Notes for Midterm Exam
Notes for Midterm Exam CSD 422
Popular in Neuroanatomy of Communication Disorders
Popular in Communication Sciences and Disorders
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CSD 422 Notes 11216 Midline axis of symmetry center LLeral away from the axis of symmetry center MLJial opposite of lateral toward the midline you are talking about a certain midline m in or toward the middle any position in the center of the skull is central m below thalamus and hypothalamus Epi above thalamus and epithalamus Peri around or next to Ventral 0 Spinal cord toward the belly 0 Brain toward the bottom of the brain DLsal opposite of ventral 0 Referring to spinal cord means toward the back of the spine 0 Brain toward the top of the brain Anterior 0 Spinal cord means toward the belly 0 Brain toward the front or the face Posterior superior dorsal 0 spinal cord toward the back I 0 brain toward the back of the head Inferior Inyaiue 0 Spinal cord toward the belly HI myamnd 0 brain toward the bottom of the brain Superior toward the top of the brain not used for the spinal cord Ventral and inferior mean the same for the brain inferi r 39 Eml39 l I Dorsal and posterior are the same for the Spinal cord 39 1 E4111 1 251 p Caudal toward the tail our tail if we had one like the tailbone Rostral opposite of caudal towards the nose Ipsilateral On the same side as something I can say that my right arm is ipsilateral to my right leg Contralateral on the opposite side of the body as something opposite of ipsilateral Decussation refers to the crossing of bers from one part of the body brain or spinal cord to the opposite part Coronal is any vertical plane that divides the body into ventral and dorsal belly and back sections Sagittal an anatomical plane which divides the body into right and left halves Transverse plane also called the horizontal plane aXial plane or transaXial plane divides the body into superior and inferior parts Historical Facts about Neuroscience what we know now comes from the works of many scholars of different branches of neuroscience these branches of neuroscience include Neuroanatomy neurology neurophysiology neuropsychology and neurochemistry Neuroanatomy the oldest branch of the neurosciences It started around the 1700s One of the classic works that grew out of it is know as Phrenology 0 German phrenologist called Franz Gall 0 Phrenology is about the mapping of the brain with respect to its functions What Gall did was to assign different human abilities to specific identifiable regions or structures in the brain 0 His colleagues who spoke a lot very eloquent had bulging foreheads making him assume that this part of the brain was bigger on those specific individuals Localization the functions are localized to particular structures Phrenology did not stand to the test of time because it was not very scientific However it did boost the study of looking at the function of the brain Mg Italian man 0 The one who developed a method by which neurons in the brain cells in the nervous system stained the so that he could see their full structure and how far they travel in the nervous system This method is still used today 0 Result he found that the cells of the nervous system constitute a large composite with continuities He concluded that the cells are not separate entities they are part of one whole structure This notion is referred to as the reticular theory of the nervous system Santiago Ramon y Cajal Spaniard man 0 Around the late 19th century and early 20th century he came into the picture He improved the work of Golgi And showed that the cells of the brain are in fact separateindividual entities although they are intermingledinterrelated 0 This conclusion has been confirmed by modern technology We know today that the cells of the nervous system are individual entities 0 This conclusion has become as the Neuron Doctrine Neurology is a branch of medicine It is specialized in the correlation in diseases of the nervous system with behavior andor function Paul Broca 0 French neurologist He demonstrated in 1861 that the posterior inferior frontal gyrus in the left part of the brain controls articulation or speech production 0 Damage to this structure can result in disturbance in ability to produce speech Carl Wernicke 0 Also showed that the posterior superior temporal gyrus in the left part of the brain is what controls language comprehension 0 Damage to this structure can result in impaired ability to comprehend language Broca and Wernicke boosted the study of localization Broca s area Motor cortex Wernicke s area Auditory cortex Hughlings Jackson British Neurologist who studied neurology Contributed to the functions of the right part of the brain which controls a lot of di erent things that are not languagerelated Wilder Penfield don t really need to know these two at this time Neurophysiology Charles Sherrington British neurophysiologist He argued that neurons in the nervous system make contact with each other He believed it is by means of these contacts that the neurons communicate with each other He named the contacts synapse