The dorsal thalamus, usually simply referred to as the thalamus is a subdivision of a brain area called the diencephalon, which also includes the eptithalamus, the ventral thalamus and the subthalamic thalamus. Show
 Vertical section of a human brain. showing the medulla, pons, cerebellum, hypothalamus, thalamus, midbrain. Image Copyright: Designua / Shutterstock The thalamus relays sensory impulses from receptors in various parts of the body to the cerebral cortex. A sensory impulse travels from the body surface towards the thalamus, which receives it as a sensation. This sensation is then passed onto the cerebral cortex for interpretation as touch, pain or temperature. The prevailing opinion among experts is that the thalamus serves as a kind of “gate,” filtering which information from various channels is allowed to be relayed by it for processing. Detailed research has shown that specific thalamic neurons can modulate informational transfer by employing specific discharge modes. Furthermore, the thalamus is crucial for perception, with 98% of all sensory input being relayed by it. The only sensory information that is not relayed by the thalamus into the cerebral cortex is information related to smell (olfaction). 2-Minute Neuroscience: The ThalamusPlay Thalamic nucleiThe thalamus is made up of three distinct groups of cells or nuclei and these include the following:
Aside from olfaction, in all sensory processing, a sensory signal is received by a thalamic nucleus and then directed to the relevant cortical area. The involvement of thalamic nuclei in sensory systemsIn the visual system, the thalamus receives input from the retina, which is relayed to the brain via the optic nerve. Signals are sent to the lateral geniculate nucleus of the thalamus which then forwards them onto the primary visual cortex (area V1) in the occipital lobe. The thalamus not only relays the information but also processes it, as each of the primary sensory relay areas receives information back from the cerebral cortex (called back projections). On the other hand, the medial geniculate nuclei relay auditory information between the inferior colliculus of the midbrain and the primary auditory cortex. The thalamus is also important for touch - the ventral posterior nuclei relay information regarding touch and perception of bodily position to the primary somatosensory cortex in the cerebral cortex. In addition, the thalamic nuclei are strongly and reciprocally linked with the cerebral cortex. These form the thalamo-cortico-thalamic circuits which are thought to regulate consciousness and the thalamus plays a significant role in arousal, wakefulness and alertness. Damage to the thalamus is associated with a significant risk of coma. Your thalamus is your body’s information relay station. All information from your body’s senses (except smell) must be processed through your thalamus before being sent to your brain’s cerebral cortex for interpretation. Your thalamus also plays a role in sleep, wakefulness, consciousness, learning and memory.
OverviewWhat is the thalamus?Your thalamus is an egg-shaped structure in the middle of your brain. It’s known as a relay station of all incoming motor (movement) and sensory information — hearing, taste, sight and touch (but not smell) — from your body to your brain. Like a relay or train station, all information must first pass through your thalamus before being routed or directed to its destination in your brain’s cerebral cortex (the outermost layer of your brain) for further processing and interpretation. FunctionWhat does the thalamus do?Your thalamus has many functions, including:
Your thalamus also contributes to perception and plays a role in sleep and wakefulness. How does your thalamus work?Sensory impulses (“information”) travel through nerve fibers from your body through brain structures to your thalamus. Specialized areas of your thalamus, called nuclei, are each responsible for processing different sensory or motor impulses received from your body and then sending the selected information through nerve fibers to the related area of your cerebral cortex for interpretation. This chart names some of the best known nuclei, their function and to what area of your cerebral cortex the information is ultimately sent. NucleusSuspected function/roleCommunicates with what section of your cerebral cortexAnterior nucleusMemory, emotions, behavior regulationConnected to the hypothalamus; projects to the cingulate gyrusDorsomedial nucleusEmotional behavior and memory; attention, organization, planning and higher cognitive thinkingProjects to the prefrontal cortex and limbic systemVentral posterolateral nucleusRelay sensory information (pain, temperature and touch)Projects to the somatosensory cortexVentral posteromedial nucleusRelay sensory information from the faceProjects to the somatosensory cortexVentral anterior nucleusRelay motor information about movement/tremorProject to the substantia nigra, premotor cortex, reticular formulation and corpus striatumVentrolateral nucleusRelay motor informationProject to the substantia nigra, premotor cortex, reticular formulation and corpus striatumLateral posterior nucleusCognitive, determine prominent visual stimuliProjects to the visual cortexPulvinar nucleusProcess