1 12 16 Notes Hippocrates Father of Medicine figured out that the brain controls all emotions not the heart o 460 377 The brain is key Probably from brain damaged patients Plato 428 347 Brain is roughly spherical so appropriate for seat of reason Aristotle 384 322 Brain s function was to cool off the heart cardiocentric view Galen 129 200CE Ventricles of the brain as main function rather than the grey matter we look at today o He thought this because they were filled with a substance Spinal fluid and they were in the center of the brain that they were important Descartes animal spirits enter the cavities of the brain o The physical world sends things to sensory organs brain muscles and then you produce the action Involuntary action Sensory motor reflex Perception conscious action controlled by mind Dualism allows clear division of sensation and perception Thomas Hobbes a man is a body substance and body signify the same thing and therefore substance incorporeal are the words which when they are joined together destroy one another He advocated that we are our bodies Central to understanding how our brain controls behavior o Stressed the importance of science John Locke o Empiricism All knowledge comes from experience o Ideas associations of sensations and or reflections o Tabula Rasa blank slate Charles Darwin o Continuity of species can study animals to learn a lot about human mechanisms we know how action potentials work in humans because of how they work in squids Conservation of a trait Traits which are adaptive are conserved ex the way an action potential works o Perception and our sense of reality are the products of evolution Reproductive success Importance of type of energy in the environment determines which senses have developed o Natural selection 2 important features 1 Variation in a trait 2 Selection o Reproduction not survival o Evolutionary Perspective Adaptive Value sensory processes are specialized for the ecological niche Divergence Diversification of traits Some species sense energies that humans cannot Bees see ultraviolet lights Rattlesnakes see infrared energy Dogs and cats can sense sounds with higher frequencies Elephants can hear very low frequency sounds which are used to communicate Sensory transduction is a biological process Materialist perspective perception is also a biological process o Brain activity related to perception o Doctrine of specific nerve energies Awareness related to WHICH nerves are activated not HOW History of Medical and Philosophical ideas they are activated o Ancient teachings o Dualism o Materialism o Empiricism o Functionalism o Evolutionary Perspective o Sensory systems and neurobiology 1 14 16 Notes Different orientations of the brain o Dorsal view Top view o Lateral view Side view o Ventral view Bottom view Cranial nerves Twelve pairs of nerves one for each side of the body that originate in the brain stem and reach sense organs and muscles through openings in the skull Lobes of the brain o Frontal o Parietal o Temporal o Occipital Cutting the brain in different ways o Horizontal cut rostral to causal cut parallel to the ground o Coronal Cut Perpendicular to the ground and midline cut from dorsal to ventral surface o Sagittal cut cut down the midline perpendicular to the ground Anterior Rostral towards the front of the brain Posterior Caudal towards the back of the brain Dorsal top of brain Ventral bottom of the brain Medial middle of the brain Midbrain very top of the brainstem Brainstem attaches to the spinal chord Lateral side of the brain Cerebellum controls coordinated movements and some learning important for remaining upright Thalamus Most sensory systems pass through the thalamus before getting to the cortex Cerebral Cortex all of the squiggly parts Corpus Collosum Fiber tracks connecting left and right hemisphere and important for communication between both side of the brain o Cutting this prevents seizures on both sides of the brain or from a seizure spreading from one side of the brain to the other Flow of Information in the brain o Receptor Brainstem Midbrain Thalamus Cortex Information comes into the receptor from the cranial nerve or spinal chord o Auditory Information Cochlea Auditory nerve Cochlear Nuclei Inferior colliculus in the midbrain Medial geniculate in the thalamus Auditory cortex in the Temporal lobe Soma Cell Body Dendrites extensions off of the Soma they receive information from other neurons Input side of the cell Axon Output side of the cell Terminal the end of the neuron Information flows from the Soma to the terminal o This information is called action potential Synapse space between the terminal of one neuron and the next dendrite Presynaptic Area before the action potential reaches the new dendrite close to the terminal of the previous neuron Postsynaptic After the action potential reaches the new dendrite located on the new dendrite Neuron Doctrine Electrical activity in neurons is IONIC ION molecule having fewer more electrons than protons They have an electrical charge o Ex Salt Sodium Chloride NaCl When dissolved Na and Cl Potassium K Calcium Ca Anion any ion with charge Cation any ion with charge Electrical even requires a battery or the equivalent In a sense the neuron is a small rechargeable battery Channels allow ions through the membrane o Some channels are voltage gated Open or close depending on voltage difference across the membrane Ex voltage gated Na channel An action potential starts with voltage gated Na channels open o During an action potential synaptic potential or receptor potential channels open and let ions through 2 Factors determine movement o Concentration gradient o Electrical forces The Sodium Potassium Pump o Acts to maintain proper concentrations of Na and K o Needed for maintaining resting potential and for recovery from action potential o Recharges the battery o Requires energy cellular energy ATP In myelinated axons action potential can jump down axons Benefits of this o Much faster o Allows long distance rapid communication o Also more energy efficient less pumping needed Timing of action potentials is often essential for coding so speed matters Neurotransmitters act as a key they attach to receptor molecules and open 11 21 16 Notes up Na channels to let sodium in o This all takes place within the synsapse Excitatory Post Synaptic Potential EPSP can be various sizes During a synaptic potential ligand gated channels open up o Chemical binding to receptor
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