Chapter 9 Flashcards
An embryo develops into a fetus over a time span of…
8 weeks
Three stages of development after conception
Zygote, embryo, fetus
When does brain development begin?
At the point of conception.
Differentiation
Various types of cells are created during the embryonic and fetal period
Layer of cells that forms linings of the body (lungs, intestines, liver, etc)
Endoderm
Layer of cells that forms connective tissue (muscle, cartilage, bones)
Mesoderm
Layer of cells that forms the nervous system, epidermis, and parts of the eyes and ears
Ectoderm
Neural plate
Thickened ectodermal layer
Neural folds
Push up to form the neural groove
Neural tube
Place from which the brain and spinal cord develop
When embryonic layers thicken, they form into…
The neural plate, neural folds, and neural tube.
Neural tube defect: how and types
When a neural tube fails to close.
Types= spina bifida, anencephaly, Down syndrome
Anencephaly is a neural tube defect that results in…
Stillborn, or death shortly after birth (literally means no brain)
Spina bifida results in_______and can be prevented how?
Paralysis, limb deformities, and mental retardation. Can be prevented with supplemental folic acid.
Ectodermal cells along the inner surface of the neural tube tighten to form the…
Ventricular layer
The ventricular layer divides into…
Daughter cells, which go to marginal layer or intermediate layer
Some become neurons or glia
Between the marginal and intermediate layers is the…
Cortical plate
The cortical plate develops into…
Neurons and glia of the cerebral cortex
The subventricular layer cells become…
Glia or interneurons
The formation of new neurons is called…
Neurogenesis
What do radial glial cells do?
Guide migrating daughter cells.
Neurons grow toward organs or other neurons called…
Target cells
The swollen end of the developing neuron from which the axon emerges
Growth cone
Spines that extend from the growth cone
Filopodia
