BIO 101: A&P 1 Learning Objectives for Exam 3

Connect the specific functions of ATP in muscle cell contraction/relaxation' (in the ____ of ATP, myosin heads will ____ detach, causing rigor mortis.) *this cycle will continue as long as ATP is available and Ca2+ is bound to troponin. If ATP is not available, the cycle stops between steps 2 and 3 (REFERS TO CROSS BIRDGE THEORY SEE CARD 50)

(in the absence of ATP, myosin heads will not detach, causing rigor mortis.) *this cycle will continue as long as ATP is available and Ca2+ is bound to troponin. If ATP is not available, the cycle stops between steps 2 and 3 (REFERS TO CROSS BIRDGE THEORY SEE CARD 50)

Define muscle fatigue and its causes. •Its ionic disruptions are important to (slide 9) -A state of physiological ____ to contract even though muscle may still be receiving stimuli. 1. During brief periods of tetany, ____ decreases as large motor units (fast twitch fibers) fatigue. a. Depletion of Creatine Phosphate ____ b. Depletion of Muscle ____ Note: A build up of lactic acid was thought to be at least partially responsible for muscle fatigue. It now appears that lactic acid build up is at least not a direct cause of muscle fatigue. May have more of an effect on psychological fatigue. 2. Intense short duration exercise produces fatigue rapidly via ____ disturbances that alter Excitation-contraction coupling, but recovery is rapid. a.) Accumulation of ____ in the T-tubules prevents calcium ____from SR b.) Accumulation of ____ from CP and ATP breakdown can reduce ____ in muscle (muscle fatigue) by *interfering with ____ release from SR *interfering with ____ release from myosin head thus altering power strokes of myosin. c.) Decreased ____ and increased ____ act to decrease calcium release from SR. 3.Slow-developing ____ of prolonged low-intensity exercise a.____depletion b.____ loss through sweating decreases muscle ____ c.____ fatigue à psychological fatigue???? d.____ SR thus interferes with calcium release "pseudo-fatigue"—a sense of fatigue unrelated to actual ____ of physiological/biochemical energy.

-A state of physiological inability to contract even though muscle may still be receiving stimuli. 1. During brief periods of tetany, tension decreases as large motor units (fast twitch fibers) fatigue. a. Depletion of Creatine Phosphate stores b. Depletion of Muscle Glycogen Note: A build up of lactic acid was thought to be at least partially responsible for muscle fatigue. It now appears that lactic acid build up is at least not a direct cause of muscle fatigue. May have more of an effect on psychological fatigue. 2. Intense short duration exercise produces fatigue rapidly via ionic disturbances that alter Excitation-contraction coupling, but recovery is rapid. a.) Accumulation of K+ in the T-tubules prevents calcium release from SR b.) Accumulation of Pi from CP and ATP breakdown can reduce tension in muscle (muscle fatigue) by *interfering with Ca 2+ release from SR *interfering with Pi release from myosin head thus altering power strokes of myosin. c.) Decreased ATP and increased magnesium act to decrease calcium release from SR. 3.Slow-developing fatigue of prolonged low-intensity exercise a.Fuel depletion b.Electrolyte loss through sweating decreases muscle excitability c.Central fatigue à psychological fatigue???? d.Damages SR thus interferes with calcium release "pseudo-fatigue"—a sense of fatigue unrelated to actual depletion of physiological/biochemical energy.

Student should be able to draw and label a typical multipolar neuron. -____ ____ -Nissl Bodies - ____ ____, and "free" ____ to make proteins for the neuron

-Axon hillock -Nissl Bodies - Rough ER, and "free" ribosomes to make proteins for the neuron

Describe the functions of Schwann cells and satellite cells (PNS). -Has ____ Cells -Satellite Cells: PNS ____ -____ the neuron cell bodies of the peripheral nervous system

-Has Schwann Cells -Satellite Cells: PNS NeuroGlia -Protect the neuron cell bodies of the peripheral nervous system

Define motor unit and describe the relationship between motor unit size and ability for fine motor control. -Muscle Fiber (another name for muscle cell) -Sacrolemmas: membrane of muscle cells 1.Motor Unit: A motor ____ and its innervated muscle ____ A motor unit consists of ____ motor neuron and ____ the muscle fibers it innervates, or supplies (Figure 9.10). When a motor neuron fires (transmits an action potential), all the muscle fibers it innervates ____. 2.Motor Unit Size; just a ____ fibers to thousands. More fibers = more ____ The number of muscle fibers per motor unit may be as high as several hundred or as few as four. Muscles that exert fine control (such as those controlling the fingers and eyes) have ____ motor units. By contrast, large, weight-bearing muscles, whose movements are less precise (such as the hip muscles), have ____ motor units. The muscle fibers in a single motor unit are ____ clustered together but are spread throughout the muscle. As a result, stimulation of a single motor unit causes a ____ but ____ contraction of the muscle. Velocity and duration of muscle contraction is determined by muscle fiber type, load, and recruitment -predominance of fast glycolytic (fatigable) fibers), small load, increased recruitment lead to higher contractile ____ -predominance of slow oxidative (fatigue-resistant) fibers, small load, and increased recruitment lead to increased contractile ____ -From generally smallest to largest, they are slow oxidative fibers (SO), fast oxidative fibers (FO), and fast glycolytic fibers (FG). The staining technique used differentiates the fibers by the ____ of their mitochondria, which contains mitochondrial enzymes.

-Muscle Fiber (another name for muscle cell) -Sacrolemmas: membrane of muscle cells 1.Motor Unit: A motor neuron and its innervated muscle fibers A motor unit consists of one motor neuron and all the muscle fibers it innervates, or supplies (Figure 9.10). When a motor neuron fires (transmits an action potential), all the muscle fibers it innervates contract. 2.Motor Unit Size; just a few fibers to thousands. More fibers = more power The number of muscle fibers per motor unit may be as high as several hundred or as few as four. Muscles that exert fine control (such as those controlling the fingers and eyes) have small motor units. By contrast, large, weight-bearing muscles, whose movements are less precise (such as the hip muscles), have large motor units. The muscle fibers in a single motor unit are not clustered together but are spread throughout the muscle. As a result, stimulation of a single motor unit causes a weak but uniform contraction of the muscle. Velocity and duration of muscle contraction is determined by muscle fiber type, load, and recruitment -predominance of fast glycolytic (fatigable) fibers), small load, increased recruitment lead to higher contractile velocity -predominance of slow oxidative (fatigue-resistant) fibers, small load, and increased recruitment lead to increased contractile duration -From generally smallest to largest, they are slow oxidative fibers (SO), fast oxidative fibers (FO), and fast glycolytic fibers (FG). The staining technique used differentiates the fibers by the abundance of their mitochondria, which contains mitochondrial enzymes.

Explain the factors contributing to the graded muscle contractions (3) •Wave summation •Multiple motor unit recruitment •Treppe (Stair-case effect) •How do all these allow whole muscles to have graded responses? •Note: Tetany - intermittent muscular spasms -Whole muscle contractions are ____ and vary in strength depending on demands placed on them. That is WHOLE MUSCLE contractions are ____. Two Main Ways in which Whole Muscles Contract in a Graded Fashion 1. Changing the ____ of Stimulation = Wave summation (a.k.a. temporal summation) and eventually tetany* -Higher frequency of stimulation leads to greater ____ in a given set of motor units. -Primary function of temporal summation is to produce smooth, ____ muscle contractions by rapidly stimulating a set number of muscle fibers. 2. Increasing the ____ of the stimulus = Motor Unit Recruitment (a.k.a. Multiple Motor Unit Summation)* -Greater strength of stimulus leads to greater ____ of motor units contracting thus stronger contraction -subthreshold stimulus: Stimuli that produce ____ observable contractions -threshold stimulus: The stimulus at which the first observable contraction occurs is called the ____ stimulus (Figure 9.13). Beyond this point, the muscle contracts more vigorously as the stimulus strength increases. -maximal stimulus: The maximal stimulus is the strongest stimulus that increases contractile force (point at which ____ muscle's motor units are recruited). No ____ contractions beyond here -recruitment and the size principle: The recruitment process is not random. Instead it is dictated by the size principle (Figure 9.14). In any muscle: The motor units with the ____ muscle fibers are activated first because they are controlled by the smallest, most highly excitable motor neurons. As motor units with larger and larger muscle fibers begin to be excited, contractile strength ____. The largest motor units, containing large, coarse muscle fibers, are controlled by the largest, least excitable (highest-threshold) ____ and are activated only when the most powerful contraction is necessary. 3. Treppe ("Stair case Effect) -Although not a main mechanism this phenomenon occurs during the first ____ seconds of a contraction and can cause an increase in strength of contraction ____ increasing firing frequency or increasing strength of stimulus. -If no Summation is occurring, why is there an increase in muscle tension? muscle stimulation at variable frequencies: low frequency, each stimulus produces an ____ twitch response. moderate frequencies, each twitch has time to recover but develops more ____ than the one before (treppe phenomenon)- calcium was not completely put back into ____ and heat of tissue increases myosin ATPase ____

-Whole muscle contractions are smooth and vary in strength depending on demands placed on them. That is WHOLE MUSCLE contractions are GRADED. Two Main Ways in which Whole Muscles Contract in a Graded Fashion 1. Changing the Frequency of Stimulation = Wave summation (a.k.a. temporal summation) and eventually tetany* -Higher frequency of stimulation leads to greater tension in a given set of motor units. -Primary function of temporal summation is to produce smooth, continuous muscle contractions by rapidly stimulating a set number of muscle fibers. 2. Increasing the STRENGTH of the stimulus = Motor Unit Recruitment (a.k.a. Multiple Motor Unit Summation)* -Greater strength of stimulus leads to greater number of motor units contracting thus stronger contraction -subthreshold stimulus: Stimuli that produce no observable contractions -threshold stimulus: The stimulus at which the first observable contraction occurs is called the threshold stimulus (Figure 9.13). Beyond this point, the muscle contracts more vigorously as the stimulus strength increases. -maximal stimulus: The maximal stimulus is the strongest stimulus that increases contractile force (point at which all muscle's motor units are recruited). No stronger contractions beyond here -recruitment and the size principle: The recruitment process is not random. Instead it is dictated by the size principle (Figure 9.14). In any muscle: The motor units with the smallest muscle fibers are activated first because they are controlled by the smallest, most highly excitable motor neurons. As motor units with larger and larger muscle fibers begin to be excited, contractile strength increases. The largest motor units, containing large, coarse muscle fibers, are controlled by the largest, least excitable (highest-threshold) neurons and are activated only when the most powerful contraction is necessary. 3. Treppe ("Stair case Effect) -Although not a main mechanism this phenomenon occurs during the first few seconds of a contraction and can cause an increase in strength of contraction without increasing firing frequency or increasing strength of stimulus. -If no Summation is occurring, why is there an increase in muscle tension? muscle stimulation at variable frequencies: low frequency, each stimulus produces an identical twitch response. moderate frequencies, each twitch has time to recover but develops more tension than the one before (treppe phenomenon)- calcium was not completely put back into SR and heat of tissue increases myosin ATPase efficiency

Compare and contrast nicotinic receptors with muscarinic receptors. -____ acetylcholine (ACh) receptors also function as ion ____. The nicotinic acetylcholine receptor contains channel that is closed until the receptor binds to ____. Na+ and K+ diffuse ____, and in ____ directions through the open ion channel -____ ACh receptors require the mediation of ____-proteins. The figure (slide 25, L 23) depicts the effects of ACh on the pacemaker cells of the heart. Binding of ACh to its muscarinic receptor causes the ____-____ subunits to ____ from the ____ subunit. The beta-gamma complex of G-proteins then binds to ____+ channel, causing it to ____. Outward diffusion of K+ results slowing the heart rate. •Muscarinic receptors: Acetyl Cholinergic (using Acetyl Choline as a NT) •5 types of Muscarinic Receptors -muscarinic receptors ____ (slow IPSP/EPSP) - 2nd messengers regulate K+ or Cl- channels and are ____

-nicotinic acetylcholine (ACh) receptors also function as ion channels. The nicotinic acetylcholine receptor contains channel that is closed until the receptor binds to ACh. Na+ and K+ diffuse simultaneously, and in opposite directions through the open ion channel -muscarinic ACh receptors require the mediation of G-proteins. The figure (slide 25, L 23) depicts the effects of ACh on the pacemaker cells of the heart. Binding of ACh to its muscarinic receptor causes the beta-gamma subunits to dissociate from the alpha subunit. The beta-gamma complex of G-proteins then binds to K+ channel, causing it to open. Outward diffusion of K+ results slowing the heart rate. •Muscarinic receptors: Acetyl Cholinergic (using Acetyl Choline as a NT) •5 types of Muscarinic Receptors -muscarinic receptors regulate (slow IPSP/EPSP) - 2nd messengers regulate K+ or Cl- channels and are slower

Recall the cause of rigor mortis and how this relates to sarcomere contraction -rigor mortis = cadaveric ____ or death ____ -Adenosine triphosphate (ATP) is a necessary component in the ____ of the myosin filaments of normal muscle. Rigor mortis commences when the rate of re-synthesis of ATP is ____ than its degradation. In the early hours after clinical death, muscle glycogen fuels the cycle of hydrolysis and re-synthesis of ATP. (MYOSIN HEADS CANNOT DETACH WO ATP)

-rigor mortis = cadaveric rigidity or death stiffening -Adenosine triphosphate (ATP) is a necessary component in the relaxation of the myosin filaments of normal muscle. Rigor mortis commences when the rate of re-synthesis of ATP is less than its degradation. In the early hours after clinical death, muscle glycogen fuels the cycle of hydrolysis and re-synthesis of ATP. (MYOSIN HEADS CANNOT DETACH WO ATP)

Know that muscle functions require nerve innervation and blood supply •What muscle structure are innervated by motor neurons? •How many motor neurons innervate these muscle structures? -the neuromuscular junction, or ____ ____ plate, is the region where the motor neuron ____ the skeletal muscle. it consists of multiple axon terminals and the underlying junctional folds of the sarcolemma on a muscle fiber -The axon of each motor neuron branches profusely as it enters the muscle so that it can innervate multiple muscle ____. When it reaches a muscle fiber, each axon divides again, giving off several short, curling branches that collectively form an oval neuromuscular junction, or motor end plate, with a ____ muscle fiber. -Each muscle fiber has only ____ neuromuscular junction, located approximately midway along its length. 2.Nerve Supply -Each muscle is usually innervated by ____ motor nerve -releases the ____, Acetylcholine. 3.Blood Supply -Served by one ____ and one or more ____.

