The Fetus And Placenta Flashcards
The period from the 💡beginning of the ninth week to 💡birth is known as the
It is characterized by 💡maturation of tissues and organs and 💡rapid growth of the body.
Fetal period.
The 💡length of the fetus is usually indicated as the?
Crown-rump length (CRL) (sitting height)
The measurement from the 💡vertex of the skull to the 💡heel (standing height).
Crown-heel length (CHL)
💡Growth in length is particularly striking during the?
Third, fourth, and fifth months
Increase in weight is most striking during the?
Last 2 months of gestation
The length of pregnancy is considered to be __ after the onset of the last normal menstrual period (LNMP) or, more accurately, __ after fertilization.
280 days, or 40 weeks
266 days or 38 weeks
One of the 💡most striking changes taking place during fetal life is the?
Relative slowdown in growth of the head
During the __, the face becomes more human looking
Third month
💡Primary ossifícation centers are present in the long bones and skull by the __.
Also, 💡external genitalia develop to such a degree that the sex of the fetus can be determined by external examination (ultrasound)
12th week
By __ intestinal loops cause a large swelling (herniation) in the umbilical cord, but by the __, the loops have withdrawn into the abdominal cavity.
Sixth week
12th week
During the __, the fetus lengthens rapidly, and at the end of the first half of intrauterine life, its CRL is approximately 15 cm, about half the total length of the newborn.
Fourth and fifth months
The fetus is covered with fine hair, called?
Lanugo hair
During the __, 💡movements of the fetus can be felt by the mother.
Fifth month
During the __,weight increases considerably, particularly during the last 2.5 months, when 50% of the full term weight (approximately 3,200 g) is added.
Second half of intrauterine life
During the __, the skin of the fetus is 💡reddish and has a 💡wrinkled appearance because of the 💡lack of underlying connective tissue.
Sixth month
At what month the fetus has a CRL of about 💡25 cm and weighs approximately 💡1,100 g. If born at this time, the infant has a 90% chance of surviving.
7 months
At what month the fetus is 💡well-rounded contours as the result of 💡deposition of subcutaneous fat
By the end of intrauterine life, the skin is covered by a whitish, fatty substance (vernix caseosa) composed of secretory products from sebaceous glands.
8th month
It is a 💡whitish, fatty substance which is composed of secretory products from 💡sebaceous glands.
vernix caseosa
At what month where the 💡skull has the largest circumference of all parts of the body, an important fact with regard to its passage through the birth canal.
The weight of a normal fetus is 💡3,000 to 3,400 g, its CRL is about 💡36 cm, and its CHL is about 💡50 cm. 💡Sexual characteristics are pronounced, and the 💡testes should be in the scrotum.
Ninth month
It is the action of giving birth to young
Parturation
The date of birth is most accurately indicated as __, after fertilization.
266 days, or 38 weeks
The obstetrician calculates the date of birth as __ from the first day of the LNMP.
This method is accurate among women with regular 28-day menstrual periods
280 days or 40 weeks
Most fetuses are born within __ of the calculated delivery date.
10 to 14 days
If the fetuses are born much earlier, they are categorized as
Premature
If the fetuses are born later, they are categorized as
Postmature
It is a valuable tool which can provide an accurate (1 to 2 days) measurement of CRL during the 7th to 14th weeks.
Ultrasound
Measurements commonly used in the 💡16th to 30th weeks are:
Biparietal diameter (BPD), Head and abdominal circumference Femur length.
It is the 💡organ that facilitates nutrient and gas exchange between the maternal and fetal compartments.
Placenta
FUNCTIONS OF PLACENTA
- Exchange of metabolic and gaseous products between maternal and fetal bloodstreams.
- Transmission of Maternal Antibodies (IgG)
- Hormone Production (Progesterone)
The fetal component of the placenta is derived from the __ and __ (the chorionic plate); the maternal component is derived from the __.
Trophoblast
Extraembryonic mesoderm
Uterine endometrium
These are formed when 💡syncytium becomes very thin, and large pieces containing several nuclei may break off and drop into the intervillous blood lakes.
They 💡enter the maternal circulation and usually 💡degenerate without causing any symptoms.
Syncytial knots
The 💡villi on the embryonic pole continue to grow and expand, giving rise to the?
It is the 💡only portion of the chorion participating in the 💡exchange process
Chorion frondosum (bushy chorion)
Villi on the abembryonic pole degenerate, and by the third month, this side of the chorion, now known as the known as the?
Chorion laeve