Limbic System Anatomy Flashcards
In the Circuit of Papez, the Anterior Nucleus of the Thalmaus projects to where?
It is then continued ventrally into the temporal lobe by what?
Cingulate Gyrus
Parahippocampal gyrus
The combination of the cingulate gyrus and the parahippocampal gyrus is considered…
the limbic gyrus
the expansive head of the hippocampus is found within the medial portion of the temporal lobe, specifically in the …
dentate gyrus, immediately superior to the uncus
What makes the hippocampal area unique?
one of the oldest portions of the cortex, has only 3 cell layers rather than 6
Fibers on the superomedial surface of the hippocampus form the … as they lead to a … extending posteriorly.
fimbriae
crus
The crura from the hippocampal fimbriae fuse to form…
This structure is suspended from the inferior edge of the …
Body of the Fornix
Septum Pellucidum
At the anterior commissure, the body of the fornix will split into what components? Where do these components lead?
- anterior component
- Septal nuclei and Nucleus Accumbens of the Basal Forebrain
- posterior component
- extends through HT to reach mammillary bodies
Mammillary bodies are immediately caudal to the …
infundibulum
What is the primary input and output of the Mammillary Bodies?
- input
- posterior component of fornix
- output
- mammillothalamic tract (to anterior nucleus of thalamus)
Mammillary bodies are frequently damaged d/t … causing…
alcoholism
memory impairment
If the cingulate gyrus, fornix, or hippocampus is damaged, the pt is likely to have what issue?
impairment of memory and/or anterograde amnesia
long term recall is not affected, but pt loses ability to make new memories
What area of the brain forms memories and what area keeps the memories?
hippocampus forms
association cortices keep the long-term memories
The papez circuit is now seen as primarily.. while the Limbic system is generally interpreted as a center for…
a functional route for long-term memory formation
emotional response
What are the 5 F’s of the Limbic system?
feeding
fleeing
fighting
feeling
fornicating
Located at the rostral tip of the hippocampus is the…
It is involved by proximity in the circuit of papez but it also receives direct input from…
What else gets direct input from here?
amygdala
olfactory
septal nuclei of basal forebrain
disruption of the amygdala leads to..
- generalized placidity and lack of fear
- hypersexuality
- hyperphagia
- oral fixation
Where are the Nucleus Accumbens and Septal Nuclei located?
Where do they receive information from?
basal forebrain
anterior component of fornix along with amygdala
What links the nucleus accumbens and the septal nuclei with the amygdala and the HT?
stria terminalis (white matter)
What is the function of nucleus accumbens and septal nuclei?
reward/pleasure centers in the brain
lesions linked to addictive, reckless, or impulsive behavior
What is the main NT of the amygdala?
What is the main NT of the Nucleus accumbens?
glutamate
dopamine
What hypothalamic nuclei produce ‘rage’ or ‘fear’ responses when activated?
Ventromedial and premammillary nuclei
What links the nucleus accumbens and septal nuclei with the Habenular Nuclei at the base of the pineal gland in the epithalamus?
Stria Medullaris
What does the Habenular Nucleus do?
relay center between the limbic system and the brainstem/spinal cord
functions in negative rewards/negative feedback
Where is the interpeduncular nucleus and what does it do?
in the midbrain tegmentum, superior to mammillary bodies
relay for limbic to brainstem
linked to withdrawal and other negative behaviors
The small cluster of neurons in the ventral tegmentum immediately adjacent to the substantia nigra is called…
What is this important for?
Ventral Tegmental nucleus
dopaminergic center - projections to limbic and other centers - plays a role in ‘reward’ behaviors
pathological changes a/w personality change in PD or Schizophrenia
The prefrontal and orbital portions of teh cerebral cortex are generally interpreted as centers for …
Affective Behavior
Specifically the rostral portion of the insula is known to be tied to the limbic system, esp. with what?
emotional evaluation and emotional desire
When talking about the emotional cortex, the nucleus accumbens is said to be part of..
basal ganglia
The limbic system has both cortical and sub-cortical components. These interact through both the thalamus and basal ganglia. What kind of signals do each of them send?
thalamus - sending excitatory signals to the cortex
basal ganglia - sending inhibitory signals
