Class 2 – Terms, historical issues Review questions 1. What is trephination or trepanning, why is it done? A surgical invention in which a hole is drilled or scraped into the human skull, exposing the dura mater to treat health problems related to intracranial diseases. The removal of part of the skuWe also discuss several other topics like csbecome.ch
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ll. It is done to remove pressure on the brain, and may also have been done to let out evil spirits. It was known in prehistoric Europe and amongst the Inca. What cultures was it known in? What do we know about the 'theory' cultures used to justify trepanning? In ancient times, holes were drilled into a person who was behaving in what was considered an abnormal way to let out what they believed were evil spirits. Evidence of trepanation has been found in prehistoric remains from Neolithic time onward. The bone that was trepanned was kept by the prehistoric people and may have been worn as a charm to keep evil spirits away. Evidence also suggests that trepanation was primate emergency surgery after head wounds to remove shattered bits of bone from a fractured skill and clean out the blood that often pools under the skull after a blow to the head. 2. What were the two theories about the structure where behavior originates? What theory was held by Hippocrates? Aristotle? Cardiac hypothesis – the heart makes you move, action had to come from the heart, the brain is bloodless and gray; Aristole – biologist Brain hypothesis – brain controls all senses and movements o Hippocrates, physician – saw head wounds, brain trauma affects movements o Galen – humors, surgeon, worked with gladiators; brain greatly controls functions, pressure on the brain causes death, pressure on the heart hurts, but does not cause death 3. What was Galen’s knowledge of anatomy based on? How did Andreas Vesalius improve upon this, how was he able to do so? Galen – observed apes, treated wounds for Gladiators, anatomy; humourism – blood, black bile, yellow bile, phlegm Vesalius – drew structures of the brain, anatomy of the body, performed dissections on human corspes 4. What is phrenology and its relation to localization of function? Phrenology – measure of the skull that tells what people are good at as a supposed indication of character and mental abilities; skull is not a reflection of what is underneath Localization of function – Broca (speech production) & Wernicke (language development)Who were the first two men famous for holding to localization of function in its weird variation? Franz Gall and Johann Spurzheim Who was famous for bringing evidence for localization of function in its non weird variation? John HughlingsJackson 5. What is equipotentiality? The brain can coopt other areas to take over the role of the damaged part, the potential of any part of the cerebral hemisphere to handle any high level task What led Flourens to hold the view of equipotentiality of function in the brain? He did surgery on animals (especially birds) to see how their behaviors would be affected and discovered plasticity – hemispheres of the brain had equal potential of taking over each other 6. What view did Hughlings Jackson propound w.r.t the organization of the nervous system? Each area of the nervous system had a specific function that contributes to the overall system. There is no speech center, rather there are parts for throat, muscle control, hearing, discriminating speech sounds, etc. 7. What was Luria’s view on the organization of the nervous system? 3 basic units of the brain: o The brainstem and nearby areas control the arousal level of the brain, and muscle tone o The posterior areas of the cortex and nearby areas control reception, integration, and analysis of sensory information o The frontal and prefrontal lobes control planning, executing, and verifying behaviors 8. What is the distinction between the central and peripheral nervous system? The central nervous system sends commands to and receives info from the PNS The peripheral nervous system gathers sense data and sends it to the CNS and acts upon instructions from the CNS 9. What parts comprise the central nervous system? The brain and the spinal cord 10. What is the difference between the somatic and autonomic nervous system? The somatic nervous system controls voluntary actions, the autonomic nervous system controls automatic functions 11. Explain the difference between efferent and afferent fibers? Efferent (motor) – going away from the brain and spinal cord; E(xit) Afferent (sensory) – going towards the brain and the spinal cord; A(bove) 12. How are the directions ventral, dorsal, rostral, caudal, medial, lateral, superior, inferior, anterior and posterior used? Ventral: toward the stomach Dorsal: toward the back Rostral: toward the beak (snot, front of brain) Caudal: toward the tail Medial: toward the middle Lateral: to the left or right relative to the middle Superior: above Inferior: below Anterior: in front Posterior: behind 13. How are dorsal, ventral, rostral and caudal different for the head and the trunk? For the head everything is rotated to account for the fact that humans evolved from animals that walked on all fours with heads and bodies parallel to the ground 14. What are the sagittal, transverse, horizontal, frontal, coronal, midsagittal planes of section? Sagittal: splitting something in half vertically into left and right Transverse: (horizontal) splitting the body into top and bottom Frontal: (coronal) splitting something in half vertically, front and back Midsagittal: splitting something in half vertically into left and right halves that are equal in sizeClass 3 – Cells, Development Review list: Cells 1. What are the two general classes of cells in the nervous system? What are