Week 15-Development Flashcards
What is an embryo?
The cell development stage preceding the foetus
What is a zygote?
A single new cell formed at conception
What is the germinal period?
The first two weeks after the sperm and egg unite
What is a gamete?
A mature male or female cell used for reproduction
What is a haploid cell?
A cell that contains only one set of chromosomes
What is a diploid?
A cell containing both sets of chromosomes
What are stem cells?
An undifferentiated cell that can divide and produce any one of a variety of differentiated cells.
What are the three layers of the embryo?
Endoderm -innermost layer. Primary germ cell layers of embryo
Mesoderm -middle layer
Ectoderm -outermost layer
What is the embryos precursor to the central nervous system?
Neural tube
What is Neurulation?
The formation of the embryonic nervous system, which will then develop into the brain and central nervous system.
What is Neural Migration?
The process through which neurons move, grow, and connect as the basic neural tube develops into a more mature brain.
What is apoptosis?
The genetically programmed process of cell death as part of normal development or normal functioning of cells and organs.
What are teratogens?
External compounds that can cause extreme deviations from typical development. Common teratogens are alcohol, tobacco products, prescription drugs, diseases.
What reflex is present from birth till death?
The eye blink
Name two reflexes that eventually disappear or are replace by voluntary behaviours.
Rooting and sucking (both are crucial to feeding)
What is synaptic pruning?
Facilitates a change in neural structure by reducing the overall number of synapses, leaving more efficient synaptic configurations. Happens throughout life.
What is Experience-Dependent Plasticity?
Te ability of the nervous system to wire and rewire itself in response to lasting changes in experience.
What is Experience-Expectant Plasticity?
Development that will not happen unless a particular experience occurs during its crucial period.
What is Myelination?
The development of the myelin sheath around the axons of neurons. This sheath insulates the neurons from each other and increases the speed at which neurons transmit information.
What is ‘the time at which the human body begins to enter sexual maturity, marking the beginning of adolescence’ called?
Puberty
Describe the foetal period
Final period. Continues from 9th week after conception until birth. At this time foetus weighs 30grams and is approx 4 centimetres long. 10 weeks foetus makes breathing like motions. 4th month sleep and awake patterns begin to emerge. Vestibular system (required sense of balance) begins to develop. Foetal heart beat changes in response to mothers voice.
