General Terms And SC Morphology Flashcards
Forebrain is composed of the cerebral hemispheres and the _____.
Brainstem lies between the ___ and spinal cord.
Diencephalon
Forebrain
Cells directly sensitive to various stimuli, touch or temp changes, or receive direct connections from non-neuronal receptor cells
Sensory neurons
Cells that directly contact muscles, glands, or other neurons (PNS ganglia)
Motor neurons
Cells that have processes confined to at single small area of the CNS
Cells with long axons connecting different areas, like the neuron in the cerebral cortex whose axon reaches the spinal cord
Local interneurons
Protection neuron
Areas that contain neuron/glial cell bodies and dendrites?
What are its two parts?
Gray matter
Nuclei: collection of cell bodies with a common fx
Cortex: layers of gray matter over other parts of the CNS (cerebral and cerebellar cortices)
Areas where there is a collection of axons, many covered with myelin?
Contains a fasciculus, funiculus, lemniscus, peduncle, and tract (all terms for white matter)
Tracts have a two part name, what are they?
White matter
1st: location of neuronal cell bodies from which axons originate
2nd: site the axons terminate
What is the fx of the spinal cord?
What are its two enlargements?
How are the 31 pairs of spinal nerves separated?
Linking the brain to the rest of the body; pathway for sensory and motor impulses, reflexes, reactions to stimuli
Cervical enlargement: innervates upper limbs
Lumbosacral enlargement: innervates lower limbs
8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal
____ is the tapering, inferior end of the spinal cord.
Inferior to this, a group of axons project from the spinal cord called ____.
____ is a thin strand of ____ that helps anchor the conus medullaris to the coccyx
Conus medullaris
Cauda equina
Pia mater; Filum terminale
Spinal cord has anterior/posterior horns. Posterior rootlets enter the SC in the _____ (shallow longitudinal groove).
Anterior rootlets leave from the ____.
Posterior and anterior rootlets become posterior and anterior roots that join to form _____.
Posterolateral sulcus
Anterolateral sulcus
Spinal nerves
Posterior horn of the SC consists of ____ whose processes remain within the SC and _____ whose axons collect into ascending sensory pathways.
What are the two parts of the posterior horn at the spinal levels?
Interneurons; projection neurons
Substantia gelatinosa: region of gray matter that caps the posterior horn
Body of the posterior horn: interneurons and projection neurons that transmit somatic and visceral sensory info
Substantia gelatinosa looks pale because it contains _____ sensory fibers that carry _____ information.
____ is white matter located between the substantia gelatinosa and the surface of the cord. It contains myelinated/unmyelinated fibers from the ____.
Myelinated/unmyelinated; pain and temperature info
Lissauer’s tract; substantia gelatinosa
The anterior horn of the SC contains cell bodies of ____ that supply skeletal muscles.
These cells allows the CNS to do ____.
Large motor neurons (lower motor neurons)
Have control over body movements (voluntary/involuntary)
Intermediate gray matter contains autonomic neurons (preganglionic), sensory neurons, projection neurons, sensory interneurons, and interneurons that synapse on motor neurons. It also contains the ____.
Preganglionic sympathetic neurons lie in segments ____ and most are located in the _____. They form a pointy lateral horn on the spinal gray matter and their axons leave through ____.
Clarke’s nucleus
T1-L3
Intermediolateral cell column
Ventral roots
Cells in S2-S4 are part of the _____ but do not form a distinct lateral horn. The axons synapse on _____ neurons for pelvic viscera.
Sacral parasympathetic nucleus
Postganglionic parasympathetic
Clark’s nucleus is a collection of large cells located on the medial surface of the base of the _____. It is part of the intermediate gray matter.
This has a role in sensory processing.
Posterior horn (T1-L2)
What are the 10 laminae of the spinal cord gray matter?
Nucleus?
Level?
Fx?
Lamina I: thin layer of gray mater covering the substantia gelatinosa (marginal zone; all levels; spinothalmic tract cells)
Lamina II: substantia gelatinosa; all levels; modulate transmission of pain and temp
Laminae III-VI: body of the posterior horn; all; sensory processing
Lamina VII: intermediate gray matter, including Clarke’s nucleus and extensions into the anterior horn; T1-L2; posterior spinocerebellar tract cells; intermediolateral column; T1-L3; preganglionic sympathetic neurons; sacral parasympathietic; S2-S4; preganglionic parasympathetic neurons -> pelvic viscera
Lamina VIII: interneuron zones of the anterior horn
Lamina IX: clusters of motor neurons embedded in the anterior horn; accessory nucleus; medulla-C5; motor neurons -> SCM, trapezius
Lamina X: zone of gray matter surrounding the central canal; phrenic nucleus; C3-C5; motor neurons -> diaphragm
Bundle of axon fibers in the posterior column-medial lemniscus pathway of the SC
It carries sensory info from the arms; the ascending tract relays info to the brain via SC
Fasciculus cuneatus
Bundle of axon fibers in the posterior column-medial lemniscus pathway of the SC
Carries sensory info from the middle thoracic and lower limbs of the body; ascending tract relays info to the brain via the SC
Fasciculus gracilis
Sensory axons from _____ enter the spinal cord, branch, and terminate on neurons in the _____.
