Chapter 8: Third Month to Birth: The Fetus and Placenta Flashcards
DEVELOPMENT OF THE FETUS
The period from the beginning of the ninth week to birth is known as the ______. It is characterized by ______ of tissues and organs and rapid ______ of the body.
fetal period, maturation, growth
DEVELOPMENT OF THE FETUS
The length of the fetus is usually indicated as the ______ (sitting height) or as the ______, the measurement from the vertex of the skull to the heel (standing height). These measurements, expressed in ______, are correlated with the ______ of the fetus in weeks or months.
crown-rump length (CRL), crown-heel length (CHL), centimeters, age
DEVELOPMENT OF THE FETUS
Growth in length is particularly striking during the ______, ______, and ______ months, whereas an increase in weight is most striking during the last ______ months of ______.
third, fourth, fifth, 2, gestation
DEVELOPMENT OF THE FETUS
In general, the length of pregnancy is considered to be ______ days, or ______ weeks after the onset of the ______ or, more accurately, ______ days or ______ weeks after ______. For the purposes of the following discussion, age is calculated from the time of fertilization and is expressed in weeks or calendar months.
280, 40, last normal menstrual period (LNMP), 266, 38, fertilization
Monthly Changes
One of the most striking changes taking place during fetal life is the relative slowdown in growth of the ______ compared with the rest of the body.
head
Monthly Changes
At the beginning of the third month, the head constitutes approximately ______ of the ______.
half, CRL
Monthly Changes
By the beginning of the fifth month, the size of the head is about ______ of the ______, and at birth, it is approximately ______ of the ______.
one-third, CHL, one-quarter, CHL
Monthly Changes
Hence, over time, growth of the ______ accelerates but that of the ______ slows down.
body, head
Monthly Changes
During the ______ month, the face becomes more human looking. The eyes, initially directed ______, move to the ______ aspect of the face, and the ears come to lie close to their definitive position at the ______ of the head. The limbs reach their relative ______ in comparison with the rest of the body, although the lower limbs are still a little ______ and less well ______ than the upper extremities.
third, laterally, ventral, side, length, shorter, developed
Monthly Changes
______ are present in the long bones and skull by the 12th week.
Primary ossification centers
