The superior colliculi play an important role in the visual pathway, while the inferior colliculi are important in the auditory pathway. Each quadrigeminal body is related to a bundle of nerve fibres called the brachium.
What is the difference between superior and inferior colliculus?
The inferior and superior colliculi are known collectively as the corpora quadrigemina (Latin for quadruplet bodies). The superior colliculi are larger than the inferior colliculi, though the inferior colliculi are more prominent.
What is the role of the superior colliculi?
The superior colliculus (SC) is a midbrain area where visual, auditory and somatosensory information are integrated to initiate motor commands. The SC plays a central role in visual information processing in the mouse; it receives projections from 85% to 90% of the retinal ganglion cells (RGCs).
What is the function of inferior colliculi?
Almost all ascending and descending auditory pathways between the brain stem and forebrain synapse within the inferior colliculus. Principal functions of the inferior colliculus involve sound localization, frequency determination, and integration of auditory with nonauditory systems.
What are the 2 functions of pons?
The pons helps to regulate the respiratory system by assisting the medulla oblongata in controlling breathing rate. The pons is also involved in the control of sleep cycles and the regulation of deep sleep. The pons activates inhibitory centers in the medulla in order to inhibit movement during sleep.
What sensory systems are the superior and inferior colliculi associated with?
The superior and inferior colliculi (Figure 1.12) are involved in visual and auditory functions respectively.
Where are colliculus found?
There are two superior colliculi in the midbrain. They are symmetrically positioned, one on either side of the midline of the brainstem; they form two bumps on the posterior external surface of the brainstem. The superior colliculi are just below the thalamus and above the two inferior colliculi.
What happens if the superior colliculus is damaged?
Direct damage to the superior colliculus has been tested in rhesus monkeys as well as rats and has resulted in clinical manifestations. Researchers found that the monkeys with damage to the superior colliculus to have visual deficits as well as impairments in gaze shifts.
What reflexes are controlled by the inferior colliculi?
Inferior colliculi act as auditory relays from hearing receptors to the sensory cortex. They help react reflexively to sounds, such as in the startle reflex. A way to remember this is to note that the eyes are superior to the ears. The oculomotor nerve (CN III) exits the midbrain ventrally in the middle.
Why is pons called bridge?
Pons is Latin for “bridge”; the structure was given its name by the Italian anatomist Costanzo Varolio, who thought that the most conspicuous portion of the pons resembled a bridge that connected the two cerebellar hemispheres.
What are pons responsible?
The pons, while involved in the regulation of functions carried out by the cranial nerves it houses, works together with the medulla oblongata to serve an especially critical role in generating the respiratory rhythm of breathing. Active functioning of the pons may also be fundamental to rapid eye movement (REM) sleep.
What is the Pontine?
Listen to pronunciation. (PON-teen) Having to do with the pons (part of the central nervous system, located at the base of the brain, between the medulla oblongata and the midbrain).
