Biology 3201 Childbirth and Fetal Health

Labour

Labour

Begins with contractions and dilation and ends with the birth of a baby

Dilation Stage

Pituatary releases oxytocin, the cervix opens and dilates up to 10cm

Expulsion Stage

Uterus contracts until the baby is delivered

Placental Stage

Placenta and umbilical cord are expelled 15 minutes after birth.

Prolactin

Causes milk to be produced in mammary glands

Oxytocin

Causes contractions of the mammary glands to allow milk to flow

Ultrasound

Sound waves sent through abdomen of woman that allow the fetus to be seen. Used to detect physical abnormalities

Amniocentesis

Amniotic fluid is collected from mother with a needle to determine chromosomal abnormalities

Fetoscopy

A camera inserted into the uterus to view the fetus for a variety of reasons, ie to guide surgeons in fixing abnormalities in the fetus while inside the uterus

Chorionic Villus Sampling

Fetal cells removed from chorion layer to detect chromosomal abnormalities

Teratogens

Any chemical or environmental agent that causes a structural abnormality in fetus

Fetal Alcohol Syndrome

Fetus exposed to alcohol during pregnancy, causes mental defects

Thalidomide

Used during the 1950s to cure morning sickness but caused fetuses to have missing limbs

Effects of cigarette smoke

Fetus can be underweight or suffer from convulsions

Chorion

Outermost layer of cells surrounding the embryo. Becomes the placenta

Allantois

Does not surround the embryo, the blood vessels become that of the umbilical cord

Yolk sac

First site of red blood cell formation

Amnion

Develops into the amniotic membrane

Amniotic membrane

Thin membrane that surrounds the fetus

Umbilical cord

Lifeline between mother and fetus

Cleavage

The series of cell division without growth of an embryo

Morula

Solid mass of identical cells

Blastocyst

Made up of an inner and outer cell mass

Gastrula

A ball of cells that consists of three germ layers. They grow into distinct layers, this is called gastrulation

Ectoderm

Outside layer of gastrula

Mesoderm

Middle layer of gastrula

Endoderm

Inner layer of gastrula

Neurula

Nervous system development