the ranges of estimates for the quantity of each of these classes? Neurons: 100 billion approximately, up to 10,000 connections Glial cells: 100 billion approximately, were thought to outnumber neurons 2. What are the parts of a neuron? What is the main function of the neuron, and which special neuron parts help with this? The cell body, axons, and dendrites Main function of a neuron: send, receive, and interpret data from the body The cell body produces proteins needed for the construction of other parts of the neuron Axons transmit information Dendrites receive information 3. What makes the difference between a unipolar, bipolar and multipolar neuron? Unipolar: sensory neurons that send information to the CNS, one process from the cell body, one axon. Bipolar: also sensory, two processes, possesses one axon and one dendrite Multipolar: motor or association neuron, multiple processes and one axon 4. What is a myelin sheath? What difference does it make if an axon is myelinated or not? A fatty layer formed by Oligodendrocytes (CNS) or Schwann Cells (PNS) around axons Their presence increases the speed of information transmission by 4 times (120 m/s). 5. What are the types of glial cells? What is the function of microglia, astrocytes, oligodendrocytes, and Schwann cells? Microglia and Macroglia Subtypes of Macroglia: Oligodendrocytes, Schwann Cells, Astrocytes Microglia multiply and metabolize tissue deris, repair and maintenance, structural support Astrocytes perform housekeeping tasks, deliver glucose, patrol the BBB, and maintain balance between groups of neurons Oligodendrocytes are myelin forming glia that wrap around multiple axons within the CNS Schwann cells from myelin around cells in the PNS, one segment per cell 6. How are oligodendrocytes and Schwann cells the same and different? They both form myelin around axons, but Oligodendrocytes do so for multiple axons and do their work in the CNS. Schwann cells work on only one segment and do their work in the PNS. 7. What is the difference in composition between white and gray matter? Where is gray matter found in the brain? Gray matter: mostly cell bodies as well as dendrites, and axons of neurons; where all synapses are White matter: mostly axons connecting different parts of grey matter to each other Gray matter is found on the outside of the brain, white matter is found on the inside (vice versa in the spinal cord) 8. What is the relationship between fibers, tracts and pathways? Pathways consists of tracts, which consists of fibers; axons traveling together MS 9. What in general is multiple sclerosis? The destruction of the myelin sheaths around axons in the white matter of the brain. Causes scarring and hardening of nerve tissues in the spinal cord, brain, and optic nerves. 10. What is the general disease mechanism in MS? Which cells appear to get attacked particularly? General disease mechanism: demyelination due to a slow acting virus or autoimmune process. Oligodendrocytes are attacked. 11. What is the proximal cause of MS? What is the thinking as to what starts that (distal cause)? Proximal cause: autoimmune Distal cause: possible genetic susceptibility and environmental trigger 12. What categories of symptoms occur in MS? What type of cognitive symptoms occur mostly? What could be the cause of the emotional symptoms? Scarring and hardening of nerve tissue Sensory – sensory data not getting through properly, visionloss, numbness Motor – motor info travels slowly, difficulty moving or keeping balance Cognitive – thinking problems, memoryloss, concentrationloss Emotional – depression, anxiety Emotional symptoms are caused by the depression engendered by the severity of the symptoms, and possibly by damage to the brain. 13. What is the incidence of MS in the US? What is the status of the latitudeobservation on the incidence of MS across the world? 1/2000 Scandinavians are more likely to get MS. When they came to the US they moved to areas with similar climates, therefore we cannot tell if MS has a genetic component or is related to latitude (possibly due to a lack of exposure to sunlight, which allows us to produce vitamin D). –could either be due to fairly high latitude or it could depend on where you were born 14. What is the usual age of onset of MS? What is the gender difference in incidence? Ages 2040 Women are one and a half to two times more likely to get MS then men 15. What are the 3 characteristics of MS that get treated Attacks – steroids Progression Symptoms Development 16. What are neurogenesis and migration? When does most neurogenesis take place? Neurogenesis: the growth and development of nervous tissue Migration: movement from one part of something to another Most neurogenesis take place in the sub ventricular zone 17. What is Synaptogenesis? When does it start and how long does it continue? The formation of synapses between neurons in the nervous system From 2 months before birth to 2 years after birth 18. What is myelination? When does it start and how long does it continue? The production of myelin sheath around a nerve to allow nerve impulses to move more quickly. From 2 months before birth to approximately 1920 years after birth 19. What is synaptic pruning? When does it start and how long does it continue? The process of synapse elimination that occurs between early childhood and the onset of puberty in many mammals. Pruning starts near the time of birth and is completed by the time of sexual maturation in humans 20. What three layers does the embryonic plate develop into? What 2 major structures does the ectoderm develop into? Ectoderm: nervous tissue & epidermis (skeleton & muscles) Mesoderm Endoderm Lecture 4 – Support structures, spinal cord 1 Review Questions: Development 1. When does the neural tube close on average at the anterior and posterior pores? The open ends of the neural tube close at approximately the 26th day of gestation, with the anterior end subsequently creating the brain, and the posterior end forming the spinal cord. The process of forming and closing the neural tube is called neurulation. 