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Reticular Activating System
The reticular formation is a set of interconnected nuclei in the brainstem that spans from the lower end of the medulla oblongata to the upper end of the midbrain. The neurons of the reticular formation make up a complex set of neural networks in the core of the brainstem. The reticular formation is made up of a diffuse net-like formation of reticular nuclei which is not well-defined. It may be seen as being made up of all the interspersed cells in the brainstem between the more compact and named structures. The reticular formation is functionally divided into the ascending reticular activating system (ARAS), ascending pathways to the cerebral cortex, and the descending reticular system, descending pathways ( reticulospinal tracts) to the spinal cord. Due to its extent along the brainstem it may be divided into different areas such as the midbrain reticular formation, the central mesencephalic reticular formation, the pontine reticular formation, the paramedian pontine reticul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronal Plane
The dorsal plane (also known as the coronal plane or frontal plane, especially in human anatomy) is an anatomical plane that divides the body into Anatomical terms of location#Dorsal and ventral, dorsal and ventral sections. It is perpendicular to the sagittal plane, sagittal and transverse plane, transverse planes. Human anatomy The coronal plane is an example of a Anatomical terms of location#General usage, longitudinal plane. For a human, the mid-coronal plane would transect a standing body into two halves (front and back, or anterior and posterior) in an imaginary line that cuts through both shoulders. The sternal plane (''planum sternale'') is a coronal plane which transects the front of the Human sternum, sternum. Etymology The term is derived from Latin ''corona'' ('garland, crown'), from Ancient Greek κορώνη (''korōnē'', 'garland, wreath'). The coronal plane is so called because it lies in the same direction as the coronal suture. Additional images File:Coronal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upper Motor Neurons
Upper motor neurons (UMNs) is a term introduced by William Gowers in 1886. They are found in the cerebral cortex and brainstem and carry information down to activate interneurons and lower motor neurons, which in turn directly signal muscles to contract or relax. UMNs represent the major origin point for voluntary somatic movement. Upper motor neurons represent the largest pyramidal cells in the motor regions of the cerebral cortex. The major cell type of the UMNs is the ''Betz cells'' residing in layer V of the primary motor cortex, located on the precentral gyrus in the posterior frontal lobe. The cell bodies of Betz cell neurons are the largest in the brain, approaching nearly 0.1 mm in diameter. The axons of the upper motor neurons project out of the precentral gyrus travelling through to the brainstem, where they will decussate (intersect) within the lower medulla oblongata to form the lateral corticospinal tract on each side of the spinal cord. The fibers that do not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalamocortical Radiations
In neuroanatomy, thalamocortical radiations, also known as thalamocortical fibers, are the efferent fibers that project from the thalamus to distinct areas of the cerebral cortex. They form fiber bundles that emerge from the lateral surface of the thalamus. Structure Thalamocortical fibers (TC fibers) have been referred to as one of the two constituents of the isothalamus, the other being microneurons. Thalamocortical fibers have a bush or tree-like appearance as they extend into the internal capsule and project to the layers of the cortex. The thalamus supplies all parts of the neocortex with afferents. The main thalamocortical fibers extend from different nuclei of the thalamus and project to the visual cortex, somatosensory (and associated sensori-motor) cortex, and the auditory cortex in the brain. Thalamocortical radiations also innervate gustatory and olfactory pathways, as well as pre-frontal motor areas. Visual input from the optic tract is processed by the lateral ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebellum
The cerebellum (: cerebella or cerebellums; Latin for 'little brain') is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as it or even larger. In humans, the cerebellum plays an important role in motor control and cognition, cognitive functions such as attention and language as well as emotion, emotional control such as regulating fear and pleasure responses, but its movement-related functions are the most solidly established. The human cerebellum does not initiate movement, but contributes to motor coordination, coordination, precision, and accurate timing: it receives input from sensory systems of the spinal cord and from other parts of the brain, and integrates these inputs to fine-tune motor activity. Cerebellar damage produces disorders in fine motor skill, fine movement, sense of balance, equilibrium, list of human positions, posture, and motor learning in humans. ... [...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 controls body temperature, reproductive functions, eating, sleeping, and the display of emotions. Vesicles of the forebrain (prosencephalon), the midbrain (mesencephalon), and hindbrain (rhombencephalon) are the three primary brain vesicles during the early development of the nervous system. 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 i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lower Pons Horizontal KB
Lower may refer to: * ''Lower'' (album), 2025 album by Benjamin Booker *Lower (surname) *Lower Township, New Jersey *Lower Receiver (firearms) *Lower Wick Lower Wick is a small hamlet located in the county of Gloucestershire, England. It is situated about five miles south west of Dursley, eighteen miles southwest of Gloucester and fifteen miles northeast of Bristol. Lower Wick is within the civil ... Gloucestershire, England See also * Nizhny {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lower Vertebrate
