Neuro Test 1
Terms
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- hierarchy
- move upt he nervous system and things become more complex, move down and things become more simple
- caudal
- tail
- Pastalkova et al 2008
- rats hippocampus snstive to location;discovered firing patter of cells forms animal spatial memory and predict which way will turn even if makes a wrong move
- Why take this course? (3)
- 1. nervous system controls speech mvmt, lang. prod., audit. percept., swallowing 2. clinical assessment of com. dis. 3. clinical managemt. of com. dis
- Nervous System controls (4)
- speech mus. mvmt., language production and comprehension, auditory perception, swallowing
- anterior
- front- usually used with head or free extremities (ventral)
- internal capsule
- white pathway through areas of brain matter; clearly stands out; anterior limb, corticothalamic (cortex and thalamus connect.) and thalamocortical (thalamus cortex conn. mvmt in other direction)
- cell body
- function cell metabolism; contains the nucleus; aka soma
- mri- Gauger et al 1997
- comp. mri of children with and without sli; broca's area smaller or irregular in sli; wernickes either smaller or = in size in sli but always bigger on left side of normals; brains were different
- Astrocytes
- provide structural matrix surrounding and supporting neuron cell boies in cns; maintains appropriate environment for neuronal function; produces neural growth factor (may play a role in neural plasticity and adaptation after injury)
- commissural pathways
- connects across hemispheres
- pros/cons mri
- pros=noninvasive, no xray, image all planes cons= LOUD, claustrophobic, powerful magnets; stay still
- Alzheimer's disease
- cytoskeleton breaks down, protein changes in microtubules, axon whithers and impedes the flow of information; cell dies
- association pathways
- connect within hemispheres;short fibers = gyri to gyri; long fibers = lobe to lobe
- posterior
- (dorsal) behind, toward the back, usually used with head and free extremities
- PET-Ali et al 2006
- adults with adsd (adductor spasmodic dysphonia compared with controls during rest and speech prod. act. before and after tx; pretx; hyper motor areas(cerebell, ant cing.) and hypoact. sensory act. (left somatosen.cort) in adsd people; posttx motor areas attenuated(cerebell) and others augmented (brainstem, insul inf fron gy)
- occipital lobe areas of interest
- seat of visual processing of brain, occipital gyri is posterior border, preooccipital notch
- Basic parts of neuron
- 1. cell body (soma) 2. axon 3. dendrites
- lateral
- away from midline
- Limbic system
- amygdala, cingulate gyrus, fornix, hippocampus, mammillary bodies, olfactory bulbs, septum, uncus; broad characterization of limbic system is memory, smell, and emotion
- superior longitudinal fasciculus
- connects frontal , parietal and occipital lobes
- projection
- corona radiate, internal capsule, genu-connect cortex to subcortical structures, brainstem and spinal cord; vertical connections; sensory and motor
- Cranial nerves 1-6
- 1. olfactory- sensory smell 2. optic-sensory vision 3. oculomotor- motor eye 4. trochlear- motor eye 5. trigeminal- sensory face 6. abducens-motor eye
- Divisions of nervous system
- 1. CNS 2. Peripheral NS
- mitochondria function
- cellular respiration system?; to produce adenosine triphosphate(ATP-energy source for biochemical reactions of cells)
- Frontal Lobe areas of interest
- Primary motor cortex (BA 4), SMA (BA 6), Broca's Area (BA 44, 45)
- Nerve cells: basic types (2)
- 1. neuron 2. neuroglial or glial
- Multiple Sclerosis
- destroys oligodendrocytes;thinning and loss of myelin; 'sclerosis'=lesions in white matter; various symptoms include; muscle weakness, mus. spasms, speech prob., swallowing prob.
