Gross Brain, Brainstem, and spinal cord Flashcards
What subdivisions is the brain composed of
Forebrain, cerebellum, and the brainstem
WHat is the forebrain composed of
Cerebral hemispheres, and the diencephalon
WHere does the brainstem lie
The brainstem lies between the forebrain and the spinal cord
What is gray matter and what are the two other definitions of them
Areas containing neuron/glial cell bodies and dendrites
nuclei: collections of cell bodies with a common function
Cortex: Layers of gray matter over other parts of the CNS, for example cerebral and cerebellar cortices
What is white matter and the other names for it
areas where there is a collection of axons and many are covered with myelin
fasiculus, funiculus, lemniscus, peduncle, and tract
What is special about names of tracts
1st part is the location of neuronal cell bodies from which the axons originate
2nd part is the site the axons terminate
How many lobes are associate with each cerebral hemisphere, and what are the names of the sulci that devide them
5 lobes seperated by 4 prominent sulci
Central sulcus
lateral sulcus
Parietooccipital sulcus
cingulate sulcus
What connects the two hemispheres
corpus callosum
What are the boundaries of the frontal lobe
Frontal pole to the central sulcus
laterally seperated by the lateral sulcus from the temporal lobe
medially it extends to the cingulate gyrus
Posteriorly it spans from top of the central sulcus to the cingulate sulcus
inferiorly it continues as the orbital part of the frontal lobe
What are the boundaries of the parietal lobe
Extends from the central sulcus to an imaginary line connecting the top of the parietooccipital sulcus and preoccipital notch
inferiorly it is bounded by the lateral sulcus and the imaginary continuation of this sulcus to the posterior boundary of the parietal lobe
Medially it is bounded inferiorly by the subparietal and calcarine sulci
bounded by the frontal lobe (anterior) and the parietoccipital sulcus (posterior)
What are the boundaries of the temporal lobe
Extends to the lateral sulcus and the line forming the inferior boundary of the parietal lobe (superior)
extends to the line connecting the top of the parietooccipital sulcus and the preoccipital notch (posterior)
Medially its posterior boundary is an imaginary line extending from the preoccipital notch toward the corpus callosum and part of its superior boundary is the collateral sulcus
What are the boundaries of the occipital lobe
bounded anteriorly by the parietal and temporal lobes on both the lateral and medial surfaces of the hemisphere
What are the boundaries of the limbic lobe
is a strip of cortex that encircles the telencephalon-diencephalon junction
interposed between the corpus callosum and the fronntal and occipital lobes
curves around to occupy part of the medial surface of what would otherwise be called the temporal lobe
What does the precentral gyrus house
the primary motor cortex
What houses the pre-motor and supplementary motor areas and what is this
remainder of the precentral gyrus and portions of the frontal gyri
the supplementary motor areas are important for planning and initiating voluntary movements
Brocas area
opercular and triangular parts of inferior frontal gyrus (one hemisphere, usually the left)
important for motor aspects of written and spoken language
What makes up the prefrontal cortex and its functions
Occupies the rest of the frontal lobe
involved with executive functions, personality, decision, making, insight, and foresight
What is the function of the post central gyrus
corresponds to primary somatosensory cortex
controls processing of tactile and proprioceptive information, sensory localization
Wernickes area
located on the posterior portion of the superior temporal gyrus (one hemisphere usualy left) which is important in the comprehension of language
What does the inferior parietal lobe and the rest of the parietal cortex play a role in?
Inferior parietal lobe: one hemisphere usually left and is involved in language comprehension
THe remainder of the parietal cortex has aspects in spatial orientation and directing attention
Homunculus
Contralateral half of the body is mapped in each post and precentral gyrus (somatosensation and motor) on a homunculus
this is spatially distorted to reflect the amount of innervation that is given to a specific body area
Primary auditory cortex
superior surface continuing as a small area of the superior temporal gyrus
is the primary cortex for auditory
What is the inferior surface and medial part of the temporal lobe associated with
inferior surface: higher order processing of visual information
most medial part: involved in learning and memory
What makes up the limbic structures
cingulate and parahippocampal gyri, and uncus
hippocampus and amygdala can be found at the base of this lobe
What is the function of the limbic role
important for emotional responses, drive related behavior and memory
where is the insula and what outlines the insula
buried deep to the lateral sulcus
the Circular sulcus outines the insula and marks its borders with the opercular areas of cortex
Where is the primary visual cortex located
contained in the walls of the calcarine sulcus of the occipital lobe
What does the remainder of the occipital lobe do
the lateral occipital gyri, and cuneus
are involved in visual association cortex
-involved in higher order processing of visual information
What makes up the diencephalon
thalamus
hypothalamus
epithalamus
subthalamus
infundibular stalk
mammillary bodies
What are the basal nuclei
group of nuclei deep to the cerebral cortex in each hemisphere
caudate and lenticular nucleus (subdivided into putament and globus pallidus) - these are associated with movement
What are arcuate fibers
White matter that connect cortical areas within the same sulci/gyri
What are longitudinal/association fasciculi
white matter that connect cortical areas within the same hemisphere
What are projection tracts
white matter that connect the cortical areas within other body regions
What is the corpus callosum
white matter that connects the two cerebral hemispheres, contains somewhere around 250 million axons
What is the anterior commissure
commissural fibers to/from temporal lobe (especially inferior parts )
What is the internal capsule and what makes it up
white matter structure divided into limbs
Anterior limb Genu - face Posterior limb Sublenticular limb retrolenticular limb
What are the three divisions of the brainstem
Midbrain
pons
medulla
What does the midbrain house?