2. What are the defects that result when the neural pores do not close? Which type of nonclosure has the more serious defects? Anencephaly – neuro pore doesn’t close, has no brain – the brain is a vascular mass and the infant does not survive Spina bifida – spine doesn’t close at the back, spinal cord could stick out 3. What is lissencephaly (or agyria)? What is thought to be the process that is disturbed in lissencephaly? Lissencephaly is a disorder that occurs during the 11th to 13th weeks of gestation and involves the underdevelopment of the cortical gyri Due to defective neuronal migration Genetic, viral, hypoxia during the 1st trimester Neurons do not travel properly Intellectual disability, possible death before age 2 4. What is microcephaly? Is the mechanism causing microcephaly known? What general types of distal causes for microcephaly are known? Which virus is in the news for its apparent relationship with microcephaly? Microcephaly – a condition in which a baby’s head is significantly smaller than expected, often due to abnormal brain development No, before, microcephaly was caused due to the possibility of a pregnant mother having rubella. Pre & post natal causes Rare In the news because of the Zika virus Chromosomal abnormality Malnutrition Genetics Blindness Death Embryo and fetus are vulnerable to the virus CNS 1. Name the 7 CNS structures caudal to rostral. Spinal cord – most vital part, nervous tissue, support cells into brain stem Medulla oblongata – sits on top of the spinal cord, digestion, breathing, heart rate, huge number of nuclei Pons – bridge, fibers toward cerebellum Cerebellum – little brain, posterior to pons, modulating movement Midbrain – rostral from pons, sensory and motor, eye coordination Corpus callosum – thalamus, hypothalamus – internal biological clock Cortex – expands and folds over the rest of the brain 2. Which structure in the adult human brain comes from the vertebrate myelencephalon? Medulla/ medulla oblongata 3. Which structures in the adult human brain come from the vertebrate metencephalon? Pons and cerebellum 4. What is another name for the vertebrate mesencephalon? midbrain 5. Which structures in the adult human brain come from the vertebrate diencephalon? Thalamus, hypothalamus Pineal body, & third ventricle 6. What structures in the adult human brain come from the vertebrate telencephalon? Forebrain, cerebral cortex, neocortex, basal ganglia, limbic system, olfactory bulb, lateral ventricles Meninges 7. What are the names of the meningeal membranes? Know the order, and how located with respect to one another. Dura Mater (outer layer) – dense, inelastic, doublelayered membrane that adheres to the inner surface of the skull, deoxygenated blood (1) Arachnoid (middle layer) – overlies the subarachnoid space, contains blood vessels, spider weblike membrane, heads toward Venus cavities, sticks to Dura (2) Pia Mater (inner layer) – overlies every detail of the outer brain, directly adheres to the surface of the CNS, thin layer bordering (3) Subarachnoid cavity with CSF circulating (13) Trabeculae (14) 8. What is the result of folding of the dura in the skull? Dura folds and divides brain into hemispheres and separates cerebrum and cerebellum 9. What is the subarachnoid space? What structures and liquid in that space? Subarachnoid space – space containing cerebrospinal fluid (CSF); below the arachnoid membrane 10. Where are subdural and subarachnoid bleeds? Subdural bleeds – often encountered after a head injury; cerebral veins crossing the subdural space have little supporting structure and, therefore, are most vulnerable to injury and bleeding as a result of trauma; subdural space – the space between the dura and the arachnoid parts of the meninges Subarachnoid bleeds – occurs when a blood vessel on the surface of the brain bursts and blood flows into the small cavity that surrounds the brain, the subarachnoid space 11. How many ventricles are there, and where in the brain are they located (i.e. what brain structures would you use to locate them), what is the fifth bit related to the mesencephalon? 1st and 2nd Lateral (between the hemispheres at the level of the thalamus and hypothalamus, biggest ventricles, surrounds cavities): in the telencephalon 3rd (sitting on phallus): Diencephalon 4th (cavity between cerebellum): Metencephalon, Myelination Cerebral Aqueduct (little cavity): Mesencephalon CSF 12. What is cerebrospinal fluid? Where is it formed? How (in general) does it drain to the venous system? How much of it (approximately) is formed on average per day? How much (approximately) is present in the ventricles & subarachnoid space at any time? Cerebrospinal fluid is liquid that protects the brain and spinal cord from chemical and physical damage, as well as disposing of waste in the brain. It is produced in the choroid plexus in the lateral and 4th ventricles. 450/mL a day are created, and 1/3rd of it is present in the ventricles and subarachnoid space at any given time. 13. What are the main functions of the CSF? Cushioning, waste disposals, distribution of chemicalsLecture 5 – leftovers, spinal cord/nerves Review Questions Blood supply & Blood brain barrier 1. Be able to describe the blood supply to the brain and the Circle of Willis (identify on picture), including: internal carotid arteries, vertebral arteries, basilar artery (1), anterior, middle and posterior cerebral arteries, anterior communicating artery (1) & posterior communicating arteries (2) Backsupply system: vertebral arteries, join together to form the basilar artery, comes off of… Posterior cerebral artery (back supply): connected to… Internal carotid artery: connected to vertebral artery (front supply) Comes off of middle cerebral artery and anterior cerebral artery (makes Circle of Willis) Posterior communicating artery – connects to the internal carotid artery into the anterior cerebral artery and middle cerebral artery, communicates with the posterior cerebral artery Anterior communicating artery – connects the left and right anterior cerebral arteries across the commencement of the longitudinal fissure. 