We can say that neurons have synapses and they communicate through this However today we do know that neurons indeed communication with each other but the synapse that Sherrington refers to are not complete contacts They are only close approximations In other words neurons do get very very close to each other but there is still a tiny gap between the two Neurons make contact with each other and muscles Gustave Fritz and Eduard Hitzig These two were the first individuals to conduct the first experimental study of higher neuron function They also provided the first evidence of what we know today of the motor cortex This occurred in 1817 Psychology contributed quite a bit to the debate of localization in the 19th and 20th centuries Carl Lashley American Psychologist Lashley removed portions of the brains of mice to run a maze He observed that wherever he removed did not affect the ability of the rats to run the maze In other words he observed that the removal of no specific part of the brain destroyed the abilities of the rats to run the maze If localization were correct that would mean that the removal of one or two parts of the brain would affect the mice s ability to run the maze That part of the brain that is removed would affect that specific ability The larger the size of the tissue that was removed the greater the deficit in the animal Even though the brain works this way neurologist still use the localization method for their diagnosis This method leads them to more correct diagnoses than not Neurochemistrya very new branch of neuroscience Growing rapidly and has great promise for diagnosis and treatment of diseases in the nervous system that are not well understood at this time The study of the nervous system spinal cord and brain and the drugs that affect it Start at the top of the brain and work our way down Gross agntomv of the Nervous System Divided into two parts 0 Central Nervous System CNS i Lies within the skull and the vertebrae I It is made up of the brai lnd the spinal cord It is the part of the nervous svstem that is responsible for cognitive or mental processg such as thinking understanding remembering problem solving and so on E It also controls perception and discrimination of sensory stimuli 0 Peripheral Nervous System PNS Lies outside the skull and the vertebrae 5 Is made up of two functional systems 0 Somatic division controls conscious sensory perception and voluntary movement gcan also be involuntary o CI ELial nerves 0 Spinal nerves 0 Autonomic division has involuntary control for the glands and the visceral system visceral system comprised of the large internal organs such as the stomach o Sympathetic fight or ight o Parasympathetic rest and digest The ervous System Central Nervous System Frontal Lobe 2 consciousness 3 quot movementand jL stimulus perception I f I K Frontal association Cerebrum aref L 4 r 39 39 v k n A wt 1 w r Temporal Lobe f y one speech recognition vision Midbrain I Cerebellum B r ai n Stem kons movement coordination basic vital functions egbreathing Medulla Splnal Chord Autonomlc Somatlc Subconscious control Voluntary muscle systems movement Lymphocytes 3 I a Mmocwes Parasympathetlc quotacrophages 0 Rest and Digest Bbod Bone esses marrow D I quotr Sympathetic Fight or Flight Peripheral Nervous System Ir test nes LI Payer plaques Central Nervous Svstem in detail 0 Protected from external hazards by structures such as Skull 0 Spinal column 0 Meninges 0 Cerebrospinal uid CSF O Bony structures that enclose the brain skull and spinal column Skull 0 The human skull is made up of eight plates that are joined together The space within the skull is called the cranial vault 0 At the base of the cranial vault is a hole called the foramen magnum it is inside toward the caudal part of the brain this opening provides a conduit for the brain to join the spinal cord Spinal column 0 The human spinal column is made up of 33 vertebrae the book will say 31 but that is a different thing 0 They are divided into 5 sectionsparts top to bottom Cervical 7 Thoracic 12 Lumbar 5 Sacral 5 Coccygeal 4 0 Each vertebrae has a opening through which the spinal cord passes 0 There are notches between the vertebrae openings those notches provide outlets for blood vessels from the spinal cord They are called intervertebral foramen OOOOO Meninges There are 3 meninges that enclose the brain and the spinal cord and they lie immediately below the skull and the spinal column 1 Dura mater farthest from the brain outermost a Tough fibrous membrane that lines the inner surface of the skull and the spinal column vertebrae They provide a protective covering for the brain and the spinal cord You cannot break it b The outer surface of the dura mater adheres closely to the skull and the inner surface is attached to the arachnoid c Ordinarily there is no space between the dura mater and the arachnoid however in some pathological positions uid may accumulate between the dura and the skull andor between the dura and the arachnoid i The most frequent source of uid is bleeding It may occur from blood vessels from the surface of the dura mater car