EXSS 380 1st EditionExam # 1 Study GuideNeed ScantronTrue/FalseMultiple ChoiceA few short answersIntroduction - What is the difference between motor control, motor learning and motor development? - Motor control: the study of how the neuromuscular system initiates and coordinates muscle activity to produce movement- Motor learning: the study of the acquisition of motor skillso Motor skills: voluntary movement to achieve a goalo New skill acquisition, enhancement of prior skills, and reacquisition after injury and disease- Motor development: changes in human motor behavior over one’s lifespan, factors that influence changes are maturation issues and age-related changes The Neuron- Know characteristics between Neurons and Glial cells- Neurons: functional unit of NS, transmit nerve impulseso Types: Sensory, Motor, and Interneurons- Glial cells: more abundant than neurons, support neuronso Provide structure, separate and insulate nerve connectionso Remove debris after neuronal deatho Direct growtho Regulate properties of presynaptic terminalso Prevent toxic substances in blood from entering the braino Release growth factors that nourish neurons- Know Types of Glial cells- Microglia: phagocytes that are mobilized after injury, infection, or disease- Macroglia: Oligodendrocytes, Schwann cells, and Astrocytes- Oligodendrocytes: each insulates multiple axons of neurons in the CNS to speed of signaltransmission- Schwann cells: each insulates one axon to speed up signal transmission in the PNS- Astrocytes: permeable to potassium, maintain potassium ion concentration in extracellular space, and clear excess neurotransmitters- Know the anatomy of the neuron- soma/cell body (metabolic center of cell)o Soma of sensory neurons are found in dorsal root ganglia of PNS on back side of spinal cordo Soma of interneurons are in the CNS gray matter of the braino Soma of motor neurons are in the CNS as well - dendrites (input neuron that conduct impulses to the soma , branched processes emerging from cell body)- axon (long thin cylindrical process that joins soma at axon hillock and transmits nerve impulses away from soma)o Oligodendrocytes or Schwann cells wrapped around to speed up signal transmission. Nodes of ranvier: spaces in between these insulated areas through which action potential jumps- presynaptic terminals at the end of axons (swollen ends of axon branches that communicate with postsynaptic terminals without touching them)o communicate with dendrites of postsynaptic cell most often, then soma, and most rarely axon- Neurons can be bipolar (dendrites out top of soma and axon out of bottom), unipolar (one branch out of middle of soma spits with dendrites on one end and axon on other), multipolar (many branched short dendrites out top and one long axon out bottom), or pyramidal (usually interneurons, random branches all around soma)- Dendrites of sensory neurons longer because have to link with receptors in periphery. - Dendrites of motor neurons shorter because get info from interneurons and want to get it quicker; have long axons to reach muscles- Nerve fiber: dendrite of axon- Nerve: bundle of nerve fibers in PNS- Tract: bundle of nerve fibers in CNS- Nucleus: cluster of somata in CNS- Ganglion: cluster of somata in PNS- Know the Principle of Dynamic Polarization and Connection Specificity- Principle of Dynamic Polarization: Electrical signals within a nerve cell flow in only one direction.- Principle of Connection Specificity: Neurons don’t connect randomly, rather they make specific connections at particular points. - Understand the difference between orthodromic and antidromic- Orthodromic transmission moves from the sensory/afferent nerve  CNS  motor/efferent nerve- Antidromic transmission moves in the opposite direction, may see when stimulate middle of an axon- What are the three factors that maintain resting membrane potential (-70 mV and -80 mV for skeletal muscle)- Concentration gradient: more K inside and more Na outside when neuron at rest. There are more K channels than Na channels so more K going out than Na coming in. Creates negative environment in cell at rest. - Nongated Channels: K ones leak K out and Na ones leak Na in- Sodium Potassium Pump: Move 3 Na out for every 2 K let in. - Know Phases of the action potential - Depolarization: decrease in membrane potential that comes from an influx on Na ions (inside becomes more positive and less negative)- When reaches threshold (-55mV) then action potential is generated- Potassium channels are opening at same time as sodium ones- Overshoot: complete reversal of the potential so now at 80 mV inside skeletal muscle cell instead of -80 mV it was at resting membrane potential- Repolarization: reestablishment of potential, potassium is leaking out because the channels are slower to close than the sodium ones- Hyperpolarization: occurs when too much potassium leaks out and results in a potential inside the cell that’s more negative than resting membrane potential- Slow to close potassium channels and hyperpolarization cause refractory period that  AP only able to travel in one direction- Ion channels function to conduct ions, recognize and select specific ions and to open andclose in response to electrical, mechanical, or chemical stimuli.- Neural info transmitted to skeletal muscle via the alpha motor neurons (NT: ACh) that originates in the spinal cord and is always excitatory- Motor unit: a single alpha motor neuron and all the muscle fibers it innervates, determines level of control- Speed of contraction is controlled by type of muscle fibers; Type IIa and b: fast twitch while Type I: slow twitch- 2 way to increase force of contraction: rate coding (frequency of firing) and motor unit recruitment- Know the Henneman Size Principle- Motor units are recruited from smallest to largest in contraction and size is determined by diameter of alpha motor neuron - In relaxation, goes in opposite- Allows for smooth, graded changes in contractile forceThe Synapse: point where two neurons communicate- What are the components of the synapse - Presynaptic cell, postsynaptic cell, synaptic cleft- What are the differences between electrical and chemical synapses- Electrical synapses: much smaller distance between neurons, gap junction channels, ion current transmits signal, basically no synaptic delay,