-the neuromuscular junction, or motor end plate, is the region where the motor neuron contacts the skeletal muscle. it consists of multiple axon terminals and the underlying junctional folds of the sarcolemma on a muscle fiber -The axon of each motor neuron branches profusely as it enters the muscle so that it can innervate multiple muscle fibers. When it reaches a muscle fiber, each axon divides again, giving off several short, curling branches that collectively form an oval neuromuscular junction, or motor end plate, with a single muscle fiber. -Each muscle fiber has only one neuromuscular junction, located approximately midway along its length. 2.Nerve Supply -Each muscle is usually innervated by 1 motor nerve -releases the neurotransmitter, Acetylcholine. 3.Blood Supply -Served by one artery and one or more veins.

Describe the steps of NT release and signal transmission at the neuromuscular junction in detail (what is happening) Describe the events at the neuromuscular junction. 1) action potential arrives at axon terminal of ____ neuron 2) voltage-gate Ca2+ channels ____ and Ca2+ enters the axon terminal 3) Ca2+ entry causes some synaptic vesicles to release their contents (acetylcholine) by ____ 4) acetylcholine, a neurotransmitter, diffuses across the synaptic cleft and binds to receptors in the ____ 5) ACh binding opens ion channels that allow ____ passage of Na+ into the muscle fiber and K+ out of the muscle fiber. More Na+ moves in than K+ out, which produces a local change in membrane potential called ____ ____ potential 6) ACh effects are terminated by its breakdown in the synaptic cleft by ____ and ____ away from the junction -How does a motor neuron stimulate a skeletal muscle fiber? Focus on Events at the Neuromuscular Junction (Focus Figure 9.1) covers this process step by step. Study this figure before continuing. -The result of the events at the neuromuscular junction is a transient change in ____ potential that causes the interior of the sarcolemma to become ____ negative (a ____). This local depolarization is called an end plate potential (EPP). The EPP spreads to the adjacent ____ and triggers an AP there. -After ACh binds to the ACh receptors, its effects are quickly terminated by ____ (as″ĕ-til-ko″lin-es′ter-ās), an enzyme located in the synaptic cleft. Acetylcholinesterase breaks down ACh to its building blocks, acetic acid and choline. Removing ACh prevents continued muscle fiber contraction in the absence of additional nervous system stimulation.

1) action potential arrives at axon terminal of motor neuron 2) voltage-gate Ca2+ channels open and Ca2+ enters the axon terminal 3) Ca2+ entry causes some synaptic vesicles to release their contents (acetylcholine) by exocytosis 4) acetylcholine, a neurotransmitter, diffuses across the synaptic cleft and binds to receptors in the sarcolemma 5) ACh binding opens ion channels that allow simultaneous passage of Na+ into the muscle fiber and K+ out of the muscle fiber. More Na+ moves in than K+ out, which produces a local change in membrane potential called end plate potential 6) ACh effects are terminated by its breakdown in the synaptic cleft by acetylcholinesterase and diffusion away from the junction -How does a motor neuron stimulate a skeletal muscle fiber? Focus on Events at the Neuromuscular Junction (Focus Figure 9.1) covers this process step by step. Study this figure before continuing. -The result of the events at the neuromuscular junction is a transient change in membrane potential that causes the interior of the sarcolemma to become less negative (a depolarization). This local depolarization is called an end plate potential (EPP). The EPP spreads to the adjacent sarcolemma and triggers an AP there. -After ACh binds to the ACh receptors, its effects are quickly terminated by acetylcholinesterase (as″ĕ-til-ko″lin-es′ter-ās), an enzyme located in the synaptic cleft. Acetylcholinesterase breaks down ACh to its building blocks, acetic acid and choline. Removing ACh prevents continued muscle fiber contraction in the absence of additional nervous system stimulation.

What are the Transverse Tubules and the Sarcoplasmic reticulum? see other card for explained relationship •Does the muscle fiber action potential and the DHP receptor allow muscle contraction? yes Excitation-contraction events explained here 1) action potential is propagated along the sarcolemma and ____ the T Tubules. 2) calcium ions are ____. transmission of the AP along the T tubules of the triads causes the voltage-sensitive tubule proteins to change shape. this shape change opens the Ca2+ release ____ in the terminal cisterns of the sarcoplasmic reticulum, allowing Ca2+ to flow into the ____ -DHP receptor: voltage sensor which undergoes fast ____ to control release of calcium from sarcoplasmic reticulum 3) calcium binds to troponin and removes the ____ action of tropomyosin. when Ca2+ binds, troponin changes shape, exposing ____-binding sites on the thin filaments 4) contraction begins: myosin binding to actin forms cross bridges and ____ (cross bride cycling) begins. At this point, E-C coupling is over. AFTERMATH: -when the muscle AP ____, the voltage-sensitive tubule proteins return to their ____ shape, closing the Ca2+ release channels of the SR. Ca2+ levels in the sarcoplasm fall as Ca2+ is continually pumped back into the SR by ____ transport. without Ca2+, the blocking action of tropomyosin is restored, myosin-actin interaction is inhibited, and ____ occurs. each time an action potential arrives at the neuromuscular junction, the sequence of E-C coupling is ____.

1) action potential is propagated along the sarcolemma and down the T Tubules. 2) calcium ions are released. transmission of the AP along the T tubules of the triads causes the voltage-sensitive tubule proteins to change shape. this shape change opens the Ca2+ release channels in the terminal cisterns of the sarcoplasmic reticulum, allowing Ca2+ to flow into the cytosol -DHP receptor: voltage sensor which undergoes fast transition to control release of calcium from sarcoplasmic reticulum 3) calcium binds to troponin and removes the blocking action of tropomyosin. when Ca2+ binds, troponin changes shape, exposing myosin-binding sites on the thin filaments 4) contraction begins: myosin binding to actin forms cross bridges and contraction (cross bride cycling) begins. At this point, E-C coupling is over. AFTERMATH: -when the muscle AP ceases, the voltage-sensitive tubule proteins return to their Orginal shape, closing the Ca2+ release channels of the SR. Ca2+ levels in the sarcoplasm fall as Ca2+ is continually pumped back into the SR by active transport. without Ca2+, the blocking action of tropomyosin is restored, myosin-actin interaction is inhibited, and relaxation occurs. each time an action potential arrives at the neuromuscular junction, the sequence of E-C coupling is repeated.

Draw and describe the events that occur at a chemical synapse. 1) action potential reaches ____ 2) voltage-gated ____+ channels open 3) ____ enters axon terminal 4) ____ is released and diffuses into the cleft 5) neurotransmitter binds to postsynaptic ____ 6) neurotransmitter ____ from synaptic cleft Do we know what these NTs will do? ____! It depends on the NT and the receptor which is shown here

1) action potential reaches terminal 2) voltage-gated Ca2+ channels open 3) calcium enters axon terminal 4) neurotransmitter is released and diffuses into the cleft 5) neurotransmitter binds to postsynaptic receptors 6) neurotransmitter removed from synaptic cleft Do we know what these NTs will do? No! It depends on the NT and the receptor which is shown here

Describe how smooth muscles contract and relax (Figure 9.26). 1) calcium ions (Ca2+) enter the cytosol from the ECF via voltage-gated or non-gated Ca2+ ____, or from the ____ 2) Ca2+ binds to and activated ____ 3) activated calmodulin activates the ____ light chain ____ enzymes 4) the activated kinase enzymes catalyze transfer of ____ to myosin, activating the myosin ____ 5) activated myosin forms ____ bridges with actin of the thin filaments just as in skeletal muscle. ____ begins. REGULATION OF SMOOTH MUSCLE CONTRACTION 1.Neurotransmitter may generate a ____ potential and/or AP that will lead to increase in cytoplasmic ____ . 2.Neurotransmitters (such as ACh or NE) or other chemical signals may ____ or ____ smooth muscles. 3.Some smooth muscle have NO nervous innervation and respond to ____, NTs, other chemicals/hormones, or depolarize spontaneously. RELAXATION 1.____ pump calcium out of the cell and into the SR and out of the cell into the ECF. 2.Calcium ____ from calmodulin which leads to ____ of myosin kinase. 3.____ of myosin by a phosphatase enzyme which decreases the myosin ATPase ____.

1) calcium ions (Ca2+) enter the cytosol from the ECF via voltage-gated or non-gated Ca2+ channels, or from the SR 2) Ca2+ binds to and activated calmodulin 3) activated calmodulin activates the myosin light chain kinase enzymes 4) the activated kinase enzymes catalyze transfer of phosphate to myosin, activating the myosin ATPases 5) activated myosin forms cross bridges with actin of the thin filaments just as in skeletal muscle. shortening begins. REGULATION OF SMOOTH MUSCLE CONTRACTION 1.Neurotransmitter may generate a graded potential and/or AP that will lead to increase in cytoplasmic calcium. 2.Neurotransmitters (such as ACh or NE) or other chemical signals may excite or inhibit smooth muscles. 3.Some smooth muscle have NO nervous innervation and respond to stretch, NTs, other chemicals/hormones, or depolarize spontaneously. RELAXATION 1.Actively pump calcium out of the cell and into the SR and out of the cell into the ECF. 2.Calcium detaches from calmodulin which leads to deactivation of myosin kinase. 3.Dephosphorylation of myosin by a phosphatase enzyme which decreases the myosin ATPase activity.

How does the action potential move (propagate) along the muscle fiber? 1) local depolarization: generation of end plate potential on the sarcolemma (An end plate potential (EPP) is generated at the ____ junction. The EPP causes a wave of ____ that spreads to the adjacent sarcolemma). 2) generation and propagation of the action potential (depolarization of the sarcolemma ____ voltage-gated sodium channels. Na+ enters, following is electrochemical gradient. At a certain membrane voltage, an action potential is generated (initiated). the AP spreads to ____ areas of the sarcolemma and ____ voltage-gate Na+ channels there, ____ the AP. the AP propagates along the sarcolemma in ____ directions, just like ripples from a pebble dropped in a pond). 3) repolarization (restores the sarcolemma to its initial polarized state, negative inside, positive outside). the repolarization wave is also a consequence of ____ and ____ ion channels--voltage-gated Na+ channels close and voltage-gated K+ channels open. The potassium ion concentration is substantially higher inside the cell than in the extracellular fluid, so K+ diffuses ____ of the muscle fiber. this restores the negatively charged conditions inside that are characteristic of a sarcolemma at rest) -Now let's consider the electrical events that trigger an action potential along the sarcolemma. An action potential is the result of a predictable sequence of electrical changes. Once initiated, an action potential sweeps along the entire surface of the sarcolemma. Three steps are involved in triggering and then propagating an action potential. These three steps—generation of an end plate potential followed by action potential depolarization and repolarization—are shown in Figure 9.8. A tracing of the resulting membrane potential changes is shown in Figure 9.9. We will describe action potentials in more detail in Chapter 11. -During repolarization, a muscle fiber is said to be in a ____ period, because the cell cannot be stimulated again until repolarization is complete. Note that repolarization restores only the electrical conditions of the ____ (polarized) state. The ATP-dependent Na+-K+ pump restores the ionic conditions of the ____ state, but ____ of action potentials can occur before ionic imbalances interfere with contractile activity. -Once initiated, the action potential is ____. It ultimately results in contraction of the muscle fiber. Although the action potential itself lasts only a few milliseconds (ms), the contraction phase of a muscle fiber may persist for 100 ms or more and far ____ the electrical event that triggers it.

1) local depolarization: generation of end plate potential on the sarcolemma (An end plate potential (EPP) is generated at the neuromuscular junction. The EPP causes a wave of depolarization that spreads to the adjacent sarcolemma). 2) generation and propagation of the action potential (depolarization of the sarcolemma opens voltage-gated sodium channels. Na+ enters, following is electrochemical gradient. At a certain membrane voltage, an action potential is generated (initiated). the AP spreads to adjacent areas of the sarcolemma and opens voltage-gate Na+ channels there, propagating the AP. the AP propagates along the sarcolemma in all directions, just like ripples from a pebble dropped in a pond). 3) repolarization (restores the sarcolemma to its initial polarized state, negative inside, positive outside). the repolarization wave is also a consequence of opening and closing ion channels--voltage-gated Na+ channels close and voltage-gated K+ channels open. The potassium ion concentration is substantially higher inside the cell than in the extracellular fluid, so K+ diffuses out of the muscle fiber. this restores the negatively charged conditions inside that are characteristic of a sarcolemma at rest) -Now let's consider the electrical events that trigger an action potential along the sarcolemma. An action potential is the result of a predictable sequence of electrical changes. Once initiated, an action potential sweeps along the entire surface of the sarcolemma. Three steps are involved in triggering and then propagating an action potential. These three steps—generation of an end plate potential followed by action potential depolarization and repolarization—are shown in Figure 9.8. A tracing of the resulting membrane potential changes is shown in Figure 9.9. We will describe action potentials in more detail in Chapter 11. -During repolarization, a muscle fiber is said to be in a refractory period, because the cell cannot be stimulated again until repolarization is complete. Note that repolarization restores only the electrical conditions of the resting (polarized) state. The ATP-dependent Na+-K+ pump restores the ionic conditions of the resting state, but thousands of action potentials can occur before ionic imbalances interfere with contractile activity. -Once initiated, the action potential is unstoppable. It ultimately results in contraction of the muscle fiber. Although the action potential itself lasts only a few milliseconds (ms), the contraction phase of a muscle fiber may persist for 100 ms or more and far outlasts the electrical event that triggers it.

Student should be able to list and explain the functional characteristics of skeletal muscles 1. Excitability or Irritability -Ability to receive and respond to a ____ by changing its membrane potential. -Responds to stimulus by producing an ____ signal -also termed ____, is the ability of a cell to receive and respond to a stimulus by changing its membrane potential. In the case of muscle, the stimulus is usually a ____—for example, a neurotransmitter released by a nerve cell. 2.Contractility -is the ability to ____ forcibly when adequately stimulated. This ability sets muscle apart from all other tissue types. 3.Extensibility -is the ability to ____ or stretch. Muscle cells shorten when contracting, but they can be stretched, even beyond their resting length, when ____. 4.Elasticity -is the ability of a muscle cell to ____ and resume its resting length after stretching.

