Histology of the CNS Flashcards
Examples of Integrative Neurons
- Pyramidal cells
- Interneurons
- Purkinje cells
Neuropil
Dense network of interwoven nerve fibers, their branches and synapses, together with glial processes
Central masses of gray matter:
Ventral, dorsal, and lateral horns
__ __ lies in the Central Commissure of gray matter
Central Canal
White matter consists of:
- Ascending tracts of sensory fibers
- Descending motor tracts
Motor neurons found in __ horn
Ventral
Sensory neurons found in ___ horn
Dorsal
Lateral corticospinal tract is associated with:
Motor control
Anterolateral system is associated with:
Pain and temperature information
Blood supply to UE and Thoracic part of Lateral Corticospinal Tract:
Sulcal A (branch of Anterior Spinal A)
Blood supply to LE part of Lateral Corticospinal Tract:
Arterial Vasocorona (AVC)
Blood supply to Anterolateral system:
Arterial Vasocorona (AVC)
Arterial Vasocorona (AVC)
- Vascular Plexus that is formed between the Posterior and Anterior Spinal Arteries
- Formed around the posterior roots of the spinal nerves
Blood supply to the Fasciculus Cuneatus and Fasciculus Gracilis:
Posterior Spinal A (specifically the AVC)
The brainstem is the passageway for __ and ___ fiber tracts
Afferent and Efferent
CN Nuclei in the Brainstem: Sensory fibers are ___ to motor fibers
Lateral
CN Nuclei in the Brainstem: Motor fibers are ___ to sensory fibers
Medial
CN that emerge from the Medulla:
- CN IX
- CN X
- CN XI
- CN XII
CN that emerge from the Pons:
- CN V
- CN VI
- CN VII
- CN VIII
CN that emerge from the Midbrain:
- CN III
- CN IV
CN that emerge outside of the brainstem:
- CN I
- CN II
Cranial Nerve Nuclei follow a __-____ pattern arising from the alar and basal plates
Medial-Lateral
Indication of brainstem problem
Vertigo or diplopia PLUS weakness/sensory disturbance in limbs/face
4 Structures that are found in the Paramedian Brainstem:
(1) Motor pathway
(2) Medial Lemnisci
(3) Motor Nuclei
(4) Motor Longitudional Fasciculus
4 CN Nuclei that lie in the Paramedian Brainstem:
- CN III
- CN IV
- CN VI
- CN XII
4 Structures that are found in the Lateral Brainstem:
(1) Spinothalamic Pathway
(2) Sympathetic Pathway
(3) Sensory Nucleus of CN V
(4) Spinocerebellar Tract
CN Nuclei found in the Midbrain:
- CN III
- CN IV
CN Nuclei found in the Pons:
- CN VI
- CN VII (Superior Salivatory Nucelus, Motor Nucleus)
CN Nuclei found in the Medulla:
- CN VII (Nucleus Solitarius)
- CN VIII
- CN IX
- CN X
Substantia Nigra
- Gray matter substance within the midbrain
- Contains pigmented multipolar neurons
Function of Substantia Nigra
- Connections with cortex, spinal cord, corpus striatum, and reticular formation
- Role in fine control of motor function
Characteristics of neurons in the Substantia Nigra
- Contain numerous membrane-bound granules of neuromelanin pigment
- Neuromelanin contains dopamine which has inhibitory effects in brain areas dedicated to movement
Parkinson’s Disease
- Clinical features: tremor, slow movement, rigidity
- Results from degeneration of neurons in the substantia nigra (results in loss of dopamine)
- Distinctive inclusions seen in remaining neurons – Lewy Bodies
- Aggregates of alpha-synuclein and other proteins
Neocortex consists of __ layers
6
What are the 6 layers of the Cerebral Cortex?
Superficial (just under Pia Mater) –> Deep
(1) Molecular
(2) External Granular
(3) External Pyramidal
(4) Inner Granular
(5) Ganglionic
(6) Multiform (Polymorphic)
Cerebral Cortex: Molecular Layer
Contains large fibers and neuroglial cells
Cerebral Cortex: External Granular Layer
Contains small pyramidal cells and granule (stellate) cells
Cerebral Cortex: External Pyramidal Layer
Contains larger pyramidal cells with a typical pyramidal shape