The anamniotes are an informal group of craniates comprising all fish and amphibians, which lay their eggs in aquatic environments. They are distinguished from the amniotes (reptiles, birds and mammals), which can reproduce on dry land either by laying shelled eggs or by carrying fertilized eggs within the female. Older sources, particularly before the 20th century, may refer to anamniotes as "lower vertebrates" and amniotes as "higher vertebrates", based on the antiquated idea of the evolutionary great chain of being. The name "anamniote" is a back-formation word created by adding the prefix '' an-'' to the word ''amniote'', which in turn refers to the amnion, an extraembryonic membrane present during the amniotes' embryonic development which serves as a biochemical barrier that shields the embryo from environmental fluctuations by regulating the oxygen, carbon dioxide and metabolic waste exchanges and secreting a cushioning fluid. As the name suggests, anamniote embryos lack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetics
In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data and observed heritable traits of DNA sequences, protein amino acid sequences, and morphology. The results are a phylogenetic tree—a diagram depicting the hypothetical relationships among the organisms, reflecting their inferred evolutionary history. The tips of a phylogenetic tree represent the observed entities, which can be living taxa or fossils. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the taxa represented on the tree. An unrooted tree diagram (a network) makes no assumption about directionality of character state transformation, and does not show the origin or "root" of the taxa in question. In addition to their use for inferring phylogenetic pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exhalation
Exhalation (or expiration) is the flow of the breathing, breath out of an organism. In animals, it is the movement of air from the lungs out of the airways, to the external environment during breathing. This happens due to elastic properties of the lungs, as well as the internal intercostal muscles which lower the rib cage and decrease thoracic volume. As the thoracic diaphragm relaxes during exhalation it causes the tissue it has depressed to rise superiorly and put pressure on the lungs to expel the air. During Hyperpnea, forced exhalation, as when blowing out a candle, expiratory muscles including the abdominal muscles and internal intercostal muscles generate abdominal and thoracic pressure, which forces air out of the lungs. Exhaled air is 4% carbon dioxide, a waste product of cellular respiration during the production of energy, which is stored as Adenosine triphosphate, ATP. Exhalation has a complementary relationship to inhalation which together make up the respirator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serotonin
Serotonin (), also known as 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter with a wide range of functions in both the central nervous system (CNS) and also peripheral tissues. It is involved in mood, cognition, reward, learning, memory, and physiological processes such as vomiting and vasoconstriction. In the CNS, serotonin regulates mood, appetite, and sleep. Most of the body's serotonin—about 90%—is synthesized in the gastrointestinal tract by enterochromaffin cells, where it regulates intestinal movements. It is also produced in smaller amounts in the brainstem's raphe nuclei, the skin's Merkel cells, pulmonary neuroendocrine cells, and taste receptor cells of the tongue. Once secreted, serotonin is taken up by platelets in the blood, which release it during clotting to promote vasoconstriction and platelet aggregation. Around 8% of the body's serotonin is stored in platelets, and 1–2% is found in the CNS. Serotonin acts as both a vasoconstrictor and vas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parvocellular Reticular Nuclei
The parvocellular reticular nucleus is part of the brain located dorsolateral to the caudal pontine reticular nucleus. The dorsal portion of the reticular nucleus has been shown to innervate the mesencephalic trigeminal nucleus and its surrounding area. Also, it projects to the facial nucleus, hypoglossal nucleus and parabrachial area along with parts of the caudal parvocellular reticular formation.Ter Horst, GJ et al. Projections from the rostral parvocellular reticular formation to pontine and medullary nuclei in the rat: involvement in autonomic regulation and orofacial motor control. Neuroscience. 1991;40(3):735-58. This nucleus is also involved in expiration Expiration or expiration date may refer to: Expiration Expiration may refer to: *Death *Exhalation of breath, breathing out * Expiration (options), the legal termination of an option to take an action *Shelf life, or the time after which a product ... with a part of the gigantocellular nucleus. References Med ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gigantocellular Reticular Nuclei
The gigantocellular reticular nucleus (also magnocellular reticular nucleus) is the (efferent/motor) medial zone of the reticular formation of the caudal pons and rostral medulla oblongata. It consists of a substantial number of giant neurons, but also contains small and medium sized neurons. It gives rise to the lateral (medullary) reticulospinal tract which influences muscle tone of limb and trunk muscles, is involved in coordination of head-eye movements, promotes parasympathetic reduction of heart rate to decrease blood pressure, induces inspiration, and participates in the descending pain-inhibiting pathway. Anatomy Afferents It receives connections from the periaqueductal gray, the paraventricular hypothalamic nucleus, central nucleus of the amygdala, lateral hypothalamic area, and parvocellular reticular nucleus. It receives afferent corticoreticular fibers from the premotor cortex and supplementary motor area which modulate the activity of reticulospinal and reticul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