2. What cerebral arteries supply the frontal, parietal, temporal and occipital lobes with blood (you don’t need to know this by surface, just which one or two for each lobe) Frontal: cerebral middle and interior Parietal: same Temporal: cerebral middle Occipital: cerebral posterior 3. What is the bloodbrain barrier? Tightly joined endothelial cells which keeps large molecules out and restricts transfer of soluble material 4. How do tight junctions, and astrocytes contribute to the BBB? Endothelial cells of brain capillaries (small tubes) have tight junctions (glue) Astrocyte (macro glial cell, barrier between blood vessels and brain) feet cover endothelial cells (wind blood cells) 5. What is the point of having an incomplete BBB in places? Important in sensory 3rd ventricle – Subfornical organ (responsive to hormones and neurotransmitters) and organum vasculosum of the lamina terminalis (primary neurons reposible for osmosensory balance) 4th ventricle – area postrema 6. Where is the area postrema and what does it have to do with BBB? 4th ventricle, makes you puke, registers toxins in your blood Spinal cord 1. What is the relationship between the spinal cord segments and spinal vertebrae? Spinal cord – most vital part of nervous system Spinal cord contains 31 segments and the vertebrae has 33 o Extends from base of brain to middle of spine o Spinal cord runs through the spine consist of vertebrae – identified by area and number (3rd lumbar) Vertebral body – weight of vertabra Spinal nerve – comes off spinal cord and exists the spine to peripheral nerve Pedicle Spinous process Spinal cord, in the back 2. How is the nomenclature of the spinal cord related to that of the spine? 8 C(ervical) 12 Th(oracic) 5 L(umbar) 5 S(acral) 1 C(occygeal) 31 spinal nerves – emerge at regular intervals from intervertebral foramina, each pair arises from a spinal segment 3. What are dermatomes? Area of skin, nerves run skins muscles; body segments innervated by spinal nerves 4. What is the cauda equina? Tail of a horse (back of spine) 5. Where is a lumbar puncture done? Why is it done there? Sampling CSF for diagnostic purpose The area is made numb by local anesthetics, and a small needle is passed between the bones (vertebrae) of the spine, and posterior to the end of the spinal cord. There is no risk of paralysis. Tells what bacteria or kinds of cells are floating around cerebrospinal fluid – vastly useful Used to avoid hitting the spinal cord 6. What characteristics of the CSF can be informative medically? Normal CSF doesn’t coagulate. After subarachnoid hemorrhage CSF may contain blood. It can also reveal cell count, glucose level, protein content.7. What are the differences between a motor neuron and a sensory neuron? Motor neuron – ephirine neurons, efferent (away from the brain) Sensory neuron – sending afferent (toward the brain) information to spinal cord from the skin 8. What is the dorsal root ganglion? Holding space next to the spinal cord, a cluster of nerve cell bodies in a posterior root of a spinal nerve, contains cell bodies of sensory neurons 9. Be able to identify the following structures in a crosssection of spinal cord: gray matter, white matter, dorsal root ganglion, dorsal and ventral roots of spinal nerves. Which ones are afferent? Which ones are efferent? Through the dorsal root ganglion: Sensory Information (afferent) Through the motor nerve: efferent information from the brain 10. What causes the differences in amount of white and gray matter along the length of the spinal cord? Gray matter depends on the amount of muscle mass. White matter depends on myelinated axons – affects learning and brain functions.Lecture 6 –cranial nerves, Review Questions Autonomic NS 1. Where do the sympathetic and parasympathetic nervous system nerves exit the spinal cord? Sympathetic – Thoracic Parasympathetic – Crania 2. What is the function of the sympathetic nervous system? What is the function of the parasympathetic nervous system? Sympathetic: autonomic; flight, fright, fight response; thoracic lumbar region; bloodpumping, shuts down digestive system Parasympathetic: rest and digest; crania – sacral regions (comes off those two stems of the brain); reduces heart rate, stimulates digestive system, increases salvation 3. What is the most important practical information about getting the parasympathetic system more active that was mentioned in class? Breathing deeply – can kick this branch into action o 4 by 4 breathing CNS 4. Where is the Medulla oblongata? Which things are regulated there? Located just above the spinal cord and could be regarded as an enlarged extension of the spinal cord Several tracts decussate here Responsible for vital reflexes such as breathing, heart rate, vomiting, salvation, coughing, and sneezing 5. What is decussation? A crossing Cranial nerves 6. What are cranial nerves? Movement of head and neck Functionally homologous to the spinal nerves Provide both somatic and visceral sensory and motor innervation of the head and neck Thomas Willis traditionally number I though XII in rostrocaudal sequence 7. For the cranial nerves, know their names, numbers, functions (i.e. in general what do they do), whether they are sensory, motor or both. Know