The CNS Part I Flashcards
What is Neuroglia astrocytes?
It acts as a metabolic buffers and detoxifies, and acute cell injury causing cellular swelling
What is Neuroglia oligodendrocytes?
It produces myelin, and injury of oligodendrocytes is a feature of acquired
demyelinating disorders
What is Neuroglia Ependymal cells?
It produces CSF
What are the major levels of CNS?
- Lower Brain or Subcortical Level
- Higher Brain or Cortical Level
- Spinal Cord Level
- Ascending Reticular Activating System (ARAS)
What role does the Ascending Reticular Activating System (ARAS) play?
relays stimulations from environmental stimuli to the thalamus and then to the cerebral cortex
What role does the Spinal Cord Level play?
the upper levels of the nervous system sends signals to the control centers of the cord
What role does the Higher Brain or Cortical Level play?
without the cerebral cortex, the functions of the lower brain centers are not often accurate
What role does the Lower Brain or Subcortical Levelplay?
subconscious activities of the body are controlled in the lower areas of the brain
What is the Normal Physiology of CSF?
- CSF production
- CSF functions
What is CSF production?
by the choroid plexus of each ventricle
What is CSF functions?
flow between the cranium and spine and compensate for changes in intracranial blood volume. Also the balance between production and absorption of CSF is critically important
What are is a Barrier Systems and, what are the different types of barriers?
It is a selectively inhibit certain potentially harmful substances in the blood from entering the brain or CSF
Blood-brain barrier (BBB), Blood-CSF barrier
What is Blood-brain barrier (BBB)?
a series tight junctions between endothelial cells and astrocytes with processes on capillary walls
What is Blood-CSF barrier?
formed by tight junctions between choroid epithelial cells
What is Intracranial Pressure (ICP)?
The pressure inside the cranial cavity, normally ≤15 mmHg
What is ICP/Cerebral Blood Flow/Autoregulation?
erebral blood flow (CBF) is maintained at a relatively constant level, within a mean arterial pressure range of 60 to 150 mmHg. At about 180 mmHg the autoregulation fails causing cerebral edema and increased ICP
What is the formula of CBF?
CBF = (CAP - JVP) ÷ CVR
What are two major cause’s of Elevated ICP?
- Vasogenic edema
- Cytotoxic edema