The Nervous SystemPhysiology 7.1 NotesVocab:- Central Nervous System: consists of brain and spinal cord- Peripheral Nervous System: has afferent (enter) and efferent (exit) neurons that are all the nerves outside of CNS.- Neurotransmitter: a chemical used to transmit impulses from one cell to the next across a synaptic gap- Autonomic NS: monitors body’s changes in homeostasis. Involuntary, unconscious reactions. - Sympathetic NS: fight or flight reaction system- Parasympathetic NS: rest and digest, stores energy- Glial Cells: supports/protects NS cells. Provides nutrients, speeds up communicationNotes:- Every organ in the body has dual modes, controlled by both sympathetic and parasympathetic NS. Each works to maintain homeostasis. - Many types of glial cells: (in PNS) satellite cells, Schwann cells, (in CNS) oligodendrocytes, microglia, astrocytes, ependymal cells.Physiology 7.2 NotesVocab:- Membrane Potential: difference in electrical charge between two sides of a membrane. Measure in volts (mV)- Active Channels: allow ions to transport only under certain conditions- Sodium/Potassium Pump: helps stabilize and regulate cell by moving sodium out and potassium in. Uses ATP to work.- Terminal Bulb: swollen terminal end of axon, releases NT- Acetylcholine: contracts muscles throughout CNS + PNS- Norepinephrine + Epinephrine: regulates attention + consciousness- Dopamine: regulates reward + pleasure sensations (emotion/addiction…)- Serotonin: Maintains emotion/moods- Glutamate: excitatory and aids memory/learning- Endorphins: pain controlNotes:- Resting neuron has membrane potential of -70mV, the difference between charges outside and inside of cell- Normal resting conditions mean more sodium ions + chloride ions outside, and more potassiumon the inside- Ion diffusion is blocked by protein channels that monitor intake and exit of ions depending on physical state of cell.- Active channels are regulated either by voltage changes or chemical (NT) changes.- Action potential is generated in 4 phaseso Resting state: ion channels are closed, more potassium on the inside and sodium on the outside. Voltage at -70mVo Depolarizing Phase: opens sodium channels, flows in to depolarize the membrane, causing more to open in chain reaction.o Repolarizing Phase: Sodium channels begin to close and Potassium begins to open at 0mV but it will reach +35mV before potassium steadily flows out. o Hyperpolarization: Potassium will leak all the way past -70mV and channels will close.o ATP will then pump sodium out and potassium in to go back to resting state.- If depolarization stimulus is not strong enough, all-or-none principle does not cause an action potential and neuron goes back to resting state.- The speed of action potential varies depending on thickness of aon and amount of myelin on ito Thicker = faster, more myelin sheath = fastero Action potentials travel faster along myelin sheaths because it goes through a leapfrog action and jumps from node to nodePhysiology 7.3 NotesVocab:- Meninges: the many layers between bone and brain in skull- Cerebrospinal Fluid: similar to plasma, protects and houses brain.- Proprioception: understanding where limbs are, general balance?- Cranial Nerves: start in brain and are responsible for organs mostly in head or upper body- Spinal Nerves: responsible for rest of body- Grey Matter: surface of cerebrum, full of naked axons + dendrites.- White Matter: contains myelinated axons that carry information, makes up most of brain.- Association Areas: all over cerebrum, integrates new information and adds richness of quality to stored memories.- Hemispheric Lateralization: separating tasks/functions to either side of cerebrum- Reticular Formation: receives all information from spinal cord and directs motor responses to appropriate bodily areas. - Spinal Cord: consists of white tracts surrounding gray matter, main route of communication between brain and body.- Reflex: an immediate life-saving response to dangerous stimuli developed through evolution and does not require brain processes.Notes:- Brain Stem = regulates all vital systems to life. o Medulla: heart rate, breathing, blood pressureo Pons: respiratory reflexes - Cerebellum = muscles + motor movement + balance. Important in learning motor skills and understanding bodily proprioception- Diencephalon = housed in the center of the brain and relays/transfors sensory information from the body to the brain. o Thalamus: relays most incoming sensory informationo Hypothalamus: secretes hormones, controlling glands + circadian rhythmo Limbic system: regulates emotions- Cerebrum = largest portion of brain (50%+) and processes/integrates information with responses for environmental stimuli + cognitive functions.o Cerebrum stores information in an unpredictable manner but houses long term memory (immediate, short term, long term)o Has “neural plasticity” characteristic where the brain can be altered to cope from damages or other changes. o Learning changes brain in positive way, more dendrite + synaptic growth- Cerebrum is divided into hemispheres that have small degrees of specialization/lateralization.o Left hemisphere: mathematics, language, logico Right hemisphere: art, patterns, emotiono Corpus Callosum: communicates + relays info between two halves- Cerebrum has 4 lobes with specialized functions in eacho Frontal Lobe: contains motor cortexo Parietal Lobe: contains sensory cortexo Temporal Lobe: auditory interpretationo Occipital Lobe: visual interpretation- The Spinal Cord connects the rest of body to the braino Reflexes bypass the brain and response is