1 General Terminology and SC Mophology - B Flashcards
What are local interneurons
Neurons that have processes confined to a single small area of the CNS
What are projection neurons
Cells with long axons connecting different areas
Gray matter
Contains cell bodies and dendrites
Nuclei are
Collections of cell bodies with a common function located within the CNS
White matter is
An area where there is a collection of axons; many covered in myelin
Fasiculus, funiculus, lemniscus, and tract are all terms for
White matter
What is the cortex
Layers of gray matter over other parts of CNS
2 part naming system of tracts is
1st part - location of neuronal cell bodies from which axons originate 2nd part - where axons terminate
The cervical enlargement is responsible for
Upper extremity
The lumbosacral enlargement is responsible for
Lower extremity
The pairs of spinal nerves are
C1-8 T1-12 L1-5 S1-5 Co1
The conus medullaris is
Tapering inferior end of spinal cord
Inferior to the conus medullaris is
Cauda equina
The filum terminale
Thin strand of pia mater that helps anchor the conus medullaris to the coccyx
Where do the posterior rootlets enter the cord
Posterolateral sulcus
Where do the anterior rootlets leave
Poorly defined anterolateral sulcus
What is the substantia gelatinosa
Distinctive region of grey matter that caps the posterior horn
SG
What is the body of posterior horn
Consists of interneurons and projection neurons that transmit somatic and visceral information
Substantia gelatinosa carries primarily
Pain and temperature information
What is Lissauer’s tract
White matter located between substantia gelatinosa and the surface of the cord
The anterior horn contains
Cell bodies of large motor neurons that supply skeletal muscle
Motor neurons that supply mm are called
Lower motor neurons
The intermediate gray matter contains
Autonomic fibers (preganglionic fibers)
Clarks nucleus is also known as
Posterior thoracic nucleus
Where is Clark’s nucleus
Medial surface of the base of posterior horn (T1 to L2)
Intermediolateral cell column contains what
Preganglionic sympathetic neurons
The sacral parasympathetic nucleus is at what level
S2-4
Clark’s nucleus plays a large role in
Sensory processing Typically treated as though it is posterior horn
What are the laminae of the gray matter
Lamina 1-10
Lamina 1 is
Thin layer of gray matter covering the substantia gelatinosa
What is lamina 2
Substantia gelatinosa
What are lamina 3-6
Body of the posterior horn
What is lamina 7
Corresponds to the intermediate gray matter (including clarks nucleus) but also into anterior horn
What is lamina 8
Comprises some fo the interneuron zones of the anterior horn
What is lamina 9
Consists of clusters of motor neurons embedded in the anterior horn
What is lamina 10
Zone of gray matter surrounding the central canal
What is the fasiculus cuneatus
Bundle of axon fibers in the posterior columnmedial lemniscus (Sensory to brain)
What is the fasiculus gracilis
Bundle of fibers in the posterior columnmedial lemniscus Carries sensory from middle thoracic and lower limbs
Where are the cell bodies for sensory fibers
DRG
What is found in the white matter
Long descending tracts Long ascending tracts Communicating axons b/n levels
What is contained in the gray matter
-Motor neuron cell bodies -Endings of sensory axons -Second order sensory cell bodies -Endings of long descending tracts and local interneurons
What are sulci
Grooves b/n gyri
What are gyri
Ridge of brain
What are fissures
Deep gyri
What are the 4 prominent sulci
Central Lateral Parietoccipital Cingulate
What joins the 2 hemispheres
Corpus callosum
Where is the frontal lobe
-extends from frontal pole to central sulcus
What separates the frontal and temporal lobes
Lateral sulcus (sylvian fissure)
Where does the frontal lobe extend to medially
Cingulate sulcus
What does the frontal lobe continue as inferiorly
Orbital part of frontal lobe
Where is the parietal lobe
Extends from the central sulcus to an imaginary line connecting the top of the parietooccipital suclus and preoccipital notch
What bounds the parietal lobe inferiorly
Lateral sulcus and imaginary continuation of the suclus to the posterior boundary of the parietal lobe
What bounds the parietal lobe medially
Bounded inferomedially by subparietal and calcarine sulci
Where is the temporal lobe
Extends to the lateral sulcus and the line forming the inferior boundary of the parietal lobe
Where is the occipital lobe
Bounded anteriorly by the parietal and temporal lobes on the lateral and medial surfaces
What is the limbic lobes
Strip of cortex that appears and encircles the telencephalon/diencephalon junction
The nervous system develops from the neural tube that contains a central cavity which persists as
ventricles
what is the flow of CSF
what are arcuate fibers
fibers that connect cortical areas within the same sulcus/gyrus
what are longitudinal/association fasiculi
connect cortical areas within the same hemisphere
what are commissural tracts
connect cortial areas within r/l hemispheres
what are projection tracts
connect cortical areas within other body regions
