Topic 2 Flashcards
congenital conditions
Conditions that arise as a result of abnormal development and which are therefore present at birth.
Diploid
The name given to a cell that carries two complete paired sets of chromosomes.
gametes
The reproductive cells (egg and sperm).
haploid
The name given to a cell (the gametes) that carries one set of unpaired chromosomes.
cell cycle
The process in which a cell prepares to divide, divides and then the new cells that are generated mature.
daughter cells
The two new cells created by the process of cell division.
Somatic cells
All cells other than reproductive cells (gametes).
Symmetrical Division
When a cell divides to create two matching copies of itself.
Asymmetrical division
When a cell divides to produce two unmatching copies.
Morula
The name given to the ball of cells that reaches the uterus at around 3 to 4 days post-fertilisation. It occurs after the 8-cell stage of cell division.
Blastocyst
The name given to the ball of cells that implants into the wall of the uterus. It can be differentiated from the morula because it has two different types of cells within it.
Gastrulation
The formation of three distinct tissue source layers via cell diversification and the movement of cells in the developing embryo.
Cell migration
The movement of cells to specific locations.
ectoderm
will form skin, hair, the lining of structures such as the nose and mouth, and, significantly, the nervous system.
mesoderm
will form the muscles, skeleton and blood.
endoderm
will form the lining of the digestive tract, respiratory tract and bladder.
neural plate
The layer of the ectoderm that will go on to form the nervous system.
neural grove
A groove in the middle of the neural plate that will go on to close and form the neural tube.
neural tube
Forms when the side edges of the neural groove fold over towards each other.
notochord
A vital skeletal structure important for the developing embryo because it signals the midline and is used for cells to orient themselves.
primitive streak
A temporary structure that appears in the developing embryo prior to gastrulation and the appearance of three different tissue source layers.
Sonic hedgehog gene (italics as is a gene name)
The gene that codes one signal used by the notochord to help cells orient themselves during development.
Neural tube defects NTDs
Congenital conditions that occur when the neural tube does not close, leaving the neural tissue exposed to amniotic fluid.
anencephaly (Anterior: Front)
A neural tube defect where the neural tube fails to close anteriorly.
spina bifida (Posterior: Back)
A neural tube defect where the neural tube fails to close posteriorly.
congenital condition
A condition that arises during development and that is present at birth.