone produced in ovaries --> uterine growth and myometrial contractility

yolk sac

8-9 days after conception --> provides nutrition and gas exchange before placenta forms --> embryonic blood cell production

umbilical cord

tube that contains two arteries and one vein --> connects placenta to embryo

When does the fetal heart begin to beat?

end of 3 weeks gestation

amnion

innermost layer of the fetal membrane -->contains amniotic fluid

chorion

Outermost layer of the two membranes surrounding the embryo --> forms the fetal part of the placenta

purpose of amniotic fluid

cushions fetus, maintains body temp, allows freedom of movement, vital to lung development

what is amniotic fluid made of

fetal urine

characteristics of amniotic fluid

800 mL

Slightly opaque

Slightly alkaline pH (>7)

trimester timelines

1st -- first day of LMP-week 13

2nd -- week 14 - week 27

3rd -- week 28 - week 40

pre embryonic phase

first 2 weeks after fertilization --> rapid mitosis and cell differentiation

embryonic period

weeks 3-8 --> placenta forms, organs and body systems form

fetal period

week 9-birth --> rapid body growth

when do vernix and lanugo appear

weeks 17-20

When is surfactant produced?

24 weeks --> from now on there is a chance of survival

TORCH infections

T - toxoplasmosis

O - other (syphilis)

R - rubella

C - cytomegalovirus

H - herpes

Toxoplasmosis

a parasite that is most commonly transmitted from pets to humans by contact with contaminated animal feces, or through uncooked meat

--> classic triad

Classic triad of toxoplasmosis

1. Chorioretinitis

2. Hydrocephalus

3. Intracranial calcifications

Other (syphilis)

sexually transmitted bacterial infection --> perforated hard palate, saddle nose, snuffles, chorioretinitis

Other (hepatitis B)

transmitted through delivery --> may develop SGA, jaundice, hepatomegaly, ascites, hyperbilirubinemia

How to prevent hebB

HBV vaccine, 3 doses

Rubella

aka german measles, viral infection transmitted through placenta/respiratory secretions --> blubbery muffin rash, cataracts/glaucoma/retinopathy, pneumonia

Cytomegalovirus

herpes-type virus transmitted through placenta --> developmental delay, microcephaly, chorioretinitis, jaundice, lethargy, poor suck reflex,

herpes

viral infection --> sores on eyes/skin/mouth