accident Bleeding on the outer surface of the dura mater is known as epidural extradural hemorrhage Hematoma the accumulation of blood that results from an epidural hemorrhage f Can occur beneath the surface of the dura mater If that happens it is known as a subdural hemorrhage g Dural re ections the inner dura layer folds on itself in a number of places and each of these folds is know as dural re ection dural septum i FalX cerebri intervenes between the two halves of the brain ii Tentorium cerebri the fold in the back of the brain iii FalX cerebelli the smaller part in the back of the brain iv Diaphragma sellae very small one found in the inside of the brain 2 Arachnoid a b C I Tentorium DBFBDBIH Tento rial notch Falx cerebelli Te nlori urn cerebelli Diaph ragma saline 1 Contains no blood vessels There is a space between the arachnoid and the pia mater The space between the arachnoid and pia mater is called the subarachnoid space i Subarachnoid space is filled with cerebrospinal uid CSF There are some relatively large spaces at the base of the brain between the arachnoid and pia mater d the subarachnoid cisterns i Subarachnoid cisterns are also filled with CSF osest to the brain rmost layer of the meninges Infundibuluminner surface of it contains no blood vessels but the outer surface does contain blood vessels veins arteries i This means that bleeding can occur here too arachnoid hemorrhage the bleeding that occurs between the pia mater and the arachnoid They are arranged in this order A The meninges are the membranes covering the brain and spinaL cord Dura mater 2 layers Arachrum rl Pia mater 39n I j 9 1 Brain WAMM httpwwwanatomyguycomneuroanatomymeningesdura1re ections Cerebrospinal Fluid CSF 0 Fills all of the subarachnoid space subarachnoid cisterns and other big spaces called ventricles The Brain Every structure we mention unless specified is in pairs 0 Hemispheres O 0 Left hemisphere Right hemisphere I They are connected underneath by a white structure called corpus callosum 0 The brain is made up of tissues and water 78 34 is made up of water 12 14 is made up of neurons glial cells and connective tissue 0 The brain weighs about 3 pounds 0 The brain is divided into four parts 0 O O O Cerebrum or cortex Diencephalon Brainstem Cerebellum Cerebrum cortex It is not a smooth tissue it is made up of ridges and valleys convolutions and depressions 0 The convolutions are called gyri singular gyrus 0 The depressions are called sulci singular sulcus Lobes The deep sulcUdepressions are called fissures The deepest and the longest fissure is called longitudinal ssure or the interhemispheric ssure or superior longitudinal ssure the one that separates the two hemispheres Central ssuresulcus Fissure of Rholando or Rholandic ssure Lateral ssuresulcus or Sylvian ssure Transverse ssuresulcus 0 The cerebrum is divided into componentslobes I Frontal lobe separates the front from the rest of the brain Speci c SulciFissures Central Sula ms lobe Fro mal me If v or I occipitalquot LungiludmalFlssure Helm mu f Sylviam39Lateral Fissure Temporal lobe CE re39JBH39UV Transverse F iss mre 0 The lower boundary of the frontal lobe is the lateral ssure 0 The posterior boundary of the frontal lobe is the central ssure 0 Involved in voluntary skilled movement of muscles on the contralateral side of the body specifically the movement on the opposite side of the body controls the other side of the body 0 The gyrus located in front of the central sulcus in the frontal lobe is called the precentral gyrus 0 That part of the brain is involved in the process of movement or motor information the part of the cortex is know as the primary motor cortex I Controls muscles on the contralateral side of the body 0 If someone has damage on the primary motor cortex on the right side they would exhibit weakness of muscles on the left side of the body 0 Body parts are disproportionally represented in the motor cortex Homunculus 0 The bottom of the frontal lobe the two strips are one of the oldest structures in the brain and it is what processes our ability to smell I That structure is called the olfactory cortex or olfactory tract with a bulb at the end called the olfactory bulb 0 Broca s Area three components left hemisphere I Triangularis I Orbitalis I Opercularis I Parietal lobe the central part of the brain 0 The posterior back boundary of the parietal lobe in an imaginary line that separates it from the occipital lobe 0 The parietal lobe controls perception visiospacial information touch and body awareness 0 Damage to the parietal lobe can results in a disorder called tactile agnosia also known as astereognosis 0 Patients with this disorder are unable to recognize objects by touch 0 Other damage to the lobe can deal with visiospacial function A person is unable to copy geometric figures or able to discriminate complex visual stimuli 0 In the love there is also the gyrus immediately behind the central sulcus called the post central gyrus there are two of these one in the left and one in the right hemisphere 0 Post central gyrus is part of the cortex that processes sensory information