Cranial Nerves

An ignorant thing to say is “forget the old and focus on the new.” Civilization has set forth the belief that when something is old and non-civilized, then it has no use. Nowadays, human beings are looking for modern and industrialized ways to teach themselves or get information into the brain without focusing on the brain itself. It is true that the human brain has greatly evolved to the point where human beings can produce all kinds of machines, but at the same time, they still rely on the primitive brain to make basic decisions like eating or sleeping. The primitive brain is at the lowest part of the brain, just above the spinal cord, and its functions is to regulate vital body functions such respiration and it also sends sensory information

The human brain is an amazing device. It controls everything we do. It controls our bodies, how we communicate, how we function. Our brains our

Next, is the nerve that is used for vision and that is Optic Nerve II. The third cranial nerve is the Oculomotor Nerve III, which allows movement of the eye in several directions including up, down, up and inward. In addition, this nerve controls the pupil. Next, is the Trochlear Nerve IV. This nerve moves the eyes in a down and inward movement.

There are 12 Cranial Nerves which all serve a very important purpose within each and every one of our bodies. The twelve cranial nerves are Olfactory, Optic, Oculomotor, Trochlear, Trigeminal, Abducens, Facial, Vestibulocochlear, Glossopharyngeal, Vagus, Accessory, and last but certain not least Hypoglossal. Each nerve plays a different role for example the Olfactory nerve gives sense to smell, and the Optic nerve gives us sense of vision. The Oculomotor give us the motor skills to adjust the size of our pupils, raise our eyelids, etc. This particular nerve is also parasympathetic to the pupil, which causes accommodation as well as constriction. Another nerve that has to do with our motor skills is the Trochlear nerve, which allows the eye

* The sixth cranial nerve is responsible for movement of the eyes, and when it malfunctions, serious problems with the eyes can occur.

Cranial Nerve II (Occipital nerve) is also sensory and conveys visual input. Cranial Nerve III (Oculomotor), IV (Trochlear) and VI (Abducens) control eye movement. Nerves III ,IV and VI are motor types of nerves. The oculomotor nerve (III) moves the eye and raises the eyelids as well as adjusts the lens and pupils of the eye. The Trochlear nerve (IV) controls the movement of the eyeball. The Abducens nerve (VI) moves the eyeballs outward. Cranial Nerve V (Trigeminal) is mixed (a mix of motor and sensory) and is divided into 3 parts: ophthalmic, maxillary and mandibular. This nerve controls the muscles of the face associated with chewing. Cranial Nerve V also controls feelings of the skin including pain and temperature. Cranial Nerve VII (Facial) is also mixed and controls facial movements. The facial nerve also controls saliva and tear

The fifth cranial nerve out of 12 is known as the trigeminal nerve. Cranial nerves are located in the brain and each have a different function. The trigeminal nerve is located in between the oculomotor nerve and the facial nerve. The trigeminal nerve performs sensor functions that involve the teeth, tongue, nose, and eyes and is covered by a myelin sheath. A myelin sheath is the protective coating that is usually found around nerves. Trigeminal neuralgia also known as TN, is a painful disease that affects the trigeminal nerve. The disorder causes severe, sporadic, sudden burning or shock-like face pain that can last as short as a few seconds to as long as two minutes per episode of pain. Patients suffering from the disorder may sometimes

-Our skull helps protect the brain, which is one of the biggest parts of our nervous system

The central nervous system consist of the brain and spinal cord. The brain plays a crucial role and is a significant function of the nervous system by using information from our senses to tell us what is going on around us, and how we should respond. Although, the brain has an essential purpose it is my belief that the spinal cord is the most important. It’s the center of many spinal reflexes, and can participate in reflex actions without checking with the brain. The spinal cord communicates with the brain it sends messages if damaged it can affect other body functions such as breathing, hormone release, body temperature, bowel and bladder, movement of food through the stomach and intestines. Messages, touch, transmitting pain movement, joints,

Cnidarians do not have a central nervous system (no local concentration of nerve cells, no brain), but the anemones simple differentiated nervous system works much the same. Arrangements of nerve cells within a loose network called nerve nets process and respond to stimuli much like a brain would. For example, in response to stimuli, nerve cells emit electrical impulses through the nerve net to all parts of the anemone’s body, causing contractions in the anemone’s muscles. The result is movement.

Cranial nerve assessment is the technique of assessing twelve cranial nerve. This assessment helps to find out the normal cranial nerve functioning, any deviations, or abnormalities. It is important that we should have good knowledge and skill for caring the patient with neurological abnormalities or neurological disorder. Cranial nerve examination involves a number of steps. The nurse should know which nerve is tested next and what test must perform for that nerve. During these procedures, the teacher faces several difficulties, this process of demonstration may not be effective if the teacher is not resourceful, if there is no adequate supply of articles required, if the demonstration is not lively or due to time constraints, are the examples

The optic nerve is the second cranial nerve (CN II) in the eye which is tasked to transfer visual information in the form of electrical impulses from the retina to the brain for interpretation. Typically, a human optic nerve is around 0.3-0.4mm in diameter and is protected by a nerve sheath, is surrounded by cerebrospinal fluid (CSF). Visual acuity and contrast sensitivity are two highly important functions that the optic nerve specialises in, and as a result, are the common issues affected by ON. Damage to the optic nerve inhibits proper functioning at the optic chiasm which, depending on the damage, causes specific problems depending on the extent of damage. Patients with MS are often revealed to develop ON as their first symptom. MS is a common central nervous system (CNS) disease that develops through issues relating to inflammatory demyelinating white matter lesions. There have been suggestions that the onset of ON is immune-mediated; activated T cells release cytokines as well as other inflammatory mediators when migrating across the blood-brain barrier and essentially degrade the axons around the optic nerve causing cell death, and thus leading to impaired visual functioning. 

The Trochlear Nerve (Cranial Nerve IV) is the longest and thinnest nerve emerging from the central nervous system, more specifically the dorsal aspect of the Midbrain, its nucleus is located just below the Oculomotor Nucleus (Cr. III) at the level of the inferior colliculus, its fibers arc around the periaqueductal grey matter, decussate before exiting the midbrain on its dorsal aspect by piercing the superior medullary vellum, goes around its dorsum, passing between the cerebral peduncles and the temporal lobe; then it courses between the Superior and Posterior Cerebral Arteries (SCA, PCA), pierces the dura just beneath the free edge of the Tentorium cerebelli behind the posterior clinoid process, enters the cavernous sinus and runs through its lateral wall above the ophthalmic nerve and below the oculomotor nerve, before exiting the cavernous sinus it positions above the oculomotor nerve and enters the superior orbital fissure lateral to its common tendinous ring, passes above the superior elevator palpebral(1,2,3) muscle attaching to the superior

The human brain is a mystery that has been studied for centuries in attempt to understand how it functions. Scientists first thought that the brain was a structure that functioned a whole. It was in the early 1600’s where the first ideas of localisation of function in the brain started. At this time Rene Descartes discovered a tiny structure called the pineal

     One of the most complex and fascinating things in the human body is the brain. The body is “capable of almost everything, but it would not be possible, without the brain receiving information, and analyzing the information.”