Prenatal Development Flashcards
Trimester
A period of three months which divides the duration of pregnancy
Zygote
A full cell resulting from the fusion of sperm and an ovum
Blastocyst
a cluster of cells, where some cell differentiation has occurred
Embryo
the collection of cells of a human especially from implantation in the uterine wall before the development of organs
Endometrium
The nutrient rich lining on the uterine wall in which the ovum embeds or that is expelled every month if pregnancy does not occur
Implantation
occurs when the closure of cells which forms embryo attaches to the uterus lining
Placenta
a temporary organ which transfers nutrients and oxygen to the foetus/embryo and excreting waste
Amnion
the fluid surrounding the foetus that protects the unborn baby
Chorion
The outermost membrane surrounding an embryo
Foetus
the unborn child within the last stage of pregnancy
Umbilical Cord
the cord like structure attaching the mother and foetus transferring nutrients and oxygen
Teratogens
atmospheric pollutants which harms the environment of the foetus and effects their development of organs
Neonate
a new born child after birth
Adaptation
the process of change when a neonate becomes better suited to its environment
Apgar Scale
method used to assess the health and adjustment of newborns after birth
Reflex
The action which is performed automatically without consciousness thought as a response to a stimulus
Fontanelles
The space between the bones of the skull in an infant/foetus, where ossification is not complete and sutures are not fully formed.
What are the three stages of prenatal development ??
- germinal, embryonic and foetal stage
What is the main feature of the Germinal Stage ?
When contraception occurs in the fallopian tube and a zygote is formed, as the sperm fertilises the ovum. Zygote travels along the fallopian tube, undergoing mitotic division to develop into a blastocyst, ends as it implants in the uterus lining.
What is the time frame of the germinal stage ?
approximately 14 days, occurring from contraception to the implantation of the uterus lining.
What are risks in the germinal stage ?
zygote becomes stuck in the fallopian tube, called an ectopic pregnancy, or the blastocyst implants further down the uterus instead of at the top
What are the main features of the Embryonic Stage ?
- referred to as the critical stage, as there is rapid development such as organs and limbs. The differentiation of cells also takes place. After implantation of cell at the top of uterus lining the cell divides into two, the embryo and the placenta. Neural tube begins to develop, as brain and spine forms.
What is the time frame of the Embryonic stage ?
approximately 12 weeks
What are the risks of the embryonic stage ?
Teratogens, as there is a large amount of development of organs and limbs, and if the environment is polluted it can cause deformities in the organ/limb which was developing
What are the features of the foetus stage ??
rapid growth and mitosis occurs and maturation of genetic potentials.
What is the time frame of the foetus stage ?
from 12 weeks - birth
What are the risks of the foetus stage ?
exposure to drugs can cause addiction
exposure to nicotine can cause low birth weight
exposure to alcohol can cause brain abnormalities
Role of the placenta
temporary organ to deliver nutrients from mothers food and oxygen, while excreting waste such as carbon dioxide
How does the mothers consumption transfer to the foetus ?
mother digests her food which travels to the intestine, absorbed into chemicals and transferred into the blood stream, passing through the placenta to deliver nutrients to the foetus
What are the three stages of labour ?
- Contractions
- Birth
- Delivery of Placenta
Key features of the first stage of Labour - Contractions
The longest and most painful stage of labour as the muscular contractions forces the baby to apply pressure to the cervix, causing the water (amniotic sac) to break as it begins to move down the birth canal. Dilation of the cervix reaches 10 cm and the cervix, vagina and uterus becomes becomes one pathway known as the birth canal.
Key features of the second stage of labour - birth
Baby passes through the birth canal and the umbilical cord is cut
Key features of the third stage of labour - placenta
last few contractions
placenta is delivered
What are the adaptations of a neonate ?
- provision of food
- lungs work independently
- swallow to gain milk
- excrete waste products
body temperature
Cell differentiation
the process where cells change from being general to being specifically formed during development to serve a certain function
Perinatal
end of pregnancy until on month after birth
Prenatal
before birth
Antenatal
existing before birth, care of mother during pregnancy and early stages of birth
Fertilisation
occurs when a sperm penetrates an ovum and the genetic materials fuse together to make a single cell called a zygote
where does fertilisation occur ?
in the fallopian tubes
