Ch 15 Development and Aging Flashcards
After 18 days of gestation what forms?
The neural plate which forms the dorsa side of the embryo
After 21 days of gestation what forms?
The neural tube which is a hollow tube of cells
After 24 days of gestation what is almost completely closed?
The neural tube
If the neural tube does not close what conditions are likely to occur?
anencephaly (lack of brain development) and spina bifida (incomplete closure of the spinal cord)
What does anencephaly result in?
an exposed brainstem and the baby dies shortly after or before birth.
Spina bifida occulta is characterized by what?
The vertebral arches are incomplete in the lumbar spine
Spina bifida cystica is characterized by what?
a large sac of meninges protrude from the back. spina bifida may result in sensory loss and poor bladder control.
When the forebrain develops what structures does it split into?
Two cerebral hemispheres, the thalamus and hypothalamus.
When the hindbrain develops what structures does it give rise to?
pons, cerebellum, medulla oblongata
Schwann cells develop from what?
The neural crest
Which two structures in the brain are the only ones that can form new neurons?
the hippocampus and the olfactory epithelium.
What is cell differentiation?
a cells ability to specialize
What condition occurs when cells do not differentiate?
Down Syndrome and fetal alcohol syndrome
When does myelination begin?
20 weeks gestation and completed around 2 years but not fully until early adulthood
What is epilepsy?
a brain disorder in which patient has repeated seizures
Why do seizures happen?
a specific area of the brain is sending action potentials randomly.
What is it called when a seizure lasts longer than 30 minutes?
status epilepticus
What is the developmental stage in which synapses are created in large numbers?
Critical periods
What two brain functions are forming during the critical periods?
the visual and language systems
What are two common pathologies that occur when a baby is born premature?
PVL and IVH
What are some causes of CP?
Bleeding in the ventricles, infection, lack of oxygen to the brain, intraventricular hemorrhage, premature birth, and brain injury
Athetoid CP is characterized by what?
Sow writhing movements of the limbs due to damage to the basil ganglia
Ataxic CP results from what?
injury to the cerebellum
What causes Arnold Chiari Malformation?
the inferior medulla and the cerebellum protrude down the foramen magnum
What are symptoms of Chiari Malformation?
severe headaches, ataxia, weakness of facial muscles and tongue