1. Excitability or Irritability -Ability to receive and respond to a stimulus by changing its membrane potential. -Responds to stimulus by producing an electric signal -also termed responsiveness, is the ability of a cell to receive and respond to a stimulus by changing its membrane potential. In the case of muscle, the stimulus is usually a chemical—for example, a neurotransmitter released by a nerve cell. 2.Contractility -is the ability to shorten forcibly when adequately stimulated. This ability sets muscle apart from all other tissue types. 3.Extensibility -is the ability to extend or stretch. Muscle cells shorten when contracting, but they can be stretched, even beyond their resting length, when relaxed. 4.Elasticity -is the ability of a muscle cell to recoil and resume its resting length after stretching.

Compare and contrast the cardiac, and skeletal muscle cells-based striations and nuclei number •Compare their innervation, which is innervated by the autonomic nervous system (one uses Ach--SKELETAL--and NE--CARDIAC) •The excitatory effect of the nervous system upon smooth and skeletal muscle should be compared also 1. Located in walls of blood ____ and walls of ____ organs. 2. Most organized into ____ -Generally arranged into 2 layers: ____ and ____ -Slow synchronized contractions; whole sheet responds as ____ due to ____ junctions. 3. Smooth Muscle Cells are ____ shaped 4. Smooth Muscle Cells Have ONLY ____ as a CT sheath 5. Innervated by ____ NS at diffuse junctions that contain numerous varicosities with wide synaptic clefts. 6. Effects of Nervous Stimulation may be either ____ or ____ in smooth muscle (and cardiac muscle), but is always ____ in skeletal muscles. 7. Smooth muscle fibers are usually (unitary type/visceral muscle) connected via ____ junctions. 8. Smooth muscles have less elaborate ____ with ____ terminal cisternae and ____ T-tubules, but sarcolemma has ____ containing calcium channels. 9. ____ muscle types require ____ for contraction to occur. The calcium comes from ____ and ____ in smooth (and cardiac) muscle, but only from ____ in skeletal muscle. 10. Myofilaments differ from skeletal muscles in the following ways: •Have fewer ____ filaments, but myosin have heads along their entire ____. The myosin heads are oriented in one ____ on one side of the filament and in the ____ direction on the other side. •Contains tropomyosin, but has NO ____. ____ acts as the calcium-binding site. •Smooth muscles contain ____-____ intermediate filaments attached at regular intervals to ____ bodies. ____ bodies are attached to the sarcolemma and _____ to actin like Z-discs in skeletal muscles. •Thick and thin filaments arranged ____ so when smooth muscles contract smooth muscle cells cells ____. 11. Contractions tend to be ____, ____ contractions that last a longer period of time before they ____ as compared to most skeletal muscles. 12.Smooth muscles use generate their ATP mainly through ____ cellular respiration. 13.Some smooth muscles have ____ cells that ____ spontaneously, however neural and chemical ____ can modify both rate and intensity of smooth muscle contraction.

1. Located in walls of blood vessels and walls of hollow organs. 2. Most organized into sheets -Generally arranged into 2 layers: Longitudinal and Circular -Slow synchronized contractions; whole sheet responds as unit due to gap junctions. 3. Smooth Muscle Cells are spindle shaped 4. Smooth Muscle Cells Have ONLY Endomysium as a CT sheath 5. Innervated by autonomic NS at diffuse junctions that contain numerous varicosities with wide synaptic clefts. 6. Effects of Nervous Stimulation may be either excitatory or inhibitory in smooth muscle (and cardiac muscle), but is always excitatory in skeletal muscles. 7. Smooth muscle fibers are usually (unitary type/visceral muscle) connected via gap junctions. 8. Smooth muscles have less elaborate SR with no terminal cisternae and no T-tubules, but sarcolemma has caveolae containing calcium channels. 9. All muscle types require calcium for contraction to occur. The calcium comes from ECF and SR in smooth (and cardiac) muscle, but only from SR in skeletal muscle. 10. Myofilaments differ from skeletal muscles in the following ways: •Have fewer thick filaments, but myosin have heads along their entire length. The myosin heads are oriented in one direction on one side of the filament and in the opposite direction on the other side. •Contains tropomyosin, but has NO TROPONIN. Calmodulin acts as the calcium-binding site. •Smooth muscles contain non-contractile intermediate filaments attached at regular intervals to dense bodies. Dense bodies are attached to the sarcolemma and anchor to actin like Z-discs in skeletal muscles. •Thick and thin filaments arranged diagonally so when smooth muscles contract smooth muscle cells cells twist. 11. Contractions tend to be slow, synchronized contractions that last a longer period of time before they fatigue as compared to most skeletal muscles. 12.Smooth muscles use generate their ATP mainly through aerobic cellular respiration. 13.Some smooth muscles have pacemaker cells that depolarize spontaneously, however neural and chemical stimuli can modify both rate and intensity of smooth muscle contraction.

Describe the causes, symptoms, and treatments of Duchenne's muscular dystrophy and Myasthenia gravis 1. Myasthenia gravis -Disease characterized by ____ eyelids, difficulty ____ (dysphagia) and talking (dysphasia), and general muscle ____. -____ disorder where ACh receptors are ____ by antibodies. -____ cure. Treatments include ACHE ____ and ____ (immunosuppressant) (acetylcholine receptors internalized and degraded. no ____+ influx. no muscle ____) 2. Duchene Muscular Dystrophy (DMD) •____-linked ____ disease where the gene for ____ is defective Dystrophin: ____n muscle fibers and protect them from ____ as muscles contract and relax. •Male children usually diagnosed in ____ (2 - 7 y.o.) when they begin to be unusually ____. •Dz progresses from extremities to ____ and ____ muscles and to ____ muscle. •____ cure. •Treatments include ____ to decrease inflammation and ____ to keep them mobile as long as possible.

1. Myasthenia gravis -Disease characterized by drooping eyelids, difficulty swallowing (dysphagia) and talking (dysphasia), and general muscle weakness. -Autoimmune disorder where ACh receptors are blocked by antibodies. -No cure. Treatments include ACHE inhibitors and corticosteroids (immunosuppressant) (acetylcholine receptors internalized and degraded. no Na+ influx. no muscle contraction) 2. Duchene Muscular Dystrophy (DMD) •X-linked recessive disease where the gene for dystrophin is defective Dystrophin: strengthen muscle fibers and protect them from injury as muscles contract and relax. •Male children usually diagnosed in childhood (2 - 7 y.o.) when they begin to be unusually clumsy. •Dz progresses from extremities to head and chest muscles and to cardiac muscle. •No cure. •Treatments include steroids to decrease inflammation and Physiotherapy to keep them mobile as long as possible.

Student should be able to compare and contrast passive, chemical gated, and voltage-gated channels. 1. Passive leakage channels -____ soluble molecules leak through channel protein -____ soluble molecules leak through plasma membrane 2. Gated Channels -ligand gated (open by ____ binding to receptor) -mechanically gated (open to ____) -voltage-gated (open to change in membrane ____) Non-gated Channels (____ Open)

1. Passive leakage channels -water soluble molecules leak through channel protein -fat soluble molecules leak through plasma membrane 2. Gated Channels -ligand gated (open by neurotransmitter binding to receptor) -mechanically gated (open to pressure) -voltage-gated (open to change in membrane potential) Non-gated Channels (Always Open)

Define nuclei, ganglion, tract, and nerve. 1.Cell Body (Soma) -Most located in ____ and spinal cord ____ matter (CNS) a.Cluster of cells bodies in the CNS = ____ b.Cluster of cell bodies in PNS = ____ 2.Neuronal Processes -Includes axons and dendrites a.Bundle of neuronal processes in the CNS = ____ b.Bundle of neuronal processes in the PNS = ____ Range from 0.1 to 20 um ____ = 2um to 20 ____ = less than 2um

1.Cell Body (Soma) -Most located in brain and spinal cord gray matter (CNS) a.Cluster of cells bodies in the CNS = Nuclei b.Cluster of cell bodies in PNS = Ganglion 2.Neuronal Processes -Includes axons and dendrites a.Bundle of neuronal processes in the CNS = Tract b.Bundle of neuronal processes in the PNS = Nerves Range from 0.1 to 20 um myelinated = 2um to 20 Unmyelinated = less than 2um

skeletal muscle fiber contraction overview 1.Events at the ____ junction 2.____ generated on the sarcolemma (Muscle Fiber excitation) 3.Excitation-Contraction ____ Events 4.Cross Bridge ____ (Sliding Filament Theory) 1) net ____ of Na+ initiates an action potential is propagated along the sarcolemma and down the T tubules 2) action potential in t tubule ____ voltage-sensitive receptors, which in turn trigger Ca2+ ____ from terminal cisternae of SR into cytosol 3) calcium ions bind to ____; troponin changes shape, removing the ____ action of tropomyosin; actin active sites exposed 4) contraction; myosin heads alternately ____ to actin and detach, pulling the actin filaments toward the center of the sarcomere; release of energy by ____ hydrolysis powers the cycling process 5) ____ of Ca2+ by active transport into the SR after the action potential ends 6) tropomyosin blockage ____, blocking myosin binding sites on actin; contraction ends and muscle fiber ____

1.Events at the Neuromuscular junction 2.AP generated on the sarcolemma (Muscle Fiber excitation) 3.Excitation-Contraction Coupling Events 4.Cross Bridge Cycling (Sliding Filament Theory) 1) net entry of Na+ initiates an action potential is propagated along the sarcolemma and down the T tubules 2) action potential in t tubule activates voltage-sensitive receptors, which in turn trigger Ca2+ release from terminal cisternae of SR into cytosol 3) calcium ions bind to troponin; troponin changes shape, removing the blocking action of tropomyosin; actin active sites exposed 4) contraction; myosin heads alternately attach to actin and detach, pulling the actin filaments toward the center of the sarcomere; release of energy by ATP hydrolysis powers the cycling process 5) removal of Ca2+ by active transport into the SR after the action potential ends 6) tropomyosin blockage restored, blocking myosin binding sites on actin; contraction ends and muscle fiber relaxes

Be familiar with the functions of skeletal muscles. 1.Produces Movement -Changes ____ energy to ____ energy (____ muscle responsible for locomotion/manipulation. blood moves through heart due to rhythmical ____ muscle of heart and ____ muscle in wall of blood vessel, maintaining blood pressure. ____ muscle in digestive/urinary/reproductive tracts propel substance through organs). 2.Maintains Posture and Body Positions (muscles function ____, making one tiny adjustment after another to ____ the never-ending downward pull of gravity) 3.Stabilizes Joints (pull on ____, strengthen/stabilize joints) 4.Generates Heat (occurs during contraction. help maintain normal body ____)

1.Produces Movement -Changes chemical energy to mechanical energy (skeletal muscle responsible for locomotion/manipulation. blood moves through heart due to rhythmical cardiac muscle of heart and smooth muscle in wall of blood vessel, maintaining blood pressure. smooth muscle in digestive/urinary/reproductive tracts propel substance through organs). 2.Maintains Posture and Body Positions (muscles function continuously, making one tiny adjustment after another to counteract the never-ending downward pull of gravity) 3.Stabilizes Joints (pull on bones, strengthen/stabilize joints) 4.Generates Heat (occurs during contraction. help maintain normal body temp)

Describe some (not all) special features of smooth muscles. (Sec. 9.9) •Stretch to contract, among others 1.____, prolonged contractions with ____ energy requirements. 2.Response to Stretch = Stress-Relaxation Response •Smooth muscle ____ contracts when it is stretched. This assist in moving ____ along tracts, but muscle quickly adapts to new length and relaxes. 3.Length and Tension Changes -Smooth muscle ____ much more and generates more ____ when stretched as compared to skeletal muscle. This allows hollow organs to tolerate large changes in ____ (can be stretched) and the muscle still maintain its ability to ____.

1.Slow, prolonged contractions with low energy requirements. 2.Response to Stretch = Stress-Relaxation Response •Smooth muscle spontaneously contracts when it is stretched. This assist in moving substances along tracts, but muscle quickly adapts to new length and relaxes. 3.Length and Tension Changes -Smooth muscle stretches much more and generates more tension when stretched as compared to skeletal muscle. This allows hollow organs to tolerate large changes in volume (can be stretched) and the muscle still maintain its ability to contract.

Know for how long and in what order ATP sources are used during high intensity exercise. How to muscles make ATP? •ATP, Creatine Phosphate, then the production of more ATP 15 seconds supported by ____, CP reserves 30-40 seconds supported by ____ (anaerobic) Anaerobic threshold has been reached

15 seconds supported by ATP, CP reserves 30-40 seconds supported by glycolysis (anaerobic) Anaerobic threshold has been reached

Neurotransmitters more details (do we need to know this level of detail or just what is in word doc?)

2. Biogenic Amines a. Catecholamines -Derived from Tyrosine -May be inhibitory or excitatory depending on receptor type (1) Dopamine -Feeling good NT -Deficient in Parkinson's Dz (2) Norepinephrine -Feeling good NT -Main NT of post-ganglionic neurons in the sympathetic NS (3)Epinephrine (Adrenalin) - acts mainly as a hormone. -Produced by adrenal gland as well as some neurons -Secreted when stimulated by sympathetic NS b. Indolamines (1) Serotonin -Mainly inhibitory in CNS -Derived from tryptophan -Plays role in sleep, appetite, migraine headaches and regulation of mood -Prozac blocks reuptake - relieves anxiety and depression (2) Histamine -CNS- hypothalamus -Increases acid secretion in stomach -Also released by mast cells during inflammatory response and acts as vasodilator 3. Amino Acids a. Gamma aminobutyric acid (GABA) -Principal inhibitory neurotransmitter in the brain b. Glycine -Principal inhibitory NT of the spinal cord c. Glutamate -Major excitatory NT in CNS -Important in learning and memory -"Stroke NT" 4. Peptides a. Substance P -Mediates pain transmission in the PNS b. Endorphins -Act as natural opiates -Inhibits pain by inhibiting Substance P -Released under stressful conditions (labor, strenuous exercise) 5. Dissolved Gases a. Nitric Oxide -Excitatory in CNS and PNS -Vasodilator b. Carbon Monoxide -Excitatory in brain and at some neuromuscular junctions.