the differences between n. III, IV and VI.8. Which cranial nerves do facial movement and sensation? V, VII 9. Which cranial nerves serve functions to do with speech (motor to larynx, tongue)? XII 10. Which cranial nerve heads outside the head/neck area? What does it innervate? X CNS 1. Where is the pons, what structures (general) are located there? The pons is located above the medulla oblongata and below the midbrain (part of the hindbrain) Origin of neuronal activity that serves to increase arousal and readiness of other parts of the brain Along with the medulla, contains the reticular information and raphe system 2. Where is the cerebellum? What are the three sections (distinguished by function) of the cerebellum, and what are the functions (generally) of these sections? Cerebellum is a structure located in the hindbrain with many deep regular folds, helps provide smooth, coordinated body movement 3 functional parts: o Flocculonodular lobe – oldest part, lowest, vestibulocerebellum helps regulate balance and eye movements o Spinocerebellum helps regulate body and limb movements (middle) o Cerebrocerebellum helps in planning movements and evaluating sensory information for action, and has some purely cognitive functions (e.g. important for shifting attention between auditory and visual stimuli) 3. What is another name for the mesencephalon? What are the tectum and tegmentum? Mesencephalon – midbrain Tectum – roof of the midbrain Tegmentum – the intermediate level of the midbrain 4. What sensory systems are the superior and inferior colliculi associated with? Superior – vision Inferior – hearing 5. What is the connection between the substantia nigra and Parkinson’s disease? Substantia nigra – gives rise to the dopamine – containing pathway, makes less dopamine higher up in the brain Parkinson’s disease – degeneration of the central nervous system that often impairs motor skills, speech, and other functions 6. From where to where does the reticular formation extend? A diffusely arranged network of neurons that extends from the mesencephalon (midbrain), through the metencephalon (where it is most concentrated) to myelencephalon Descending portion is one of the several brain areas that control the motor neurons of the spinal cord Ascending portion projects to much of the cerebral cortex, selectively increasing arousal and attention 7. What are the two main structures in the diencephalon? Thalamus Hypothalamus Lecture 7 Anatomy, General brain damage processes Review questions CNS anatomy 1. Where is the thalamus located, why is the thalamus important? The thalamus (relay station) is located just above the brain stem between the cerebral cortex and the midbrain (diencephalon – below the cerebral cortex) Ipsilateral (selfside) Right thalamus connects to the right cortex Has nuclei in certain areas – input and output to other areas Each thalamic nucleus projects its axons to a different location in the cortex Relays motor and sensory signals to the cerebral cortex 2. What is general is the function of the limbic system? Consists of a number of other interlinked subcortical structures that form a ringlike border (limbus) around the brainstem Includes: o Olfactory bulb o Hypothalamus (under) – controls body temperature, thirst, hunger, and other homeostatic systems o Hippocampus – Para hippocampal gyrus, forming new memories about past experiences, center of emotion, autonomic nervous system o Amygdala – fear o Cingulate gyrus of the cerebral cortex – smells and sights, induces emotional reaction to pain, helps regulate behavior3. Be able to identify on a diagram the amygdala, hippocampus, hypothalamus, pituitary gland, the cingulate gyrus 4. What type of mental states are especially associated with the amygdala? What mental function is associated with the hippocampus? (Refer back to Question #3) 5. What are the functions of the hypothalamus? Integrates info to pituitary gland to trigger release of hormines Autonomic processes Small area near the base of the brain Associated with eating, drinking, sexual behavior, and other motivated behaviors Below the thalamus (thalamus and hypothalamus together for “diencephalon”) 6. What is the pituitary gland, and what is its function? Hormone producing gland Found at the base of hypothalamus 7. Where are the basal ganglia located in the brain? They are situated on the base of the forebrain 8. What are the three basal ganglia structures that we discussed? Caudate nucleus (aka striatum) The putamen (aka striatum) The globus pallidus 9. What functions is the basal ganglia associated with? The basal ganglia are responsible for voluntary motor control, procedural learning, and eye movement, as well as cognitive and emotional functions. 10. What are sulci and what are gyri? Sulci – small grooves in the cerebral cortex Gyri – bulges (ridges) in the cerebral cortex generally surrounded by other sulci11. Where are the longitudinal fissure, lateral fissure? What is the Sylvian fissure? Longitudinal fissure – a groove that separates right and left hemispheres Lateral (or Sylvian) fissure – a groove that separates the frontal, temporal, and parietal lobes of the cerebrum General disease processes 1. What are the research strategies used to figure out what different parts of the brain do? Examine the effects of brain damage on behavior Image brain Record brain activity during behavior Examine the effects of stimulating particular parts of the brain (rare) 2. What is inflammation? What is the function of inflammation? Process that comes in anytime a part of the body is damaged Normal response to harmful stimuli Vasodilation (redness/warmth) Tissue swelling o Fluid buildup (edema) o Cell infiltration Pain Loss of function3. What are the 5 classic signs of inflammation? (Latin and English), Which ones are