primary somatorsensory cortex is responsible for processing somesthetic informationsensation skin muscles and tendon sensation pain temperature pressure and touch from the contralateral side of the body I Body representation is also disproportionate O Damage to this they would not be able to feel pain or touch on the contralateral side of the damage 0 Angular Gyrus amp Supramarginal Gyrus 0 These two structure integrate information related to hearing Vision and touch 0 The ones that are in the left hemisphere if they are damaged they result in disturbance of language comprehension and object recognition I Occipital lobe in the back I Temporal lobe on the side January 26 2016 The brain is divided into four parts Cerebrum Diencephalon Brain stem Cerebellum The deepest longest the superior longitudinal fissure Lobes of the brain Frontal parietal occipital and temporal Frontal Precentral Gyrus primary motor cortex voluntary skilled movement Fissures central ssure Fissure big sulci but there is no clear cut distinction between sulci and fissures Temporal Lobe I Involved in comprehension of written or spoken verbal language in the left hemisphere 0 Recognition and comprehension nonverbal information includes music in the right hemisphere 0 Also processes complex Visual stimuli 0 3 important gyri in the Temporal 1 Inferior temporal Gyrus 2 Middle Temporal Gyrus 3 Superior Temporal Gyrus a posterior superior temporal gyrus Wernicke associated this with language comprehension in the left hemisphere 0 Transverse temporal gyrus Herschl s gyrus 0 Primary Motor cortex frontal lobe 0 Primary Auditory Cortex Auditory processing In the temporal lobe has input from both ears Occipital Lobe 0 Smaller than some of the other lobes I Is the part of the brain that processes Visual information 0 Structures to take note of O Calcarine Sulcus O Lingual Gyrus important for color perception 0 Primary Visual Cortex where visual information is processed The visual cortex in each hemisphere receives half of the visual input from each eye PmQM m CHINE I5 Emca39g EarEa Mal ll Eva nsury ssuciia a n l5 Tl r vi uaj Asuncia n Illa19 r 1 r 391 Primary T lmal Errtjuex 1 i x fl 39 lfl 4 42 22 Werniclreh area phat 22 part5 if 39 4111 J y a quot i I I dquotriunii Ill rmarm Wm 31 Primary auditory rem ex ml He aehl all 2 Broad functions of the brain 0 Motor functions 0 Touch fine touch registering what is being touched this is because you move yourself finger hand etc 0 Anything in which you use movement 0 Sensory functions 0 Feeling if the wind blows and you feel the cold you don t move the wind does if someone touches you it is sensory O The temperature changes and you feel it 0 If you touch something you move that is motor but if someone touches you they move and you are still then that is sensory 0 Moving your eyes to look at something is motor but the actual seeing of the object or scene is sensory I All hearing is sensory because you do not move to hear I Some portions of the cortex are not sensory or motor They do not process sensory or motor information These are referred to as association areas Inside the brain there is another lobe Limbic Lobe 0 Important Structures r pangu39 0 Amygdala 39 quot3 O Hippocampus 39 O Para hippocampal gyrus O Cingulate Gyrus above the limbic lobe O Uncus O FromiX O Thalamus O Hypothalamus I I 0 These structures as a group are involved in processil gnsdiiv39e emotions and memory 7 I a l 0 Lateral Fissure underneath the lateral sulcus lies beneath the silvian fissure operculum latin for lid Limbic System is known mostly for emotion processing 0 In the same area as limbic lobe but not part of it Insula Island of Reil encircling the insula circular sulcus cognitive and motor control perception self awareness and interpersonal eXperience are control here I Some people with insula damage eXhibit apraXia of speech January 28 2016 I The Limbic Lobe curves and lies below the frontal parietal and is incased in the Corpus Callosum The Gyrus above the corpus callosum is the silvian gyrus I Limbic System 0 Amygdula I Involved in fear sexuality etc 0 Parahippocampus O Parahippocamous Gyrus 0 Plays a role in emotions drives and memories I These are usually the first wiped out in someone with Alzheimer s disease 0 Singular gyrus part of limbic lobe above the corpus callosum 0 Structure below the CorteX and Corpus Callosum and above the collective brain stem 0 Diencephalon means between brain 0 A structure that lies between the cerebrum Above and the brain stem below 0 4 major components 0 Thalamus O Largest portion of the Diencephalon 0 Plays important role in alertness attention 0 Involved in language processing 0 O I Nuclei of the Thalamus Hesse Internal inltwmeuia Inmi nn Medial nucleus Damage to this area can lead to language problems like aphasia Serves as a relay station where motor information coming from the motor corteX down and sensory info Going up to the somatosensory corteX is first process M If f p 39 gagging I Motor information down I l l 39 I Sensory Information Up nucleus Iu39el39l trn letera ll 739 39 39 39 nucleus x lleniral pnelle llar