Limbic System PDF

LIMBIC SYSTEM YOUSIF ABDALLA MBBS, MSc. play a role in Much of its function was thought to be concerned with olfaction Emotion Behaviour Mood Memory YOUSIF ABDALLA. MBBS, MSc. Components: The hippocampus, fimbria, fornix, dentate gyrus and mammillary body The uncus...

LIMBIC SYSTEM YOUSIF ABDALLA MBBS, MSc. play a role in Much of its function was thought to be concerned with olfaction Emotion Behaviour Mood Memory YOUSIF ABDALLA. MBBS, MSc. Components: The hippocampus, fimbria, fornix, dentate gyrus and mammillary body The uncus , and the cingulate and parahippocampal gyri The amygdaloid body The septal and piriform areas of and the anterior thalamic nucleus. YOUSIF ABDALLA. MBBS, MSc. Hippocampus: above the anterior part of the parahippocampal gyrus projected into the floor of the inferior horn of the lateral ventricle YOUSIF ABDALLA. MBBS, MSc. Hippocampus: Anterior part of the hippocampus is named the pes hippocampi Alveus: thin film of white matter thickens medially to form the fimbria YOUSIF ABDALLA. MBBS, MSc. Hippocampus: Alveus breaks free from the hippocampus as the crus of the fornix The dentate gyrus : Is a small part of the hippocampus on the medial side between the fimbria and the parahippocampal gyrus YOUSIF ABDALLA. MBBS, MSc. fornix Great efferent pathway from the hippocampus An association tract as well as a commissure Fibres from the anterior column of the fornix pass both anterior and posterior to the anterior commissure YOUSIF ABDALLA. MBBS, MSc. Fornix: Anterior fibres : to the septal nuclei Posterior fibres : to the thalamus / mamillary body Mamillo-thalamic tract to the anterior nucleus of the thalamus Through the internal capsule to the cingulate gyrus YOUSIF ABDALLA. MBBS, MSc. Papez curcuit: YOUSIF ABDALLA. MBBS, MSc. Septal area an area of gray matter lying above the lamina terminalis near and around the anterior commissure A portion of it, the septum plucidum YOUSIF ABDALLA. MBBS, MSc. Olfactory pathways: Olfactory tract: In the olfactory sulcus beside the gyrus rectus Its anterior end is expanded as the olfactory bulb Cells of the second order neuron YOUSIF ABDALLA. MBBS, MSc. Olfactory pathways: Axons of these cells run back in the tract At anterior perforated substance, divides into Lateral striae:to the uncus Medial striae: connections with other parts of the limbic system. YOUSIF ABDALLA. MBBS, MSc. FUNCTIONS AND DISORDERS YOUSIF ABDALLA. MBBS, MSc. Autonomic Nervous System: Most of the limbic system output connects to the hypothalamus in part via the medial forebrain bundle. YOUSIF ABDALLA. MBBS, MSc. Behavior: The hypothalamic regions associated with typical patterns of behavior such as eating, drinking, sexual behavior. Lesions in the lateral amygdala induce unrestrained eating (bulimia), whereas those in the medial amygdala induce anorexia, accompanied by hypersexuality Electrical stimulation of the amygdala in humans may produce fear, anxiety YOUSIF ABDALLA. MBBS, MSc. Memory: The hippocampus is involved in converting short-term memory (up to 60 minutes)to long- term memory (several days or more). Patients with bilateral damage to the hippocampus can demonstrate a profound anterograde amnesia YOUSIF ABDALLA. MBBS, MSc. Spatial Problem Solving: The hippocampus contains "place cells" that encode spatial memory ("Where have I been?"). Recalling of places, and of the routes required to navigate to them, requires hippocampal activation. YOUSIF ABDALLA. MBBS, MSc.  YOUSIF ABDALLA. MBBS, MSc.