Flashcards in 3.6 Limbic system anatomy and memory Deck (14):
What is the limbic system composed of? (7 points)
Hippocampus and dentate gyrus
Anterior thalamic nuclei
The anterior thalamus relates information to which part of the limbic system?
First the cingulate gyrus.
The cingulate gyrus relates information to the:
1. Hippocampal formation
2. Amygdala, and
3. The Septum
These then project fibres elsewhere, then finally to the hypothalamus, which ends again in the anterior thalamus.
What 4 parts compose the hippocampal formation?
Parts of the parahippocampal gyrus
What is the embryological origin of the hippocampus?
It is formed by infolding of the inferomedial part of the TEMPORAL LOBE into the inferior horn of the lateral ventricle.
What is Sommer's sector?
The CA1 region of the hippocampus (most lateral) that is +++ sensitive to hypoxia and die after a few minutes.
Where does the hippocampus receive input from? (afferents) (3 points)
Inferior temporal cortex (adjacent to it)
Contralateral hippocampus (via fornix)
Where does the hippocampus send outputs to? (Efferents)
Mamillary body of the hypothalamus via the fornix.
Where does the hypothalamus receive input from? (4 points)
Somatosensory afferents (esp erotogenic)
Input from septal area - responsible for basic emotional drives
What are the efferents out of the hypothalamus?
To the anterior thalamus- Mamillothalamic fasciculus (largest bundle)
Vagal nuclei- parasympathetic
Interomediolateral cell column of spinal cord (sympathetic)
Sacral autonomic nucleus- Parasympathetic
Also thought to have role in memory acquisition, visceral manifestation of emotions
What is the circuit of Papez?
It connects the hippocampus to the cingulate cortex via mamillary bodies of hypothalamus and anterior thalamus.
3. mamillary body
4. anterior thalamic nuclei
5. cingulate gyrus
6. parahippocampal gyri
New memories require circuit of Papez to be intact in min. 1 hemisphere
What are the inputs (afferents) into the amygdala?
1. Temporal cortex
2. Frontal cortex
4. Olfactory cortex
5. Brain stem
What are the outputs of the amygdala?
2. Septal area
What is the role of the amygdala?
Evaluating the significance of environmental events, and reinforcement