Lateral nue eus 39 geniculete Emailflees until we Anterior nue lfeue Lateral posterior nucleus Maea f genlculate nucleus O I Both are first processed in the Thalamus Receives input from many sources and projects to many parts of the corteX Has many nuclei plural of nucleus in the nervous system has 2 meanings I lrefers to collection of cell bodiesneuron bodies I 2 part of the cell that contains genetic information of the cell I definition meant in the meaning for the thalamus Appears as a swelling on the posterior surface of the thalamus inside medial geniculate nucleus I Forms part of the auditory pathway one structure through which information passes on the way to the auditory corteX Outside Lateral Geniculate nucleus forms part of the visual pathway 0 Hypothalamus Hypnthala mug Pituitary Water balance 3 Etreaa Hun get Reproduction Therrmnmgula nn Sleepwake iptit chiasm Pituitary 4 0 00000 O Lies below the thalamus Ventricles of the brain form the oor for the hypothalamus Optic chiasm Tuber Cinereum Mammilary body A small structure of the brain but physiologically there is hardly any activity in the body that is not in uenced by the hypothalamus Functions are as follows Regulation of the pituitary glandhypophysis homeostasis Swelling at the base of the hypothalamus Small pea sized structure that sits in a protective bony cavity called the sella turcica see dural folds 0 Pituitary Gland Consists of relatively large anterior lobe called the adenohypophysis this is where PG forms part of the endocrine system endocrine glands produce hormones directly secreted into the bloodstream 0 PG secrets 9 Hormones involved in maintaining homeostasis 0 Endocrine cells in the adenohypophysis in hypothalamus The hypothalamus is what controls release of hormones Autonomic Function of the hypothalamus has to do with the control of the internal organs controls the sympathetic nervous system is responsible for the regulation of blood pressure respiration pupil dilation and bowel and bladder divisions I Anterior and medial Hypothalamic regions control the parasympathetic nervous system Feeding our ability to feel hungry and eat I Phagic feedingdrinking regioncenter regulates eating phagia comes from this It mean eating or consumption D IENIICE F39HALDN Tha lamu s Hypolhnala mus Pineal gland pa rt of epilhalamus BFI AIN STEM Midbrain Pens Medulla oblongeta C EIFI E BE LLLll iM Spinal card POSTERIOH a Medial View of sagitlal section ANTEFIIOFI I Aphagia or Dysphagia over excessive appetite or loss of appetite I Small lesions may result in adipsia which is the impaired ability of the desire to drink water not alcohol I Bilateral Hypothalamic lesions may result in a complete halt in food intake I Satiety Center is located in the ventramedial portion of the hypothalamus 0 Hyperphagia eating too muchobesity is caused when there is damagea lesion 0 Also result in aggressive behavior is there is a lesion to the ventramedial area Drinking anterior part of the hypothalamus has nucleus referred to as the supraoptic nucleus which regulates water intake and water balance in the body for example physiological mechanisms tuned on when it recognizes there is inadequate water in the body I If there is too much water in the body the opposite occurs turns on physiological mechanisms that get rid of the excess uid through urination I Lesion in this area leads to polydipsia increased water intake and polyuria which means increased urination Body Temperature Control hypothalamus always regulates body temperature If there is an increase in body temperature it is detect in neurons in the anterior portion of the hypothalamus and they respond by activating mechanisms that lead to heat dissipation which can be achieved through sweatingdilatation of blood vessels in the skin Neurons in the posterior hypothalamus sensitive to downward changes in the body temperature they react to the change by turning on mechanisms that lead to heat production in the body Sweat glands are blocked this prevents them from secreasing sweat muscles are signaled to shiver which raises the body temp known as vasoconstriction 2216 Damage to the lateral portion of the hypothalamus can result in dysphagia the ability to eat Emotional Response hypothalamus is involved in physical reaction to emotional stimuli as a child you did something that was bad and your parents are going to punish you but your parents are not at home but you panic when they get back I Increase in heart rate I If the degree of the emotion is high you may sweat I Your blood pressure may go up Hypothalamus regulates what controls the autonomous nervous system Damage to the dorsomedial nucleus of the hypothalamus will cause the person or animal to become aggressive hypothalamus controls rage or aggression The liliencephalon and Brainstem Cerebral hemisphere Septum pellucidum eral ventricl s anteriorl lnterthalamic O Reproduction The control of hormones there is a nucleus in the front part of the hypothalaumus preoptic alia that nucleus has cells that use several of the hormonal mechanisms talked about earlier Those cells control menstrual cycles