Hypothalamospinal tract | |
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Details | |
Identifiers | |
Latin | tractus hypothalamospinalis |
TA98 | A14.1.05.329 |
TA2 | 6098 |
FMA | 77482 |
Anatomical terminology |
The hypothalamospinal tract is a nerve tract that arises mainly from the paraventricular nucleus of hypothalamus, and lateral and posterior areas of the hypothalamus. The tract descends through the periaqueductal gray and adjacent reticular formation. [1] It is found in the dorsolateral quadrant of the lateral funiculus, in the lateral tegmentum of the medulla, pons and midbrain. [2]
The hypothalamospinal tract includes fibres by which the hypothalamus projects to the ciliospinal center in the spinal cord, a part of a brain circuit regulating pupillary dilatation as part of the pupillary reflex. [3]
Lesions of the hypothalamospinal tract cause ipsilateral Horner's syndrome. [2]
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 part of the diencephalon. All vertebrate brains contain a hypothalamus. In humans, it is the size of an almond.
The brainstem is the stalk-like part of the brain that interconnects the cerebrum and diencephalon with the spinal cord. In the human brain the brainstem is composed of the midbrain, the pons, and the medulla oblongata. The midbrain is continuous with the thalamus of the diencephalon through the tentorial notch.
In neuroanatomy, a nucleus is a cluster of neurons in the central nervous system, located deep within the cerebral hemispheres and brainstem. The neurons in one nucleus usually have roughly similar connections and functions. Nuclei are connected to other nuclei by tracts, the bundles (fascicles) of axons extending from the cell bodies. A nucleus is one of the two most common forms of nerve cell organization, the other being layered structures such as the cerebral cortex or cerebellar cortex. In anatomical sections, a nucleus shows up as a region of gray matter, often bordered by white matter. The vertebrate brain contains hundreds of distinguishable nuclei, varying widely in shape and size. A nucleus may itself have a complex internal structure, with multiple types of neurons arranged in clumps (subnuclei) or layers.
The pyramidal tracts include both the corticobulbar tract and the corticospinal tract. These are aggregations of efferent nerve fibers from the upper motor neurons that travel from the cerebral cortex and terminate either in the brainstem (corticobulbar) or spinal cord (corticospinal) and are involved in the control of motor functions of the body.
The solitary nucleus is a series of sensory nuclei forming a vertical column of grey matter in the medulla oblongata of the brainstem. It receives general visceral and/or special visceral inputs from the facial nerve, glossopharyngeal nerve and vagus nerve ; it receives and relays stimuli related to taste and visceral sensation. It sends outputs to various parts of the brain. Neuron cell bodies of the SN are roughly somatotopically arranged along its length according to function.
In neuroanatomy, the optic tract is a part of the visual system in the brain. It is a continuation of the optic nerve that relays information from the optic chiasm to the ipsilateral lateral geniculate nucleus (LGN), pretectal nuclei, and superior colliculus.
In neuroanatomy, the pretectal area, or pretectum, is a midbrain structure composed of seven nuclei and comprises part of the subcortical visual system. Through reciprocal bilateral projections from the retina, it is involved primarily in mediating behavioral responses to acute changes in ambient light such as the pupillary light reflex, the optokinetic reflex, and temporary changes to the circadian rhythm. In addition to the pretectum's role in the visual system, the anterior pretectal nucleus has been found to mediate somatosensory and nociceptive information.
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.
The rubrospinal tract is a part of the nervous system. It is a part of the lateral indirect extra-pyramidal tract.
The Edinger–Westphal nucleus is one of two nuclei of the oculomotor nerve. It is located in the midbrain. It receives afferents from the both pretectal nuclei. It contains parasympathetic pre-ganglionic neuron cell bodies that synapse in the ciliary ganglion. It contributes the autonomic, parasympathetic component to the oculomotor nerve, ultimately providing innervation to the iris sphincter muscle and ciliary muscle to mediate the pupillary light reflex and accommodation, respectively.
The posterior nucleus of the hypothalamus is one of the many nuclei that make up the hypothalamic region of the brain.
The nucleus raphe magnus is one of the seven raphe nuclei. It is situated in the pons in the brainstem, just rostral to the nucleus raphe obscurus.
The internal carotid plexus is a nerve plexus situated upon the lateral side of the internal carotid artery. It is composed of post-ganglionic sympathetic fibres which have synapsed at the superior cervical ganglion. The plexus gives rise to the deep petrosal nerve.
The sympathetic trunks are a paired bundle of nerve fibers that run from the base of the skull to the coccyx. They are a major component of the sympathetic nervous system.
The mammillothalamic tract is an efferent pathway of the mammillary body which projects to the anterior nuclei of thalamus. It consists of heavily myelinated fibres. It is part of a brain circuit involved in spatial memory.
The primary olfactory cortex (POC) is a portion of the cerebral cortex. It is found in the inferior part of the temporal lobe of the brain. It receives input from the olfactory tract. It is involved in the sense of smell (olfaction).
In evolutionary psychology, people often speak of the four Fs which are said to be the four basic and most primal drives that animals are evolutionarily adapted to have, follow, and achieve: fighting, fleeing, feeding and mating.
The basilar part of pons, also known as basis pontis, is the ventral part of the pons; the dorsal part is known as the pontine tegmentum.
The ciliospinal center is a cluster of pre-ganglionic sympathetic neuron cell bodies located in the intermediolateral cell column of the spinal cord at the (C8) T1-T2 spinal levels.
The visual pathway consists of structures that carry visual information from the retina to the brain. Lesions in that pathway cause a variety of visual field defects. In the visual system of human eye, the visual information processed by retinal photoreceptor cells travel in the following way:
Retina→Optic nerve→Optic chiasma →Optic tract→Lateral geniculate body→Optic radiation→Primary visual cortex