related to the vasodilation, increased permeability parts of the inflammatory cascade? What is are some standard remedies for inflammation? Tumor = swelling Rubor = redness (vasodilation) Calor = warmth (vasodilation) Dolor = pain Function laeso = poor function Nsids (ibuprofen) for minor or corticosteroids for serious inflammation Immune cells produce chemical messengers that o Recruit more cells o Change local conditions (e.g., further vasodilation – dilation of blood vessels) Tumors 1. What are tumors, what is the distinction between a malignant and a benign tumor? Neoplasm – new growth of tissue Morbid enlargement Cell division and proliferation is uncontrolled Malignant tumor – cancerous, progressive, keeps growing Benign tumor – noncancerous, cell growth is arrested, still capable of producing neurobiological problem 2. What is the difference between an infiltrative and noninfiltrative tumor? Infiltrative tumors have a tendency to grow into adjacent areas while noninfiltrative tumors don’t grow. Infiltrative – expands and causes compression symptoms/enters different region Noninfiltrative – can cause release of neuroendocrine mediators 3. What is the difference between a local and a metastasized tumor? Local tumors arise from any local cells residing in affected organs (brain/skull origin) Metastasized tumors land in various parts of the brain (origin of tumor elsewhere – lungs, breast, skin), they are in secondary sites and are not the same type as the infiltrated organ/tissue, sends ambassadors from these areas to affect the brain 4. Which types of brain tissue can give rise to tumors? Blood vessels (uncommon) Meninges (15% of all tumors, although it is technically not part of the brain, mostly benign) Glial Cells (4050% of brain tumors) Ependymal Cells (lining ventricles) Acoustic Neuroma (myelinating cells around an auditory nerve – Schwann cells)5. What are meningiomas? What percentage of local tumors in the brain are meningiomas? Are they benign or malignant (in general) Tumor of the meninges, second most common tumor in CNS, 15%, generally benign 6. What is an acoustic neuroma, what is the originating cell type? What is the better name for acoustic neuroma? Myelinating cells surrounding auditory nerve, noncancerous tumor on the main nerve leading from the inner ear to the brain Originating cell type: Schwann cells Vestibular Schwannoma 7. What percentage of local tumors are glioma's? 4050% 8. What is a glioblastoma multiforme? Is it benign or malignant, local or metastatic, infiltrative or noninfiltrative? A malignant tumor affecting the brain or spine, glial tumor Malignant, local, infiltrative, grows quickly (30%) 9. Why are there no common tumors originating from neurons? Neurons aren’t made to divide 10. What percentage of brain tumors are metastatic? 40% 11. Which types of cancers are commonly the primary source for metastatic brain tumors? Breast, lung, skin, lymph cancers Cerebrovascular accidents 1. What is the difference between anoxia and hypoxia? Anoxia – no oxygen Hypoxia – absence of enough oxygen in blood 2. What is the difference between ischemia and infarction? Ischemia – very low blood flow to some tissue, results to anoxia Infarction – tissue death, caused by hypoxia, results in cerebrovascular accidents 3. What does CVA stand for? What are the two general types of CVAs? Cerebrovascular Accidents – problem with blood supply to the brain Ischemic (blood vessel is blocked and apportion of the brain becomes deprived of oxygen) and hemorrhagic (ruptured blood vessel causes bleeding inside the brain) 4. What are TIAs? What does a TIA put you at risk for? Transient ischemic attack Puts you at a risk of strokes if ignored Anterior circulation: temperature clumsiness, weak limbs, aphasia Posterior circulation: dizziness, double vision, numb or weak extremitiesLectures 8 – Brain anatomy, general brain damage I Review questions Cerebrovascular accidents 1. What is FAST? Face is drooping Ask person to smile, is one side drooping, are the arms numb? Speech is weird and slurred Time, get person to the ER as fast as possible 2. What are two possible (general) causes of ischemic CVA? What are the symptoms of CVAs? Clot (i.e., thrombus: clump of coagulated blood) Embolus (e.g., air bubbles or some other particles) – typically a substance that travels in blood until it creates a blockage Symptoms: o Sudden reaction or loss of: Consciousness Sensation (numbness, vision problems) Voluntary movement 3. What is an aneurysm? What do aneurysms in the brain put you at risk for? A blood vessel that have cells that are not elastic, flubbery, weak walls, weak because of brain trauma Puts you at risk for a cerebrovascular accident 4. Which has the worse survival, hemorrhagic or ischemic stroke? Which generally has the worse recovery after survival? Worst survival: hemorrhagic stroke Worse recovery after survival: ischemic stroke TBI 1. What is TBI? Traumatic brain injury 2. What are the major causes of TBI? Which age groups are particularly likely to fall? What gender suffers more TBI? What appears to be the biggest cause of TBI resulting in death, overall? Falls (biggest cause, mainly in little children and elderly) Motor vehicle accidents Struck by… (including sports) Assault Suicide (1%) Women 3. What is the difference between open/penetrating and closed TBI? Open/penetrating: penetration of skull and brain by an object Closed: no damage to the skull, concussions (mild) 4. Name some causes of open TBI? Bullets, weapons, knives Skull fractures: a piece of bone from the skull penetrates the brain5. What is the difference between a concussion and mild TBI? Concussion: a mild brain injury caused by a blow to the head or a violent shaking of the head and body 80% of hospital admission for head injury are “mild TBI” In high