MIP 101 1st Edition Lecture 12 Outline of Last Lecture XIX Cancer A Vocabulary B Classification of cancer C Risk factors of cancer Outline of Current Lecture XX The Nervous System A Central Nervous System B Strokes C Multiple Sclerosis D Alzheimer s Disease Dementia E Parkinson s Disease Current Lecture XX The Nervous System Phineas Gage stake impaled his frontal lobe and his behavior changed We live in our brains A Central Nervous System Brain brain stem and spinal cord Spinal cord stacked vertebrate there are particular kinds of nerves in specific parts of the spinal cord meaning where the spinal cord is injured affects the resulting type of immobility Each bundle of nerves is a group of axons the neuron may start in the brain The entire central nervous system is surrounded by a membrane called the meninges this consists of the arachnoid dura and pia Numbers Roughly 86 billion neurons Roughly 10 trillion synapses 20 of our oxygen intake goes to our brains Most of our oxygen is used for metabolism Key parts of a neuron dendrites processes that come off the cell body cell body and the axon Axon terminals synapse with the dendrite on target cell carries nerve signal Synapse gap between neurons These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Signal comes down the axon tip releasing neurotransmitters ex serotonin Re uptake sucking up or recycling of a neurotransmitter Changing the amount of time serotonin spends in synapses affects emotion Myelin sheath surrounding axon not continuous Each axon relies on one transmitter different types of nerves for different neurotransmitters Examples of neurotransmitters Norepinephrine adrenaline Glutamate Gamma Amino Butyric Acid GABA Glia connective tissue of the nervous system that consists of ogliodendrocytes and astrocytes and more Ogliodendrocyte produce myelin sheath probably does more as well Astrocyte support the neuron pass on nutrients from blood to the neuron important in memory Microglial cell clips synapses reconnects nerves with new ones helps with defense Ventricles make spinal fluid and are lined by ependymal cells B Strokes Stroke is one of the leading causes of death in the United States 4 in 2013 A stroke is caused by a change in blood flow 1 Ischemic stroke reduced blood flow due to a clot in the brain thrombotic or elsewhere in the body embolic ex a clot in the carotid artery both cause brain tissue to be cut off Someone suffering from an ischemic stroke has 10 seconds to unconsciousness 20 seconds to cessation of electrical activity and a few minutes until irreversible damage 2 Hemorrhagic stroke caused by a hemorrhage inside brain Different parts of the brain serve different functions and due to blain plasticity if one part is injured one may be able to regain the abilities lost C Multiple Sclerosis Multiple sclerosis autoimmune disease causes damage to the myelin sheath Those suffering experience tingling and a change in their vision Because it is an autoimmune disease that means the person s own immune system is damaging the myelin sheath Multiple sclerosis makes it appear as though scars have formed on the central nervous system because there are white spots where the myelin sheath has been stripped off White matter in the brain myelinated gray matter is not Multiple sclerosis has a weird geographical distribution Canada northern part of U S and northern Europe at high risk Puberty affecting multiple sclerosis if you move to a place at 15 or younger you are at the same risk of developing it as someone born there after 15 you are at the risk of where you moved from Trigger of multiple sclerosis unknown some antigens proposed to be a virus that looks like myelin sheath confuses the immune system Loss of motor and sometimes cognitive function D Alzheimer s Disease Dementia There are dramatically increasing instances of Alzheimer s Causes progressive memory loss a process causes nerve loss and in turn loss of cognitive function Agnosia the loss of ability to understand perception ex recognize daughter Aphasia inability to comprehend language Low incidence in Africa possibly because life span is shorter and high in Asia Risk factors age and genes Neuritic plaque made up of protein E Parkinson s Disease The basal ganglia affects coordination Acetylcholine functions as a neurotransmitter to the basal ganglia Symptoms shuffling stooped posture reduced facial expressions tremor especially when at rest Parkinson s represses dopamine this is responsible for many of the symptoms Parkinson s cannot be treated by simply adding dopamine Parkinson s and Alzheimer s are in a way like prion diseases