Module 1 - general CNS anatomy Flashcards
(53 cards)
Define the Horizontal Plane.
AKA the axial or transverse plane, looking at the brain from above or below.
Define the Coronal Plane.
AKA the frontal plane, looking at the brain from the front or the back.
Define the Sagittal Plane.
Looking at the brain from the left or the right.
Mid-sagittal plane: when the slice is along the midline.
Para-sagittal plane: when the slice is off the midline.
Above the midbrain, what are the relationships between absolute and relative orientation terms?
Anterior = rostral
Posterior = caudal
superior = dorsal
inferior = ventral
In/below the midbrain, what are the relationships between absolute and relative orientation terms?
anterior = ventral
posterior = dorsal
superior = rostral
inferior = caudal
What is gray matter made of, and what are other names for it?
Unmyelinated cell bodies. When grouped together, they are called nuclei, cortex, or laminae.
What is white matter made of, and what are other names for it?
Axons that are concentrated together. AKA nerves, fibers, tracts, lemniscus, or commissures.
What are projection fibers?
Axons that relay impulses between the cortex, brainstem, and spinal cord.
What are commissural fibers?
Fibers that cross between hemispheres, and connect the same structure on R/L sides of the brain.
What are association fibers?
Fibers that connect cortical areas within a hemisphere.
What is the cortex, and define a gyrus, sulcus, and fissure?
Cortex: the folded layer of gray matter on the outer surface of the brain.
Gyrus: outward fold
Sulcus: inward fold
Fissure: a deep sulcus
Where are the following fissures located? (longitudinal fissure, sylvian fissure, central sulcus, parietal-occipital sulcus, precentral and postcentral gyri, and the cingulate sulcus and gyrus)
Longitudinal fissure: large fissure at the top + center of the brain that runs down the entire length, separating the hemispheres.
Sylvian fissure: on the lateral aspect of the brain, and separates the frontal lobe from the temporal lobe.
Central sulcus: superior and runs down the lateral aspect of the brain, separates the frontal and parietal lobes.
Parietal-occipital sulcus: separates the parietal and occipital lobes, can only be seen medially.
pre-central gyrus: the gyrus anterior to the central sulcus.
post-central gyrus: the gyrus posterior to the central sulcus.
cingulate gyrus and sulcus: surround the corpus collosum.
From top to bottom, what is the order of brainstem structures?
Midbrain, pons, medulla.
Where is the cerebellum located?
Posterior/dorsal to the brainstem.
Where is the thalamus located?
On top of the brainstem, but is not part of the brainstem.
What are interthalamic adhesions?
Bands of white matter that connect the R/L sides of the thalamus.
What does the anterior fossa hold, and how is it separated from the middle fossa?
It carries the frontal lobe, and is separated from the middle fossa by the lesser wing of the sphenoid bone.
What does the middle fossa hold, and how is it separated from the posterior fossa?
It carries the temporal lobe, and is separated from the posterior fossa by the petrous ridge of the temporal bone.
What does the posterior fossa carry?
The cerebellum and brainstem.
What is the foramen magnum?
The large opening at the base of the skull that allows the spinal cord and brainstem to enter the skull.
What is the cervicomedullary junction?
Where the spinal cord ends and the medulla begins. It sits right at the level of the foramen magnum.
What is the dura mater, and what are its features (2 layers)?
It is the hard, fibrous, outermost meningeal layer.
Outer periosteal layer: adhered to the inner skull surface.
Inner meningeal layer: fused to the periosteal layer, except when it extends inwards to separate hemispheres + cortex from the cerebellum.
What is the falx cerebri?
A flat sheet of dura that separates the R/L cerebral hemispheres.
What is the tentorium cerebelli?
A tent-like sheet of dura that separates the cerebellum from the cerebrum. It is superiorly attached to the falx cerebri.