Axons emerge from motor neurons on the _____ and exit the spinal cord to innervate skeletal muscle.
Cell bodies in the DRG; spinal gray matter
Anterior horn
White matter contains what three things?
Long descending tracts (from brainstem and forebrain)
Long ascending tracts (to brainstem, cerebellum, and forebrain)
Local axons interconnecting different spinal levels
Gray matter contains what four things?
Motor neuron cell bodies
Endings of incoming sensory axons
Second order sensory cell bodies (axons entering ascending tracts to relay sensory info to brainstem and forebrain)
Endings of long descending tracts and local interneurons
What are the four main sulci that divide the cerebral hemisphere into five lobes?
Central sulcus
Lateral sulcus
Parietooccipital sulcus
Cingulate sulcus
Frontal lobe of the brain extends from the frontal pole to the ____. It is laterally separated from the temporal lobe by the ____.
Medially it extends to the ____. And inferiorly it continues as the orbital part of the frontal lobe.
Central sulcus
Lateral sulcus
Cingulate sulcus
The parietal lobe of the brain extends from the ____ to an imaginary line connecting the top of the _____ and preoccipital notch.
Inferiorly it is bounded by the ____ and the imaginary continuation of this sulcus to the posterior boundary of the parietal lobe.
Medially, it is bounded inferiorly the _____. Bounded by frontal lobe (anterior) and _____ (posterior).
Central sulcus; parietooccipital sulcus
Lateral sulcus
Subparietal and calcarine sulci; parietooccipital sulcus
Temporal lobe of the brain extends to the ____ and the line forming the inferior boundary of the parietal lobe (superior).
It extends to the line connecting the top of the parietooccipital sulcus and the _____.
Medially its posterior boundary is an imaginary line extending from the preoccipital notch towards the _____ and part of its superior boundary is the collateral sulcus.
Lateral sulcus
Preoccipital notch (posterior)
Corpus callosum
The occipital lobe of the brain is bounded anteriorly by the _____ and _____ on both the lateral and medial surfaces of the hemispheres.
Parietal and temporal lobes
The limbic lobe of the brain is a strip of cortex that encircles the _____. It is between the corpus callosum, frontal, parietal, and occipital lobes and occupies the medial surface of the temporal lobe.
Telencephalon-diencephalon
The neural system develops from the neural tube that contains a ____. This cavity persists in adults as a system of _____.
What is the pathway of ventricles?
Central cavity
Interconnected ventricles
Lateral ventricles -> interventricular foramen (foramen of Monro) -> 3rd ventricle -> cerebral aqueduct (aqueduct of Sylvius) -> 4th ventricle -> central canal
Parts of central white matter:
Connect cortical areas within the same sulci/gyri
Connect cortical areas within the same hemisphere
Connect cortical areas within the R/L hemispheres
Connect cortical areas within other body regions
Arcuate fibers
Longitudinal/Association fasciculi
Commissural tracts
Projection tracts
____ interconnects the two cerebral hemispheres. It contains ____ tracts.
____ are commissural fibers to/from the temporal lobe.
Corpus callosum; comissural tracts
Anterior commissure
____ is an additional area of the cerebral cortex. It is buried in the _____ and concealed by portions of the frontal, parietal, and temporal lobes.
The ____ are parts of the frontal, parietal, and temporal lobes that overlay this area of cortex.
___ outlines the insula and marks its borders with the opercular areas of cortex.
Insula; lateral sulcus
Opercula
Circular sulcus
_____ and ____ make up the lateral surface of the frontal lobe.
Precentral gyrus houses the ____; it is the origin of the descending motor pathways and voluntary movements.
____ and ____ occupy the reminder of the precentral gyrus and the posterior portions of the superior and middle frontal gyri.
Precentral gyrus, superior, middle, and inferior frontal gyri
Primary motor cortex
Premotor and supplementary motor: related to planning and initiation of voluntary movements
____ is the left opercular and triangular parts of the inferior frontal gyrus; important in written and spoken language.
____ is the rest of frontal lobe; involved with executive functions, personality, decision making, insight, and foresight.
Broca’a area
Prefrontal cortex
The parietal lobe includes the ____ and ______.
Fx of each?
Postcentral gyrus and the superior and inferior parietal lobules
Postcentral gyrus: corresponds to primary somatosensory cortex; controls the processing of tactile and proprioceptive info and sensory localization
Inferior parietal lobe: involved in language comprehension
Remainder controls spatial orientation and direction attention
Somatosensory info from different parts of the body enter the _____ at different levels.
Different parts travel together, but in separate bundles.
____ is a somatotopic map that maps the contralateral half of the body in each postcentral gyrus. The map is spatially distorted and reflects the amount of ____ to a given body area.
Spinal cord
Homonculus
Innervation
Temporal lobe is composed of the _____.
The inferior surface is made up of the broad _____.
The superior surface of the temporal lobe including the area of the superior temporal gyrus is the _____.
