PCB3743 Exam 2 Study Guide 1 What are the properties of neuroglia a Neuroglia or nerve glue compose about 90 of the cells within the CNS b They do not initiate or conduct nerve impulses however they do communicate with neurons and amongst themselves by means of chemical signals c The help support the neurons both physically and metabolically d They homeostatically maintain the composition of the specialized extracellular environment surrounding the neurons within the narrow limits optimal for normal neuronal function e They also actively modulate depress or enhance synaptic function and are considered nearly as important as neurons to learning and memory 2 What are the four classes of neuroglia a The four classes of neuroglia include astrocytes oligodendrocytes ependymal cells and microglia Which class is important during a stroke and why Astrocytes are critical during a stroke because they form the neural scar tissue after a brain injury They also take up excess glutamate and potassium to prevent excess build up in the extracellular fluid During a stroke the astrocytes are not able to keep up because they cannot take up the excess glutamate and potassium in the ECF which leads to hyperexcitability Which class is protective against brain damage Astrocytes are also important for protecting against brain damage because they help form neural scar tissue Which assists to increase the conduction velocity of nerve impulses Oligodendrocytes assist in the increase of conduction velocity because they form the myelin sheaths of the CNS Which assists in immune responses Microglia are the immune defense cells of the CNS They are cousins of the monocytes During embryonic development microglia migrate to the CNS where they remain stationary until activated by an infection or injury They then release low levels of growth factors such as nerve growth factor which help neurons and other glial cells survive and thrive When trouble occurs in the CNS microglia retract their branches round up and become highly mobile and move toward the affected area to remove any foreign invaders or tissue debris via phagocytosis 3 Know the structure functions of the major brain regions and which common diseases are associated with which brain regions a Cerebral Cortex The largest part of the brain that is associated with higher brain function such as thought and action It also assists with the language center i Brain damage 1 Jarring or forceful impact 2 Causes scarring and tissue damage 3 Caused by serious head injuries ii Oxygen deprivation 1 Brain cannot store glucose 2 Glucose must be pumped across the Blood Brain Barrier BBB 3 Glucose is used for Oxidative Phosphorylation produces 36 38 4 There s a 10 15 minute window where the brain will utilize all of its ATP glucose 5 Does not have Anaerobic Glycolysis therefore it only has a 4 5 minute period that it can survive without oxygen iii Stroke Cerebral Vascular Accident or CVA 1 Caused by a rupture or block of a vessel in the brain 2 Causes the brain to become O2 starved which leads to massive neuronal death which then leads to motor memory loss following stroke iv Headaches 1 Increased psi within cranium 2 May be caused by brain tumors or hemorrhaging 3 May be caused by Meningitis Encephalitis 4 May be a pre event to a stroke 5 Common headaches no long term structural damage are primarily caused by tension respiratory issues and blood pressure changes v Brain Tumors that destroy brain tissue 1 Tumors that affect gliae are called gliomas 2 Tumors are detected using scanning technologies a CAT Scan Computerized Axial Tomography Used for looking at abnormal structures and hemorrhages by absorbing X rays b MRI Scan Magnetic Resonance Imaging Uses the vibration of protons c PET Scan Positron Emission Tomography Uses O2 positrons It also analyzes blood flow irregulations and used to guide surgeons in assisting them to finding tumors b Basal Nuclei These play a complex role in controlling movement In particular they are important in inhibiting muscle tone throughout the body selecting and maintaining purposeful motor activity while suppressing useless or unwanted patterns of movement and helping monitor and coordinate slow sustained contractions especially those related to posture and support i Parkinson s Disease 1 Due to loss of basal nuclei influence which is typically inhibitory 2 Loss of dopaminergic neurons dopamine which increases muscle 3 The 1st symptoms are usually involuntary tremors at rest 4 Later symptoms are usually loss of the facial motor cortex speech inflections and shuttled gait walk 5 Even later symptoms are usually loss of memory or thought rigidity processes a Treatments for Parkinson s Disease includes i L dopa Has the ability to cross the BBB and can be ii Selegiline Has the ability to mimic the activity of converted to dopamine dopaminergic synapses iii Fetal transplants no longer legal in the U S c Hippocampus Amygdala Temporal Lobes Important for Memory i Alzheimer s Disease 1 Effects up to 4 million people in the U S alone 2 Is co morbid with obesity a Prediction by 2060 that 80 of 80 year olds will have Alzheimer s 3 It neurofibrillary tangles plaques 4 Contains cholinergic neurons which degenerates axons and dendritic endings 5 It deposits fibrous proteins such as B amyloid 6 Causes the tangle of synaptic transmissions 7 Decreases the amount of Acetylcholine synthesized 8 Causes the destruction of cholinergic neurons 9 Diagnosed via a Poor transmission of cholinergic neurons b Confusion and disorientation c Personality changes d Accelerated process of aging d Brain Stem Contains 12 cranial nerves and involved in reticular formation level of alertness i Responsible for Comas and Sleep Centers 4 What are some common clinical causes of brain damage Jarring or forceful impact a b Any event that causes scarring and tissue damage Stroke c Serious head injuries 5 What are the physiological mechanisms underlying a cerebrovascular accident and what are some new treatments to prevent further neuronal cell death a A cerebral vascular accident or stroke is usually caused by a rupture or block of a vessel in the brain This will prevent oxygen uptake in the brain increasing the levels of glutamate which then leads to massive neuronal death and causes severe motor memory loss b Two possible treatments i Anti coagulants to assist in endogenous strokes ii NMDA R blockers that silence glutamate receptors in the brain 6 What are some modern technical
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