the tectum
su[perior and inferior colliculi
cerebral peduncles
What does the pons house
Protruding pons
pontine tegmentum forms part of the floor of the 4th ventricle
Whad does the medulla house
rostral open portion, contains part of the 4th ventricle
caudal is the closed portion and is continuous with the SC
What is the function and anatomy of the cerebellum
functunings in sensory information processing and influences motor neurons
(fine and fluid mvmts)
cerebellar damage results in abnormalities of equilibrium, postral control and cordination of voluntary mvmts
surface is made up of folia
prominent fissures divide it into lobes and lobules
White matter in the medullary center, composed of afferent and or efferent fibers
what is the significance of the posterior rootlets of the spinal cord
posterior rootlets enter the SC via the posterolateral sulcus
what is the significance of the anterior rootlets of the spinal cord
anterior rootlets leave the SC via the anterolateral sulcus
components of the posterior horn
Substantia gelatinosa: gray matter that caps the posterior horn
Body: interneurons and projection neurons that transmit information
lissauers tract: white matter located btwn the substantia gelatinosa and the surface of the SC
what is clarks nucleus
also called posterior thoracic nucleus
cells located on the medial surface of the base of the posterior horn (T1 to L2)
has a prominent role in sensory processing and typically treated as part of the posterior horn
what makes up the intermediate gray matter
Collection of various projection neurons, sensory interneurons, and interneurons
preganglionic sympathetic neurons (T1-L3) in the intermediolateral cell column, form the lateral horn
- leave via ventral roots
Sacral parasympathetic nucleus spans S2-S4 but does not form a distinct lateral horn
Nucleus, level and function of Lamina: I
Nucleus: Marginal zone
Levels: all
Function: some spinothalamic tract cells
Nucleus, level and function of Lamina: II
Nucleus: substantia gelatinosa
levels: all
Function: Modulate the transmission of pain and temperature information
Nucleus, level and function of Lamina: III-VI
Nucleus: Body of posterior horn
levels: all
Function: sensory processing
Nucleus, level and function of Lamina: VII
nucleus: Clarkes nucleus
levels: T1 -L2
function: Posterior spinocerebellar tract cells
Nucleus, level and function of Lamina: VII
nucleus: sacral parasympathetic nucleus
levels: S2- S4
function: Preganglionic parasympathetic neurons to the pelvic viscera
Nucleus, level and function of Lamina: IX
nucleus: Accessory nucleus
levels: medulla - C5
function: Motor neurons to sternocleidomastoid and trapezius
Nucleus, level and function of Lamina: IX
Nucleus: Phrenic nucleus
levels: C3-C5
function: Motor neurons to the diaphragm
what does the 2nd order neuron do
relay a signal from the primary afferents in the periphery to a target in the CNS
may or may not cross midline
what does the 3rd order neuron do
relay messages to a final target in a specific cortical area
cortex then decides on given output
What are three main ascending tracts
Posterior columns
spinocerebellar tracts
anterolateral system
what relays in the posterior column
convey ipsilateral proprioceptive, tactile and vibratory info from the body (not face)
what relays in the spinocerebellar tract
information relays to cerebellum, thalamus, and motor cortex to influence efficiency of motor activity
what relays in anterolateral system
relays pain, temperature, and nondiscriminative touch from body (not face)
What are three main descending tracts
Corticospinal tract
vestibulospinal tract
rubrospinal tract
what relays in the corticospinal tract
controls voluntary, fine movements of the musculature
what relays in the vestibulospinal tract
influence motor neurons innervating primarily axial and neck musculature
what relays in the rubrospinal tract
excite flexor motor neurons and inhibit extensor motor neurons
