Physiology Exam 6 Study Guide Visual System Info energy waves Ex birds can see UV rays that we can t Type photoreceptors Components of the eye Cornea and lens focus image All about what receptors we have which waves we register We pick up only a specific range of waves only certain energy levels Glasses lens doesn t match up to the shape of the eye problem is the position of the retina relative to where the cornea and lens create the focused image Retina registers information and transforms into signal Receptors located at the back light must be intense enough to get through all other cells like afferent neurons Not very properly design reason we are daytime mammals Info must travel forward then U turn to back by the brain Light enters the eye pass through around small blood vessels capillaries ganglion neuronal cell bodies and bipolar neurons on its way to back of the eye absorbed by pigments picked up by cones and rods in the retina information carried back towards light by the bipolar cells condensed in the ganglion cells Info carried by the ganglion cell s axons to the blind spot turns again now the U is complete back into the head Ex octopus has receptors in the front good nighttime vision Afferent neurons in the front Ex Glow in pet s eyes allows them to visual success in low light nighttime have an extra coating at the back of their eyes that reflects photons that have gone past the receptors back towards them the light you are seeing actually made it past their receptors twice without actually hitting them Where afferents exit NO receptors no detection blind spot Have 1 blind spot in each side brain doesn t see hole but makes up image based on surroundings Encoding based on receptors in retina Rods bigger activated more in dim light Cone smaller only activated in bright light colors As light gets dimmer rods activated more and cones are lost less color gray wash Color Vision based on 3 cone pigments RGB red green blue Pigments respond differentially range of colors via algorithm translating the amount of response coming from each cone Ex yellow color no blue activated little green activated lot of red activated Signals inputs sent to visual cortex of brain translate into color Colorblind lacking pigments Receptors cones are present but not responding as in one w normal vision For every possible input combination algorithm has a color associated with it and assigns it wrong translation in colorblind people There is a problem with the receptors which causes translation problems in the brain Red green is most common in white males 10 20 Problem for everyone traffic accidents Solution reflector added around whole perimeter of traffic light Border to match up light to its position Chemosensory System Info dissolved chemicals Type chemoreceptors Components External Taste and smell used to do so Internal Tracks changes in pH Oxygen CO2 etc in body Must constantly be monitoring levels Taste In mouth throat area Aftertaste is different activating receptors in throat not mouth Lots of surface area bumpy more receptors Categories Salt Sodium binding to sodium channels vital for APs Want more salt if low levels in body Many animals lick roads for salt used to be limited Sour H blocks potassium channels potassium accumulates in receptor cell can t diffuse down gradient out of cell depolarization Necessary to maintain acidity in the body Sweet sugars bind used for energy Bitter various substances bind high levels can be toxic Avoid want to eat less of it Umami Glutamate agonist MSG binds savory flavorful taste Eat more if present ex MSG vs non MSG brownies Glutamate key for cell metabolism Likely adding a 6th receptor category soon fat Olfaction In nasal passages dissolved chemicals Receptors differing types and quantities among people Same general categories but don t all take in the same chemicals Last only about 2 months then change over affect inputs Ex farmers don t register poop info but register trash in NYC Ex You won t smell bad roommate after 2 months Ex People bathe in cologne they can t smell it as well Perception How we interpret signals putting all together in cerebrum Signals often combine Ex Taste is not just in the mouth don t taste as well when nose stuffed up or ears are plugged think chips are stale if don t hear the crunch Ex autism auditory visual not occurring at the same pace don t process together Like when lips and voices on screen are different We are better at detection that consciously aware Guys know when a girl is ovulating You alter your choices behavior based on certain chemicals in the air even though if asked to say if there was a reason for your choice you would not believe that you had even registered the chemical difference let alone based your decision on it Types of Muscle 1 Skeletal striated Attaches to bone via tendons Supports and moves skeleton via contractions Voluntary control 2 Cardiac striated Heart muscle Autonomic involuntary control 3 Smooth GI tract Sheets surrounding organs Contraction alters flow ex of air in lungs or blood circulating Anatomy of Skeletal Muscle Muscle skeletal implied for now is an organ Myofibers called fibers because of appearance of cells many are long Muscle cells fibers Multi nucleated another reason muscle cells are referred to as fibers multiple cells that have been fused together to create 1 long myofiber Movement would otherwise rip individual cells apart Myofibrils bundles of protein myofilaments within a myofiber Myofilaments within myofibrils 2 different kinds Basic structure protein interactions affect how muscles work Thick myosin bunch of myosin put together myosin myofilament Thin actin bunch of actin put together actin myofilament Sarcoplasmic Reticulum SR surrounding myofibrils Without the SR bundles would not exist would lose myofibrils Holds Ca2 necessary for exocytosis of NTs Basic intracellular fluid in muscle is low holds Calcium like a bank Transverse Tubules TT plasma membrane extensions that go down into cell like funnel Interstitial fluid channels allows IF to gain access to inside parts of myofiber Critical to function of muscle fibers increases their surface access Mitochondria tons used for aerobic ATP synthesis Need tons of ATP for muscle movement Anatomy of a myofilament Z line disc connections between thins look like a line but form a disc in the 3D Sarcomere functional unit z to z Trying to understand how they change in size shorten in contraction How do we get z lines to move
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