Quiz One - 1-5 PDF

somantic nervous system the part of the peripheral nervous system that transmits information between the central nervous system and the sensory organs and muscles (external environment) autonomic nervous system The part of the PNS that controls the bodies internal environment Afferent nerves In...

somantic nervous system the part of the peripheral nervous system that transmits information between the central nervous system and the sensory organs and muscles (external environment) autonomic nervous system The part of the PNS that controls the bodies internal environment Afferent nerves Input Efferent nerves Output sympathetic nervous system the division of the autonomic nervous system (Efferent) that arouses the body, fight or flight parasympathetic nervous system the division of the autonomic nervous system (Efferent) a set of nerves that helps the body return to a normal resting state, relaxed spinal nerves cervical, thoracic, lumbar, sacral, coccygeal sensory information enters spinal cord via...? Dorsal; unipolar sensory neuron motor commands exit spinal cord through...? ventral horn, travelling along multipolar motor neurons (output) area of the adult human forebrain telecephalon diencephalon area of the midbrain mesencephalon areas of the hindbrain metencephalon > forms cerebellum myelencephalon > forms medulla Pons Neuron external features Cell body, dendrites, axon, ions (sodium and chloride) Neuron internal features Membrane potential (-70mV) ions potassium and proteins What is the role of ion channels in information transmission? Ion channels open to allow ions to flow across the membrane, leading to changes in membrane potential. How does a graded potential differ from an action potential? A graded potential varies in size, while an action potential is an all-or-nothing response. What determines if a graded potential will reach the threshold to trigger an action potential? If the pulses from graded potentials add together to meet the threshold. How do ion channels open or close? By receptor activation, which is triggered by a signaling molecule (neurotransmitter) or an environmental event (e.g., light, touch, sound). What ion flow is responsible for the generation of an EPSP? Inward flow of sodium (Na⁺) ions. What happens to the membrane potential during an EPSP? The cell depolarizes to reach approximately 30 mV. What is the sequence of events in the Hodgkin-Huxley cycle? 1. Synaptic or receptor potential 2. Depolarization of the membrane. 3. Opening of voltage-gated Na⁺ channels 4. Na⁺ flows into the neuron. What triggers the opening of voltage-gated sodium channels in the Hodgkin-Huxley cycle? Depolarization of the membrane. what is the purpose of myelin? Acts as electrical insulation so signal travels faster and reduces interference from nearby axons (mix of fat and protein) What causes multiple sclerosis? Multiple Sclerosis is the process of demyelination/damage to the myelin sheath and subsequent disruption of the nerve impulse flow. symptoms of multiple sclerosis? Numb or weak in one or more limbs. Partial or complete loss of central vision, usually in one eye. Double or blurry vision. Tingling or pains in parts of body. Electric shock sensations that occur with certain head movements Tremors, lack of coordination or unsteady gait Slurred speech Fatigue Dizziness Photopic Vision High acuity color vision in bright light. Scotopic Vision Low acuity achromatic vision in dim light. Brainpower Cone-fed Circuits Low convergence; one ganglion cell per cone. Rod-fed Circuits High convergence; one ganglion cell feeds multiple rods. ipRGC Intrinsically photosensitive retinal ganglion cells. Melanopsin Photopigment sensitive to blue light in ipRGC. Circadian Rhythms Biological processes regulated by light exposure. The blind spot of the eye is where ________. 15 degrees from the center of the fovea. Vesicle Steps? Loading, storage, mobilization, docking, priming, fusion. Glutamate Neurotransmitter activating Na+ channels for EPSP? GABA Neurotransmitter activating K+ channels for IPSP? Amacrine Cells Release GABA to inhibit retinal signals. Horizontal Cells Support cells releasing GABA in the retina. Lateral Inhibition Surrounding cells inhibit a cell's response. Monochromatic View Vision limited to shades of grey, no red, blue or red Dichromatic View Vision limited to blues and greens. Trichromatic View Vision including blues, greens, and reds. Tetrachromatic Vision A visual system where there are four different types of cone Color Blindness in males and females is...? 5-10% of males, 0.1% of females affected. Deuteranomaly Weakness in green perception. Protanopia Inability to perceive red color. Opponent Process Theory Color perception controlled by opposing color systems. Homeostasis Self-regulation to maintain internal stability. hot =sweating cold = shivering Ca2+ arrives at the pre-synaptic terminal & depolarisation occurs > causes the action potential to drive the voltage-gated ion Ca2+ channel to open. Then the influx of Ca2+ ions triggers...?...synapse vesicles to fuse with the cell membrane, releasing neurotransmitters into the synaptic cleft Topographic Organization Reduces axon size, optimizing brain volume. Previous Play Next Rewind 10 seconds Move forward 10 seconds Unmute 0:00 / 0:15 Full screen Brainpower Read More Axon Length? Shorter axons allow more neurons and conserve resources. Dense Connectivity Neurons clustered for efficient local processing. Lateral Inhibition? Enhances contrast and sharpens sensory signals. Auditory Range of humans? frequencies from 20 to 20,000 Hz. Sound Wave Transmission? Outer ear to ear drum, then to cochlea. Cochlea Function? Transforms pressure waves into electrical signals. Mechanotransducers do what? Amplify cellular responses to membrane movement. Tonotopic Representation? Different frequencies activate specific cochlear zones. Optic Nerve Fibres? 