Week 27 Flashcards
(17 cards)
What is the gestation period?
Fertilization to birth (38 weeks)
The gestation period is the time from fertilization until birth, typically lasting around 38 weeks.
What occurs during the prenatal period?
Development before birth
The prenatal period encompasses all developmental stages before birth, including embryological and fetal development.
What is embryological development?
First 2 months after fertilization (embryo)
During embryological development, all principal adult organs are present by the end of the first two months.
What is fetal development?
From 9 weeks until birth (foetus)
Fetal development starts at week 9 and continues until birth, with the placenta functioning by the end of the third month.
What is the neonatal period?
First 42 days after birth
The neonatal period is crucial for the adjustment of the newborn to life outside the womb.
What is the morula?
A solid ball of 16 cells by the 3rd day
The morula forms before developing into a blastocyst and remains unattached in the uterine cavity.
What is a blastocyst?
A hollow ball of cells that attaches to the endometrium
The blastocyst forms from the morula and begins implantation around day 6.
What are the two layers of the trophoblast?
- Syncytiotrophoblast
- Cytotrophoblast
These layers differentiate during implantation and contribute to the placenta’s development.
What are the primary germ layers formed during gastrulation?
- Endoderm
- Mesoderm
- Ectoderm
These layers give rise to different tissues and organs in the body.
What does the chorion secrete during pregnancy?
hCG (human Chorionic Gonadotropin)
hCG is crucial for maintaining pregnancy and is the hormone detected in pregnancy tests.
What does the umbilical cord contain?
- 2 arteries (carry blood to the placenta)
- 1 vein (carries oxygenated blood to the foetus)
- Primitive connective tissue
The umbilical cord connects the fetus to the placenta and facilitates nutrient and gas exchange.
What are some anatomical changes during pregnancy?
- Weight gain
- Increased protein, fat & mineral storage
- Marked breast enlargement
- Lower back pain
- Increased heart rate
- GI tract compression
- Pressure on bladder
These changes are adaptations to support the developing fetus.
What is true labour?
Uterine contractions at regular intervals producing pain
True labour is characterized by cervical dilation and specific pain localization.
What are the stages of labour?
- Dilation (6-12 hours)
- Expulsion (10 minutes to several hours)
- Placental (30 minutes)
Each stage has distinct processes and durations, leading to the birth of the baby.
What hormone increases during lactation?
Prolactin
Prolactin is responsible for milk production and is regulated by suckling and hormonal changes after delivery.
What triggers the milk ejection reflex?
Suckling and stimulation of the nipple
This reflex is mediated by oxytocin, which causes contraction of myoepithelial cells to release milk.
Fill in the blank: The _______ is the part of the endometrium that is lost as the placenta develops.
Decidua
The decidua comprises most of the endometrium except for the stratum basalis.
