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.
risk factor (folic acid 70% improvement)
A condition that arises during development and that is present at birth.
Genotype
The complete genetic code contained within the chemical composition of DNA within a cell or organism.
gene–environment interaction
The interaction of environmental factors with an individual’s genetic information to produce a particular outcome, for example a behavioural trait or an increased risk of developing a health condition.
A condition has a heritability value of 0.35. What percentage value is this?
A heritability value of 0.35 is the same as 35%, calculated as 0.35 × 100.
What mostly determines a condition with a heritability value of 0.85?
Genes because the heritability value is close to 1 or 100%.
Heritability
The extent to which the variation of a particular characteristic in a population can be determined purely by genes.
fetal alcohol spectrum disorders (FASD)
A set of health conditions that occur in offspring that is related to the maternal consumption of alcohol.
spectrum
In health terms this refers to a set of symptoms that can be experienced over a range of severity.
segmentation
The development of distinct sections or segments within the neural tube.
neuromeres
A term used to refer to segments in the developing nervous system.
prosencephalon
A segment of the developing neural tube that will go on to form the forebrain.
mesencephalon
A segment of the developing neural tube that will go on to form the midbrain.
rhombencephalon
A segment of the developing neural tube that will go on to form the hindbrain and spinal cord.
secondary segments
The five segments that form in the neural tube after the initial three-segment stage.
cell fate
The final identity or type of a cell at the end of its cell lineage.
cell lineage
The history of a differentiated cell traced back to the original cell from which it developed.
totipotent
Describes a cell that is capable of becoming any type of cell within an organism including placental cells.
pluripotent
Describes a cell that is capable of becoming almost any type of cell within an organism, except placental cells.
multipotent
Describes a cell that is capable of becoming any of a limited range of cell types within an organism, compared with pluripotent cells.
progenitor cells
Cells that become a specific type (or types) of cell. They have a more restricted cell fate than multipotent cells.
biopotential progenitor cells
Cells that can become one of two types of cell; for example, in the developing nervous system these cells are capable of producing either neurons or glial cells.
neuroblast
An embryonic cell that will become a neuron.
neurogenesis
The creation of new neurons.
What is the neurotransmitter used by the neurons that die in Parkinson’s disease?
Dopamine
radial glial cells
A type of glial cell in the developing nervous system that provides a structural scaffold for migrating neurons to move along.
What are the names given to the ridges and grooves that create this ‘wrinkled’ appearance in the cortex?
ridges = Gyri, groves = Sulci
outer subventricular zone (oSVZ)
A developmental region of the ventricular zone in the developing nervous system that is unique to primates.
inside-first outside-last principle of cortical development,
The way in which the cortex develops in its layered arrangement. The innermost layers close to the ventricular zone develop first, whilst the outermost layers develop last.
leading process
An extending structure formed by a migrating neuron that senses the surrounding environment.
pial surface
The outer edge of the developing neural tube.
tangential migration
Migration that occurs tangentially to the ventricular zone.
nucleokinesis
The process that occurs when the nucleus of a migrating cell moves into the leading arm.
chemotactic guidance
The use of chemical cues as a guide during cell migration.
What are the names given to these neuronal processes? (Hint: there are two different types.)
axons and dendrites
dendrite
receives information from synapses and passes it on to the cell body for processing
axon
passes on the integrated information from the cell body to different synapses
What term is used to describe the formation of new synaptic connections?
Synaptogenesis
What component of a cell is responsible for making proteins?
The ribosome.
Where are the instructions located for making proteins?
In the DNA located in the nucleus of the cell.
How does the ribosome get the instructions it needs to begin making the proteins that will be involved in neuronal communication?
Through messenger RNA which transcribes the coded instructions from the DNA and carries them to the ribosome.
brain-derived neurotrophic factor (BDNF),
A key molecule for signalling synaptogenesis and neurogenesis.