Although terminology seems to indicate otherwise, there is really only one nervous system in the body. Although each subdivision of the system is also called a "nervous system," all of these smaller systems belong to the single, highly integrated nervous system. Each subdivision has structural and functional characteristics that distinguish it from the others. The nervous system as a whole is divided into two subdivisions: the central nervous system (CNS) and the peripheral nervous system (PNS). The Central Nervous System The ____ and ____ cord are the organs of the central nervous system. Because they are so vitally important, the brain and spinal cord, located in the ____ body cavity, are encased in ____ for protection. The brain is in the cranial vault, and the spinal cord is in the vertebral canal of the vertebral column. Although considered to be two separate organs, the brain and spinal cord are ____ at the foramen ____. The Peripheral Nervous System The organs of the peripheral nervous system are the ____ and ____. Nerves are bundles of nerve ____, much like muscles are bundles of muscle fibers. Cranial nerves and spinal nerves extend ____ the CNS ____ peripheral organs such as muscles and glands. Ganglia are collections, or small knots, of nerve cell bodies outside the CNS. The peripheral nervous system is further subdivided into an afferent (____) division and an efferent (____) division. The afferent or sensory division transmits impulses from ____ organs to the CNS. The efferent or motor division transmits impulses from the ____ out to the peripheral organs to cause an effect or action. Finally, the efferent or motor division is again subdivided into the ____ nervous system and the ____ nervous system. The somatic nervous system, also called the somatomotor or somatic efferent nervous system, supplies motor impulses to the skeletal ____. Because these nerves permit conscious control of the skeletal muscles, it is sometimes called the ____ nervous system. The autonomic nervous system, also called the ____ efferent nervous system, supplies motor impulses to cardiac muscle, to smooth muscle, and to glandular epithelium. It is further subdivided into ____ and ____ divisions. Because the autonomic nervous system regulates ____ or automatic functions, it is called the involuntary nervous system.

Although terminology seems to indicate otherwise, there is really only one nervous system in the body. Although each subdivision of the system is also called a "nervous system," all of these smaller systems belong to the single, highly integrated nervous system. Each subdivision has structural and functional characteristics that distinguish it from the others. The nervous system as a whole is divided into two subdivisions: the central nervous system (CNS) and the peripheral nervous system (PNS). The Central Nervous System The brain and spinal cord are the organs of the central nervous system. Because they are so vitally important, the brain and spinal cord, located in the dorsal body cavity, are encased in bone for protection. The brain is in the cranial vault, and the spinal cord is in the vertebral canal of the vertebral column. Although considered to be two separate organs, the brain and spinal cord are continuous at the foramen magnum. The Peripheral Nervous System The organs of the peripheral nervous system are the nerves and ganglia. Nerves are bundles of nerve fibers, much like muscles are bundles of muscle fibers. Cranial nerves and spinal nerves extend from the CNS to peripheral organs such as muscles and glands. Ganglia are collections, or small knots, of nerve cell bodies outside the CNS. The peripheral nervous system is further subdivided into an afferent (sensory) division and an efferent (motor) division. The afferent or sensory division transmits impulses from peripheral organs to the CNS. The efferent or motor division transmits impulses from the CNS out to the peripheral organs to cause an effect or action. Finally, the efferent or motor division is again subdivided into the somatic nervous system and the autonomic nervous system. The somatic nervous system, also called the somatomotor or somatic efferent nervous system, supplies motor impulses to the skeletal muscles. Because these nerves permit conscious control of the skeletal muscles, it is sometimes called the voluntary nervous system. The autonomic nervous system, also called the visceral efferent nervous system, supplies motor impulses to cardiac muscle, to smooth muscle, and to glandular epithelium. It is further subdivided into sympathetic and parasympathetic divisions. Because the autonomic nervous system regulates involuntary or automatic functions, it is called the involuntary nervous system.

Compare and contrast temporal summation in neurons and temporal summation in muscles. An increase in the ____ of stimulation causes temporal summation. The higher the frequency, the greater the ____ of contraction of a given motor unit. The nervous system can achieve greater muscular force by increasing the ____ rate of motor neurons. For example, if two identical stimuli (electrical shocks or nerve impulses) are delivered to a muscle in rapid succession, the ____ twitch will be stronger than the first. This phenomenon is called temporal, or wave, summation. It occurs because the second contraction begins ____ the muscle has completely relaxed. The second contraction is greater than the first because the muscle is already ____ contracted and because even more ____ is squirted into the cytosol. In other words, the contractions are added together. (However, the refractory period is always honored. So if a second stimulus arrives before ____ is complete, no wave summation occurs.) Temporal summation contributes to contractile force, but its primary function is to produce smooth, ____ muscle contractions by rapidly stimulating a specific number of muscle cells. For neurons its for an action potential is fire. For muscle, its muscle twitch to occur.

An increase in the frequency of stimulation causes temporal summation. The higher the frequency, the greater the strength of contraction of a given motor unit. The nervous system can achieve greater muscular force by increasing the firing rate of motor neurons. For example, if two identical stimuli (electrical shocks or nerve impulses) are delivered to a muscle in rapid succession, the second twitch will be stronger than the first. This phenomenon is called temporal, or wave, summation. It occurs because the second contraction begins before the muscle has completely relaxed. The second contraction is greater than the first because the muscle is already partially contracted and because even more calcium is squirted into the cytosol. In other words, the contractions are added together. (However, the refractory period is always honored. So if a second stimulus arrives before repolarization is complete, no wave summation occurs.) Temporal summation contributes to contractile force, but its primary function is to produce smooth, continuous muscle contractions by rapidly stimulating a specific number of muscle cells. For neurons its for an action potential is fire. For muscle, its muscle twitch to occur

Lastly, why do muscles have to make more ATP themselves? Because the muscle stores a limited amount of ATP for continued muscle activity ATP is ____.

Because the muscle stores a limited amount of ATP for continued muscle activity ATP is needed.

Draw and describe how an action potential is generated. By _____ of graded potentials. -small stimulus cause small depolarization of the cell membrane -larger stimulus causes more depolarization -a stimulus of longer durations causes a longer lasting depolarization but not of any greater strength than the previous stimulus -a ____ stimulus that ____ above ____ may trigger an action potential in a postsynaptic neuron -some stimuli result in hyperpolarization, which depends on the specific ion channels activated in the cell membrane •When (mV) does an Action potential happen? •-____mV Threshold •How do we get there? •____ the neuron to -55mV •Does an IPSP completely stop it? Why or Why not? •____. just need a stronger depolarizing stimulus •How? •_____. Depolarization stimulation that brings the neuron to threshold

By summation of graded potentials. -small stimulus cause small depolarization of the cell membrane -larger stimulus causes more depolarization -a stimulus of longer durations causes a longer lasting depolarization but not of any greater strength than the previous stimulus -a larger stimulus that depolarizes above threshold may trigger an action potential in a postsynaptic neuron -some stimuli result in hyperpolarization, which depends on the specific ion channels activated in the cell membrane •When (mV) does an Action potential happen? •-55mV Threshold •How do we get there? •Depolarize the neuron to -55mV •Does an IPSP completely stop it? Why or Why not? •No. just need a stronger depolarizing stimulus •How? •EPSP's. Depolarization stimulation that brings the neuron to threshold

Graded potential versus Action potential • Describe their differences • Using threshold, be able to tell if the summation of IPSP and EPSPs would or would not create an action potential (see slide 26 on L21) • Where does graded potential summation take place in a neuron? Changes in Membrane Potentials that act as signals: •Graded Potentials refers to a membrane potential, which ____ vary in amplitude -can occur either due to ____ or ____ -may have ____ signal strengths which are ____ than an action potential -generated by ____-gated ion channels -may be transmitted over ____ distances -may ____ its strength during transmission -two graded potentials can be ____ together •Action Potentials refers to a change in the electrical potential, associated with the transmission of ____ along the membrane of a nerve cell or muscle cell -can ____ occur due to depolarization -a large depolarization, which reaches the ____ (+40mV) -generated by ____-gated ion channels -may be transmitted over ____ distances -does ____ lose its strength during transmission -two action potentials ____ be added together Graded Potentials -____ term ____ changes in the membrane potential (Vm) due to opening or closing of ion channels and whose magnitude changes with the ____ of the stimulus and ____ over distance. Characteristics of Graded Potentials: -Location and Generation of GP - On the cell ____ and ____. -Synaptic Potential - ____ potential across a synapse. Examples: ____ -Receptor Potential - Potential changes based on a ____. Examples: ____ Gated Receptors, ____ Corpuscle -The ____ of graded potentials change with the strength of the stimulus. -Graded potentials may ____ or ____ the membrane. -Excitatory Post-synaptic Potential (____) -Inhibitory Post-synaptic Potential (____) -graded potential ____ occurs at the axon ____ -Graded potentials spread over the membrane via local ____ circuits and ____ over distance due to cations leaking out through ____ channels (voltage is ____ since it declines with distance from the stimulus) (slide 27 and 28 for image) Action Potentials -A ____ and ____ reversal of Vm that is conducted along the membrane of a muscle cell or nerve without loss of ____. -Threshold Potential - Once you cross this voltage, an ____ ____ is produced. "Threshold" @ -55 mV Characteristics of Action Potentials : -Location and Generation: ____ -voltage-gated Na+ channels have a ____, ____, and ____ state -voltage-gated K+ channels have a ____ or ____ state only -Resting potential (Na+/K+ pump has action. But the voltage-gated Na+ and K+ channels are ____). Depolarization (voltage-gated Na+ channels ____ while K+ voltage-gated are delayed and still ____). Repolarization (voltage-gated K+ channels ____. Na+ voltage-gated are ____). Hyperpolarization (Na+ voltage-gated channels ____ but ____, while K+ voltage-gated channels are still ____) Resting potential (Na+/K+ channel)

Changes in Membrane Potentials that act as signals: •Graded Potentials refers to a membrane potential, which can vary in amplitude -can occur either due to depolarization or hyperpolarization -may have variable signal strengths which are less than an action potential -generated by ligand-gated ion channels -may be transmitted over short distances -may lose its strength during transmission -two graded potentials can be added together •Action Potentials refers to a change in the electrical potential, associated with the transmission of impulses along the membrane of a nerve cell or muscle cell -can only occur due to depolarization -a large depolarization, which reaches the threshold (+40mV) -generated by voltage-gated ion channels -may be transmitted over long distances -does not lose its strength during transmission -two action potentials cannot be added together Graded Potentials -Short term local changes in the membrane potential (Vm) due to opening or closing of ion channels and whose magnitude changes with the strength of the stimulus and decays over distance. Characteristics of Graded Potentials: -Location and Generation of GP - On the cell body and dendrites. -Synaptic Potential - Electrical potential across a synapse. Examples: Neurotransmitters -Receptor Potential - Potential changes based on a receptor. Examples: Mechanically Gated Receptors, Pacinian Corpuscle -The magnitude of graded potentials change with the strength of the stimulus. -Graded potentials may depolarize or hyperpolarize the membrane. -Excitatory Post-synaptic Potential (EPSP) -Inhibitory Post-synaptic Potential (IPSP) -graded potential summation occurs at the axon hillock -Graded potentials spread over the membrane via local current circuits and decays over distance due to cations leaking out through leakage channels (voltage is decremental since it declines with distance from the stimulus) (slide 27 and 28 for image) Action Potentials -A large and brief reversal of Vm that is conducted along the membrane of a muscle cell or nerve without loss of amplitude. -Threshold Potential - Once you cross this voltage, an action potential is produced. "Threshold" @ -55 mV Characteristics of Action Potentials : -Location and Generation: axon -voltage-gated Na+ channels have a closed, opened, and inactivated state -voltage-gated K+ channels have a closed or opened state only -Resting potential (Na+/K+ pump has action. But the voltage-gated Na+ and K+ channels are closed). Depolarization (voltage-gated Na+ channels open while K+ voltage-gated are delayed and still closed). Repolarization (voltage-gated K+ channels open. Na+ voltage-gated are inactive). Hyperpolarization (Na+ voltage-gated channels activate but closed, while K+ voltage-gated channels are still open) Resting potential (Na+/K+ channel)

Classify smooth muscle on location, contraction pattern, and communication with neighboring cells (single, multi-unit). Classified by Location: •____ •____ Tract •____ Tract •____ Tract •____ tract •Ocular - ____ Body & ____ Classified by Contraction Pattern (SLIDE 19) : •____ -> muscles that undergo periodic contraction and relaxation •____ -> muscles that are continuously contracted thus maintain some level of muscle tone. Classified by Communication with Neighboring Cells: •____-Unit (a.k.a. visceral smooth muscle)* -> cells electrically coupled by gap junctions. Contract as a unit. •____-Unit -> Not coupled by gap junction; each cell closely associated with an axon terminal or varicosity. Very fine control.

Classified by Location: •Vascular •Gastrointestinal Tract •Urinary Tract •Respiratory Tract •Reproductive tract •Ocular - Ciliary Body & Iris Classified by Contraction Pattern (SLIDE 19) : •Phasic -> muscles that undergo periodic contraction and relaxation •Tonic -> muscles that are continuously contracted thus maintain some level of muscle tone. Classified by Communication with Neighboring Cells: •Single-Unit (a.k.a. visceral smooth muscle)* -> cells electrically coupled by gap junctions. Contract as a unit. •Multi-Unit -> Not coupled by gap junction; each cell closely associated with an axon terminal or varicosity. Very fine control.