in female human beings and other reproductive functions and behaviors pithalamus O Lies above the thalamus 0 It is a small structure but it has three subcomponents Corpus callesum Cheruid plexus in 3rd ventricle 39ampamp39 JP adhesien r W t I f k Thalamus netalways presentl l l 7 quot I 7 r A V 39 39 r I Plneal body gland ildizrgzrncmar u r quot quot I Pineal gland 39 39 I 7 tmainp m prfthaiamusJ 0 In the reglon of the m1dbra1n but stlll part of the Hypnihalamus W a 39 Optic chiasma r Cerebral mMIdhram aqueduct Pituitaryr gland la I Habenula habenulae plural Stria Medullaris stria medullare plural llllamm illary bind3 x Pans y quot55 Me dulla ublungaia 397quot quot4quotquot Spinal cord Feurth ventricle Chereid plexus I Cereb ellum m 0 Lies in the caudal section in the diencephalon 0 It consists of three structures I Subthalamic nucleus I Field of Forel I Zona Incerta 0 There is a hole behind the medulla but it is not actually separated 0 The hypothalamus is separated by the thalamus from the hypothalamic sulcus The Brain Stem consists of three structures 0 Midbrain 0 Also called Mesencephalon it connects the brainstem to the diencephalon above and the pons below 0 It has large swellings on both sides of its anterior lateral surface I These swellings are called cerebral peduncles NOT gyri I In between the peduncles are depressions or grooves called interpeduncular fossa NOT sulci I In the midbrain there are some nerves important for speech production called cranial nerves 0 Cranial Nerve 3 amp 4 I The midbrain also contains two important nuclei on each side 4 what connect the cerebellum to the brainstem O Inferior Colliculus 0 Audition 0 Superior Colliculus 0 Vision 0 Lateral Lemniscus runs into the inferior colliculus this tract is connected to the tract below coccular nucleus 0 The lateral lemniscus provide auditory input to the inferior colliculus and then the auditory corteX and then the primary auditory corteX heschl s gyrus 0 Pons 0 Connected to the cerebellum by fibers called cerebellar peduncles there are 3 of them I Inferior cerebella peduncle restiform body lower I Middle cerebella peduncle branchium pontis middle I Superior cerebella peduncle branchium conjuntivum uppermost 0 Large lesions in the anterior portion of the pons can cause a problem called lockedin syndrome I This is a condition in which the patients are conscious but unable to talk and they are quadriplegic all limbs are paralyzed I These patients can hear and comprehend what you are saying they just cannot talk 0 Medulla Oblongata 0 Located between the pons and the spinal cord 0 On the anterior portion front of the medulla oblongata is a swelling that is called pyramid 0 Cells in the precentral gyrus process motor information they travel all the way down through the pyramid on their way to the spinal cord 0 When they reach the pyramid they decussate in the pyramid that decussation is known as pyramidal decussation 0 Interior portion of the medulla also has a swelling and there are two tracts that are called I fasciculus cuneatus I fasciculus gracilis 0 These bundles of fibers synapse in a nucleaus also in the same region that are called I nucleus cuneatus I nucleus gracilis 0 Motor information descends 0 Sensory information ascends 0 There are 5 cranial nerves in the medulla O Damage to the medulla causes vertigo I Dizziness paralysis of muscles in the throat amp larynx I Various combinations of sensory loss in the limbs amp face I Trouble producing voiced sounds and V1 7 Corpus Callosum Ventriclea 1 St 2 9 l V i 0 Genu front 0 Rostrum These are on the handout 0 Splenium back Other structures connecting to the corpus callosum O Antenor commlsure Cerebral aqueduct V eentram 0 Posterior Commisure 39 eanal Hypothalamic Sulcus separates the thalamus from the hypothalamus spaarm Optic Chiasm very close to the hypothalamus The Bra i39nstem from the front and below The brain has 4 interconnected ventricles 0 A lateral ventricles one in each hemisphere 0 3rd ventricle the thalamus and hypothalamus form the oor of the 3rd ventricle 0 4th ventricle between the cerebellum and the pons O Ventricles are lled with CSF ows from the lateral into the 3rd ventricle there is an opening through which it goes from the lateral and the 3 that opening is called the Foramen of Monro interventricular foramen O CSF goes from the 3rd ventricle to the 4th ventricle through the cerebral aqueduct aqueduct of Sylvius O From the 4th ventricle to subarachnoid space through the Foramen of Magendi and Luschka 0 Choroid plexus is the main producer of CSF so it is found in all of the ventricles Verntricles of the Brain Lafileral venltriielie mtarier hrarn P aata riar Intawantriaularr harn V1 v 7 39 hvarn E and 3mm Infarianr harn I Lateral E I r a 11 Eerebral aque ueil Median partura If rifle a A a yenmneetari and all if j 39 aperture5 uf I 39 FD39H ll39l V39E tII39IBIE H Aperture 4 1Inquot lead ta f 39 3quot Lateral aubarachnaid spaca W 39 f E Entral canal quot5 aperture ef apinal card a Antenter Flew h Left lateral 1miniear Cerebellum 0 The cerebellum lies dorsal to the pons and the medulla 0 Separated