Image 1. Represents the different cranial nerves and their areas of innervation in the human being.
https://www.thoughtco.com/cranial-nerves-function-373179
Now, in the first instance we have:
Sensory nerve which has its actual origin in the telencephalon, and an apparent origin in the olfactory flow in the cribous lamina of the ethmoid bone, its function is to transmit the olfactory impulses. As we explored semiologically the smooth functioning of this pair in a simple way, we use a stimulus at the level of each nostril, with test odors such as soap, coffee, lemon flavor, to see if the patient is able to detect the smell and identify it correctly.
Image 2. Olfactory nerve.
http://antranik.org/peripheral-nervous-system-cranial-nerves/
Exclusively sensorial its real origin is in the Diencefalo and with its apparent origin in the Optical Hole. Function transmit the visual impulse to the brain.
His method of exploration is to sit in front of the patient (60-90 cm away) to ask him to cover one eye gently and with the other to look at our nose. A small white object (eg, a cotton swab) is then moved slowly from the periphery of the field to the center until the patient detects its presence, thus comparing the patient's visual field with the explored. Regulated campimetry and tangential screen examination are essential for identifying and delimiting small campimetric defects.
)Image 3. Optic nerve.
https://www.slideshare.net/irfanziad1/cranial-nerve-examination
III cranial nerve Oculomotor Nerve (the Common Ocular Motor Nerve).
Motor and parasympathic.
Real origin: interpenetrating fossa of the Mesencefalo. Apparent origin in the sphenoidal cleft. Its function is to innervate the muscles of the upper right upper eyelid, medial rectus, lower rectus and lower oblique muscle.
Pure engine.
Real origin in Mesencefalo. Apparent origin in the sphenoidal cleft. Its function is to innervate superior oblique muscle, which depresses, rotates laterally (around the optic axis) and rotates the eyeball in between.
Pure engine.
Apparent origin at the level of the sphenoid groove, whose function is to innervate the lateral rectus muscle which abducts the eyeball.
During the examination of these cranial nerves, the size, regularity and shape of the pupils should be described, as well as their direct and consensual reaction to light and ocular convergence (following an approaching object). if there is palpebral patosis, delayed closure or retraction. The patient will be asked to follow the explorer's finger as he or she moves it horizontally from right to left and vertically in each eye, first in complete adduction and then in complete abduction, thus verifying the inability or ability to perform complete movements of certain directions, as well as the presence of regular, rhythmic and involuntary oscillations of the eyes such as occurs in nystagmus, as well as rapid voluntary eye movements and pursuit of objects.
Image 4. Representation of 3, 4 and 6 cranial nerves.
http://accessmedicine.mhmedical.com/content.aspx?bookid=673§ionid=45395970
Mixed both sensitive and motor.
Its function is to perceive sensitive information of the face and to innervate the muscles of the mastication (mesetero-temporal muscle). Its exploration is quick and simple, it is necessary to feel the masseter and temporal muscles, asking the patient to bite, also to check the mandibular opening, the forward and lateral movement against a resistance. Sensitivity will be examined throughout the face as well as the response to the gentle contact of a small piece of cotton.
Image 5. fifth cranial nerve
http://droualb.faculty.mjc.edu/Lecture%20Notes/Unit%205/cranial_nerves%20Spring%202007%20with%20figures.htm
Therefore, motor and sensory with real origin in the angle of the cerebellum on the olive and apparent origin travels the internal auditory canal until the facial canal until the stylomastoid hole. Its function is the motor innervation of the muscles responsible for facial expression, it also receives sensory impulses from the anterior two-thirds of the tongue and provides secretive innervation of the salivary glands except for the parotid gland and also innervation of the lacrimal gland. It explores the asymmetry of the face at rest and with the spontaneous movements and those induced by emotions (such as laughing, annoying, happy, etc) will be checked the ability to raise the eyebrows, wrinkle the forehead, close your eyes, smile, frown frown, swollen cheeks, whistling, pursing lips and contracting the muscles of the chin. The taste of the anterior two-thirds of the tongue may be affected by injuries of the VII cranial nerve proximal to the tympanic cord, taste for the sweet (sugar), salty, acid (lemon) and bitter tastes, using a portion of cotton impregnated with solution of different flavors, placing it on the lateral edge while the patient pulls the tongue in the middle distance of the tip of the tongue.
Image 6. Seventh cranial nerve (facial nerve).
https://www.slideshare.net/ddert/150-cranial-nerves
Sensorial lateral real origin to the VII cranial pair by the pontocerebellous angle, apparent origin internal auditory canal. Its function is the perception of sound rotation and gravity (essential for balance) the vestibular branch carries impulse to coordinate the balance and the cochlear arm brings auditory impulse.
It explores the ability of hearing with the diapason, the click of the fingers, the ticking of the clock and the whispered voice at specific distances in each ear. The air conduction will be checked to the mastoid bone (Rinne) and lateralization of the noise of a diaposon by placing in the center of the front (weber).
Image 7. Eighth cranial nerve.
https://www.pinterest.com/pin/379498706072142350/
IX cranial nerve, glossopharyngeal.
Mixed origin real bulb rachid apparent origin jugular hole. Its function is to receive the gustatory impulses of the posterior third of the tongue and provides secretory-motor innervation to the parotid gland, innervation muscle,
Mixed real origin of the spinal bulb and apparent origin of the jugular foramen, its function is to innervate most of the laryngeal and pharyngeal muscles, exept the style of pharynx, and it carries parasympathetic fibers to the proximities of all the abdominal viscera. Below the splenic flexure and receives the sense of taste from the epiglottis.
These cranial nerves are explored by the symmetrical elevation of the uvula and palate during formation as well as the position of the uvulopalatine arch at rest. The pharyngus reflex is explored by stimulating both sides of the posterior wall of the pharynx with a rhombic object.
Mixed origin real roots spinal and cervical origin apparent jugular hole its function is control of sternocleidomastoid and trapezius muscles.
It is explored by asking the patient to shrug the shoulder (trapezius muscle) and rotating the head on each side (sternocleidomastoid muscle) against resistance.
Mixed its function is the motor innervation of the muscles of leengua except the palatoglossus and other lingual muscles important in the swallowing and to articulate the sound. This time the volume and strength of the tongue will be examined. The presence of atrophy, deviation of the midline when removing the tongue, trembling and small vibrations or shaking (fibrillations or fasciculations) will be sought.
Credits:
Harrison. (2004). Principles of Internal Medicine. Fifteenth edition. Madrid. Editorial Mc graw Hill. Pag 38-44.
By Dr Johana Albarran