Superior, middle, inferior temporal gyri
Occipitotemporal gyrus
Primary auditory cortex
_____ is located on the posterior portion of the L superior temporal gyrus. It is important in the comprehension of language.
The interior surface of the temporal lobe is involved in the higher order processing of ____.
The medial part is involved in ____.
Wernicke’s area
Visual info
Learning and memory
The lateral surface of the occipital lobe contains the ____.
The _____ is an area between the parietooccipital and calcarine sulci
The calcarine sulcus contains the _____; the reminder of the lobe is the _____.
The lingual gyrus is inferior to the calcarine sulcus and is continuous with the _____.
Lateral occipital gyri
Cuneus
Primary visual cortex; visual association cortex (involved with higher order processing of visual info)
Parahippocampal gyrus
The limbic lobe is mostly composed of the ____ and ____. It is important in emotional responses, drive-related behavior, and memory.
The anterior end of the parahippocampal gyrus hooks backward on itself forming a medial bump called the ____.
The ____ is folded into the temporal lobe at the hippocampal sulcus. ____ is beneath the uncus of the temporal lobe.
Cingulate and parahippocampal gyri
Uncus
Hippocampus; amygdala
What are the four divisions in the diencephalon?
Thalamus, hypothalamus, epithalamus, subthalamus
____ relays into to the cerebral cortex. It is an _____ that borders the third ventricle.
Every pathway carrying info bound for the cerebral cortex from a subcortical site stops in the ____.
All sensory info EXCLUDING the ___ stop in the thalamus. Motor pathways between the cerebellum and cerebral cortex and between the basal nuclei and cerebral cortex involve the thalamus; _____ also go through the thalamus.
Thalamus; ovoid nuclear mass
Thalamus
Olfactory; limbic projections
The _____ controls the autonomic NS. It regulates visceral responses, temp, and limbic fx.
It lies inferior and anterior to the thalamus. The inferior surface is one of the few parts of the ____ visible on the brain and contains the _____. Two protuberances called the ____ are also visible.
Hypothalamus
Diencephalon
Infundibular stalk
Mammillary bodies
The brainstem is subdivided into what three parts?
Midbrain (continuous with the diencephalon)
Pons
Medulla (continuous with the spinal cord)
The cerebellum contains a midline _____ and a lateral hemisphere on each side.
What are the three lobes of the cerebellum and what do they receive?
Vermis
Anterior lobe: receives large number of afferents from spinal cord; plays role in coordinating trunk and limb movements
Flocculonodular lobe: receives afferents from the vestibular system; involved in controlling eye movements and postural adjustments to gravity
Posterior lobe: receives a majority of afferents from the cerebral cortex via the pons; plays a role in coordination of voluntary movements
____ are a group of nuclei that lie deep to the cerebral cortex in each hemisphere.
What are these nuclei?
____ are physically separated from the thalamus and caudate by a thick sheet of fibers called the internal capsule.
____ contains moist of the fibers interconnecting the cerebral cortex and deep structures (thalamus, basal nuclei, brainstem)
Basal nuclei
Caudate nucleus
Lenticular nucleus (subdivided into putamen and globus pallidus)
Lenticular nuclei
Internal capsule
_____ and _____ convey info to/from the CNS. The peripheral nerve axons come from ____ that convey info into the CNS from the periphery.
Other axons of ____ convey messages to skeletal muscles causing them to contract.
Primary afferents and lower motor neurons
Primary afferents
Lower motor neurons
Axons of ____ enter the CNS without crossing the midline.
Sensory info is carried by axons in ____.
Primary afferents terminate in the CNS on ____ which project to _____.
The components of sensory primary afferents are all _____.
Primary afferents
Peripheral nerves (cell bodies are DRG)
Second order neurons ; third order neurons
Ipsilateral
____ relay a signal from primary afferents in the periphery to a target in the CNS. They can cross the midline of the body.
____ relay the message to a final target in a specific cortical area. The cortex decides on the given output.
Second-order neurons
Third-order neurons
Axons of the _____ leave the CNS without crossing midline. These cells are the only way the CNS can cause muscle contraction.
They have their cell bodies _____ in the CNS (anterior horn of SC).
They also have axons that travel through peripheral nerves to end on _____.
Lower motor neurons
Within
Ipsilateral muscle fibers
____ and ____ can cross the midline.
Pain and temp pathways and the touch pathway cross at different levels.
Second order neurons; first order neurons (afferents)
Lower motor neurons are subject to control of voluntary movement via the ____. _____ extend axons from motor areas of the cerebral cortex that terminate in the SC.
Corticospinal tract
Upper motor neurons
Cell bodies of Corticospinal neurons are distributed in the ____. This pattern parallels the somatosensory homunculus.
Damage to the Corticospinal tract causes what?
Precentral gyrus
Weakness of half of the body, but reflexes are still functional
The upper motor neurons (UMN) of the corticospinal tract cross the ___.
Damage to one cerebral hemisphere results in weakness in the ____ arm/leg.
Single neurons with long axons project all the way from the motor cortex to the _____ half of the SC.
Midline
Contralateral
Contralateral
