Question

What is corpora quadrigemina?

Answer 1

Hint: Have you ever wondered why you react to a rapid flash of light, a startling sound, or when someone calls your name by looking in that direction? Even if you do these things a dozen times a day, they are so automatic and frequent that you don't notice them. Four very little swellings at the rear of your brainstem are responsible for these reflexive movements. The corpora quadrigemina is their collective name. These structures will be described in this article, with a focus on their afferent and efferent connections, as well as their functions.

Complete answer:
The midbrain contains the corpora quadrigemina. The quadrigeminal plate on the posterior surface of the midbrain houses the four colliculi, two inferior and two superior. Auditory and visual reflexes are controlled by them. The superior colliculi are responsible for visual processing and eye movement control, while the inferior colliculi are responsible for auditory processing.
The corpora quadrigemina is a crucial component of the mammalian midbrain. It's on the dorsal side of the brain, and it's usually entirely obscured by the larger cerebral hemispheres.
The Latin phrase for the quadruple bodies, sometimes known as the colliculi, is corpora quadrigemina. These spherical eminences are found on the midbrain's posterior surface, immediately behind the thalamus. There are two superior colliculi and two inferior colliculi, one on each side of the midline. The tectum, or tectal plate, refers to the entire region made up of the four colliculi. In the optical circuit, the superior colliculi are crucial, while the inferior colliculi are vital in the auditory system.
The brachium connects each triple body to a bundle of nerve fibres. The connection between the two superior colliculi, the lateral geniculate body, and the optic tract is established by the superior brachium. The inferior brachium connects the two inferior colliculi to the medial geniculate body, which leads to the auditory cortex. The geniculate bodies are a type of relay centre that helps with vision and hearing. They protrude posteriorly from the thalamus's pulvinar and contain sets of nuclei with the appropriate nomenclature.
Superior colliculi function:
Visual body reflexes are one of the most significant functions of the superior colliculi. Scanning while reading, shielding your eyes in bright regions, or tilting your head towards abrupt and unexpected visual stimulation are examples of automatic and involuntary actions.
The stimuli reach the superior colliculi through the visual pathway and are conveyed to the anterior grey column of the spinal cord and the motor nuclei of the cranial nerves through the tectospinal and tectobulbar tracts, respectively, during these reflexes.
Inferior colliculus function:
The reflex component of the auditory system is controlled by the inferior colliculi. Small efferent projections that go via the superior colliculi and interact with the tectospinal and tectobulbar tracts mediate this participation. The auditory reflex, like the visual ones, is reflexive and involuntary, allowing you to tilt your head toward unexpected audio stimuli like someone shouting your name or a loud noise.

Note:-
Progressive supranuclear palsy (PSP) is a degenerative brain illness that makes it difficult to move normally. Patients experience symptoms that are similar to Parkinson's disease, such as shaky gait and balance. Those who have PSP, unlike those who have Parkinson's disease, also experience visual impairments, which is a factor that is considered in making a differential diagnosis.