The trochlear nerve is the fourth cranial nerve (CN IV). It is a motor nerve that solely innervates the superior oblique muscle of the eye. This muscle allows the eye to: Rotate internally (intorsion) Move downwards (depression) Rotate laterally (abduction) The trochlear nerve is a...
Neurons are the fundamental cells of the brain and nervous system. They are responsible for receiving the input from the senses and relaying this information to the brain where it is interpreted so a response is formed. This response is then sent back through different...
The ninth cranial nerve (CN IX) is the glossopharyngeal nerve. This nerve is a mixed nerve which means that it receives sensory information and is able to send motor information. The functions of this nerve are as follows: It receives afferent sensory information from the...
The central sulcus is a prominent sulcus in the brain. This is a groove in the cerebral cortex that separates the frontal lobes from the parietal lobes. This structure is also known as the central fissure, the fissure of Rolando, or the Rolandic fissure.
The brain is one of the most complex organs in the human body. It contains about 14-16 billion neurons that control most of the activities of the body and process the information given to them by the senses. The brain consists of a few structures:...
The auxiliary respiratory muscles include the scalene, the sternocleidomastoid, the pectoralis major, the trapezius, and the external intercostals. The scalene muscles are located in the neck, and they can be divided into three muscles: Anterior scalene: this muscle lies deep in the neck behind the...