Prenatal Development Flashcards
The first 2 weeks after fertilisation are called the _____ period
germinal
during the germinal period the ______ travels down the fallopian tubes to the uterus and implants in the uterine wall
zygote
During the second week after conception, _________ occurs
implantation
the ______ stageoccurs between 3-8 weeks after conception
embryonic
During the first week of the embryonic period—the third week after conception—the embryonic disk forms three layers. The outer layer, the __________, will become the skin, hair, nails, sensory organs and nervous system.
ectoderm
During the first week of the embryonic period—The middle layer, the ________, will become the muscles, bones, reproductive system and circulatory system.
mesoderm
During the first week of the embryonic period— The inner layer, the endoderm, will become the digestive system and the respiratory system.
endoderm
the ______ period occurs from 9 weeks after conception to birth
fetal
During the ________ trimester, the fetus becomes active and begins to respond to its environment
second
During the ________ period of prenatal development, nearly all the major organs are formed.
embryonic
the most common teratogen The major teratogens are -______ and ________ in developing countries
malnutrition
infectious diseases
ver the 6 weeks of the ______ period, 3–8 weeks’ gestation, nearly all the major organ systems are formed
embryonic
the digestive and respiratory system form the outer layer of the ______ _____
embryonic disk.
In developed countries, the teratogen that causes the most widespread damage to prenatal development is ________
- alcohol
The ________ period is a critical period for prenatal development since all the major organ systems are forming at a rapid rate
embryonic