from the brainstem pons by the 4th ventricle 0 Made up of tightly packed rows of gyri 0 Folia folium singular 0 Is a wrinkle gyrus on the surface of the cerebellum 0 It doesn t initiate motor activity by itself 0 Coracle motor functions 0 The cerebellum is also involved in maintaining equilibrium 0 Coordination and modification of the speed range force and the timing of muscular excursions 0 It monitors all motor activities by comparing intended movements against available sensory information 0 Makes alteration for smoothness Disorders associated with cerebellum lesionsdysfunction 0 Results in mild weakness tremors poverty paucity of movement and ataxia and impaired equilibrium Lesions in the cerebellum have ipsilateral effectsimpairments In general the impairment is characterized by reduction in smoothness and accuracy of movement Ensure precision of muscular movement is the main job of the cerebellum Ataxia incoordination of movement 0 Patient with ataxia exhibits an unsteady gait and a drunken behavior 0 Dysdidochokinesia unable to perform sequences of rapid alternating movements OOOO Theodor Schwann Dysarthria speech production problem it is marked by slow slurred and disjointed production of speech sounds Dysmetria refers to inability to estimate or judge the range of voluntary movement 0 Unable to judge the distance of a target from them undershoot or overshoot a target because you are not able to judge it correctly Dyssynergia jerky uneven and sometimes tremulous movement which is voluntary Intention tremor patients exhibit tremor when they are engaged in skilled movement 0 The tremor becomes more sever as the target is approached Hypertonia Reduction in muscle tension patients exhibit a loss of muscle tone resistance in the ability of the muscle to stretch tight not exible when an animal dies it become tight Rebounding unable to predict or stop a movement patient has a exed muscle and if someone is holding on and then lets go the arm will bounce back because they can not prevent this Disequilibrium unsteady gait as well and walk as if they are drunk the body sways toward the side of the lesion 21116 Every living thing is composed of microscopic units called cells this became known as the cell theory Cell is the basic functional unit of the nervous system There are two distinct classes of cells in the nervous system 0 Neurons 0 Glial cells Neurons are the information processing agents of the nervous system They are the things that process information Lots of them Nobody knows exactly how many estimates about 100 billion of them in the human nervous system 0 There are considerable differences among the types of neurons the typical neuron has 3 parts I Cell body Soma 0 Contains uid called cytoplasm cytoplasm contains many elements called organelles 0 Some of the organelles include the nucleus the machinery for the life of the cell and its repair 0 Endoplasmic Reticulum 0 Golgi Apparatus 0 Mitochondria scattered all over the cell body and they contain enzymes that are involved in the metabolism of the cell they are sometimes referred to as the cell s powerhouse the more mitochondria the cell has the higher the rate of metabolism the cell has 0 Nissl body 0 Neurofilaments neurofibrils delicate fibers that are in the cytoplasm serve as channels for intercebular communication for the organelles allow the organelles to communicate I Dendrites extension from the cell body in the mature brain they have spines on them E Axon typically leave the soma cell body part of the cell that is specialized in transferring information to other neurons it extends up to about 1 meter in humans 0 It is the structure that is responsible for transferring information from the soma to other neurons it conducts impulses away from the soma NOT into the soma Derldr ite Nucleus Cell body ef 39wl o 0 Large axons are surrounded by a fatty substance called Myelin Sheath serves as an insulation it is interacted spaced out at regular intervals throughout the length of the axon those interactions are called Node of Ranvier Axon Terminal 0 Node of Ra nvier O Schwann cello Myelin sheath Myelin sheath is important for the normal function of the cell because the ability of the cells to conduct impulses depends on the myelin sheath make it possible for the cell to have highspeed relay of information Multiple Sclerosis demylination disease there are no myelin sheath Long axons naturally conduct information across long distances across the brain different brain regions these are called Golgi Type I cells Short only a limited region of the brain these are called Golgi Type II cells 0 The axon can be divided into 3 parts these parts all looks different from one another 0 O O O Axon Hillock beginning comes before the trigger zone Axon Proper middle Terminal end looks like a swollen disk the part of the axon which the neuron makes contact with other neurons I Contains lots of tiny membranes called synaptic vesicles I Makes contact with the cell body of the other cell or the cell body of the other cell this is the synapse not a complete contact there is still a tiny gap between the