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Hypothalamotegmental Tract
In human neuroanatomy, the hypothalamotegmental tract is a pathway from the hypothalamus to the reticular formation. Axons from the posterior hypothalamus descend through the mesencephalic and pontine reticular formations. They connect with reticular neurons important in visceral and autonomic activity. The tract is a continuation of the medial forebrain bundle in the lateral portion of the tegmentum. It is not visible without special stains. See also *Mammillothalamic tract *Medial forebrain bundle *Midbrain reticular formation The midbrain reticular formation (MRF), also known as reticular formation of midbrain, mesencephalic reticular formation, tegmental reticular formation, and formatio reticularis (tegmenti) mesencephali, is a structure in the midbrain consisting of ... References Hypothalamus {{neuroanatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuroanatomy
Neuroanatomy is the study of the structure and organization of the nervous system. In contrast to animals with radial symmetry, whose nervous system consists of a distributed network of cells, animals with bilateral symmetry have segregated, defined nervous systems. Their neuroanatomy is therefore better understood. In vertebrates, the nervous system is segregated into the internal structure of the brain and spinal cord (together called the central nervous system, or CNS) and the routes of the nerves that connect to the rest of the body (known as the peripheral nervous system, or PNS). The delineation of distinct structures and regions of the nervous system has been critical in investigating how it works. For example, much of what neuroscientists have learned comes from observing how damage or "lesions" to specific brain areas affects behavior or other neural functions. For information about the composition of non-human animal nervous systems, see nervous system. For information a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypothalamus
The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamus is located below the thalamus and is part of the limbic system. In the terminology of neuroanatomy, it forms the ventral Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ... part of the diencephalon. All vertebrate brains contain a hypothalamus. In humans, it is the size of an Almond#Nut, almond. The hypothalamus is responsible for regulating certain Metabolism, metabolic biological process, processes and other activities of the autonomic nervous system. It biosynthesis, synthesizes and secretes certain neurohormones, called releasing hor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reticular Formation
The reticular formation is a set of interconnected nuclei that are located throughout the brainstem. It is not anatomically well defined, because it includes neurons located in different parts of the brain. The neurons of the reticular formation make up a complex set of networks in the core of the brainstem that extend from the upper part of the midbrain to the lower part of the medulla oblongata. The reticular formation includes ascending pathways to the cortex in the ascending reticular activating system (ARAS) and descending pathways to the spinal cord via the reticulospinal tracts. Neurons of the reticular formation, particularly those of the ascending reticular activating system, play a crucial role in maintaining behavioral arousal and consciousness. The overall functions of the reticular formation are modulatory and premotor, involving somatic motor control, cardiovascular control, pain modulation, sleep and consciousness, and habituation. The modulatory functions are pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axons
An axon (from Greek ἄξων ''áxōn'', axis), or nerve fiber (or nerve fibre: see spelling differences), is a long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action potentials away from the nerve cell body. The function of the axon is to transmit information to different neurons, muscles, and glands. In certain sensory neurons ( pseudounipolar neurons), such as those for touch and warmth, the axons are called afferent nerve fibers and the electrical impulse travels along these from the periphery to the cell body and from the cell body to the spinal cord along another branch of the same axon. Axon dysfunction can be the cause of many inherited and acquired neurological disorders that affect both the peripheral and central neurons. Nerve fibers are classed into three types group A nerve fibers, group B nerve fibers, and group C nerve fibers. Groups A and B are myelinated, and group C are unmyelinate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Midbrain Reticular Formation
The midbrain reticular formation (MRF), also known as reticular formation of midbrain, mesencephalic reticular formation, tegmental reticular formation, and formatio reticularis (tegmenti) mesencephali, is a structure in the midbrain consisting of the dorsal tegmental nucleus, ventral tegmental nucleus, and cuneiform nucleus. These are also known as the tegmental nuclei.NeuroNamestegmental nuclei BrainInfo. Accessed January 25, 2011. The dorsal and ventral tegmental nuclei receive connections from the mammillo-tegmental ''bundle of Gudden'', a branch of the mammillothalamic tract. The bundle of Gudden might be identical to the hypothalamotegmental tract. Along with the oral pontine reticular nucleus, the midbrain reticular formation projects to the gigantocellular reticular nucleus. The midbrain reticular formation is the point at which the different algedonic signals come together, ensuring that the organism is aware of potential threats. See also *Hypothalamotegmental tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pontine Reticular Formation