- 4 types of glia
- astrocytes, oligodendrocytes-cns (schwann cells-pns), microglia, ependyma-do not propagate nerve impulses, but provide supportive function to ns
- temporal lobe areas of interest
- wernicke's area(BA 22), Primary auditory cortex (Heschl's gyrus BA 41,42)
- Gelbard-sagiv et al 2008
- implanted wires for 7-10 days in hippocampus amygdala, entorhinal cortex, parahppocamp. gyrus, anterior cingulate; movie clips; could predict what clip being remembered
- Angiography
- xray image of blood vessels; inject radiopaque contrast; prov. pict. of arterial and venous supply of brain; identifies arterial pathology
- axon structure
- cytoskeleton (cyto= gk. cell); microtubules; neurofilaments
- wilder penfield studies (stim. living brain)
- researcher/neurosurgeon; montreal institute; stim. conscious epileptic with electric probe to determine areas to ablate; mapped localized brain funct.
- imaging living brain
- single neuron recording- deep needle electrodes, respond to axonal spikes; sample 10-100 neurons; cons=invasive so used on animals or humans with epilepsy
- thalamus
- relays and integrates sensory input and motor output; known as grand central station
- quadraped orientation
- cerebrum= superior/dorsal, inferior/ventral, anterior/rostral, posterior/caudal
- 4 lsuperficial lobes
- frontal, parietal, temporal, occipital (deep lobe insula)
- medial
- toward midline
- Magnetic resonance imaging-MRI
- determines amount of hydrogen in different locations of body; mag. field makes high or low energy; makes protons jump from one state to another;
- golgi apparatus function
- for protein delivery
- Neuroglia or glia
- majority of cells in NS
- Broca's aphasia
- inferior frontal gyrus/ was unable to speak clearly anything but tan/postmortem revealed lesion in left hemisphere due to syphillis
- spinal cord
- is extension of brain and link to spinal nerves; 8cervical, 12 thoracic, 5 lumbar, 5 saccral, 1 coccygeal
- laterality
- a. anatomical symmetry (2 hemispheres anatomically similar) b. functional differences (each hemisphere has specialized function) c. contralateral control (sensory and motor fibers cross at midline) the left = verbal, language, analytical and the right = emotional, holistic, artistic (visual and spatial skills)
- PNS includes...
- Spinal nerves, (all tissues located outside the skull and vertebral column) and ANS
- phrenic nerve
- motor, comprised of cervical spinal nerves c3 c4 c5; innervates the diaphragm
- interconnectivity
- very well connected nervous system- 3 pathways (commissural, association, projection)
- PNS cranial nerves
- 12 pairs, are a complex mix, somato motor, somatic sensory, ans, exteroceptive senses (smell, sight, taste, hearing, touch)
- How mri works
- looks at main tissues of brain- gray matter, white matter and csf which prod. different signal intensity making it easier to disting. b/t them
- Transcranial Magnetic Stimulation- TMS
- noninvasive, excite or inhibit neurons using weak electric currents induced in tissue by rapidly changing mag. fields(manipulate neurons on superficial struct.)
- spinal nerves for speech
- phrenic, thoracic
- neroglial or glial
- gk for glue, support, insulation and nourishment, there are 10x100 billion
- superficial
- toward the surface
- proximal
- next to, toward the body, toward the root of the extremity
- distal
- away from root of free extremity
- Methods of investigating the NS
- animal models, human disease models, stimulating living brain, recording and imaging living brain
- Myelin sheath
- thick axons conduct impulses more rapidly than thin ones; usually due to myelin; is white glistening lipoprotein; encases most of axon like a sword in a scabbard; insulates axon and allows more rapid movement of impulse along axons; most axons and some dendrites are myelinated
- neurofilaments function
- maintain structure, transport organelles and metabolic substances along the axon
- spinal nerves
- 31 pairs; are extensions of spinal cord
- ependymal
- make up the lining of fluid filled ventricles of the brain
- centrality
- CNS, all decision making occurs in CNS a. volitional involves the brain b. non volitional (at the level of the spinal cord
- fMRI- Hugdahl et al 2004
- looked at fmri changes in sli family members with controls while list. to vowels, psudowords, real words; found bilateral activ. of sup. temp. gyrus and mid temp gyrus with slightly stronger left activation but sli much reduced act. than controls
- CNS includes...
