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Parvocellular Reticular Nucleus
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] |
Brain
The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for special senses such as visual perception, vision, hearing, and olfaction. Being the most specialized organ, it is responsible for receiving information from the sensory nervous system, processing that information (thought, cognition, and intelligence) and the coordination of motor control (muscle activity and endocrine system). While invertebrate brains arise from paired segmental ganglia (each of which is only responsible for the respective segmentation (biology), body segment) of the ventral nerve cord, vertebrate brains develop axially from the midline dorsal nerve cord as a brain vesicle, vesicular enlargement at the rostral (anatomical term), rostral end of the neural tube, with centralized control over all body segments. All vertebr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudal Pontine Reticular Nucleus
The caudal pontine reticular nucleus or nucleus reticularis pontis caudalis is a portion of the reticular formation, composed of gigantocellular neurons. In rabbits and cats it is exclusively giant cells, however in humans there are normally sized cells as well. In rodents, it has been shown to play a role in the acoustic startle response. The caudal pontine reticular nucleus is rostral to the gigantocellular reticular nucleus and is located in the caudal pons. The caudal pontine reticular nucleus has been known to mediate head movement, in concert with the gigantocellular nucleus and the superior colliculus. The neurons in the dorsal half of this nucleus fire rhythmically during mastication, and in an anesthetized animal it is possible to induce mastication via electrical stimulation of the nucleus reticularis pontis caudalis or adjacent areas of the gigantocellular nucleus.Scott G, Effect of lidocaine and NMDA injections into the medial pontobulbar reticular formation on ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesencephalic Trigeminal Nucleus
The mesencephalic nucleus of trigeminal nerve is one of the sensory nuclei of the trigeminal nerve (cranial nerve V). It is located in the brainstem. It receives proprioceptive sensory information from the muscles of mastication and other muscles of the head and neck. It is involved in processing information about the position of the jaw/teeth. It is functionally responsible for preventing excessive biting that may damage the dentition, regulating tooth pain perception, and mediating the jaw jerk reflex (by means of projecting to the motor nucleus of the trigeminal nerve). The axons of the neuron cell bodies of this nucleus provide sensory innervation to target tissues directly, whereas other sensory nuclei of the trigeminal nerve receive their sensory inputs by synapsing with primary sensory neurons in the trigeminal ganglion. Anatomy The MNTN is located in the brainstem, more specifically (sources vary) spanning the length of the midbrain/in the caudal midbrain and rostral p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Facial Nucleus
The facial motor nucleus is a collection of neurons in the brainstem that belong to the facial nerve ( cranial nerve VII). These lower motor neurons innervate the muscles of facial expression and the stapedius. Structure The nucleus is situated in the caudal portion of the ventrolateral pontine tegmentum. Its axons take an unusual course, traveling dorsally and looping around the abducens nucleus, then traveling ventrally to exit the ventral pons medial to the spinal trigeminal nucleus. These axons form the motor component of the facial nerve, with parasympathetic and sensory components forming the intermediate nerve. The nucleus has a dorsal and ventral region, with neurons in the dorsal region innervating muscles of the upper face and neurons in the ventral region innervating muscles of the lower face. Function Because it innervates muscles derived from pharyngeal arches, the facial motor nucleus is considered part of the special visceral efferent (SVE) cell column, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypoglossal Nucleus
The hypoglossal nucleus is a cranial nerve nucleus, found within the medulla. Being a motor nucleus, it is close to the midline. In the open medulla, it is visible as what is known as the '' hypoglossal trigone'', a raised area (medial to the vagal trigone) protruding slightly into the fourth ventricle. The hypoglossal nucleus is located between the dorsal motor nucleus of the vagus and the midline of the medulla. Axons from the hypoglossal nucleus pass anteriorly through the medulla forming the hypoglossal nerve which exits between the pyramid and olive in a groove called the anterolateral sulcus. See also * Hypoglossal nerve Additional images File:Gray695.png, Transverse section of medulla oblongata below the middle of the olive. File:Gray697.png, Nuclei of origin of cranial motor nerves schematically represented; lateral view. File:Medulla_oblongata_-_posterior_-_very_low_mag.jpg, Micrograph showing the hypoglossal nuclei in relation to their surrounding structures. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parabrachial Area
The parabrachial nuclei, also known as the parabrachial complex, are a group of nuclei in the dorsolateral pons that surrounds the superior cerebellar peduncle as it enters the brainstem from the cerebellum. They are named from the Latin term for the superior cerebellar peduncle, the ''brachium conjunctivum''. In the human brain, the expansion of the superior cerebellar peduncle expands the parabrachial nuclei, which form a thin strip of grey matter over most of the peduncle. The parabrachial nuclei are typically divided along the lines suggested by Baxter and Olszewski in humans, into a medial parabrachial nucleus and lateral parabrachial nucleus. These have in turn been subdivided into a dozen subnuclei: the superior, dorsal, ventral, internal, external and extreme lateral subnuclei; the lateral crescent and subparabrachial nucleus (Kolliker-Fuse nucleus) along the ventrolateral margin of the lateral parabrachial complex; and the medial and external medial subnuclei Anatomy ... [...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] |
Gigantocellular Nucleus
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] |