visual informationProjects to the visual cortexMedial geniculate nucleusProcess auditory informationPrimary auditory cortexLateral geniculate nucleusProcess visual informationVisual cortexReticular nucleusMakes up the outer covering of the thalamus; influences the activity of other nuclei within the thalamusDoesn’t project to the cerebral cortexAnatomyWhere is the thalamus located?Your thalamus lies above your brainstem in the middle of your brain. Although it may look like a single structure, you actually have two, side-by-side thalami, one in each hemisphere (side) of your brain. Being located in this central area — like the central hub on a bike wheel — allows nerve fibers connections (like the bike wheel’s spokes) to reach all areas of your cerebral cortex (the outer layer of your brain). Technically, your thalamus is part of an area of your brain called the diencephalon, which includes your hypothalamus, subthalamus and epithalamus. Conditions and DisordersWhat happens if my thalamus is damaged?Your thalamus is a central relay station for receiving incoming sensory and motor information. Your thalamus then sends this information to other parts of your brain. So, damage to your thalamus can affect many functions. Symptoms of damage to your thalamus include:
Damage to your thalamus can result in:
The main causes of damage to your thalamus include:
What conditions affect the thalamus?Certain conditions that are affected by or damage your thalamus include:
CareIs the thalamus a target for any treatment?The ventral intermediate nucleus of your thalamus is a target for deep brain stimulation for people with Parkinson’s disease that hasn’t been successfully treated with medications. A note from Cleveland Clinic Your thalamus serves as the main relay station for your brain. All motor and sensory signals (except smell) pass through this structure in the center of your brain. Your thalamus is arranged in regions, called nuclei, that each possesses specialization for dealing with that particular information. For example, information coming through your eye travels to your retina, and then onto your optic nerve. It then travels to the lateral geniculate nucleus of your thalamus, which processes the information and sends it to your primary visual cortex for interpretation. The signals are then passed onto your cerebral cortex for interpretation. Your thalamus also plays a role in regulating sleep and wakefulness, and is involved with consciousness. Share Email Print Last reviewed by a Cleveland Clinic medical professional on 03/30/2022. References
Get useful, helpful and relevant health + wellness information enews Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy Related Institutes & ServicesNeurological InstituteThe Neurological Institute is a leader in treating and researching the most complex neurological disorders and advancing innovations in neurology. Related Institutes & ServicesNeurological InstituteThe Neurological Institute is a leader in treating and researching the most complex neurological disorders and advancing innovations in neurology. More health news + info
Facebook Twitter YouTube Instagram LinkedIn Pinterest Snapchat ActionsAppointments & AccessAccepted InsuranceEvents CalendarFinancial AssistanceGive to Cleveland ClinicPay Your Bill OnlineRefer a PatientPhone DirectoryVirtual Second OpinionsVirtual VisitsBlog, News & AppsConsult QDHealth EssentialsNewsroomMyClevelandClinicMyChartAbout Cleveland Clinic100 Years of Cleveland ClinicAbout UsLocationsQuality & Patient SafetyOffice of Diversity & InclusionPatient ExperienceResearch & InnovationsCommunity CommitmentCareersFor EmployeesResources for Medical ProfessionalsSite Information & PoliciesSend Us FeedbackSite MapAbout this WebsiteCopyright, Reprint & LicensingWebsite Terms of UsePrivacy PolicyNotice of Privacy PracticesNon-Discrimination Notice9500 Euclid Avenue, Cleveland, Ohio 44195 | 800.223.2273 | © 2023 Cleveland Clinic. All Rights Reserved. Is unique among the senses in that it can bypass the thalamus?Smell bypasses the thalamus, which Dalton calls the 'consciousness detector. ' “(It goes) directly to the primary olfactory cortex, and that may be why we experience odors in a different way than we do other kinds of sensory stimuli,” Dalton said.
What is one sense that bypasses the thalamus quizlet?Smell/ Olfactory Bulb. The only sense that completely bypasses the thalamus is the sense of smell.
When an object blocks our view of a second object we see the second object as more distant?Interposition is a monocular cue that occurs when one object obscures another, which causes the object that is partially covered to appear more distant. Because we only see part of what we expect, we interpret the object that is partially covered as being further away.
Who found that difference thresholds reflect ratios rather than absolute amounts?To quantify the difference threshold, psycho-physicist Ernst Weber developed what is known as the Weber's Law. Weber's Law states that rather than a constant, absolute amount of change, there must be a constant percentage change for two stimuli to be perceived as different.
|
What is unique among the senses in its pathway does not include the thalamus?
zusammenhängende Posts
Urheberrechte © © 2024 ketiadaan Inc.
