CH.13 Flashcards
Lateral ventricles serve which brain structures?
Cerebrum: cerebral hemispheres (cortex, white matter, basal nuclei.
Third Ventricle serves which brain structures?
Diencephalon (thalamus, hypothalamus, epithalamus), retina
Cerebral aquaduct serves which brain structures?
Brain stem: midbrain, pons, medulla oblongata
-cerebellum
Central canal serves which CNS structure?
spinal cord
What are the major diviions of the brain?
Cerebrum, diencephalon, cerebellum, brain stem.
Where is CSF made?
Made inside all of the ventricles
Describe the brain ventricles
- Continuous with each other and the central canal
- lined with ependymal cells
- provide CSF to nearby brain regions
Anterior horn of the lateral horns serve what brain region?
frontal lobes
Posterior horn of the lateral horns serve what brain region?
occipital lobe
Inferior horn of the lateral horns serve what brain region?
the temporal lobes and insular lobes of the cerebral cortex
Main body of the lateral ventricles serve what region of the brain?
The parietal lobes
What is the function of the cerebral aqueduct?
drains CSF from third ventricle into the fourth ventricle
What is the function of the interventricular foramen (foramina)?
Allow CSF to drain form the lateral ventricles into the third ventricle
Where does CSF go from the fourth ventricle?
Two places
- into the central canal
- back up into the brain into the subarachnoid space.
How does CSF escape the fourth ventricle?
Via apertures
- two lateral
- one medial
Why does the cerebrum have wrinkles on the external surface?
To increase surface area to make room for more neurons.
Describe the gross anatomy of the cerebrum
Three layers. Deep gray (neuronal soma), cerebral white matter (axonal tracts), cerebral cortex (neuronal soma-outer gray matter) -separated into the left and right hemispheres
The deep gray matter is always near what?
The lateral ventricles
What is a fissure?
A very large groove between structures in the brain
What is a sulcus?
small indentation or a small groove (sulci plural)
What is a gyrus, gyri plural?
Bumps in the brain caused by fissures and sulci.
What lobes are part of the cerebral cortex?
Frontal, parietal lobes, occipital lobes, temporal lobes, insular lobes
What separates the parietal and frontal lobes?
The central sulcus
What separates the cerebral cortex from the cerebellum?
The transverse cerebral fissure
What separates the temporal lobes from the parietal and frontal lobes?
The lateral sulcus
What is the insular lobe?
More gray cortex matter underneath the temporal, frontal and parietal lobes. must pry the brain open at the lateral sulcus to see.
What is the longitudinal fissure?
Fissure that runs anterior to posterior and separates the cerebrum into the left and right hemispheres.
What is unique about the central sulcus?
It is the only sulcus that runs from the longitudinal fissure all the way down to the lateral sulcus. Making a clear marker between the frontal and parietal lobes.
What separates the occiptal lobe from the parietal lobes?
The parieto-occipial sulcus. Not very distinct but seen very well from a medial view.
Where are the precentral and postcentral gyrus and what are their functions?
Rostral and caudal to the central sulcus. Precentral gyrus (frontal lobe) =primary motor cortex Postcentral gyrus (parietal lobes)= primary somatosensory cortex
What are associational areas?
They are adjacent to their respective functional regions.
-their function is not a primary function. they just integrate that information and start putting things together in the brain.
What are some functional regions of the cerebral cortex?
Primary motor cortex, primary somatocensory cortex, primary auditory cortex, primary visual cortex.
Where is the primary auditory cortex?
On the superior lip of the temporal lobe and dives down and faces the insular lobe as well.
Where is the primary visual cortex?
At the point of the occipital lobe and dips into the longitudinal fissure and runs internally as well.
Where is somatotopy revelant?
Primary motor cortex and primary somatosensory cortex.
When sensory information comes in, where is the first place it goes to?
Thalamus then it lands somewhere in the primary somatosensory cortex
How is information integrated in our brain?
sensory Information gets processed by a bunch of interneurons and associational areas give it meaning and eventually a blueprint is made and sent to the primary motor cortex and the primary motor cortex says yes or no to the action.
-essentially, information gets processed by a bunch of interneurons that inevitably activate the primary motor cortex so that we can have a motor response to those sensations.
White matter in the cerebrum can be classified into what?
Commisural fibers, associational fibers, projection fibers
What are commisural fibers?
Axons running from one hemisphere to the other.
- from a medial view they look like little dots.
- these fibers are going to cross the midline of the brain.
- the vast majority of axons that cross the midline of the brain do so at the very largest commissure (corpus callosum)
What is the corpus callosum?
largest commissural fiber in the cerebral white matter
What are projection fibers/tracts?
Running north-south in the CNS
Cortex lower cns areas
example: internal capsule
What are associational fibers?
Axons traveling on the same side of the hemisphere (intrahemispheric)
- going from one gyrus to the next
- can skip gyri and can be long or be short
- contribute to the white matter that is branching off towards the edge of the cerebrum
What makes the deep cerebral gray matter?
Basal nuclei (ganglia is cluster of cells bodies in the PNS not CNS)
- basal forebrain nuclei
- claustrum
- amygdala
What is the function of the Basal nuclei in the deep cerebral gray matter?
- Initiates and terminates body movements
- –example people with parkinsons want to initiate movement and struggle, its because they have a problem with this area
- suppress unwanted movements by regulating the primary motor cortex (ceo guy that likes to say yes to everything)
- –example: people who tremor and cannot stop that tremor they have a problem with the basal nuclei
What makes the diencephalon?
Thalamus, hypothalamus, pituitary gland, pineal gland, posterior commissure.
Describe the structure of the thalamus
Right and left hemisphere
-held together by the interthalamic adhesion or the intermediate mass of the thalamus
What is the thalamus?
- has a bunch of subnuclei that are responsbile for relaying sensory information to the cortex
- giant relay station
What is the function of the hypothalamus?
- has an abundance of subnuclei (about 12)
- plays an important role in homesotasis, making sure all of the biological variables are kepy in a tight range—> temperature, hunger, lung, heart function
What forms the walls of the third ventricle?
the hypothalamus
-forms two columns one on either side of the lower portion of the third ventricle
Where is the pituitary gland located?
Hangs off of the hypothalamus on the anterior side of the brain
What is the infundibulum?
a cherry stem that connects the pituitary gland to the hypothalamus