two cells I The tiny opening is called Synaptic Cleft I The side of the synapse that is made up of the terminal is called the presynaptic side region I The other one is called the postsynaptic side region The transfer of information from one neuron to the other at the synapse is called Synaptic Transmission When a neurons makes contact with another neuron the neuron is said to innervate innervation the other neuron cell A innervates cell B The energy that is transferred is in the form of electrical signals at the beginning it is then converted into chemical signal in the terminal which is release and communicated with the other cell when the cells receives the chemical signal it converts it back in to an electrical signal and so on Neurotransmitter the chemical signal I Glial Cells protect and support the nerve cells they are typically small and they do not generate active electrical signals as neurons do estimate 10X more glial cells than neurons in the human nervous system 0 There are 2 types of glial cells 0 Macroglial cells there are two common types called astrocytes and oligodendrocytes others include Schwann Cells and Ependymal Cells I Astrocytes star shaped cells with small irregular shaped bodies they have numerous extensions they are divided into two parts brous astrocytes and protoplasmic astrocytes 0 Fibrous Astrocytes contain many filaments and found mostly in the part of the nervous system known as the White matter lots of axons which appear white 0 Protoplasmic Astrocytes have shorter processes only a few filaments associated with the neuron cells bodies dendrites and synapses wrap around synapse Part of the nervous system that contain mostly cells bodies are called grey matter I Oligodendrocytes Small glial cells found in myelinated fiber tracts wrap around axons and contribute to the formation of the myelin sheath 0 Found only in the CNS I Schwann cells counterparts of the oligodendrocytes found in the PNS do the same job as the Oligodendrocytes but in a different location I Ependymal Cells found in the ventricles they line up the ventricles and secrete CSF 0 There are two structures that create CSF Chloroid plexus and Ependymal cells 0 Microglial cells small glial cells that are found scattered throughout the brain and they act as what is known as Phagocytes collect garbage they seal off damaged brain tissue to prevent the place from being infected by poisonous things in the body prevents disease causing agents Nerve Impulse 0 How the cells communicate with each other 0 K NA CL I Inside of the cell are concentrations of these elements ions I The concentration inside of the cell is more negative than positive unequally distributed inside and outside of the cell I The concentration outside of the cell is more positive than negative I The cell is negatively charged inside and positively charged outside Chemical properties can be affected by a number of factors I Mechanical stimulation it can affect the chemical properties I Chemical stimulus if we were to introduce a chemical inside of the cell it would disturb the setup I Temperature change affect the electrical properties of the neuron membrane I Electrical pulse affects the electrical properties of the membrane Perturbation disturbance in the cell Unperturbed is 70 mV but it varies for different cells I Resting potential of the cell is what it is called when it is unperturbed When perturbation occurs it can cause negative ions andor positive ions to move in or out of the cell O In some types of perturbations negative ions ow into the cell positive ions ow out of the cell or both may occur I If this happens the resting potential of the cell will become more negative 0 When that happens we say that the cell is hyperpolarized O Negative ions can ow out of the cell and positive ions can ow in to it or both can occur I If this this happens it causes depolarization or decreased negativity into the cell Action potential in some perturbations positive ions can ow into the cell and negative ions can ow out of it that leads to an increase in positive ions inside of the cell which means that the negativity will reduce when that happens there is a threshold at which the cell cant take the reduction anymore and so it fires the charge back down the length of the axon to the terminal 0 When the action potential reaches the terminal of the cell it causes the synaptic vesicles to be released into the synaptic cleft 0 There are chemicals inside of them called neurotransmitters 0 When it gets into the new cell it should cause a chemical stimulus which causes a change in the resting potential of the new cell if that change results in depolarization of the cell then this cell also transmits it into another cell through action potential goes on and on O Goes from electrical to chemical when it is going through the action potential electrical in the neuron and chemical in the terminal Excitatory depolarization causes the action potential and makes the cell excited which we call excitatory Inhibition hyperpolarization makes the cell not excited
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