school athletes: 15% of all evaluated sportrelated injuries are concussions But less that 50% of concussions are reported, so that percentage will likely rise 6. What are coup and contracoup in TBI? When is it thought you get the one, rather than the other. Coup: brain damage at the site of blow (ex: soccer ball hitting face) Contracoup: brain damage opposite to site of blow (falling to the ground, perpendicular to point of impact) Terms for location of brain relative to TBI CoupContrecoup: brain damage on both sites 7. What is diffuse axonal injury? How does it cause problems? Ripping of the axons Causes brain cells to die, which cause swelling in the brain 8. What are edema and hematoma, how do they cause problems? Edema – swelling from injury or inflammation of certain parts of the body, caused by ischemic stroke, cerebral, the BBB may break down, allowing fluid to accumulate in the brain’s extracellular space Hematoma – caused by a hemorrhage, a collection of blood outside of a blood vessel, subdural, inflammation, if pressure inside the skull rises to a very high level, a subdural hematoma can lead to unconsciousness and death 9. What are symptoms of TBI? Inability to speak or understand Difficulty with memory or concentrating Irritability Loss of balance, dizziness, fatigue Anger, anxiety Dilated pupils Vomiting or nausea Sensitivity to light and sound Slurred speech Blurred vision Headaches Depression Bleeding 10. What is the Glasgow coma scale? What categories of responses does it score? From what number to what number does it run? What does a high score mean, what does a low score mean? Assessing the damage of the brain, records the conscious state of a person Scale 315 Eye, verbal, motor responses Classification of brain injury:o Severe: 38 o Moderate: 912 o Mild: 1315 11. In the video we saw on TBI, what bodily function was suggested would be very useful for making a diagnosis of TBI? Eye movement 12. What is postconcussion syndrome? A complex disorder in which various symptoms – such as headaches and dizziness – last for weeks and sometimes months after the injury that caused the concussion 13. What is chronic traumatic encephalopathy? Who is affected by CTE? Major brain damage, loss of cognitive function in more than one area of the brain Mainly boxers and football players 14. What is ImPACT testing, how is it supposed to work? A computerized neurocognitive test to help evaluate and manage concussions 25minute online test for ages 1259 Delivered via a secure web portal Taken via a desktop computer Administered in the presence of a physician, nurse, athletic trainer, athletic director, or coachLectures 9 – General brain damage 3, Visualization Review questions Infections 1. What is the difference between inflammation and infection? Infections: caused by exogenous pathogen, viruses (encapsulated nucleic acid – e.g., DNA or RNA), bacteria, fungus Inflammation: respoce to presence of microbial agents 2. What is meningitis, what types of pathogen can cause it? Not an infection of the brain, can be lifethreatening Inflammation of the meninges Fungal is the most serious Neisseria meningitides Streptococcus pneumoniae Hib 3. What is encephalitis? Give examples of two viruses that can cause encephalitis. Affects medical temporal lobe (where memory structures are located) and limbic system in general, inflammation of the brain Herpes Arboviruses (transmitted by bloodsucking insects such as insects) 4. What is the way in which herpes virus “works”? What areas of the brain are usually affected by herpes encephalitis? The herpes simplex virus spreads when it comes in contact with broken skin, or with the lining of the mouth and genitals. It penetrates cell nuclei and replicates. Sometimes the virus’ replication process destroys the cells it has invaded, causing blisters or ulcers to form under the skin. Usually caused by sexually transmitted diseases Affects the temporal lobe and frontal lobe 5. What are neurotoxins? Give some examples. A toxin that works specifically on nerve cells (venoms, environmental chemical toxicants: Glutamate excitotoxin) Examples: o Mercury o Lead o Drugs of abuse (alcohol, stimulants (e.g., cocaine, methamphetamine) Imaging of brain 1. What is histology? Determination of the structure and morphology of tissue, for brain: only for postmortem or biopsy 2. What do the Golgi, Nissl stains, myelin staining procedures show of the microscopic structure of the brain? Golgi: stains some neurons black, needed to see what cells were in the brain Nissl: doesn’t stain axons, pink stained, showed inside of cells Myelin: staining myelin, seeing tracts, neurons are affected, traced (only done on animals)3. How do cranial Xrays work in general? What structures or damage show up how? Discrimination of low and high density regions in the body High density areas (e.g., bone) seen as white on Xray film Low density seen as dark 4. What are the advantages and disadvantages of cranial Xrays? Advantages: o Picks up tumors, skull fractures and hemorrhage, cheap, easily available Disadvantages: o Poor discrimination between brain tissue and cerebrospinal fluid o Only 2dimensional images, poor structural resolution (i.e., brain regions difficult to discern), cumulative radiation o Not as good as experimental tool o Same value as diagnostic tool 5. What is the general procedure in angiography? What things can angiographies detect? Use of Xrays, making blood vessels visible Visualization of cerebral vasculature Catheter inserted via an external artery (e.g., femoral artery) and guided close to the site of entry of arterial supply of brain – e.g., internal carotid Contrasting dye is injected Skull Xray or CT Of diagnostic use only Can detect: o Aneurysms o Tumors (access to blood) with new vasculature – high on sugar o Vascular