- Brain, Spinal cord (all tissues in skull and vertebral column)
- Wada test
- sodium amytal infusion; truth serum; induces funtional loss of hemisphere in minutes; immediate effects-contralateral paralysis and loss of speech funct., determine dominant hem. for speech
- corpus callosum 4 parts
- genu-interconnect anterior aspects of frontal lobes, rostrum-interconnect anterior asects of frontal lobes; body- interconnect posterior aspect of frontall lobes, all regions of parietal lobe and superior temporal lobe; splenium- interconnect occipital lobes and inferior temporal lobes
- arcuate fasciculus
- part of the sup. long. fasciculus; connects temporal to frontal lobe; fasciculus = 'little bundle'
- Angio- Jones 1966
- stuttering paintients with intracranial lesions; preop wada test showed bilateral rep. for speech; post op left hemis. only with no more stuttering
- thoracic nerves
- t1-t6 innervates the upper rib cage mus. ; t7-t11 innervates the lower rib cage mus. and all abdominal mus.
- corona radiate
- large areas with fibers converging towards the middle to project to thalamus and brainstem
- genu
- corticobulbar tract-cortex and cranial nerve nuclei; posterior limb-corticopontine (cortex and pons) and corticospinal (cortex and spine)
- projection
- connect brain to body
- ventricles
- hollow spaces deep within the cns filled with cerebrospinal fluid (CSF); protects adn cushions brain and spinal cord; lateral, third, fourth, spinal canal; cerebral aqueduct and 4th vent. are at level of brainstem
- commissural pathways
- corpus callosum, anterior commissure
- cranial nerves 7-12
- 7. facial-motor face sensory oral 8. auditory-sensory hearing 9. glossopharyngeal- sensory pharynx motor- velum 10. vagus sensory/motor larynx 11. accessory motor neck 12. hypoglossal moto tongue
- 3 functions spinal cord
- 1. sensory -proprioceptive that is related to mus. (via dorsal roots) 2. motor-motor instruction from the brain to spinal cord (via ventral roots) 3. reflexive- sensory input leading to stereotypical motor output (knee jerk reflex)
- superior
- upper or closer to the head
- axon
- function signal output;one axon with collateral branches (most neurons) conduct impulse away from cell body
- EEG- Bobereg et al 1983
- looked at eeg act. before and after tx for stuttering; found that greater than normal activation of post. front. region of right hem.; after tx increased act. of posterior frontal region of left hemisphere
- TMS- Fox et al 1997
- used tms to stimulate precentral gyrus for hand area and looked to see what other areas stim as well--sma on opposite side stim. too
- polyribosomes function
- for protein synthesis
- association
- superior longitudinal fasciculus, arcuate fasciculus
- DTI Sommer et al 2002
- compared 15 stutterers with controls; fewer white fiber tracts of left hemisphere arcuate fasciculus in stutterers compared to normals (arcuate fas. conn. broca's and wernicke's)
- synapse
- axon loses myelin sheath at final destination; divides into several small terminal branches consisting of axon buttons; bouton establishes contact with another neuron or cells of a mus. or gland; elicits response in target cell by release of chemical called a neurotransmitter
- Oligodendrcytes
- form and maintain myelin sheath; schwann cells in pns do the same
- Insula
- island of Reil, deep to lateral sulcus-left anterior insula function is coordination of mus. movement for articulationi and phonation
- diencephalon
- l. 'between brain', thalamus, hypothalamus
- hypothalamus
- controls autonomic functions, regulates hormones, regulates feeding, fight/flight response and sexual behavior
- Olds and milner 1954
- inserted electrode in septal area of live rat; rat self stimulated 7500 times /hr compared to less than 100/hr for areas like caudate nucleus, hippocampus (not pleasure areas)
- Positron emission tomography- PET
- to observe and measure changes in brain activity associated with planning and executing tasks; measures meabolic act. in brain; diff tasks light up diff brain areas; rest and act. states are compared
- Neuron
- latin sinew tendon, the basic functional unit of nervous system, receives and transmits neural info to the muscle, gland, or other nerve cell, there are 100 billion
