Monday, 3-21-CNS Histology (Olinger) Flashcards
Where would you tend to find a bipolar neuron?
Sensory structures:
Retina
Olfactory epithelium
Vestibular and auditory systems
A ___ neuron is described as a single axon dividing a short distance from the cell body. The short axon of this type of neuron divides into 2 branches: The peripheral branch that carries info from the periphery and the Central branch ending in the SC
Pseudounipolar
Where do you find pseudounipolar neurons?
Sensory ganglia of cranial and spinal nerves
List 2 examples of a multipolar neurons:
Pyramidal cells and Purkinje cells
This multipolar neuron cell type is found in the cerebral cortex: ___
This multipolar neuron cell type is found in the cerebellar cortex and tends to have a HUGE dendritic tree: ___
Pyramidal cell
Purkinje cell
List the cerebral cortex layers beginning with the superficial most layer and ending with the deep layer
Molecular layer –> External granular layer –> external pyramidal cell layer –> Internal granular layer –> Internal pyramidal cell layer –> Multiform cell layer –> White matter
What are the components of the gray matter in terms of the cerebral cortex layers?
Molecular layer –> External granular layer –> External pyramidal cell layer –> Internal granular layer –> Internal pyramidal cell layer –> Multiform cell layer
List the organization of the cerebellum beginning with the outer-most layer:
Molecular layer –> Purkinje cell layer (dendrites then cell bodies) –> Granular (granule cell) layer –> white matter
In a histological stain of a synapse, synaptic vesicles would be found in which cell?
The pre-synaptic
___ synapse: An axon terminal ending on the soma of a neuron
___ synapse: An axon terminal contacting another axon terminal
___ synapse: An axon ending on a dendrite
___ synapse: An axon terminal facing a dendritic spine
Axosomatic
Axoaxonic
Axodendritic
Axospinous
A ___ consists of an expanded head connected to the dendrite shaft by a neck.
Dendritic spine
In contrast to the dendritic shaft that contains microtubules, the dendritic spine cytoskeleton consists of ___ associated with the postsynaptic density which is where neurotransmitter receptors and ion channels are localized
Actin filaments
___ are present in the CNS and make up the blood-brain-barrier (BBB)
Astrocytes
Astrocytes are branching cells of the CNS with cytoplasmic processes ending in expansions called ___
End-feet
___ cover neurons (dendrites and cell bodies), the inner surface of the pia mater, and every blood vessel in the CNS
End-feet
What are the components of the BBB?
- Tight junctions between endothelial cells are the main components of the BBB
- Basal lamina of the endothelial capillaries
- Perivascular astrocyte end-feet
In the CNS, ____ form myelin sheaths around the axons
Oligodendrocytes (derived from glioblasts)
Which cell type is responsible for myelination in the CNS?
Oligodendrocytes
__ are the phagocytic cells of the CNS
Microglial cells
The brain ventricles and the central canal of the SC are lined by a simple cuboidal epithelium known as ___
Ependyma
The ependyma consists of these 2 cell types:
- Ependymal cells
- Tanycytes
This cell type of the ependyma has cilia and microvilli on the apical domain and abundant mitochondria. The basal domain is in contact with astrocytic processes. Theses cells are attached to each other by belt desmosomes
Ependymal cells
These cells of the ependyma are in the 3rd ventricle and specialized with 2 different observable features: 1) basal processes that extend through the astrocytic processes layer to form end-feet on a blood vessel and 2) it’s own cell type that are attached to each other and to ependymal cells by tight junctions
Tanycytes
The ___ of the brainstem is lined primarily by ependymal cells (no tanycytes)
Central canal
The ___ is ependyma wrapped around fenestrated blood vessels
Choroid plexus
The ___ membrane prevents the CSF in the subarachnoid space from coming in contact with the fluid of the EC space of the dura mater.
Arachnoid
CSF drains around the cerebral hemispheres to the __ placed along the venous sinus
Arachnoid villi
The formation of CSF by the choroid plexus involves the passage of an ultrafiltrate of plasma through the fenestrated endothelium of the blood capillary and the surrounding connective tissue. The ___ cells transform this ultrafiltrate into an excretory product: the CSF
Choroidal epithelial
List the layers of meninges from outer to inner:
Dura mater –> Arachnoid mater –> subarachnoid space –> pia mater
___ is a single layer of flat cells on the brain surface
Pia mater
___ reabsorb CSF
Arachnoid granulations and arachnoid villi
___ is tough and collagenous and surrounds the brain and SC
Dura mater
A __ neuron has a single axon emerging from either side of the cell body.
Bipolar
