Question
The marked structure sends the efferent to which nucleus of the thalamus?
| A. |
Anterior nucleus of thalamus
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| B. |
Lateral nucleus of thalamus
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| C. |
Ventro -postero-lateral nucleus of thalamus
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| D. |
Posterior nucleus of thalamus
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Show Answer
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Correct Answer � A
Explanation
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The marked structure is the fornix. Fornix is the major efferent tract of the hippocampus. The fornix sends efferents to the mammillary bodies, and the mammillothalamic tract connects the mammillary bodies to the anterior nucleus of the thalamus. This pathway is part of the Papez circuit, involved in memory and emotional processing.
Incorrect options:
Lateral nucleus of thalamus: The lateral nucleus functions as the hunger center, promoting eating when stimulated, while its destruction leads to starvation.
Ventro -postero-lateral nucleus of thalamus: The ventro-postero-lateral nucleus of the thalamus receives input from the spinothalamic tract and dorsal column pathways, conveying sensations such as pain, vibration, proprioception, and light touch. It terminates in the primary somatosensory cortex.
Posterior nucleus of the thalamus: The posterior nucleus is involved in thermoregulation, promoting the conservation of heat. It activates the sympathetic nervous system, leading to peripheral vasoconstriction and further heat conservation.
