Hindi, asked by tgrasp28, 1 year ago

write a short note on midbrain

Answers

Answered by vishal3316
2
STRUCTURE OF MID BRAIN

The midbrain comprises the tectum,tegmentum, the cerebral aqueduct, and thecerebral peduncles, as well as several nuclei and fasciculi. Caudally the midbrain adjoins the metencephalon (afterbrain) (pons andcerebellum). Rostrally it adjoins thediencephalon (thalamus, hypothalamus, etc.).[4]

Specifically, the midbrain consists of:

TectumEdit

Inferior colliculiSuperior colliculi

Medial and lateral pathways of tectumEdit

The medial descending pathway comprises the vestibulospinal tracts (lateral and medial tracts with control from thecerebellum), reticulospinal tract, and thetectospinal tract. These tracts run through the medial reticular formation, the lateral and medial vestibular nuclei.[5] These tracts extend rostrally and caudally of the tectum. The vestibulospinal tracts; the medial tract originate in the medial and inferior vestibular nuclei moving caudally to theanterior funiculus controlling muscle tone, while the lateral tract originates from lateral vestibular nuclei also referred to as Deiters' nucleus named after Otto Deiters (1834–1863). The reticulospinal tract consists of dense cortical neurons which direct motor input as the tract terminates sequentially down the spine. The tectospinal tract provides stability and posture control.The lateral descending pathway consists of the rubrospinal tract originating from thered nucleus responsible for voluntary motor movement, and partially of the lateral corticospinal tract as this tract does not originate or terminate in the tectum but does play a critical role with afferent and efferent motor control along sidetone rubrospinal tract of the tectum.

FUNCTIONS:::::

The mesencephalon is considered part of thebrainstem. Its substantia nigra is closely associated with motor system PATHWAYS of the basal ganglia. The human mesencephalon is archipallian in origin, meaning that its general architecture is shared with the most ancient of vertebrates.Dopamine produced in the substantia nigraand ventral tegmental area plays a role in excitation, motivation and habituation of species from humans to the most elementary animals such as insects. Laboratory house mice from lines that have been selectively bred for high voluntary wheel running have enlarged midbrains.[15] The midbrain helps to relay information for vision and hearing.
Answered by varshadakhle
13
Hi.


here is your answer. .



MIDBRAIN; -- Midbrain is a middle part of the brain present between diancephalon and ppns virolli.A narrow passage called Iter runs through it's length and connects 3rd ventricle to 4th It consists of corpora quadrigemina is formed by 2 pairs of lobes present in dorsal thick wall of midbrain.



Upper pair called superior colliculi control and coordinate movement of head in response to the visual stimulas Crura ceribra is a pair of thick band of anterior longitudinal nerve fibres.



hope it helps you ☺
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