15: Human Development Flashcards
(27 cards)
What begins human prenatal development?
Fertilization
Fertilization is the joining of a sperm and an egg to form a zygote.
What is formed when a sperm joins with an egg?
Zygote
The zygote is the initial cell formed when a sperm fertilizes an egg.
What period occurs during the first two months of the first trimester?
Embryonic period
The embryonic period is crucial for early development.
What follows cleavage during embryonic development?
Successive mitotic cell divisions
Cleavage leads to multiple cell divisions, resulting in a morula.
What does the morula form when it arrives at the uterus?
Blastocyst
The blastocyst consists of an outer trophoblast layer and an inner cell mass.
What prevents menstruation during early pregnancy?
Human chorionic gonadotropin
This hormone is secreted by trophoblast cells after implantation.
What forms during the second week of development?
Amniotic cavity
The amniotic cavity forms as the inner cell mass flattens.
What are the three primary germ layers formed during gastrulation?
Ectoderm, mesoderm, endoderm
These layers are crucial for the development of various tissues and organs.
What is the process called where cells differentiate into specific organs?
Morphogenesis
Morphogenesis is essential for the formation of organs and organ systems.
What structures begin to appear during the third week of development?
Notochord, neural tube, arm and leg buds, heart, facial structures, skin specializations, skeleton
These structures are pivotal in early fetal development.
What period occurs during the last month of the first trimester and the remaining two trimesters?
Fetal period
The fetal period involves the refinement of structures formed earlier.
What can teratogens affect during prenatal development?
Health of the embryo and fetus
Teratogens are substances that can cause developmental abnormalities.
What is expelled during parturition?
Baby, placenta, umbilical cord
Parturition is the process of childbirth.
What are some reproductive technologies designed to enhance reproductive potential?
In vitro fertilization, superovulation
These technologies assist in conception.
What are some reproductive technologies designed to restrict reproductive potential?
Condoms, surgical sterilization
These methods help prevent pregnancy.
True or False: Issues surround the use of reproductive technologies.
True
Ethical and practical concerns exist regarding reproductive technologies.
What is the embryonic period duration?
8 weeks
The embryonic period is crucial for early development.
What is the process of gastrulation?
A phase in embryonic development where the single-layered blastula reorganizes into a multi-layered structure
Gastrulation is essential for the formation of different tissues.
Define fertilization.
The fusion of sperm and egg to form a zygote
This marks the beginning of embryonic development.
What is morphogenesis?
The biological process that causes an organism to develop its shape
Morphogenesis involves the organization of cells into tissues and organs.
What does differentiation refer to in embryonic development?
The process by which cells become specialized in structure and function
Differentiation is vital for the formation of various cell types.
How can reproductive technologies impact development?
They can aid or hinder development
Reproductive technologies may include IVF, genetic screening, and more.
What is the duration of the fetal period?
30 weeks
The fetal period focuses on the growth and maturation of established organs.
What factors can affect the health of the embryo and fetus?
Teratogens and other factors
Teratogens are substances that can cause developmental malformations.