Extra Info Topic? Eyes and Recreational Drug Use ____ = parasympathetic ____ = Sympathetic Constricted pupils: -____ -____ -____ -____ -____ -____ -____ Red eyes: -____ -____ or crack -____ (i.e. xanax) -____ (i.e. alcohol or sedatives) Dilated Pupils -____ -____ -____ or crack -____ (i.e. LSD or mushrooms) -____ (prescription painkillers) -____ -____ -____

Constricted = parasympathetic Dilated = Sympathetic Constricted pupils: -heroin -morphine -oxycodone -fentanyl -methadone -codeine -hydrocodone Red eyes: -marijuana -cocaine or crack -benzodiazepine (i.e. xanax) -depressants (i.e. alcohol or sedatives) Dilated Pupils -amphetamines -methamphetamine -cocaine or crack -hallucinogens (i.e. LSD or mushrooms) -opiates (prescription painkillers) -heroin -marijuana -speed

In what ways are ATP is generated during mild and strenuous exercise (Sec. 9.6) See slides 21, 24-25 in L27 Energy Systems Used During Sporting Activities 1.Aerobic Endurance -The length of ____ a muscle can contract using ____ metabolism 2.Anaerobic Threshold -Point at which muscle metabolism converts to ____ glycolysis. -About 50-70% VO2 max = ____ oxygen uptake and utilization by skeletal muscles (a.k.a. aerobic capacity) -endurance activity when first start running, first contractions are using ATP reserve by using ____. then, aerobic exercise stays in aerobic range (does not cross anaerobic activity). in ____. -strenuous activity is in ____. within 15 seconds use all ____ and have max muscle ____ around 30-40 seconds.

Energy Systems Used During Sporting Activities 1.Aerobic Endurance -The length of time a muscle can contract using aerobic metabolism 2.Anaerobic Threshold -Point at which muscle metabolism converts to anaerobic glycolysis. -About 50-70% VO2 max = maximal oxygen uptake and utilization by skeletal muscles (a.k.a. aerobic capacity) -endurance activity when first start running, first contractions are using ATP reserve by using CP. then, aerobic exercise stays in aerobic range (does not cross anaerobic activity). in hours. -strenuous activity is in minutes. within 15 seconds use all reserves and have max muscle fatigue around 30-40 seconds.

Talk about Oxygen Debt (EPOC) and what needs to be restored following strenuous exercise. •Following less strenuous exercise, what needs to be replenished? Excess Post-exercise Oxygen Consumption (EPOC) (a.k.a. Oxygen Debt) -Volume of ____ required to return the muscle back to its resting state after exercise. (1)Oxygen reserves (stored in ____ ) must be replenished (2)Lactic acid must be converted back to ____ acid (3)____ stores must be replaced (4)CP and ATP reserves must be ____. -EPOC represents the difference between the amount of oxygen ____ for totally aerobic muscle activity and the amount actually ____. Example: Running a 200 yd dash in 28sec would require 12L of O2 for totally aerobic activity. VO2 max during this time was 6.8L. What is the oxygen debt? -Oxygen debt repaid by rapid ____, triggered by decreasing ____. Myoglobin Location: -____ and ____ muscles Function: -____ of oxygen for muscles -An oxygen carrier that increase the rate of ____ of oxygen within the muscle cell Structure: -Myoglobin I composed of a ____ polypeptide chain that is structurally similar to the individual subunit of hemoglobin.

Excess Post-exercise Oxygen Consumption (EPOC) (a.k.a. Oxygen Debt) -Volume of oxygen required to return the muscle back to its resting state after exercise. (1)Oxygen reserves (stored in myoglobin) must be replenished (2)Lactic acid must be converted back to pyruvic acid (3)Glycogen stores must be replaced (4)CP and ATP reserves must be resynthesized. -EPOC represents the difference between the amount of oxygen needed for totally aerobic muscle activity and the amount actually used. Example: Running a 200 yd dash in 28sec would require 12L of O2 for totally aerobic activity. VO2 max during this time was 6.8L. What is the oxygen debt? -Oxygen debt repaid by rapid breathing, triggered by decreasing pH. Myoglobin Location: -Heart and Skeletal muscles Function: -reservoir of oxygen for muscles -An oxygen carrier that increase the rate of transport of oxygen within the muscle cell Structure: -Myoglobin I composed of a single polypeptide chain that is structurally similar to the individual subunit of hemoglobin.

Force of Muscle Contraction •Depends on ____ of myosin cross-bridges attached to actin à determined by four factors. 4 Factors that Determine Force of Contraction: 1.____ of Stimulation 2.____ of motor units/muscle fibers recruited 3.____ of muscle fibers 4.____ of muscle stretch •____ loads allow for faster velocities and longer contractions •The ____ the number of motors units contracting, the faster the velocity and longer the contraction. -the greater the load, the ____ the duration of muscular shortening. the greater the load, the slower the muscle shortening (slide 15 in L 29) Sec. 9.8: How does Skeletal Muscle Respond to Exercise 1.Aerobic Exercise a.Regular aerobic exercise may convert a ____ fast glycolytic fibers to fast oxidative fibers. b.Overall: increases the efficiency of muscle ____, greater ____, strength and resistance to ____. 2. Resistance Exercise •Mainly ____ exercises and weightlifting. Increases ____ of muscle by causing ____ (i.e. increase size of each fiber) especially in fast ____ fibers. •A few slow oxidative fibers may be converted to ____ oxidative fibers

Force of Muscle Contraction •Depends on # of myosin cross-bridges attached to actin à determined by four factors. 4 Factors that Determine Force of Contraction: 1.Frequency of Stimulation 2.Number of motor units/muscle fibers recruited 3.Size of muscle fibers 4.Degree of muscle stretch •Smaller loads allow for faster velocities and longer contractions •The greater the number of motors units contracting, the faster the velocity and longer the contraction. -the greater the load, the briefer the duration of muscular shortening. the greater the load, the slower the muscle shortening (slide 15 in L 29) Sec. 9.8: How does Skeletal Muscle Respond to Exercise 1.Aerobic Exercise a.Regular aerobic exercise may convert a few fast glycolytic fibers to fast oxidative fibers. b.Overall: increases the efficiency of muscle metabolism, greater endurance, strength and resistance to fatigue. 2. Resistance Exercise •Mainly isometric exercises and weightlifting. Increases bulk of muscle by causing hypertrophy (i.e. increase size of each fiber) especially in fast glycolytic fibers. •A few slow oxidative fibers may be converted to fast oxidative fibers

Know the 3 ways neurotransmitters are removed from the synapse How do we rid the synaptic cleft of the Neurotransmitter? 1.____ of the NT by ____ and by the ____ terminal 2.____ ____ of NT 3.____ of NT ____ from the synaptic cleft Drug-based Examples: 1.Reuptake of the NT by astrocytes and by the Presynaptic terminal •____ this to get more and longer neutrotransmission •Serotonin Re-uptake inhibitors (____) •Commonly used for ____ 2.Enzymatic degradation of NT •Acetyl Choline is hydrolyzed by ____ ____ •____ acetyl cholinesterase; too much acetyl choline •Example: ____ Nerve Gas

How do we rid the synaptic cleft of the Neurotransmitter? 1.Reuptake of the NT by astrocytes and by the Presynaptic terminal 2.Enzymatic degradation of NT 3.Diffusion of NT away from the synaptic cleft Drug-based Examples: 1.Reuptake of the NT by astrocytes and by the Presynaptic terminal •Block this to get more and longer neutrotransmission •Serotonin Re-uptake inhibitors (SSRI's) •Commonly used for depression 2.Enzymatic degradation of NT •Acetyl Choline is hydrolyzed by acetyl cholinesterase •Block acetyl cholinesterase; too much acetyl choline •Example: Sarin Nerve Gas

Describe how an action potential is propagated down a myelinated and an unmyelinated neuron. How is an AP propagated down an unmyelinated neuron? In the direction of synaptic terminal. Why is an AP not generated in the membrane behind the AP? due to ____ periods that make it difficult to elicit another one. During absolute, the Na+ Voltage-gated channels are ____. During relative, the Na+ Voltage-gated channels are ____, just ____ (but membrane potential is farther from ____ compared to resting membrane potential so a much stronger stimulus is needed). -At resting potential (-70mV) Na+ voltage-gated channels are ____ but capable of opening. -From threshold to peak potential (-50mV to +30mV) Na+ voltage-gated channels are ____ and activated. -From peak to resting potential (+30mV to -70mV) Na+ voltage-gated channels are ____ and ____ capable of opening (inactivated) How Does an AP Propagate Down a Myelinated Axon? -____ Conduction: Na+ channels ____, generating an action potential. Spreading current from the upstream ____ brings the membrane at the next node to ____ Classification of Nerve Fiber: Based on diameter and degree of myelination -Fiber A: ____ diameter, ____ myelination, 150 m/s (300mph) velocity, example: ____ motor -Fiber B: ____ diameter, ____ myelination, 15 in/s (40mph) velocity, example: ____ sensory and ____ fibers -Fiber C: ____ diameter, ____ myelination, 1 m/s (2mph) velocity, example: ____ sensory and ____ fibers

How is an AP propagated down an unmyelinated neuron? In the direction of synaptic terminal. Why is an AP not generated in the membrane behind the AP? due to refractory periods that make it difficult to elicit another one. During absolute, the Na+ Voltage-gated channels are inactive. During relative, the Na+ Voltage-gated channels are active, just closed (but membrane potential is farther from threshold compared to resting membrane potential so a much stronger stimulus is needed). -At resting potential (-70mV) Na+ voltage-gated channels are closed but capable of opening. -From threshold to peak potential (-50mV to +30mV) Na+ voltage-gated channels are open and activated. -From peak to resting potential (+30mV to -70mV) Na+ voltage-gated channels are closed and not capable of opening (inactivated) How Does an AP Propagate Down a Myelinated Axon? -Saltatory Conduction: Na+ channels open, generating an action potential. Spreading current from the upstream node brings the membrane at the next node to threshold Classification of Nerve Fiber: Based on diameter and degree of myelination -Fiber A: largest diameter, thick myelination, 150 m/s (300mph) velocity, example: somatic motor -Fiber B: intermediate diameter, light myelination, 15 in/s (40mph) velocity, example: autonomic sensory and motor fibers -Fiber C: smallest diameter, no myelination, 1 m/s (2mph) velocity, example: autonomic sensory and motor fibers

Describe the two main mechanisms in which stimulus intensity is encoded. If APs are All or None Events, how is stimulus intensity encoded? 1) ____ coding, where the ____ rate of sensory neurons increases with increased ____ 2) ____ coding, where the ____ of primary afferents responding increases (also called ____).

If APs are All or None Events, how is stimulus intensity encoded? 1) frequency coding, where the firing rate of sensory neurons increases with increased intensity 2) population coding, where the number of primary afferents responding increases (also called RECRUITMENT).

Understand the importance of and describe the differences between absolute and relative refractory periods. Important to prevent ____ propagation of action potential and make sure it arrives at the ____. Essentially absolute refractory periods ensures that each AP is a separate, ____-or-____ event. And enforce ____-way transmission of the AP. Because the area where the AP originated has just generated an AP, the Na+ channels in that area are ____ and no new AP is generated there. For this reason, the AP propagates ____ from its point of origin. In the body, APs are initiated at one end of the axon and conducted away from that point toward the other end. For relative refractory periods, an exceptionally ____ stimulus can reopen the Na+ channels that have already returned to their resting state and generate another AP. Strong stimuli trigger more ____ APs by intruding into the relative refractory period.

Important to prevent backward propagation of action potential and make sure it arrives at the terminal. Essentially absolute refractory periods ensures that each AP is a separate, all-or-none event. And enforce one-way transmission of the AP. Because the area where the AP originated has just generated an AP, theNa+ channels in that area are inactivated and no new AP is generated there. For this reason, the AP propagates away from its point of origin. In the body, APs are initiated at one end of the axon and conducted away from that point toward the other end. For relative refractory periods, an exceptionally strong stimulus can reopen the Na+ channels that have already returned to their resting state and generate another AP. Strong stimuli trigger more frequent APs by intruding into the relative refractory period.

Know the relative ionic concentrations (high/low) of Na+, Cl-, K+ anionic proteins inside and outside of a typical cell that sets up a resting membrane potential. Intracellular [Na+] = ____ mM [K+] = ____ mM [Cl- ]= ____ mM [A-] = ____ mM Extracellular [Na+] = ____ mM [K+] = ____ mM [Cl-] = ____ mM [A-] = ____ mM Na+] is high on ____ [Cl-] is high on ____ [K+] is high on ____ [A-] is high on ____

Intracellular [Na+] = 15 mM [K+] = 150 mM [Cl- ]= 10 mM [A-] = 100 mM Extracellular [Na+] = 150 mM [K+] = 5 mM [Cl-] = 120 mM [A-] = 0.2 mM Na+] is high on outside [Cl-] is high on outside [K+] is high on inside [A-] is high on inside

List the neuroglial cells of the CNS and be able to describe their functions Neurons -Nerve cells that conduct messages in the form of nerve ____ from one part of the body to another -can have ____ (CNS) or ____ cells (PNS) for myelination Neuroglia Cells of the CNS 1.Astrocytes - Most ____, ____-shaped •____ Neurons, can alter neuronal functions •Always Neurons to assess the ____ 2.Microglial Cells •Small ____ cells, migrate to ____ neurons •Can become a macrophage and "____" dead neurons 3.Ependymal Cells •May be ____, circulate ____ Fluid •Form a ____ between CSF and tissue fluids 4.Oligodendrocytes •Wrap CNS nerve fibers forming ____ sheaths Supporting Cells •Supporting cells of the CNS - ____ cells

Neurons -Nerve cells that conduct messages in the form of nerve impulses from one part of the body to another -can have Oligodendrocytes (CNS) or Schwann cells (PNS) for myelination Neuroglia Cells of the CNS 1.Astrocytes - Most abundant, star-shaped •Supports Neurons, can alter neuronal functions •Always Neurons to assess the Blood 2.Microglial Cells •Small oval cells, migrate to injured neurons •Can become a macrophage and "eat" dead neurons 3.Ependymal Cells •May be ciliated, circulate cerebrospinal Fluid •Form a barrier between CSF and tissue fluids 4.Oligodendrocytes •Wrap CNS nerve fibers forming myelin sheaths Supporting Cells •Supporting cells of the CNS - Neuroglial cells

Be able to explain why a neurotransmitter may be excitatory or inhibitory. Neurotransmitters -Chemical released by ____ that stimulates or inhibits another neuron or effector cell. General Information 1.Over ____ NT known 2.Neurons may make ____ than one NT -Different NTs are released at different stimulation frequencies. Whether a neurotransmitter is excitatory or inhibitory depends on the ____ it binds to. Acetylcholine (ACh) - 1st NT to be identified -Excitatory at ____ junctions. Binds to Nicotinic Receptors. Allows both ____+ and ____+ to move creating ____ -Inhibitory on ____ Cells. Binds to Muscarinic receptors. Leads to opening of ____+ chemical gated channels; creating ____ -Degraded by ____ (AChE). ACh -> Acetate + Choline •What would happen if AChE was blocked by nerve gas or organophosphates (insecticides)? •Botulinum toxin inhibits the release of ACh. What is the result?

