cunotice's version from 2016-01-25 21:42

Brain Histology





Question Answer
Neurons: ____ nucleus; ____ nucleolus; ____ substance, which stains dark bluelarge; prominent; Nissl
Astrocytes: ____ nucleus; ____ nucleolus; have ____ in their cytoplasmnaked; no; can’t see cytoplasm, but have GFAP
Oligos: ____ nucleus, ____ cytoplasm with ____.small, dense round; scant with perinuclear halo
What are ependymal cells?lining ventricular system
Where is the choroid plexus found?lateral and 4th ventricles
Microglia: ____ nucleus; ____ cytoplasmelongated; scant
Order of sensitivity to hypoxia: ____, ___, ____.neuron; oligo, astrocytes
Ischemia to neurons manifests its apperance as ____ color and ____ size. Nucleus?red and small; nucleus condense (pyknosis) or fragments (karyorrhesis)
What do these have in common? CA1 region of Ammon’s horn (in hippocampus), purkinje cells, neurons in layers III and V of cerebral cortex (>____necrosis).most sensitive to hypoxia (CA2 is most resistant); laminar
What morphological change can happen to a neuron after axonal injury?central chromatolysis – nucleus and Nissl substance pushed to the side
How do astrocytes respond to damage? (3)hyperplasia, hypertrophy, reactive gliosis – surrounding of damage
What happens if oligos are damaged?loss of myelin
What do microglia do in response to damage?become foamy macrophages


Question Answer
Why does edema occur? 2 named types?breakdown of gap junctions; vasogenic – damage to endothelial cells > fluid leaks into brain; cytotoxic > metabolic problem causes accumulation of Na > water
What is the difference between cerebral edema and increased intercranial pressure?edema is fluid in the cells; ICP is increased pressure of the CSF (from 7-15 > 25-30); NOTE: edema is a major cause of ICP
What are three other common reasons for ICP (other than edema)?hemorrhage, tumor, hydrocephalus
Type 1 brain herniation ____ (aka ____). Causes hemiparesis (weakness on one side of the body), compression of ____ CN > ____, and can cause compression of ____.transtentorial (uncal), CN III > fixed, dilated pupil; posterial cerebral artery > occipital infarction
What is a Duret hemorrhage?pontine artery hemorrhage due to uncal herniation
Type 2 brain herniation: ____. Generally have mass in ____, which causes ____ to be pushed through ____. Causes ____.Cerebellar tonsillar; supratentorial region; tonsils to be pushed through foramen magnum, medulla can be strangulated > death
Type 3 of brain herniation: subfalcine (____) – hernation under the ____. Generally have infarction in ____. Causes damage to ____.subfalcine (cingulate gyrus); falx cerebri, infarction in anterior cerebral a., corpus callosum
Two reasons of hydrocephalus?increase in volume of CSF due to 1. Increased production 2. decreased, blocked absorbtion
Two types of hydrocephalus?non-communicating (obstruction in ventricles – no communication with subarachnoid space); communicating (obstruction in subarachnoid space)
What are the 3 sucessive outcomes of hydrocephalus?expansion of ventricles > increased intracranial pressure > may lead to brain herniation
What is hydrocephalus ex-vacuo? ICP?compsenatory expasion of ventricles for atrophy of brain (as in Alz); ICP stays same