Lab 2 Flashcards
What is the thalamus, and where is its location in the brain?
It’s responsible for relaying sensory and motor information to the primary cortices.
It’s shaped like a dumbell, with a lobe on either side of the third ventricle, connected by a thin ‘bar’
What is the function of the mamillary body?
smell
What produces CSF?
Chorioid plexuses
Where does the third ventricle extend relative to the thalamus?
Anterior and posterior to it.
Where is peripheral vs. central vision in the primary visual cortex?
Peripheral is more anterior, central is peripheral (thus it’s more easily damaged by a knock)
Where does the midbrain begin and end?
Upper boundary: Runs from the occular motor nerve to the top of the superior colliculus
Lower boundary: From top of pons to bottom of inferior colliculus
What is the cerebral aqueduct?
Transports CSF from third to fourth ventricle
What are the cerebral peduncles?
Located above the pons in the midbrain, responsible for refining movement
What are the colliculi?
Superior colliculus: Reflexes to sight
Inferior colliculus: Reflexes to sound
What structure contains both white and gray matter?
Pons
What does the 4th ventral look like in cross section?
A little triangle
What is interesting about the cerebellum?
It doesn’t decussate (ipsilateral). Ie. the right cerebellum controls the right side of the body.
What are the features of the brain in lateral view which can help us identify the lobes?
The central sulcus
The lateral fissure
The parieto-occipital sulcus runs from the notch at the superior surface of the brain, which runs down to the pre-occipital notch (where the angle of the brain’s base changes).
By extending the central sulcus to meet the lateral fissure, and the lateral fissure to meet the parieto-occipital sulcus, the lobes of the brain can be identified.
What is interesting about where primary vs secondary association areas are located in the brain?
Primary areas are located in both hemispheres, whereas secondary areas are only located in the dominant hemisphere
Where is the striatum relative to the thalamus?
Lateral and anterior to the thalamus
What is the form of the caudate nucleus?
It is lateral to the lateral ventricles, and is C shaped, with a bulbous anterior head and a thin tail
How do you tell the putamen from the caudate nucleus in an anterior coronal slice (when they are connected)?
The caudate nucleus is more solid looking than the putamen
What does the corpus callosum look like in a coronal slice?
A white bridge just inferior to the longitudinal fissure
What do the lateral ventricles look like in a coronal slice?
Holes just below the corpus callosum
What do the internal capsules look like in coronal slices?
They are only visible when the middle of the brain is sliced- they come between the putamen and the thalami, and are two vertical ish white matter lines
How can you find the caudate nuclei on a coronal slice?
They are always just touching the superior lateral ventricles.
What does the third ventricle look like in coronal slice?
It is a small, oval hole between two gray matter bulbs (the thalamus)
How can you identify the substantia nigra?
it is always very, very dark.
What does the fourth ventricle look like in coronal slice?
It’s in the white matter of the cerebellum, a small hole.
What are association fibres?
They run anterior to posterior
Stay in a single hemisphere (eg. arcuate fasciculus)
What are commissural fibres?
They link hemisheres together
Run lateral to medial
Eg. corpus callosum
What are projection fibres?
Run inferior to superior
Eg. corticospinal fibres
What are the general steps of receiving input and performing an output in the brain?
- Receive input
- Understand
- Plan response
- Conduct response
- Feedback
What are the steps of hearing a question and speaking a reply?
- Receive input (Primary auditory cortex separates sound tonotopically)
- Understand (Wernicke’s area receives sounds, understands them)
- Plan response (brocas area)
- Conduct response (Motor cortes)
- Feedback (Auditory cortex, ensuring what you’ve said is right
What are the steps of reading a question and writing a reply?
- Receive input (Visual cortex) –> Supplementary visual cortices for interpretation of what you’re seeing
- Understand (SMAGLA / AGLA)
- Plan response (association fibre to exener’s area)
- Conduct reponse (Motor cortex)
- Feedback (Visual cortices)