- anterior commissure
- area of occipital lobe associated with eye movement and papillary response
- dendrites
- gk=tree; receives impulse toward cell body; signal receptor; most neurons = multipolar; several dendrites which expands surface area
- ANS
- controls involuntary activity of the body; glands, smooth mus. and heart; sympathetic prepares body for stress (increase heart rate, breath, perspire) parasympathetic returns body to normal
- microglial
- remove debris left by dead or dying neurons; the 'garbage men' of the NS
- 3 Functional types of neurons
- afferent-sensory to cns; efferent-from cns to muscle; interneurons-connects to other neurons
- Functional MRI-fMRI
- observes/meas changes in brain act. assoc w/ planning and executing tasks; reveals regions of brain most act. under differing cond. by detecting changes in blood flow; detects locat. of incr. neural act. by meas. ratio of oxyhemoglobin to deoxyhemoglobin
- topography
- 1. motor-spatial arrangement of motor control at brain maintained at the body (homunculus=little person) 2. sensory- spatial arrangement of sensory receptors maintained at the brain
- basal ganglia
- also referred to as corpus striatum or basal nuclei; consists of caudate nucleus, putamen, globus pallidus (related structure substantia nigra) function: regulate and refine motor mvtments
- lower motor neuron
- the final commo pathway ; this is it for motor intructions the last place before the mus.
- anatomical planes
- 1. coronal (vertical cut into front and back halves) 2. transverse (horizontal cut into upper and lower) 3. sagittal (vertical cut into left and right halves)
- dendritic spines
- hairlike/bulbous structures on dendrite membrane further expands contact area
- cephalic
- cranial
- biped orientation
- body= superior or rostral brainstem= inferior or caudal spinal cord= anterior or ventral and posterior or dorsal
- Nucleus contains (6)
- DNA and RNA; endoplasmic reticulum; polyribosomes; golgi apparatus; mitochondria;NS cells
- Applications of EEG
- looking at right and left hemisph. act. , cognitive processes, sleep act. , epilepsy, auditory evoked potentials
- functionality
- sensory specific pathways (touch, hearing visual) Motor specific pathways (body motor, postural adjustment, face and neck)
- Computed Tomography CT scan
- xray film shows shadow made by radiopaque tissues; xray rotated around head in slices, relative radiopacity is reconst by comp; high dens -white (skull), low dens. is in shades of gray (white/gray matter); least density is black (air/fluid);cons; exp. to xrays/radiation
- Parietal lobe areas of interest
- Supramarginal gyrus (40), somatosensory and visual association functions
- inferior
- lower or closer to the feet
- Human disease models
- infer brain function from areas of brain destruction ex. paul broca
- Organizing Principles of the Brain (8)
- interconnectivity, centrality, heirarchy, laterality, functionality, topography, plasticity, cultural neutrality
- cultural neutrality
- anatomically the same but functionally different(ex. same attention machinery but culturally influenced)
- CT-Cox et al. 2003
- ct scan of temp. bone of 61yr male with cond. hl but normal middle ear funct.; scan showed splitting of semicircular canals
- animal models
- most knowledge of ns from animal studies; basic neurophysiology of ns- animal species less related to humans (squid): higher order ns processes such as mvmt, perception, memory-anima progressively closer to human (rats, mice, cats, dogs, monkeys)
- PNS divisions
- cranial nerves ( skull), ANS, spinal nerves (related to vertebral column) afferent-to cns efferent from cns
- EEG-electroencephalogram
- noninvasive; detects electrical act. of neurons from surface of head; 1000s neurons must act. for signal to be detected; cons: aver. of reg. repeated act. is requ. to desting. it from mus. noise and brain noise
- Diffusion Tensor Imaging DTI
- mri technol. used to measure mvt of water over time; measures direct. and integrit of white matter tracts
- cons of pet
- spatial resolution limited to 1000's of cells, readiation exp. limitss number of scans during a time period