Neuropath Lecture 1 Flashcards
what is the calvarium?
the convex dome shaped part of the skull that protects soft tissues and the brain
what is the tentorium cerebelli?
an invagination of dura mater divides the brain cranial and caudal; ossified in cats
what is the falx cerebri?
sickle shaped fold of dura mater that separates the brain into left and right
be able to label all the anatomy in this ppt! including the layers of the cerebellar cortex
do it!
what is in the cerebral cortex?
gray matter; made up of neuron and neuropil
what is in the corona radiata?
white matter made up of myelin and axons
what are the 4 layers of the cerebellar cortex?
- molecular layer
- purkinje cell layer
- internal granular layer
- cerebellar white matter
what is a lesion of the cerebral cortex called? what about the corona radiata?
cerebral cortex: polioencephalopathy
corona radiata: leukoencephalopathy
what is malacia?
softening and liquefactive necrosis of the neuroparenchyma
can have poliomyelomalacia or leukoencephalomalacia or any combo if in brain or spinal cord
what are the 4 factors considered when assigning a morphological diagnosis to a neurological lesion?
- focal versus diffuse
- symmetrical versus asymmetrical
- root for brain part
- process
ex. focal symmetrical encephalomalacia
describe the choroid plexus; give function, possible pathologies, and what inflammation of this region is called
function: produce CSF
pathologies: bacterial or viral disease may start here and then spread
inflammation: choroid plexitis or choroiditis
describe hydrocephalus (3) what might a dog with hydrocephalus also have?
- dilated lateral ventricles
- atrophy of surrounding neuroparynchema
- loss of septum pellucidum
might also have hydromelia
what is ependyma?
single layer of epithelium lining the ventricular system and central canal of spinal cord; keeps CSF in
what can ependymitis result in?
obstructive hydrocephalus; exudate in aqueduct, surface is irregular and no longer smooth due to inflammation and necrosis of the ependymal lining
what covers the CNS?
the meninges!
- dura mater: attached to cranial vault; loose in the spinal column
-inflammation = pacymeningitis - arachnoid: avascular
- pia mater: where the vessels are
leptomeninges: arachnoid + pia
-inflammation = leptomeningitis
what are the 2 types of cells in the CNS?
- neurons with dendrites and axons
- glial cells:
-oligodendrocytes
-astrocytes
-microglia
describe normal neurons (4)
- large nucleus with nucleolus
- visible cytoplasm
- axon and dendrites
- nissl substance outside
describe chromatolysis
- degenerative change usually associated with axonal injury
- results in neurons with swollen cells bodies and loss of Nissl substance
describe ischemic neuronal necrosis
- neurons look shrunken, eosinophilic, and angular
- in the CNS, neurons are most sensitive to hypoxia but this varies by location
describe neuronophagia
- piecemeal fragmentation and phagocytosis of dead neurons
- due to neuronal infection: viruses or listeria
describe lysosomal storage disease
- cytoplasmic vacuolation
- mannosidosis in cattle with locoweed toxicosis
how can rabies alter neurons? what about prions?
rabies: intracytoplasmic inclusion bodies
prions: cytoplasmic vacuolation
describe axons
- many surrounded by myelin sheath that is produced by:
-oligodendrocytes in the CNS or
-Schwann cells in PNS - reaction to injury:
-spheroids: swollen axons
-wallerian degeneration: interruption of axon causes dissolution and loss of axon distal to damage, resulting in myelin removed by phagocytosis in digestion chambers
-astrocytosis: increase in number (hyperplasia)
-astrogliosis: increase in cell processes (hypertrophy)
what do axons do? (3)
- structural support: brain glue
- repair: CNS fibroblasts
- blood-brain barrier
what are gemistocytes?
reactive astrocytes with visible eosinophilic cytoplasm
what are alzheimer type II cells?
astrocytes with clear, swollen nuclei seen in hepatic and renal encepholapathies (no relation to alzheimers disease)
what do oligodendrocytes do?; describe demyelination
myelin formation
loss of myelin, seen as holes
describe status spongiosus
vacuolation of neuroparenchyma due to
1. demyelination (white matter)
2. edema
3. prion diseases
4. artifact
what are microglia?
- macrophages in the brain
- phagocytic
- immune defenders of the brain
describe microgliosis
- diffuse or focal proliferation of microglia
- glial nodule: hallmark of viral encephalitis
what are gitter cells?
- foamy, lipid-laden macrophages bc they ingested a lot of brain stuff (lipid)
- two sources:
-circulating monocytes: primary source
-resident microglia
