PHIS 206 1st EditionExam # 1 Study Guide Lectures: 1 - 9Lecture 1 (August 23)Introduction/Homeostasis-Homeostasis: maintaining constancy-Negative Feedback: homeostatic response in the opposite direction-Positive feedback: homeostatic response in the same directionLecture 2 (August 26)Cell StructureIntracellular (ICF): inside cells Extracellular (ECF): outside cells-LOW concentrations of Na+ -HIGH concentrations of K+-HIGH concentrations of Na+ (15-20 × greater)-LOW concentrations of K+-simple diffusion: random motion of molecules caused by heat- Diffusion rate is proportional to conc. of diffusion × area × Kelvin FIGG’S EQUATION viscosity × thickness × mol. size(Not sensitive to temperature since it does not change much)-How Do Large Molecules Get Across? Facilitated diffusion: proteins embedded in membranes can weakly bind certain molecules carrier proteins: the side that the molecules attaches has higher concentrations NO ENERGY for facilitated or simple diffusionLecture 3 (August 28)Diffusion, Osmosis, and Transport-Osmosis/Osmotic Pressure Water diffusing down its own gradient hydrostatic pressure: depends on height of column Membrane: water can cross easily, but water-soluble (big) molecules cannot cross freely Osmotic Pressure: force exerted on water as it goes downhill Van’t Hoff: pressure exerted on molecules would be exactly the same as pressure exerted by anygasSeparated by cell membrane:permeable to Na+ and K+- Cell Membrane Actual concentration of biological fluids = 310 mM (millimols) osmolarity (Osm): introduced to measure molarity of all osmotic substances *Osmosis is the only mechanism that deals with water in our bodies- Active Transport Molecules move “uphill” (low to high concentrations) Requires Energy b/c molecules move in the opposite direction ATP= ADP (basic subunit of biological systems) + P1 ( inorganic phosphate) + ENERGY Membrane ATPase: sodium pumped out of cell, potassium pumped into cellFor stable K+ levels, the rate of diffusion = rate of pump pumping K+ into cellInside | Outside K high | K low Na low | Na highLectures 4 and 5 (August 30-September 4)Cellular Neurophysiology- Nervous System―Units-2 Basic Types of Cells1. Neurons: “businessman”; info transferred from one place to another (plural: nodes)2. Glia: “glue”; provide environment that allows neurons to do their job- Glial Cells―4 Types1. Oligodendroglia: glial cells that have many branches wrap around axons in neurons insulators in brain + spinal chord2. Schwann Cells: glial cells wrapped around an axon (1 thing wrapped around) are NOT branched in the nerves leading to brain and spinal 3. Astroglia: points will touch nearest capillary and nearest neuron facilitates movement of nutrients/waste products between blood stream and nerve cells4. Microglia: heals damage to nerve cells accumulates site of injury in masses- Neurons-2 ways to classify1. Functional: which direction information is travelling sensory neurons/afferent: info towards CNS motor neurons/efferent: info away from CNS (muscles) interneurons: towards each other (neuron to neuron)2. Structural: dendrite (branches), soma (body), axon (exterior of cell membrane), terminals (distilling neurons) Neurons have ONE axon, but MANY dendrites bipolar neuron: dendrite and axon connect to different places of soma uniport: both come from single projection; 1 place where information comes out multiport: single axon; many dendrites; many routes out-Some axons are wrapped in Schwann cells in many ways and so tightly, so almost no cytoplasm is left and lots of cell membrane is -Wrap in segments but always spaces (Nodes of Ranvier) -myelin sheath: coated axon with a substantial layer of liquids -myelinated axons: tightly wrapped Schwann cells- Electrical Properties of Membranes-cell membrane (+) on the outside, (-) in the inside-resting potential: usually -70 mV-stimuli: gradient responses; mimics: if gradient up, then stimuli up-If voltage exceeds threshold, then single spike (constant #): suprathreshold-Action potential: spike; CAN move; created by stimulating the threshold-Threshold: stationary (measure on soma of cell; nothing on axon)-All-or-nothing: either generate action potential or do not-Grading potentials: only occur in the soma (body); changes in mV-Refractory period: resistance to responding to a stimulus Consequences: limits the # of action potentials in a nerve-Voltage gated channels: embedded in neurons; can be open or closed for a specific ion The voltage gradient across the membrane determines whether it is open (when threshold is reached) or closed- Neurons-Inhibited neuron: becomes MORE (-) and harder to reach threshold with a stimulus-Excited neuron: becomes LESS (-) and easier to reach threshold with a stimulus-Myelinated axons: can transmit action potentials faster- Myelinated and Nonmyelinated-Action potentials can only go AWAY from the soma!-synapse: where axon terminal (pre-synaptic) of one neuron comes into contact with thedendrites or soma of another neuron (post-synaptic)-synaptic cleft: does not let cytoplasm interact- Neurotransmitters-One neuron only releases one neurotransmitter-Most common neurotransmitter: Acetylcholine (ACh)-ACh in the synapse binds to receptors in the post-synaptic cell-actively transported- Neurons-Convergence: several neurons are postsynaptic to 1 neuron-Divergence: 1 neuron is postsynaptic to many neurons - ConvergenceAcetylcholine = Acetate + Choline-Excitatory neurons: decreases (-) input of membrane potential-Inhibitory neurons: increases (-) input of membrane potential-When the excitatory > inhibitory, then change is called Excitatory Postsynaptic Potential (EPSP).-When the inhibitory > excitatory, then change is called Inhibitory Postsynaptic Potential(IPSP). (MORE NEGATIVE)Lectures 6 and 7 (September 6- September 9)Central Nervous System- Peripheral Nervous System-Every neuron apart from the CNS-Afferent: nerve impulses to the brain-Efferent: nerve impulses away from the brainA. Somatic: part that control the muscle’s activityB. Autonomic: controls/efference that goes to other organs internally- Central Nervous System-Brain: between it and the skull is called meninges Dura mater: outer furry layer “tough mother” Arachnoid mater: extremely vascular and looks