Neurotransmitters -Chemical released by neuron that stimulates or inhibits another neuron or effector cell. General Information 1.Over 50 NT known 2.Neurons may make more than one NT -Different NTs are released at different stimulation frequencies. Whether a neurotransmitter is excitatory or inhibitory depends on the receptor it binds to. Acetylcholine (ACh) - 1st NT to be identified -Excitatory at neuromuscular junctions. Binds to Nicotinic Receptors. Allows both Na+ and K+ to move creating EPSP -Inhibitory on Cardiac Cells. Binds to Muscarinic receptors. Leads to opening of K+ chemical gated channels; creating IPSP -Degraded by Acetylcholinesterase (AChE). ACh -> Acetate + Choline •What would happen if AChE was blocked by nerve gas or organophosphates (insecticides)? •Botulinum toxin inhibits the release of ACh. What is the result?

Skeletal Muscle Attachments Origin - Attachment site that is ____ (Coracoid process) Insertion - Attachment site that ____ "during the action"

Origin - Attachment site that is immobile (Coracoid process) Insertion - Attachment site that moves "during the action"

Why does the krebs cycle and ETC require oxygen? Oxygen is the ____ acceptor of electrons in the electron transport chain. Without oxygen, the electron transport chain becomes jammed with electrons. Consequently, ____ cannot be produced, thereby causing glycolysis to produce lactic acid instead of ____, which is a necessary component of the Krebs Cycle.

Oxygen is the final acceptor of electrons in the electron transport chain. Without oxygen, the electron transport chain becomes jammed with electrons. Consequently, NAD cannot be produced, thereby causing glycolysis to produce lactic acid instead of pyruvate, which is a necessary component of the Krebs Cycle.

Parasympathetic versus sympathetic • Must know parasympathetic and sympathetic effects on the eyes and heart • Must also know these functions for one other organ (Beyond eyes and heart) Peripheral autonomic nervous system: -Rest and Digest -> ____ (rest) -Fight or Flight -> ____ (stress) parasympathetic effects: -heart: ____ heart rate -eyes: pupil ____ -bronchi: ____ bronchi sympathetic effects: -heart: ____ heartbeat -eyes: ____ pupils -bronchi: ____ bronchi

Peripheral autonomic nervous system: -Rest and Digest -> parasympathetic (rest) -Fight or Flight -> sympathetic (stress) parasympathetic effects: -heart: slow heart rate -eyes: pupil constriction -bronchi: constricts bronchi sympathetic effects: -heart: increased heartbeat -eyes: dilated pupils -bronchi: relaxes bronchi

Recognize an EPSP or an IPSP (on a membrane potential graph) •Where do these come from? Neurotransmitter signals from other neurons Postsynaptic Potentials: (These are the same graded potentials we have previously discussed) •____= Inhibitory Post Synaptic potential -____ •____= Excitatory Post Synaptic potential -____ •Both are ____ potentials

Postsynaptic Potentials: (These are the same graded potentials we have previously discussed) •IPSP = Inhibitory Post Synaptic potential -Hyperpolarization •EPSP = Excitatory Post Synaptic potential -Depolarization •Both are Graded potentials

Describe the reflex center and the functions of sensory, motor and interneurons acting together • Be able to label these neurons both structurally and functionally Reflex Arc: 1) ____ 2) ____ neuron 3) ____ center (in ____ matter) 4) ____ neuron 5) ____ -the integration centers is where you would find ____ -the image is a ____ ____ cross section -The neuron sending info to the interneuron is the ____ neuron. The neuron receiving info from the interneuron is the ____ neuron. -White matter consists of ____ axons passing to and from the ____, or different segments of the ____ cord -Gray matter consists of nerve cell ____ and ____ -White matter - Consists of ____ axons passing to and from the brain; ____ -Grey matter - Consists of nerve cell bodies and interneurons; ____ of ____ -gray matter is where the ____ is done and the white matter is the channels of ____.

Reflex Arc: 1) receptor 2) sensory neuron 3) integration center (in gray matter) 4) motor neuron 5) effector -the integration centers is where you would find interneurons -the image is a spinal cord cross section -The neuron sending info to the interneuron is the sensory neuron. The neuron receiving info from the interneuron is the motor neuron. -White matter consists of myelinated axons passing to and from the brain, or different segments of the spinal cord -Gray matter consists of nerve cell bodies and interneurons -White matter - Consists of myelinated axons passing to and from the brain; Communication -Grey matter - Consists of nerve cell bodies and interneurons; Processing of information -gray matter is where the processing is done and the white matter is the channels of communication.

Describe the absolute and relative refractory periods. •Are action potentials possible during the absolute refractory period? •Why are action potential more difficult during the relative refractory period? Refractory Periods: ____ the next action potential Absolute: Another AP is ____ possible at this time. Due to ____ Na+ channels Relative: Another AP is more ____, but can happen (because membrane potential is even further from ____ than it was when it was at resting membrane potential). Due to continued ____ diffusion of K+ -Even after the Na+ channels are reactivated, there is a period of time which it is still difficult to fire an action potential due to the fact that the K+ channels are still in the process of closing. This time period is referred to as the ____ refractory period. In other words, a cell that is hyperpolarized (M.P. < -70mV) requires more ____ to get to threshold than does a cell at its resting membrane potential -At rest -70mV -> -55mV = +15mV worth of depolarization needed -Hyperpolarized -80mV -> -55mV = +25mV worth of depolarization needed

Refractory Periods: Delay the next action potential Absolute: Another AP is not possible at this time. Due to inactivated Na+ channels Relative: Another AP is more difficult, but can happen (because membrane potential is even further from threshold than it was when it was at resting membrane potential). Due to continued outward diffusion of K+ -Even after the Na+ channels are reactivated, there is a period of time which it is still difficult to fire an action potential due to the fact that the K+ channels are still in the process of closing. This time period is referred to as the relative refractory period. In other words, a cell that is hyperpolarized (M.P. < -70mV) requires more depolarization to get to threshold than does a cell at its resting membrane potential -At rest -70mV -> -55mV = +15mV worth of depolarization needed -Hyperpolarized -80mV -> -55mV = +25mV worth of depolarization needed

Know the values of: Resting potential and Threshold potential Resting = -____mV Threshold = -____mV Depolarization = greater than ____mV (-60mV) Hyperpolarization = less than ____mV (-75mV)

Resting = -70mV Threshold = -55mV Depolarization = greater than -70mV (-60mV) Hyperpolarization = less than -70mV (-75mV)

Know and describe how the 3 ways that resting membrane potential is maintained? Resting Membrane Potential (Vr) -The ____ difference in a resting neuron (-____ mV) -Generated by differences in ____ composition of the intracellular and extracellular fluid -A- = large an-ionic ____ proteins (____ on inside) Why do neurons have a negative resting membrane potential? 1.Resting membrane is ____ to the large anionic cytoplasmic proteins 2.Cell membrane is 75-100x ____ permeable to ____+ than to Na+. Thus, more positive charges moving ____ than in, therefore inside of cell is slightly more negative. ****** 3.Na+/K+ Pump -Pumps ____ Na+ out for every ____ K+ in -Maintains _____, stabilizing the resting membrane potential -The concentration of Na+ and K+ on each side of the membrane are different. Na+ is higher ____ the cell. K+ is higher ____ the cell. Na+/K+ ATPase (____) maintain the concentration gradients of Na+ and K+ across the membrane. -Suppose a cell only has K+ channels. K+ loss through abundant leakage channels establishes a ____ membrane potential -Now let's add some Na+ channels to our cell. Na+ entry through leakage channels reduces the negative membrane potential ____. -Finally, let's add a pump to compensate for leaking ions. Na+/K+ ATPase (pumps) maintain the ____ gradients, resulting in the resting membrane potential

Resting Membrane Potential (Vr) -The potential difference in a resting neuron (-70 mV) -Generated by differences in ionic composition of the intracellular and extracellular fluid -A- = large an-ionic cytoplasmic proteins (high on inside) Why do neurons have a negative resting membrane potential? 1.Resting membrane is impermeable to the large anionic cytoplasmic proteins 2.Cell membrane is 75-100x more permeable to K+ than to Na+. Thus, more positive charges moving out than in, therefore inside of cell is slightly more negative. ****** 3.Na+/K+ Pump -Pumps 3 Na+ out for every 2 K+ in -Maintains gradients, stabilizing the resting membrane potential -The concentration of Na+ and K+ on each side of the membrane are different. Na+ is higher outside the cell. K+ is higher inside the cell. Na+/K+ ATPase (pump) maintain the concentration gradients of Na+ and K+ across the membrane. -Suppose a cell only has K+ channels. K+ loss through abundant leakage channels establishes a negative membrane potential -Now let's add some Na+ channels to our cell. Na+ entry through leakage channels reduces the negative membrane potential slightly. -Finally, let's add a pump to compensate for leaking ions. Na+/K+ ATPase (pumps) maintain the concentration gradients, resulting in the resting membrane potential

Compare and contrast skeletal, smooth and cardiac muscle •Fill out the table for these details. Skeletal -stripes? -nucleus? -____ cell shape -location? -function? -____ nervous system. ____ motor neuron, ____ ____ -branching? Cardiac -stripes -nucleus? -____, ____ cell shape -location? -function? -can beat with out ____. ____ nervous system and ____ nervous system -branching? Smooth -stripes? -nucleus? -____ cell shape -location? -function? -dually ____. ____ nervous system and ____ nervous system -branching?

Skeletal -striated -multinucleated -cylindrical cell shape -attached to muscles -voluntary motion -somatic nervous system. 1 motor neuron, acetyl choline -non-branched Cardiac -striated -single nucleus -rectangular, branched cell shape -heart -help the heart beat. involuntary -can beat with out innervations. sympathetic nervous system and parasympathetic nervous system -branched Smooth -nonstriated -single nucleus -spindle cell shape -walls of hollow organs (respiratory, etc.). -move things along the tract, food in the GI, eggs. involuntary -dually innervated. sympathetic nervous system and parasympathetic nervous system -tapered

Compare and contrast electrical and chemical synapses. Synapse -Unique junction that transfers information from one neuron to the ____ or from one neuron to an ____ cell (e.g. gland or muscle) 1.Electrical Synapse (presynaptic and postsynaptic terminal connected by ____ junction channels) 2.Chemical Synapse (there is a synaptic ____ between the two neurons. exocytosis required for release of neurotransmitters that bind to receptors on postsynaptic cell) •Presynaptic Neuron •Postsynaptic Neuron Examples of a chemical synapse: CNS and ____ neurons

Synapse -Unique junction that transfers information from one neuron to the next or from one neuron to an effecter cell (e.g. gland or muscle) 1.Electrical Synapse (presynaptic and postsynaptic terminal connected by gap junction channels) 2.Chemical Synapse (there is a synaptic cleft between the two neurons. exocytosis required for release of neurotransmitters that bind to receptors on postsynaptic cell) •Presynaptic Neuron •Postsynaptic Neuron Examples of a chemical synapse: CNS and GABAnergic neurons

Define and describe temporal and spatial summation. Synaptic Integration -Temporal Summation The summation of the synaptic potentials generated when a post-synaptic neuron receives ____ stimuli from ____ pre-synaptic neuron. -Spatial Summation When progressively larger ____ of primary afferent (presynaptic) neurons are activated ____, until sufficient neurotransmitter is released to activate an action potential in the spinal cord (postsynaptic) neuron. Note: Recording Electrode is at the ____ hillock in the figure below (in the image)

Synaptic Integration -Temporal Summation The summation of the synaptic potentials generated when a post-synaptic neuron receives rapid stimuli from ONE pre-synaptic neuron. -Spatial Summation When progressively larger numbers of primary afferent (presynaptic) neurons are activated simultaneously, until sufficient neurotransmitter is released to activate an action potential in the spinal cord (postsynaptic) neuron. Note: Recording Electrode is at the axonal hillock in the figure below (in the image)

What are the T tubules and its relationship to the Sarcoplamic Reticulum? The ____ in the sarcolemma propagates along the T tubules and causes release of Ca2+ from the terminal cisterns of the ____. -Along its length, each T tubule runs ____ the paired terminal cisterns of the SR, forming triads. Because T tubules are continuations of the sarcolemma, they conduct ____ to the deepest regions of the muscle cell and every sarcomere. These impulses trigger the release of ____ from the adjacent terminal cisterns.

The AP in the sarcolemma propagates along the T tubules and causes release of Ca2+ from the terminal cisterns of the SR. -Along its length, each T tubule runs between the paired terminal cisterns of the SR, forming triads. Because T tubules are continuations of the sarcolemma, they conduct impulses to the deepest regions of the muscle cell and every sarcomere. These impulses trigger the release of calcium from the adjacent terminal cisterns.

What is used as energy first during muscle contraction •How long can muscle cells use ATP stores, Creatine Phosphate, etc... The ATP-creatine phosphate system transfers a high-energy phosphate from creatine phosphate to adenosine diphosphate (ADP) to regenerate ATP. This anaerobic system can provide ATP for approximately 30 seconds for activities such as ____ and ____.

The ATP-creatine phosphate system transfers a high-energy phosphate from creatine phosphate to adenosine diphosphate (ADP) to regenerate ATP. This anaerobic system can provide ATP for approximately 30 seconds for activities such as sprinting and weightlifting.

