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28 items · Last updated Thursday 19th May 2016
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Brain Atlas for Medical Education

Brain exploration and automatic testing  
Thirunavuukarasuu Arumugam
almost 11 years ago
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Cerebellar Neuroanatomy

Introduction Examination of the cranial nerves allows one to "view" the brainstem all the way from its rostral to caudal extent. The brainstem can be divided into three levels, the midbrain, the pons and the medulla. The cranial nerves for each of these are: 2 for the midbrain (CN 3 & 4), 4 for the pons (CN 5-8), and 4 for the medulla (CN 9-12). It is important to remember that cranial nerves never cross (except for one exception, the 4th CN) and clinical findings are always on the same side as the cranial nerve involved. Cranial nerve findings when combined with long tract findings (corticospinal and somatosensory) are powerful for localizing lesions in the brainstem. Cranial Nerve 1 Olfaction is the only sensory modality with direct access to cerebral cortex without going through the thalamus. The olfactory tracts project mainly to the uncus of the temporal lobes. Cranial Nerve 2 This cranial nerve has important localizing value because of its "x" axis course from the eye to the occipital cortex. The pattern of a visual field deficit indicates whether an anatomical lesion is pre- or postchiasmal, optic tract, optic radiation or calcarine cortex. Cranial Nerve 3 and 4 These cranial nerves give us a view of the midbrain. The 3rd nerve in particular can give important anatomical localization because it exits the midbrain just medial to the cerebral peduncle. The 3rd nerve controls eye adduction (medial rectus), elevation (superior rectus), depression (inferior rectus), elevation of the eyelid (levator palpebrae superioris), and parasympathetics for the pupil. The 4th CN supplies the superior oblique muscle, which is important to looking down and in (towards the midline). Pontine Level Cranial nerves 5, 6, 7, and 8 are located in the pons and give us a view of this level of the brainstem. Cranial Nerve 6 This cranial nerve innervates the lateral rectus for eye abduction. Remember that cranial nerves 3, 4 and 6 must work in concert for conjugate eye movements; if they don't then diplopia (double vision) results. The medial longitudinal fasciculus (MLF) connects the 6th nerve nucleus to the 3rd nerve nucleus for conjugate movement. Major Oculomotor Gaze Systems Eye movements are controlled by 4 major oculomotor gaze systems, which are tested for on the neurological exam. They are briefly outlined here: Saccadic (frontal gaze center to PPRF (paramedian pontine reticular formation) for rapid eye movements to bring new objects being viewed on to the fovea. Smooth Pursuit (parietal-occipital gaze center via cerebellar and vestibular pathways) for eye movements to keep a moving image centered on the fovea. Vestibulo-ocular (vestibular input) keeps image steady on fovea during head movements. Vergence (optic pathways to oculomotor nuclei) to keep image on fovea predominantly when the viewed object is moved near (near triad- convergence, accommodation and pupillary constriction) Cranial Nerve 5 The entry zone for this cranial nerve is at the mid pons with the motor and main sensory (discriminatory touch) nucleus located at the same level. The axons for the descending tract of the 5th nerve (pain and temperature) descend to the level of the upper cervical spinal cord before they synapse with neurons of the nucleus of the descending tract of the 5th nerve. Second order neurons then cross over and ascend to the VPM of the thalamus. Cranial Nerve 7 This cranial nerve has a motor component for muscles of facial expression (and, don't forget, the strapedius muscle which is important for the acoustic reflex), parasympathetics for tear and salivary glands, and sensory for taste (anterior two-thirds of the tongue). Central (upper motor neuron-UMN) versus Peripheral (lower motor neuron-LMN) 7th nerve weakness- with a peripheral 7th nerve lesion all of the muscles ipsilateral to the affected nerve will be weak whereas with a "central 7th ", only the muscles of the lower half of the face contralateral to the lesion will be weak because the portion of the 7th nerve nucleus that supplies the upper face receives bilateral corticobulbar (UMN) input. Cranial Nerve 8 This nerve is a sensory nerve with two divisions- acoustic and vestibular. The acoustic division is tested by checking auditory acuity and with the Rinne and Weber tests. The vestibular division of this nerve is important for balance. Clinically it be tested with the oculocephalic reflex (Doll's eye maneuver) and oculovestibular reflex (ice water calorics). Medullary Level Cranial nerves 9,10,11, and 12 are located in the medulla and have localizing value for lesions in this most caudal part of the brainstem. Cranial nerves 9 and 10 These two nerves are clinically lumped together. Motor wise, they innervate pharyngeal and laryngeal muscles. Their sensory component is sensation for the pharynx and taste for the posterior one-third of the tongue. Cranial Nerve 11 This nerve is a motor nerve for the sternocleidomastoid and trapezius muscles. The UMN control for the sternocleidomastoid (SCM) is an exception to the rule of the ipsilateral cerebral hemisphere controls the movement of the contralateral side of the body. Because of the crossing then recrossing of the corticobulbar tracts at the high cervical level, the ipsilateral cerebral hemisphere controls the ipsilateral SCM muscle. This makes sense as far as coordinating head movement with body movement if you think about it (remember that the SCM turns the head to the opposite side). So if I want to work with the left side of my body I would want to turn my head to the left so the right SCM would be activated. Cranial Nerve 12 The last of the cranial nerves, CN 12 supplies motor innervation for the tongue. Traps A 6th nerve palsy may be a "false localizing sign". The reason for this is that it has the longest intracranial route of the cranial nerves, therefore it is the most susceptible to pressure that can occur with any cause of increased intracranial pressure.  
Neurologic Exam
over 9 years ago
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Headaches at a Glance - Usman Ahmed