shifting due to lesions or degeneration of brain tissue 6. What is the general process in computerized axial tomography, how is it different from an Xray? What disadvantage of Xrays goes for CT scans also? Xray scanner is rotated slowly until a measurement has been taken at each angle and ac computer constructs the image Xray delivered as a thin beam o This allows for “slices” of the brain to be constructed along each of the planes of the axis o A computer reconstructs a 3dimensional image o Discrimination between brain structures is superior to that of skull X rays Can use contrast medium to enhance image Disadvantage: high increase of radiation 7. Which has the higher radiation dose: a skull Xray or a head CT? why is that? CT scanners sue Xray beams which can cause damage to the DNA and create mutations that spur cells to grow into tumors 8. How in general does an MRI work? Involves the application of a powerful magnetic field to image the brain Magnetic field aligns axes of the natural spin or rotation of atoms in water molecules (especially hydrogen atoms) Radiofrequency signal causes all aligned axes to spin like gyros Termination of radiofrequency signal causes nuclear atoms to return to original state, releasing electromagnetic energy in the process Released energy is measured and used to visualize the structure of the brain Note: MRI is applicable to any body organ 9. What are the advantages of MRIs? Does not involve radiation Contrasting agent is less likely to produce an allergic reaction that may occur when iodinebased substances are used for Xrays and CT scans Gives extremely clear, detailed images of softtissue structures that other imaging techniques cannot not achieve 10. What does an fMRI measure? How does it work in general, what does subtraction have to do with it? Only one that looks at function, all others look at structure Functional Magnetic Resonance Imaging uses oxygen consumption in the brain to provide a moving (i.e. dynamic) and detailed image of the functioning brain fMRI will also calculate regional blood flow (CBF: cerebral blood flow) Subtraction techniques are used to ensure that a given task or stimulus is responsible for the activity detected in a particular area of the brain The fMRI is a powerful tool since it reveals the level of activity of a particular brain region, as well as the size and appearance of various areas of the brain 11. What is difficult about an fMRI for patients, and what effect does this have for ability to use fMRI? They have to hold still Therefore, it cannot be preformed on some of the people we would most like to use it on: babies, people who are mentally handicapped, claustrophobic, Alzheimer’s patients, etc. 12. What does a DTI visualize? How is this useful? MRI in which water diffusion at a location is calculated DTI shows preferred direction of diffusion Allows for visualization of directional fibers Different programs are used for this type of MRI It allows us to see white matter 13. How does a PET work? What is PET used for? Records emission of radioactivity from injected radioactive chemicals to produce a highresolution image PET typically uses radioactively labelled glucose Radiolabelled neurotransmitterrelated substances now used Variants of PET are o rCBF (regional cerebral blood flow)Class 10 Sleep EEG 1. What types of electrical recordings of brain activity are there (we mention 3)? Single/multiple Cell recording Electroencephalograph (EEG) Recording Event Related Potential 2. What is the general process in single cell recordings? Who is this process used with? Recording voltage between different cells An electrode is inserted into the brain, adjacent to a neuron, the neurons activity is recorded Most commonly done with animals Many individual neurons can be recorded simultaneously Can record a single action potential or many action potentials 3. What is the general process in an EEG? What can be studied with EEGs? Discovered by Hans Berger in the 1930s EEG records electrical potentials or “brain waves” in the brain Reflects the collective (and synchronous) activity of neurons in the cortex Requires a “Generator” Neurons that produce the rhythmical signal EEG used for o Sleep studies o Epilepsy diagnosis o Monitoring the depth of anesthesia o Studying normal brain function 4. ERP, what is it, how does it work? Brief change in a slowwave EEG signal in response to a discrete sensory stimulus is classified as an ERP Often referred to as evoked potentials o E.g., Auditory evoked potential 5. What is function of averaging in ERPs? Stimulus is presented repeatedly and the recorded responses are averaged 6. TMS what is it? What is it mostly used for? The application of intense magnetic fields to temporarily inactivate neurons Useful for therapy and depression 7. Think through situations in which you would use each of these methods.FOR EXAM 2 Sleep 1. What types of recordings are part of a polysomnogram? 2. What kind of waves during normal awake time on EEG? 3. What kind of waves during relaxation on EEG? 4. What 2 weird phenomena during stage 2 sleep on EEG? 5. What kind of waves during deeper sleep (3 & 4) on EEG? What is N3? 6. What is the general trend in the amplitude/frequency from awake to deep sleep? 7. How are the waves on an EEG during coma? How are they different from delta waves? 8. What are the differences between REM and NREM sleep w.r.t. movement of body parts (eyes, limbs etc). 9. Explain the sleep cycles that one goes through in a normal night (both stages and REM/NREM alternation). 10. How does the % of REM sleep change during your lifespan? (infants, grandparents) 11. What is the circadian rhythm? Which sense acts on which part of the brain? 12. What did the movie suggests happens during sleep? During which type of sleep does this process happen?