90% terminate in lateral geniculate nucleus (LGN). Retinotopic Mapping? Visual field mapped onto LGN and V1 neurons. Simple Cells? Orientation selective, respond to bars and edges; have seperate on and off regions and can be monocular or binocular Complex Cells? Orientation selective, no ON/OFF subregions, nearly all binocular Cortical Magnification? Fovea processing largely from the centre of visual field than peripheral vision. Appears much larger on cortical map than retinal image Top-Down Processing? Uses prior knowledge to interpret sensory input. Bottom-Up Processing? Processes sensory information from receptors. Visual Input Percentage? 6% of inputs help understand distorted images. Cortical Connectivity is...? Predominantly top-down, integrating multisensory input. McGurk Effect? Visual cues influence auditory speech perception. Retinotopy? remapping of retinal image onto cortical surface Top-down auditory processing allows what..? - allows content and procedural demands to bias perception - allows for integration of multi-sensory input Ventral Stream Temporal lobe pathway for object identification. MTL Responses Firing rates vary with familiarity of faces. Grandmother Cells Hypothetical cells firing for specific familiar faces (debunked) Gnostic Cells Cells processing simple features to form images. Local Coding Specific features combined for object recognition. Object Discrimination Ability to distinguish between different objects. Cell Ensemble Group of cells firing together for image representation. Pattern Completion Recognizing incomplete patterns based on context. Pattern Separation Distinguishing between similar patterns or objects. Generalization Recognizing objects in varied contexts and positions. Trade-off in Processing Balancing pattern completion, separation, and generalization. Dense Encoding Requires overlap for pattern completion and generalization. Sparse Encoding Requires separation for distinct object representation. Face Patches (middle lateral, middle fundus, and anterior medial) There are specific cells in each of these areas that respond when one of the dimensions have been altered. If there's a certain amount of shading in an area etc. Chang and Tsao Experiment Demonstrated distributed facial representation in cells. Face Space Dimensional space representing facial features. Selective Cells Cells responding to specific features in faces. Pareidolia Perceiving familiar patterns, like faces or animals, in objects. 86 Billion Neurons Total neurons in the human brain. 40 Million Neurons Neurons present in the hippocampus. Chang and Tsao Experiment found Found that single cells are linked to one axis of face space and are blind to changes orthogonal to this axis. Multiple cells are active for a particular face, each coding a particular feature dimension. Dorsal Stream? Parietal lobe pathway for object location and movement. Hebbian Learning Cells that fire together strengthen their connections. AKINETOPSIA Inability to perceive motion, despite intact vision. Brainpower Read More V4 Area Brain region for color detection and processing. V5 Area Responsible for motion perception in the visual system. Binding Problem Challenge of linking features to form a unified object. Temporal Binding Synchronization of neural firing; links features together. Cell Assemblies Groups of neurons firing together to represent objects. Ambiguous Figure Visual illusion where perception shifts between interpretations. Foreground-Background Segmentation Distinguishing main objects from their surroundings. 3D Shape Computation Determining the shape of objects in three dimensions. Looming Perception of approaching objects based on visual angle. Fear Response Activation of amygdala due to perceived threats. Short Term Memory? Retention of information for 10-20 seconds. Reverberating cells that happen to be connected with one another that sufficiently drive recurrent activity amongst themselves (reverberating neural activity in closed-loop circuitry) Reverberating Cells Neurons connected to sustain activity in loops. Long Term Memory Requires strengthened connections for lasting retention. - Stronger synapse after consolidation - Neurons with an increased potential for activation Synaptic Strengthening Increased synaptic connections enhance future neuron activation. Consolidation Process that strengthens synapses post-experience. Reactivation Neural patterns from experiences re-expressed during recall. Long-Term Potentiation (LTP) Persistent increase in synaptic strength following stimulation. EPSP Excitatory postsynaptic potential indicating synaptic strength. NMDA Antagonist Blocks LTP and disrupts memory formation. ZIP Drug Weakens synaptic connections, impairing memory recall. Two Photon Microscopy Imaging technique for observing dendritic changes. Synaptic Scaling Adjustment of synaptic strength for homeostasis.