Describe the organization of the nervous system. https://training.seer.cancer.gov/anatomy/nervous/organization/ The Nervous system is a master control system of the body *Communicates via electrical and chemical signals -Rapid and Specific -Responses are nearly instant Functions of the Nervous System: 1.____ input -Information gathering by sensory ____ from internal and external ____ 2.Integration -The Nervous system then processes and ____ these data (____) 3.____ Output -Activation of ____ organs (muscles or glands) to produce a response Central Nervous System (CNS) CNS = ____ and ____ Cord. Integrates, processes and coordinates sensory data and motor commands -Brain and Nervous System -Function: Integration and ____ ____. Sensory input. Controls motor output, ideas, memories Peripheral Nervous System (PNS) PNS = All the nerves and neural tissues outside (____ from), or ____, to the CNS. -____ Nerves, ____ Nerves, ____ -Function: Sensory data sent to and the Brains response. Sensory nerves ____ to the spinal cord. Brain signals coming ____ the Brain PNS Functional Divisions: -Sensory (____ division). Conveys sensory impulses to the CNS. Somatic: ____, skeletal ____ and ____. Visceral: From the ____ organs -Motor (____ division). Impulses away from the CNS to effector organs. Somatic nervous system - ____, you are aware of it. Autonomic - ____, you are not aware of these Part of autonomic: -Rest and Digest ____ (maintains homeostasis) = Rest -Fight or Flight ____ (mobilizes reserves under stress) = Stress SEE Image on slide 16.

The Nervous system is a master control system of the body *Communicates via electrical and chemical signals -Rapid and Specific -Responses are nearly instant Functions of the Nervous System: 1.Sensory input -Information gathering by sensory receptors from internal and external changes 2.Integration -The Nervous system then processes and interprets these data (afferent) 3.Motor Output -Activation of effector organs (muscles or glands) to produce a response Central Nervous System (CNS) CNS = Brain and Spinal Cord. Integrates, processes and coordinates sensory data and motor commands -Brain and Nervous System -Function: Integration and control center. Sensory input. Controls motor output, ideas, memories Peripheral Nervous System (PNS) PNS = All the nerves and neural tissues outside (extend from), or peripheral, to the CNS. -Cranial Nerves, Spinal Nerves, Ganglia -Function: Sensory data sent to and the Brains response. Sensory nerves signaling to the spinal cord. Brain signals coming from the Brain PNS Functional Divisions: -Sensory (afferent division). Conveys sensory impulses to the CNS. Somatic: skin, skeletal muscles and joints. Visceral: From the visceral organs -Motor (efferent division). Impulses away from the CNS to effector organs. Somatic nervous system - Voluntary, you are aware of it. Autonomic - Involuntary, you are not aware of these Part of autonomic: -Rest and Digest Parasympathetic (maintains homeostasis) = Rest -Fight or Flight Sympathetic (mobilizes reserves under stress) = Stress SEE Image on slide 16 for flowchart.

Student should know the cellular basis for both current and resistance. • Thicker axons have ____ resistance, transmit signals ____ • The action potential traveling is the current (electrical flow), faster with less resistance 1. Potential Energy -____ electrical charges of opposite signs = potential difference -Measured in ____ (mV; Voltage) -____ inserted in axon reads this (-70mv is rest typically) 2. Current Factors that determine current flow: (1)Resistance - Depends on axon ____ (2)Potential ____ (Measured in Volts) Ohm's Law: I (current) = Voltage (V) / Resistance(R) What Factors Affect Conduction Velocity of APs? -Factors that Decrease Speed of Conduction 1.Decreased ____ 2.Decreased axon ____ MS = is the most common and severe ____-____ disease

Thicker axons have less resistance, transmit signals faster 1. Potential Energy -Separated electrical charges of opposite signs = potential difference -Measured in millivolts (mV; Voltage) -microelectrode inserted in axon reads this (-70mv is rest typically) 2. Current Factors that determine current flow: (1)Resistance - Depends on axon diameter (2)Potential Difference (Measured in Volts) Ohm's Law: I (current) = Voltage (V) / Resistance(R) What Factors Affect Conduction Velocity of APs? -Factors that Decrease Speed of Conduction 1.Decreased myelination 2.Decreased axon diameter MS = is the most common and severe de-myelination disease

Student should be able to describe the functions of the myoproteins (myosin, actin, troponin, tropomyosin, nebulin, dystrophin, and titin). Be able to describe the functions of the myoproteins during muscle contration (myosin, actin, troponin C, T, I, tropomysium, and titin). •Titin is mainly structural, but its role is important as well Tropomyosin -Covers ____-____ site on Actin at rest -Polypeptide strands of tropomyosin (tro″po-mi′o-sin), a rod-shaped protein, ____ about the actin core and help ____ and ____ it. Successive tropomyosin molecules are arranged end to end along the actin filaments, and in a relaxed muscle fiber, they ____ myosin-binding sites on actin so that myosin heads on the thick filaments cannot bind to the thin filaments. Troponin (tro′po-nin), the other major protein in thin filaments, is a globular protein with three polypeptide subunits (Figure 9.3). One subunit attaches troponin to actin. Another subunit binds tropomyosin and helps position it on actin. The third subunit binds calcium ions. Troponin Subunits: Troponin ____ - Bound to tropomyosin Troponin ____ - Binds to calcium (4) when available Troponin ____ - Bound to Actin Another important structural protein is dystrophin, which ____ the thin filaments to the integral proteins of the sarcolemma (which in turn are anchored to the extracellular matrix). Other proteins that bind filaments or sarcomeres together and maintain their ____ include nebulin, myomesin, and C proteins. The ____ filament we referred to earlier is composed of the giant protein titin (Figure 9.2d). Titin extends from the ____ disc to the ____ filament, and then runs within the thick filament (forming its core) to attach to the M line. It holds the thick filaments in ____, maintaining the organization of the A band, and helps the muscle cell spring back into shape after stretching. (The part of the titin that spans the I bands is extensible, unfolding when the muscle stretches and recoiling when the tension is released.) Titin does not ____ stretching in the ordinary range of extension, but it ____ as it uncoils, helping the muscle resist excessive ____, which might pull the sarcomeres apart. Myosin and actin = ____ proteins -____ filaments are composed primarily of the protein myosin. Each myosin molecule consists of six polypeptide chains: two heavy (high-molecular-weight) chains and four light chains. The heavy chains twist together to form myosin's rodlike tail, and each heavy chain ends in a globular head that is attached to the tail via a flexible ____ -The ____ filaments are composed chiefly of the protein actin (blue in Figure 9.3). Actin has kidney-shaped polypeptide subunits, called globular actin or G actin. Each G actin has a ____-binding site (or active site) to which the myosin heads attach during ____. G actin subunits polymerize into long actin filaments called filamentous, or F, actin. Two intertwined actin filaments, resembling a twisted double strand of pearls, form the backbone of each thin filament Excitation: ____ signal (EPSP) Contraction: Actin Myosin ____ Tropo: "____," "reaction, response," or "change." Tropomyosin: Protein ____ that ____

Tropomyosin -Covers X-bridge site on Actin at rest -Polypeptide strands of tropomyosin (tro″po-mi′o-sin), a rod-shaped protein, spiral about the actin core and help stiffen and stabilize it. Successive tropomyosin molecules are arranged end to end along the actin filaments, and in a relaxed muscle fiber, they block myosin-binding sites on actin so that myosin heads on the thick filaments cannot bind to the thin filaments. Troponin (tro′po-nin), the other major protein in thin filaments, is a globular protein with three polypeptide subunits (Figure 9.3). One subunit attaches troponin to actin. Another subunit binds tropomyosin and helps position it on actin. The third subunit binds calcium ions. Troponin Subunits: Troponin T - Bound to tropomyosin Troponin C - Binds to calcium (4) when available Troponin I - Bound to Actin Another important structural protein is dystrophin, which links the thin filaments to the integral proteins of the sarcolemma (which in turn are anchored to the extracellular matrix). Other proteins that bind filaments or sarcomeres together and maintain their alignment include nebulin, myomesin, and C proteins. The elastic filament we referred to earlier is composed of the giant protein titin (Figure 9.2d). Titin extends from the Z disc to the thick filament, and then runs within the thick filament (forming its core) to attach to the M line. It holds the thick filaments in place, maintaining the organization of the A band, and helps the muscle cell spring back into shape after stretching. (The part of the titin that spans the I bands is extensible, unfolding when the muscle stretches and recoiling when the tension is released.) Titin does not resist stretching in the ordinary range of extension, but it stiffens as it uncoils, helping the muscle resist excessive stretching, which might pull the sarcomeres apart. Myosin and actin = contractile proteins -thick filaments are composed primarily of the protein myosin. Each myosin molecule consists of six polypeptide chains: two heavy (high-molecular-weight) chains and four light chains. The heavy chains twist together to form myosin's rodlike tail, and each heavy chain ends in a globular head that is attached to the tail via a flexible hinge -The thin filaments are composed chiefly of the protein actin (blue in Figure 9.3). Actin has kidney-shaped polypeptide subunits, called globular actin or G actin. Each G actin has a myosin-binding site (or active site) to which the myosin heads attach during contraction. G actin subunits polymerize into long actin filaments called filamentous, or F, actin. Two intertwined actin filaments, resembling a twisted double strand of pearls, form the backbone of each thin filament Excitation: Electrical signal (EPSP) Contraction: Actin Myosin Crossbridging Tropo: "turn," "reaction, response," or "change." Tropomyosin: Protein fiber that rotates

Know that when nicotinic receptors bind Acetylcholine (ACh), that it allows both Na+ and K+ to flow through the membrane. True Classification of NT by Chemical Structure (See Table 11.3) 1. Acetylcholine (ACh) - 1st NT to be identified -____ at neuromuscular junctions •Binds to ____ Receptors •Allows both Na+ and K+ to move creating ____ -____ on Cardiac Cells •Binds to ____ receptors •Leads to opening of K+ chemical gated channels; creating ____

True Classification of NT by Chemical Structure (See Table 11.3) 1. Acetylcholine (ACh) - 1st NT to be identified -Excitatory at neuromuscular junctions •Binds to Nicotinic Receptors •Allows both Na+ and K+ to move creating EPSP -inhibitory on Cardiac Cells •Binds to Muscarinic receptors •Leads to opening of K+ chemical gated channels; creating IPSP

Know what binds calcium and the effect it has on tropomyosin •Induce the actin binding sites in this statement for full understanding. When intracellular calcium levels are ____, the muscle cell is relaxed because tropomyosin molecules physically ____ the myosin-binding sites on actin. As Ca2+ levels rise, the ions bind to regulatory sites on ____. Two calcium ions must bind to a troponin, causing it to change ____ and roll ____ into the groove of the actin helix, away from the myosin-binding sites. In short, the tropomyosin blockade is removed when sufficient calcium is present. Once binding sites on actin are exposed, the events of the cross bridge ____ occur in rapid succession, as depicted in Focus on the Cross Bridge Cycle (Focus Figure 9.3). The cycle repeats and with each cycle, the ____ head takes another "step" by attaching to an actin site further along the ____ filament. The thin filaments continue to ____ as long as ____ and adequate ____ are present.

When intracellular calcium levels are low, the muscle cell is relaxed because tropomyosin molecules physically block the myosin-binding sites on actin. As Ca2+ levels rise, the ions bind to regulatory sites on troponin. Two calcium ions must bind to a troponin, causing it to change shape and roll tropomyosin into the groove of the actin helix, away from the myosin-binding sites. In short, the tropomyosin blockade is removed when sufficient calcium is present. Once binding sites on actin are exposed, the events of the cross bridge cycle occur in rapid succession, as depicted in Focus on the Cross Bridge Cycle (Focus Figure 9.3). The cycle repeats and with each cycle, the myosin head takes another "step" by attaching to an actin site further along the thin filament. The thin filaments continue to slide as long as calcium and adequate ATP are present.

Label and define phases of a muscle twitch. • Describe the events that occur during each phase of a muscle twitch. Whole Muscles are organized into Motor Units Activation of Motor Units result in Muscle ____ Muscle Twitch -> When an action potential travels down the motor neuron for a muscle to ____, divided into 3 parts Threshold Stimulus -> Minimum intensity required to produce a ____ from a human or animal -latent period: very brief ____ between stimulus and contraction. time required for excitation, excitation-contraction coupling, and tensing of elastic components of muscle (generating internal tension) -contraction phase: time when muscle generates ____ tension. force generated can overcome the ____ and cause movement -relaxation phase: time when tension ____ to baseline. SR reabsorbs ____+, myosin ____ actin and tension ____. takes longer than contraction -entire twitch duration varies between 7 and 100ms Comparing three muscles from lasting for a little time to a longer amount of time: lateral rectus, gastrocnemius, and soleus (SEE slide 18 in L 27)

Whole Muscles are organized into Motor Units Activation of Motor Units result in Muscle Twitches Muscle Twitch -> When an action potential travels down the motor neuron for a muscle to contract, divided into 3 parts Threshold Stimulus -> Minimum intensity required to produce a response from a human or animal -latent period: very brief delay between stimulus and contraction. time required for excitation, excitation-contraction coupling, and tensing of elastic components of muscle (generating internal tension) -contraction phase: time when muscle generates external tension. force generated can overcome the load and cause movement -relaxation phase: time when tension declines to baseline. SR reabsorbs Ca2+, myosin releases actin and tension decreases. takes longer than contraction -entire twitch duration varies between 7 and 100ms Comparing three muscles from lasting for a little time to a longer amount of time: lateral rectus, gastrocnemius, and soleus (SEE slide 18 in L 27)

Compare and contrast between isometric and isotonic (eccentric and concentric) muscle contractions. Work Performed by Muscle -Before load can be lifted the ____ components must be stretched. -The elastic components = ____, ____, ____, connective tissue ____ (endomysium, perimysium, epimysium). 1.Isotonic - ("Same ____") -Muscle generates enough tension to change ____ and lift the ____ -Two flavors: Concentric (muscle ____) and eccentric (muscle ____). 2.Isometric - ("Same ____") -Muscle generates ____ but muscle ____ does NOT change.

Work Performed by Muscle -Before load can be lifted the elastic components must be stretched. -The elastic components = tendons, titin, sarcolemma, connective tissue sheaths (endomysium, perimysium, epimysium). 1.Isotonic - ("Same tension") -Muscle generates enough tension to change length and lift the load -Two flavors: Concentric (muscle shortens) and eccentric (muscle lengthens). 2.Isometric - ("Same length") -Muscle generates tension but muscle length does NOT change.