Teaching resource designed for Peninsula Medical School Students, who sit an exam called the AMK. This exam is an MCQ based exam and covers a number of clinical scenarios. This booklet specifically looks at the common causes of headaches.  
Usman Ahmed
over 9 years ago
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Cranial Nerves - Anatomy, Clinical Signs and Study Tips

This is a teaching resource that aids the student in memorisation of the Cranial Nerves, their anatomical path and function. Additionally, it stimulates a clinical approach to the functions of the Cranial Nerves, with some 'not to be missed' signs.  
Thomas Lemon
about 8 years ago
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A Brief Introduction to Neuro Anatomy: The Major Cord (part1)

The Major Cord: A very brief introduction to the anatomy of the spinal cord with points of clinical relevance.  
Lucas Brammar
almost 8 years ago
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Overview of Cranial Nerve Examinations

Guide for beginning a cranial exam by the clinical skills tutors at the University of Liverpool  
Mary
almost 8 years ago
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Continuation of Cranial Nerve Exam

Continuing on a previous presentation for cranial nerve exams by the clinical skills tutors at the University of Liverpool  
Mary
almost 8 years ago
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Cranial Nerves

A table listing the cranial nerves, their fibre type, attachment, cranial exit, function and method of testing  
Dahlia Abdul-Rahman
almost 8 years ago
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Foramina of the Skull (Visual mnemonic)

The skull has numerous holes (foramina) through which various cranial nerves, arteries, veins and other structures pass. To aid learning of these important foramina, I have created this visual mnemonic.  
Sunjay Parmar
over 7 years ago
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Neurology - Topic 11 - Extra pyramidal examination

Neurology - Topic 11 - Extra pyramidal examination  
MRCP Videos
over 6 years ago
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Brain Anatomy 1 - Gross Cortical Anatomy (Lateral Surface)

http://www.handwrittentutorials.com - This tutorial is the first in a series on the anatomy of the cortex. This video looks specifically at the gross anatomy of the lateral surface of the brain. Functional anatomy is addressed in the next video. For more entirely FREE medical tutorials and their accompanying PDFs, visit http://www.handwrittentutorials.com  
HelpHippo.com
over 6 years ago
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Cranial Nerves - Functions and Disorders

Cranial nerves function and related disorders as well as possible causes Facebook : http://www.facebook.com/ArmandoHasudungan  
Nicole Chalmers
over 6 years ago
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Brain Anatomy Overview - Lobes, Diencephalon, Brain Stem & Limbic System

Four Major Lober Diencephalon - Homeostasis Brain stem - Relay Station Limic System - Memory and Emotion Image: https://docs.google.com/open?id=0B8Ss3-wJfHrpejFtSkdLWHlNdWs Facebook: http://www.facebook.com/home.php#!/ArmandoHasudungan  
Nicole Chalmers
over 6 years ago
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Cranial nerves mnemonic

A nice visual mnemonic to recall the cranial nerves and their foramen.  
Waleed Tariq
over 6 years ago
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Neurology - Spinal Cord Introduction

https://www.facebook.com/ArmandoHasudungan Support me: http://www.patreon.com/armando Instagram: http://instagram.com/armandohasudungan Twitter: https://twit...  
YouTube
over 6 years ago
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Larynx Anatomy (3 of 5): Cartilages and Membranes (Part 3) - Head and Neck Anatomy 101

We've had a great response to our last set of videos so far, so we're thrilled that some of you are finding them helpful! One of the first year dental studen...  
YouTube
over 6 years ago
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Cranial Nerves (7 of 12): Facial Nerve -- Head and Neck Anatomy 101

A quick guide to the Facial Nerve . More detailed blurb below! If you'd like to contact us, email anatomyroom@gmail.com Welcome to our series of videos on he...  
YouTube
over 6 years ago
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Introduction to the Cranial Nerves -- Head and Neck Anatomy 101

This is the first in a series of videos broadly detailing the location and function of the 12 cranial nerves. More detailed blurb below! If you'd like to con...  
YouTube
over 6 years ago