Anatomy - embryology Flashcards
proliferation
Early development is characterized by the rapid proliferation of embryonic cells, which then differentiate to produce the many specialized types of cells that make up the tissues and organs of multicellular animals.
Fate determination
Cell fate determination is the programming of a cell to follow a specified path of cell differentiation. Often, cells are discussed in terms of their terminal differentiation state. During development, fates of some few cells may be specified at certain times
Cell differentiation
The process during which young, immature (unspecialized) cells take on individual characteristics and reach their mature (specialized) form and function.
Apoptosis
Apoptosis is the process of programmed cell death. It is used during early development to eliminate unwanted cells; for example, those between the fingers of a developing hand. In adults, apoptosis is used to rid the body of cells that have been damaged beyond repair. Apoptosis also plays a role in preventing cancer.
Cell migration
During embryonic development, tissues undergo major rearrangements that lead to germ layer positioning, patterning, and organ morphogenesis. Often these morphogenetic movements are accomplished by the coordinated and cooperative migration of the constituent cells, referred to as collective cell migration.
Cell adhesion
Cell adhesion is the process by which cells interact and attach to neighbouring cells through specialised molecules of the cell surface.
Cell shape changes
During preimplantation development, cells of the mammalian embryo must resolve their shape and position to ensure the future viability of the fetus
Teratogen
A teratogen is a substance that can cause abnormalities or birth defects in a developing fetus. Common teratogens include some medications, recreational drugs, tobacco products, chemicals, alcohol, certain infections, and in some cases, uncontrolled health problems in the birthing parent.
What is gestation?
the process or period of developing inside the womb between conception and birth. usually 37-40 weeks
How many weeks are in the first trimester?
12
What is a haploid cell?
Egg and sperm - contain only a single strand of DNA or 23 chromosomes
What is Totipatence?
occurs after the union of two cells (egg and sperm). It refers to if the inital cell has the ability to develop into any cell in the body
What is a zygote?
Fertilised egg
What is mitosis?
Cell division. This is the process which turns the morula into a blastocyst
What is stage one?
Fertilisation
What is stage two?
When the egg has been fertilised and thus forms a zygote. At this stage, identical (monozygomatic) twins are formed. Zygote undergoes cell division through a process called mitosis where it turns into a morula.
What is stage three?
Occurs two days after fertilisation. Blastocyst is formed. Cal tell the difference between cells in the embryo and cells around the outside which support the life of the embryo (yolk sack and placenta)
What is stage four?
Implantation. Zygote burrows into the uterine lining (genes required to do this is expressed by the male). The purpose of this is to secure blood supply
What occurs at two weeks post fertilisation?
The zygote becomes a bilaminar disc (flat and two layers thick) with a formation of a cavity.
What occurs at three weeks?
Movement (cell migration) from the bilaminar layer into a trilaminar layer. Cells migrate between epiblast to hypoblast to form the mesoderm.
What are the germ layers?
Endoderm (Inner organs), ectoderm (Epidermis of the skin, hair, nails, neural tissues), mesoderm (muscles, heart and skeleton)
When can we hear a heartbeat?
4 weeks
When does face start to become more central?
6 weeks
What are the stages?
Fertilisation, 4 cell stage, morula, blastocyst, implantation