what is the corpus callosum
part of the brain that connects the two halves
what is the anterior commissure (of the corpus callosum)
commissural fibers to and from the temporal lobe (especially inferior parts)
what is the insula and how can you find it
area buried in the lateral sulcus; can be found by prying open the lateral sulcus or by removing opercula
what is the circular sulcus
outlines the insula and marks its borders with the opercular areas of the cortex
what gyri make up the frontal lobe
precentral, superior, middle and inferior gyri
what is housed within the precentral gyrus
primary motor cortex (origin of the descending motor pathways and voluntary movements)
where are the premotor and supplementary motor areas
occupy the remainder of the precentral gyrus and the posterior portions of the superior and middle frontal gyri
(related to planning movement)
what is brocas area
opercular and triangular parts of interior frontal gyrus
(impportant in motor aspects of written and spoken languages)
what is the prefrontal cortex
occupies the rest of the frontal lobe (not taken up by motor cortices or brocas)
- invovled in executive functions
- personality
- decision making
- foresight
- insight
the parietal lobe includes what landmarks
postcentral gyrus and superior and inferior parietal lobules
what are the functions of the parietal lobe
- post central gyrus corresponds to primary somatosensory cortex (processing tactile, proprioceptive info, and sensory localization)
- inferior paritetal lobule is involved in language comprehension
- remainder has aspects in spatial orientation and directing attention
the homunculus is made of sensory and motor innervation of areas of the body
the temporal lobe contains what gyri
superior, middle, and inferior temporal gyri
the inferior surface of the temporal lobe is made up of
occipitotemporal (fusiform) gyrus
what functions are associated with the temporal lobe
- superior surface, continuing as a small area of the superior temporal gyrus is the primary auditory cortex
- wernickes area is located on the posterior portion of the superior temporal gyrus and is important in the comprehension of language
- inferior surface is involved in higher-order processing of visual information
- most medial part is invovled in learning and memory
The lateral surface of the occipital lobe contains the
lateral occipital gyri
the cuneus is
a wedge-shaped area b/n the parietooccipital and calcarine sulci
the lingual gyrus is inferior to what
calcarine sulcus sand is usually continuous with the parahippocampal gyrus
the primary visual cortex is located where
walls of calcarine sulcus
the remainder of the the occipital lobe is
the visual association cortex
-involved in higher order processing of visual information
the limbic lobe is mostly composed of
cingulate and parahippocampal gyri
the anterior end of the parahippocampal gyri hooks backward on itself forming a medial bump called
the uncus
folded into the temporal lobe at the hippocampal sulcus is the
hippocampus
where is the amygdala
beneath the uncus of the temporal lobe
the limbic lobe is important in
emotional responses, drive-related behavior, and memory
the diencephalon has what divisions
thalamus, hypothalamus, epithalamus, subthalamus
what is the job of the thalamus
relaying information to the cerebral cortex
- all sensory info besides olfactory goes here
- limbic connects here as well
what is the function of the hypothalamus
controls the autonomic nervous system
- connected to thalamus via infundibular stalk
- two rounded protuberances called mammillary bodies are visible
- regulates visceral responses, temperature, and some limbic functions
what are the portions of the brainstem
midbrain, continuous with diencephalon
pons
medulla, continuous with spinal cord
what are the divisions of the cerebellum
vermis when viewed superior to inferior with lateral hemispheres
lobes:
- anterior
- flocculonodular
- posterior
what is the job of the anterior lobe of the cerebellum
receieves a large number of afferents from the spinal cord; plays a role in coordinating trunk and limb movements
what is the job of the flocculonodular lobe of the cerebellum
receives afferents from the vestibular system and is involved in controlling eye movements and posterural adjustments to gravity
what is the role of the posterior lobe of the cerebellum
receives majority of afferents from the cerebral cortex via pons; plays a role in coordination of voluntary movements
what is the basal nuclei
group of nuclei that lie deep to the cerebral cortex in each hemisphere
what are the nuclei of the basal nuclei
caudate and lenticular nucleus (subdivided into putamen and globus pallidus)
what separates the lenticular nuclei from the thalamus and caudate
internal capsule
what does the internal capsule contain
most of the fibers interconnecting the cerebral cortex and deep structures (thalamus, basal nuclei, and brainstem)
what cells provide the only pathway for the CNS to cause motor contraction
lower motor neurons
where along the motor pathway to fibers decussate
UMN of the corticospinal tract
