Notes on Limbic System
Rahul's Noteblog Notes on Neurology Subcortical Grey Matter Notes on Limbic System
LIMBIC SYSTEM - EMOTIONAL OR SMELL BRAIN
Note: Limbic means "border."
• Emotion, memory, attention, feeding, mating, olfactory.
• Represented by the Papez circuit, which begins and ends in the hippocampus.
General:
Formerly called the rhinencephalon. Limbic lobes consist of limbic cortical tissue sited around the hilum of the cerebral hemispheres (allocortex) associated with the amygdala, cingulate gyrus, certain thalamic nuclei, mammillary bodies of hypothalamus, hippocampus, olfactory bulbs, cingulate and parahippocampal gyri and septal nuclei.
Limbic system ("border"):
Prev: Rhinencephalon ("emotional brain").
Site: Limbic cortex Assoc: Amyg/Cing/subthal nucleus/ mamm bod/hypohtal/hypocamp/olf bulb/septal.
Function:
a. Emotional aspects of behavior and memory.
b. Pleasure and pain.
c. Olfactory.
d. Biol rhyth / sexual behavior.
f. Emotion (rage, fever, motivation).
Associations:
a. Brainstem/hypothal/thal/BG/hypocamp/CC.
Functions:
Chiefly governs emotional aspects of behavior and memory ("emotional brain"). Associated with pleasure and pain sensations. Olfaction, control of biologic rhythms (circadian or diurnal rhythms), sexual behaviour, hunger and emotions (rage, aggression, fear, motivation). Sometimes called the "emotional" brain.
Connections:
1. Hippocampus (ie subiculum, hippocampus and dentate gyrus) is connected to the mammilary bodies by the fornix.
2. Mammilothalamic tract of Vicq d' Azur connects the mammilary body to the thalamic nuclei (stria medullaris thalami) and habenular nucleus.
Anterograde amnesia:
• Bilaterally damaged medial temporal lobes including hippocampus.
• New information cannot be learned.
Korsakoff syndrome:
• Seen in alcoholics with thiamine deficiency.
• Wernike encephalopathy also present.
• Patients make up stories of forgotten past experiences.
Kluver-Bucy syndrome:
• Bilateral lesions in amygdala and hippocampus.
• Aggressive, fearlessness, tendency to orally explore objects, hypersexuality, anterograde amnesia.
Summary:
Limbic system governs emotional aspects of behavior.
Further Topics on Subcortical Grey Matter:
1. Notes on Thalamus
2. Notes on Pineal Gland
3. Notes on Hypothalamus
4. Notes on Limbic System
5. Notes on Pituitary Gland
6. Notes on Basal Nuclei
7. Amygdaloid Body and Temporal Lobe
Additional Reading:
Basic Neurology
1. Peripheral Nervous System
2. Central Nervous System
3. The Ventricular System
4. The Spinal Cord
5. The Brain Stem
6. The Cerebellum
7. Visual Pathways
8. Diencephalon
9. Basal Ganglia
10. Cerebral Cortex
11. Sleep Disorders
12. Autonomic Nervous System
13. Cranial Nerves and Parasympathetic Ganglia
14. Cells of the Nervous System
15. Cerebrospinal fluid
16. Additional short notes on Cerebrum
17. Functions and Diseases of Cerebrum
18. Subcortical Grey Matter
19. Notes on The Spinal Cord
20. Regulation of Heart Rate by Autonomic Nervous System
21. Action Potentials, Axon Conduction, and Neuromuscular Junction
22. Types of Seizures
23. What is a Cough Reflex?
24. Notes on Congenital Prosopagnosia
25. Findings in Parkinson's Disease
26. Types of Heat Strokes
27. Types of Strokes
28. What is Benign Intracranial Hypertension?
29. What is Cauda Equina Syndrome?
30. Cranial Nerve Locations in Brain Stem
31. What is a Cluster Headache?
32. What is a Subarachnoid Hemorrhage?
33. What is a Tension Headache?
Neurology Videos
1. Video of Neurology Examination in a Clinical Setting
Medical Images
Useful Medical Images & Diagrams (link opens in a new window)
Related Topics
1. Nervous System Disorders
2. Histology of Nervous Tissue
3. Cranial Nerve Reflexes
4. Motor System Examination
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