The functions of Creatine Phosphate, how is it similar to ATP. for brief periods (<15 seconds) creatine phosphate can act as an ____ "store" Creatine phosphate + ADP = creatine + ATP Anaerobic The ATP-creatine phosphate system transfers a high-energy phosphate from creatine phosphate to adenosine diphosphate (ADP) to regenerate ____. This anaerobic system can provide ATP for approximately ____ seconds for activities such as sprinting and weightlifting. CP acts like ATP. ATP is best choice. CP stores phosphates and add it back to ADP.

for brief periods (<15 seconds) creatine phosphate can act as an ATP "store" Creatine phosphate +ADP = creatine + ATP Anaerobic The ATP-creatine phosphate system transfers a high-energy phosphate from creatine phosphate to adenosine diphosphate (ADP) to regenerate ATP. This anaerobic system can provide ATP for approximately 30 seconds for activities such as sprinting and weightlifting. CP acts like ATP. ATP is best choice. CP stores phosphates and add it back to ADP.

Be able to recognize, label and note the order of skeletal muscles organization (largest to smallest, smallest to largest). ____ (organ) > ____ (portion of the muscle) > muscle ____ (cell) > ____ (complex organelle composed of bundles of myofilaments) > ____ (a segment of a myofibril) > ____ or ____ (extended macromolecular structure)

muscle (organ) > fascicle (portion of the muscle) > muscle fiber (cell) > myofibril (complex organelle composed of bundles of myofilaments) > sarcomere (a segment of a myofibril) > myofilament or filament (extended macromolecular structure)

Student should be able to define, draw and label a sarcomere. Sarcomere - the functional ____ unit of a skeletal muscle; region of myofibril that extends from z-disc to z-disc. (Avg. length = 2 µm) -Z-line: disc in ____ I bands. Appears as a series of dark lines -I-band is the zone of ____ filaments that is not superimposed by ____ filaments -A-band contains the entire length of a single ____ filament -H-band is the zone of the ____ filaments that is not superimposed by the ____ filaments -finally, inside the h-zone is a thin m-line formed of ____-____ elements of the cytoskeleton

okay! see homework drawing! Sarcomere - the functional contractile unit of a skeletal muscle; region of myofibril that extends from z-disc to z-disc. (Avg. length = 2 µm) -Z-line: disc in between I bands. Appears as a series of dark lines -I-band is the zone of thin filaments that is not superimposed by thick filaments -A-band contains the entire length of a single thick filament -H-band is the zone of the thick filaments that is not superimposed by the thin filaments -finally, inside the h-zone is a thin m-line formed of cross-connecting elements of the cytoskeleton

Write a well-formed description of muscle fiber contraction and relaxation. •Lots of steps here and this overview will be on the test. Neuron, to Neuromuscular junction, to muscle fiber action potential, to cross bridging and eventually sarcomere relaxation Steps to Skeletal Muscle Fiber Relaxation 1. Motor neuron stops ____ and ACh in cleft and on postsynaptic membrane is ____ by AChE, taken back ____ into the pre- synaptic terminal, and ____ away from the sarcolemma. 2. Calcium is actively transported back into ____ 3. Troponin ____ releases ____ and goes back to original conformation allowing tropomyosin to once again ____ the cross bridge binding sites.

overview explained on card 43 Steps to Skeletal Muscle Fiber Relaxation 1. Motor neuron stops firing and ACh in cleft and on postsynaptic membrane is degraded by AChE, taken back up into the pre- synaptic terminal, and diffuses away from the sarcolemma. 2. Calcium is actively transported back into SR 3. Troponin C releases calcium and goes back to original conformation allowing tropomyosin to once again block the cross bridge binding sites.

List and explain the events associated with skeletal muscle cell contraction. see card above for events of excitation-contraction coupling How much calcium is in the myoplasm at rest? 5 x 10^-8 or 10^-8 at ____ How much calcium is required to generate the maximum force of contraction? 10^-8 at ____ 10^-6 at ____ force 100-time more when contracting at ____ force -higher relative force, higher ____ concentration -higher ATPase activity, higher ____ concentration -Excitation: Electrical signal (____) -Contraction: Actin Myosin ____ Tropo: "turn," "reaction, response," or "change." Tropomyosin: ____ fiber that ____ Cross Bridge Cycling (Sliding filament theory) steps: 1) cross bridge formation. energized ____ head attaches to an ____ myofilament, forming a cross bridge 2) the power (working) stroke. ____ and Pi are released and the myosin head ____ and ____, changing to its bent ____-energy state. As a result, it pulls the actin filament ____ the M line. (in the absence of ATP, myosin heads will not ____, causing rigor mortis.) 3) cross bridge detachment. after ____ attaches to myosin, the link between myosin and actin ____, and the myosin head ____ (the cross bridge "breaks"). 4) cocking of the myosin head. as myosin ____ ATP to ADP and Pi, the myosin head returns to its prestroke ____-energy, or "cocked" position* *this cycle will continue as long as ATP is available and Ca2+ is ____ to troponin. If ATP is not available, the cycle stops between steps 2 and 3 Which bands Changed Size? -____, ____ -but ____-band stayed the same

see card above for events of excitation-contraction coupling How much calcium is in the myoplasm at rest? 5 x 10^-8 or 10^-8 at rest How much calcium is required to generate the maximum force of contraction? 10^-8 at rest 10^-6 at maximum force 100-time more when contracting at full force -higher relative force, higher calcium concentration -higher ATPase activity, higher calcium concentration -Excitation: Electrical signal (EPSP) -Contraction: Actin Myosin Crossbridging Tropo: "turn," "reaction, response," or "change." Tropomyosin: Protein fiber that rotates Cross Bridge Cycling (Sliding filament theory) steps: 1) cross bridge formation. energized myosin head attaches to an actin myofilament, forming a cross bridge 2) the power (working) stroke. ADP and Pi are released and the myosin head pivots and bends, changing to its bent low-energy state. As a result, it pulls the actin filament toward the M line. (in the absence of ATP, myosin heads will not detach, causing rigor mortis.) 3) cross bridge detachment. after ATP attaches to myosin, the link between myosin and actin weakens, and the myosin head detaches (the cross bridge "breaks"). 4) cocking of the myosin head. as myosin hydrolyzes ATP to ADP and Pi, the myosin head returns to its prestroke high-energy, or "cocked" position* *this cycle will continue as long as ATP is available and Ca2+ is bound to troponin. If ATP is not available, the cycle stops between steps 2 and 3 Which bands Changed Size? -H, I -but A-band stayed the same

Student should be able to draw a cross section of a spinal cord and label the neurons both structurally and functionally. *The picture we had of the drinking water example and the neurons used in that process.

see image

Recognize the type of neurons for a cartoon illustration of their shape. see image -Integration Centers are where you would find ____

see image -Integration Centers are where you would find interneurons

PNS (parasympathetic VS sympathetic)

see image and slide 15, 19

Describe the paths by which ATP is generated during mild and strenuous exercise •Can high intensity exercise use fatty acids as a fuel source? Why or why not?

see slide 7 on L 29

Interpret and recognize the graphs that represent •Wave summation •Tetany •Multiple motor unit recruitment •Treppe slide 20-25 in L27 has pictures for this! -A muscle's response to changes in stimulation ____. -Relationship between stimulus intensity (graph at top) and muscle tension (myogram below). Below threshold voltage, the myogram shows no muscle ____ (stimuli 1 and 2). Once threshold (3) is reached, increases in voltage excite (recruit) more and more motor units until the ____ stimulus is reached (7). Further increases in stimulus voltage produce no ____ increase in contractile strength. -Motor units with the ____ fibers are recruited first, allowing fine control of contraction.

slide 20-25 in L27 has pictures for this! -A muscle's response to changes in stimulation frequency. -Relationship between stimulus intensity (graph at top) and muscle tension (myogram below). Below threshold voltage, the myogram shows no muscle response (stimuli 1 and 2). Once threshold (3) is reached, increases in voltage excite (recruit) more and more motor units until the maximal stimulus is reached (7). Further increases in stimulus voltage produce no further increase in contractile strength. -Motor units with the smallest fibers are recruited first, allowing fine control of contraction.

Neurotransmitters Learning Objectives: study these • Acetylcholine - EPSP (____) or IPSP (____), degraded by ____ in the synapse • Catecholamines: 1.Dopamine - ____ neurotransmitter, deficient in ____ disease 2.Norepinephrine - Feel ____, ____ 3.Epinephrine - Stimulates ____ NS • Indolamines: 1.Serotonin - CNS ____. Aids ____, ____ and ____ regulation. ____ increases these effects 2.Histamine - CNS, release during ____ responses. ____ blocks histamine to promote ____ and improve ____ symptoms • Aminoacids: 1.GABA - CNS (____), ____ 2.Glycine - CNS (____ cord), ____ 3.Glutamate - CNS, ____ important for ____ and ____ • Peptides: 1.Substance P - ____ transmission ____ 2.Endorphins - natural ____, blocks substance ____ to give pain ____

• Acetylcholine - EPSP (nicotinic) or IPSP (muscarinic), degraded by acetylcholinease in the synapse • Catecholamines: 1.Dopamine - Reward neurotransmitter, deficient in Parkinson's disease 2.Norepinephrine - Feel good, sympathetic 3.Epinephrine - Stimulates sympathetic NS • Indolamines: 1.Serotonin - CNS IPSP. Aids sleep, appetite and mood regulation. Prozac increases these effects 2.Histamine - CNS, release during inflammatory responses. Benedryl blocks histamine to promote sleep and improve allergy symptoms • Aminoacids: 1.GABA - CNS (brain), IPSP 2.Glycine - CNS (spinal cord), IPSP 3.Glutamate - CNS, EPSP important for learning and memory • Peptides: 1.Substance P - pain transmission PNS 2.Endorphins - natural opiates, blocks substance P to give pain relief

Know the order of Skeletal Muscle organization form largest to smallest •Fascia > Fascicle > Muscle fiber (cells) > Myofibrils > Filaments (Myosin & Actin) •Notes: Deep Fascia binds the muscle (+ tendon to the bone) •Notes: Sarcomeres are not cells and are seen at the level of the myofibrils •____> ____> Muscle ____ (cells) > ____> ____(Myosin & Actin) •Notes: Deep Fascia ____ the muscle (+ tendon to the bone) •Notes: Sarcomeres are not cells and are seen at the level of the ____ Study Slide 9, Lecture 25

•Fascia > Fascicle > Muscle fiber (cells) > Myofibrils > Filaments (Myosin & Actin) •Notes: Deep Fascia binds the muscle (+ tendon to the bone) •Notes: Sarcomeres are not cells and are seen at the level of the myofibrils Study Slide 9, Lecture 25

Classify neurons structurally and functionally. •Structural Classification- based on the ____ of processes -Peripheral Process - information form the ____ -Central Process - carries information ____ the Brain -Multipolar neurons have one ____ and many ____ extending from the cell body. (Can be motor or sensory) -Bipolar neurons have one ____ and one ____ . -Unipolar neurons have only one ____ process extending from the cell body. -Multipolar neurons are the most ____ while there are many bipolar neurons. However, there are unipolar neurons present in the nervous system, but their number is very ____ compared to the other two types. -Anaxonic is an ____ -Multipolar can be ____ or ____ (see labeled on slide 10, L 23) •Functional Classification- based on ____ of nerve impulse relative to the Brain 1. Sensory Neurons (____) - ____ the Brain 2. Motor Neurons (____) - ____ from the Brain 3. Association Neurons (____) - ____ one another

•Structural Classification- based on the number of processes -Peripheral Process - information form the periphery -Central Process - carries information toward the Brain -Multipolar neurons have one axon and many dendrites extending from the cell body. (Can be motor or sensory) -Bipolar neurons have one axon and one dendrite. -Unipolar neurons have only one protoplasmic process extending from the cell body. -Multipolar neurons are the most common while there are many bipolar neurons. However, there are unipolar neurons present in the nervous system, but their number is very low compared to the other two types. -Anaxonic is an interneuron -Multipolar can be motor or sensory (see labeled on slide 10, L 23) •Functional Classification- based on direction of nerve impulse relative to the Brain 1. Sensory Neurons (Afferent) - Towards the Brain 2. Motor Neurons (Efferent) - Away from the Brain 3. Association Neurons (Interneurons) - Between one another

Describe the 3 basic ways which ATP is generated in skeletal muscles (Sec. 9.6) (I guess relearn that flashcard) DIRECT PHOSPHORYLATION Creatine phosphate + ADP (creatinekinase) → creatine + ATP ANAEROBIC Where does Glycolysis and lactic acid fermentation occur in the cell? In cytosol What fuel is required for Glycolysis/Lactic Acid Fermentation? glucose What are the end products of Glycolysis? 2 ATP and pyruvic acid What determines if Pyruvic Acid is shuttled to the mitochondria or converted to lactic acid? Oxygen presence What are the end products of lactic acid fermentation? Lactic acid What happens to the lactic acid? Released to blood AEROBIC What is the summary equation for this process? glucose + oxygen -> carbon dioxide + water + ATP What is oxygen used for in aerobic cellular respiration? electron acceptor Where does the Oxygen end up at the end of this process? electron transport chain (oxidative phosphorylation) What happens to the CO2 generated by aerobic cellular respiration? released as a product

•What is ATP used for during Skeletal Muscle Contractions/relaxation? •Muscles store very little ATP (4 - 6 seconds) so ATP must be constantly generated. •How do your cells generate ATP? ATP is generated by 3 mechanisms (See Figure 9-16) 1.Direct Phosphorylation -coupled reaction of creatine phosphate (CP) and ADP. -energy source: CP. -products: 1 ATP per CP, creatine -duration of energy provided: 15 seconds 2.Anaerobic Respiration (i.e. Lactic Acid Fermentation or Anaerobic Glycolysis) -energy source: glucose -oxygen use: none -products: 2 ATP per glucose, lactic acid -duration of energy provided: 30-20 seconds 3.Aerobic Cellular Respiration -energy source: glucose, pyruvic acid, free fatty acids from adipose tissue; amino acids from protein catabolism -oxygen use: required -products: 32 ATP per glucose, CO2, H2O -duration of energy provided: hours Aerobic 1) digestion in GI tract lumen to absorbable forms. transport via blood to tissue cells 2) anabolism (incorporation into molecules) and catabolism of nutrients to form intermediates within tissue cells 3) oxidative breakdown of products of stage 2 in mitochondria of tissue cells. CO2 is liberated, and H atoms removed are ultimately delivered to molecular oxygen, forming water. some energy released is used to form ATP Production of ATP (mmols/sec): creatine phosphate > glycolysis > aerobic -carbs > aerobic -fats