Categories
Uncategorized

Thalamus

1590

The large mass of gray matter in the dorsal part of the diencephalon of the brain.

Has several functions such as relaying of sensory signals, including motor signals, to the cerebral cortex, and the regulation of consciousness, sleep, and alertness.

The thalamus is a midline symmetrical structure of two halves, within the brain, situated between the cerebral cortex and the midbrain.

A paired grey matter structure located in the forebrain which is superior to the midbrain, near the center of the brain, with nerve fibers projecting out to the cerebral cortex in all directions.

The medial surface of the thalamus is the upper part of the lateral wall of the third ventricle, and is connected to the corresponding surface of the opposite thalamus the interthalamic adhesion band.

The lateral part of the thalamus includes the lateral nuclei, the pulvinar and the medial and lateral geniculate nuclei.

It derives its blood supply from branches of the posterior cerebral artery, including: the posterior communicating artery, paramedian thalamic-subthalamic arteries, inferolateral arteries, and posterior arteries.

The thalamus is composed of the hypothalamus, epithalamus, the ventral thalamus, dorsal thalamus, and metathalamus.

The thalamus is connected to the spinal cord by the spinothalamic tract, and has many connections to the hippocampus via the mammillothalamic tract, this tract comprises the mammillary bodies and fornix.

The mammillothalamic tract is comprised of the mammillary bodies and fornix.

It is connected to the cerebral cortex via the thalamocortical radiations.

The spinothalamic tract originates in the spinal cord and is a sensory pathway transmitting information to the thalamus about pain, temperature, itch and crude touch.

There are two main parts to the spinothalamic tract.

The lateral spinothalamic tract, transmits pain and temperature.

The anterior spinothalamic tract, transmits crude touch and pressure.

It acts as a relay station, relaying information between different subcortical areas and the cerebral cortex.

All sensory systems, with the exception of the olfactory system, includes a thalamic nucleus that receives sensory signals and sends them to the associated primary cortical area.

Inputs from the retina are sent to the lateral geniculate nucleus of the thalamus, projecting information to the visual cortex in the occipital lobe.

The thalamus both processes sensory information as well as relays it.

The primary sensory relay areas receive feedback connections from the cerebral cortex.

It helps regulate states of sleep and wakefulness.

Thalamic nuclei have strong reciprocal connections with the cerebral cortex, involved with consciousness.

It plays a major role in regulating arousal, the level of awareness, and activity.

Thalamic damage can lead to permanent coma.

A common genetic variation in the promotor region of the serotonin transporter affects the development of several regions of the thalamus in adults.

People who inherit two short alleles (SERT-ss) have more neurons and a larger volume in regions of the thalamus, and are more vulnerable to major depression, posttraumatic stress disorder, and suicide.

The thalamic pain syndrome refers to a one-sided burning or aching sensation often accompanied by mood swings may be a result of a stroke.

Bilateral ischemia of the area supplied by the paramedian artery can cause serious problems including akinetic mutism, and be accompanied by oculomotor problems.

Korsakoff syndrome stems from damage to the mammillary body, the mammillothalamic fasciculus or the thalamus.

Leave a Reply

Your email address will not be published. Required fields are marked *