The reticular formation is a set of interconnected nuclei that are located throughout the brainstem. It is not anatomically well defined, because it includes neurons located in different parts of the brain. The neurons of the reticular formation make up a complex set of networks in the core of the brainstem that extend from the upper part of the midbrain to the lower part of the medulla oblongata. The reticular formation includes ascending pathways to the cortex in the ascending reticular activating system (ARAS) and descending pathways to the spinal cord via the reticulospinal tracts. Neurons of the reticular formation, particularly those of the ascending reticular activating system, play a crucial role in maintaining behavioral arousal and consciousness. The overall functions of the reticular formation are modulatory and premotor, involving somatic motor control, cardiovascular control, pain modulation, sleep and consciousness, and habituation. The modulatory functions are pri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forebrain
In the anatomy of the brain of vertebrates, the forebrain or prosencephalon is the rostral (forward-most) portion of the brain. The forebrain (prosencephalon), the midbrain (mesencephalon), and hindbrain (rhombencephalon) are the three primary brain vesicles during the early development of the nervous system. The forebrain controls body temperature, reproductive functions, eating, sleeping, and the display of emotions. At the five-vesicle stage, the forebrain separates into the diencephalon (thalamus, hypothalamus, subthalamus, and epithalamus) and the telencephalon which develops into the cerebrum. The cerebrum consists of the cerebral cortex, underlying white matter, and the basal ganglia. In humans, by 5 weeks in utero it is visible as a single portion toward the front of the fetus. At 8 weeks in utero, the forebrain splits into the left and right cerebral hemispheres. When the embryonic forebrain fails to divide the brain into two lobes, it results in a condition known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammillothalamic Tract
The mammillothalamic tract (mammillothalamic fasciculus, thalamomammillary fasciculus, bundle of Vicq d’Azyr) arises from cells in both the medial and lateral nuclei of the mammillary body and by fibers that are directly continued from the fornix. The mammillothalamic tract then connects the mammillary body to the dorsal tegmental nuclei, the ventral tegmental nuclei, and the anterior thalamic nuclei. Structure The mammillothalamic tract was first described by the French physician, Félix Vicq d'Azyr, from whom it takes its alternate name (bundle of Vicq d'Azyr). There, axons divide within the gray matter; the coarser branches pass into the anterior nucleus of the thalamus as the ''bundle of Vicq d’Azyr''. The finer branches pass downward as the mammillotegmental ''bundle of Gudden''. The bundle of Vicq d’Azyr spreads fan-like as it terminates in the medial dorsal nucleus. Some fibers pass through the dorsal nucleus to the angular nucleus of the thalamus. ("The term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medial Forebrain Bundle
The medial forebrain bundle (MFB), is a neural pathway containing fibers from the basal olfactory regions, the periamygdaloid region and the septal nuclei, as well as fibers from brainstem regions, including the ventral tegmental area and nigrostriatal pathway. Anatomy The MFB passes through the lateral hypothalamus and the basal forebrain in a rostral-caudal direction. The MFB has its main projections to these regions of Brodmann areas (BA) 8, 9, 10, 11, 11m. The superior frontal region of MFB projects to BA 8, 9, 10; the rostral middle frontal projects to dorsolateral prefrontal cortex (BA 9, 10); lateral orbitofrontal of MFB shows its projections to nucleus accumbens septi (NAC) and ventral striatum as subcortical reward associated structures. It contains both ascending and descending fibers. The mesolimbic pathway, which is a collection of dopaminergic neurons that projects from the ventral tegmental area to the nucleus accumbens, is a component pathway of the MFB. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Midbrain Reticular Formation
The midbrain reticular formation (MRF), also known as reticular formation of midbrain, mesencephalic reticular formation, tegmental reticular formation, and formatio reticularis (tegmenti) mesencephali, is a structure in the midbrain consisting of the dorsal tegmental nucleus, ventral tegmental nucleus, and cuneiform nucleus. These are also known as the tegmental nuclei.NeuroNamestegmental nuclei BrainInfo. Accessed January 25, 2011. The dorsal and ventral tegmental nuclei receive connections from the mammillo-tegmental ''bundle of Gudden'', a branch of the mammillothalamic tract. The bundle of Gudden might be identical to the hypothalamotegmental tract. Along with the oral pontine reticular nucleus, the midbrain reticular formation projects to the gigantocellular reticular nucleus. The midbrain reticular formation is the point at which the different algedonic signals come together, ensuring that the organism is aware of potential threats. See also *Hypothalamotegmental tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
