Term
| What is the relationship between the surface area and the energy of a liquid? |
|
Definition
|
|
Term
|
Definition
| They are amphiphilic molecules that lower surface tension. |
|
|
Term
| What 3 factors affect phospholipid bilayer fluidity? |
|
Definition
| Temperature, phospholipid saturation, and cholesterol content. |
|
|
Term
| What is the effect of double bonds on membrane fluidity? |
|
Definition
| Double bonds increase fluidity. |
|
|
Term
| What is the effect of cholesterol on membrane fluidity? |
|
Definition
| Cholesterol decreases membrane fluidity. |
|
|
Term
| Lipid rafts are enriched in what kind of lipids? |
|
Definition
| Cholesterol and sphingolipids. |
|
|
Term
| Caveolae are enriched with what kinds of lipids? |
|
Definition
| Cholesterol and phosphatidylserine. |
|
|
Term
|
Definition
| A protein in caveolae that has a high affinity for cholesterol. |
|
|
Term
| What are two roles of caveolae? |
|
Definition
| Caveolae are implicated in signal transduction and mechanical stretch sensing. |
|
|
Term
| Describe the two modes of vesicle recycling. |
|
Definition
Fast mode (kiss and run): No full collapse or fusion of the vesicle with the pre-synaptic membrane.
Slow mode: Vesicle completely fuses with membrane and is then recycled by endocytosis, involving clathrin and dynamin. |
|
|
Term
| How do vesicles re-load with neurotransmitters? |
|
Definition
| Secondary active transport powered by the vacuolar H+-ATPase. |
|
|
Term
| What is the role of the dystro/sarcoglycan complex? |
|
Definition
| It stabilizes the plasma membrane of muscle cells by binding to the extracellular matrix and to dystrophin in the intracellular space. |
|
|
Term
| What is the equation for Fick's Dilution Principle? |
|
Definition
| Volume = Amount/Concentration. |
|
|
Term
| What marker is used for total body water? |
|
Definition
|
|
Term
| On average, what percentage of body weight is water? |
|
Definition
|
|
Term
| How does body fat affect the percentage of total body water? |
|
Definition
|
|
Term
| How does the percent body water in females compare with that in males? |
|
Definition
| Females have a lower percent of total body water because of a greater amount of adipose tissue. |
|
|
Term
| How does age affect total body water? |
|
Definition
| Neonates>adults>older adults (obesity) |
|
|
Term
| What is the marker for ECF? |
|
Definition
|
|
Term
| What is the marker for plasma volume? |
|
Definition
|
|
Term
| What is the formula for ICF? |
|
Definition
|
|
Term
| What is the formula for ISF? |
|
Definition
|
|
Term
| What proportion of total body water is intracellular fluid? |
|
Definition
|
|
Term
| What proportion of total body water is extracellular fluid? |
|
Definition
|
|
Term
| What proportion of extracellular fluid is interstitial fluid? |
|
Definition
|
|
Term
| What proportion of extracellular fluid is plasma? |
|
Definition
|
|
Term
| How does the amount of protein in plasma and ICF compare with the amount of protein in ISF? |
|
Definition
| ISF has less protein than plasma and ICF. |
|
|
Term
| What is macroscopic electroneutrality? |
|
Definition
| The total amount of positive charge equals the total amount of negative charge. |
|
|
Term
| What is the Nernst equation? |
|
Definition
|
|
Term
| What is the equation for the Gibbs-Donan ratio? |
|
Definition
| [Na+]i/[Na+]o=[Cl-]o/[Cl-]i=r=1.05 |
|
|
Term
| What part of the neuron is mostly responsible for macromolecule synthesis? |
|
Definition
|
|
Term
| What part of the neuron is specialized for reception of signals? |
|
Definition
|
|
Term
| In what part of the neuron does integration and triggering occur? |
|
Definition
|
|
Term
| What part of the neuron is responsible for propagation and communication? |
|
Definition
|
|
Term
| What is the name for the protein synthesizing structures in a neuron that are present everywhere except in the axon? |
|
Definition
|
|
Term
| Is signalling within individual neurons ionic or chemical? |
|
Definition
|
|
Term
| Is signalling between neurons usually ionic or chemical? |
|
Definition
|
|
Term
| What is multiple sclerosis? |
|
Definition
| Multiple sclerosis is an autoimmune disease that involves inflammation and loss of myelination in the CNS (loss of oligodendrocytes). |
|
|
Term
|
Definition
| Convection is when the solute is dragged along by solvent. |
|
|
Term
| What is the formula for flux? |
|
Definition
|
|
Term
| What is Fick's First Law of Diffusion? |
|
Definition
| Js = -D(deltaC)/(delta X) |
|
|
Term
| What is the relationship between diffusion coefficient and temperature? |
|
Definition
| Diffusion coefficient is directly proportional to temperature. |
|
|
Term
| What is the relationship between diffusion coefficient and the radius of the solute? |
|
Definition
| Diffusion coefficient is inversely proportional to the radius of the solute. |
|
|
Term
| What is the relationship between diffusion coefficient and the viscosity of the medium? |
|
Definition
| Diffusion coefficient is inversely proportional to the viscosity of the medium. |
|
|
Term
| What is the relationship between diffusion time and distance? |
|
Definition
| Time for diffusion goes up with the square of the distance. |
|
|
Term
| What is the formula for the flux of a solute being carried by the bulk movement of a fluid? |
|
Definition
| Js = JvC = (velocity of solvent)(concentration of solute). |
|
|
Term
| What is the formula for passive diffusion transport across a membrane? |
|
Definition
|
|
Term
| What is the relationship between permeability and diffusion coefficient? |
|
Definition
| Permeability is directly proportional to the diffusion coefficient of the solute in the lipid bilayer. |
|
|
Term
| What is the relationship between permeability and partition coefficient? |
|
Definition
| Permeability is directly proportional to partition coefficient. |
|
|
Term
| What is the relationship between permeability and membrane thickness? |
|
Definition
| Permeability is inversely proportional to membrane thickness. |
|
|
Term
| What is the relationship between permeability and the number of pores? |
|
Definition
| Permeability is directly proportional to the number of pores. |
|
|
Term
| What is the relationship between permeability and membrane area? |
|
Definition
| Permeability is inversely proportional to membrane area. |
|
|
Term
| What is the relationship between permeability and the area of the pore? |
|
Definition
| Permeability is directly proportional to the area of the pore. |
|
|
Term
| How many subunits are in a cysteine-loop receptor? |
|
Definition
|
|
Term
| What is one example of a cysteine-loop receptor? |
|
Definition
|
|
Term
| How many subunits are in glutamate receptors? |
|
Definition
|
|
Term
| Give one example of a glutamate receptor. |
|
Definition
|
|
Term
| How many subunits are in ATP-sensitive P2X receptors? |
|
Definition
|
|
Term
|
Definition
| A GEF causes a G protein to exchange its GDP for GTP. |
|
|
Term
|
Definition
| It accelerates the GTPase activity of a G protein. |
|
|
Term
| What is the effect of acetylcholine on skeletal muscle cells? |
|
Definition
| Activation (ligand-gated nicotinic receptors) |
|
|
Term
| What is the effect of acetylcholine on cardiac muscle cells? |
|
Definition
| Inhibition (G-protein-coupled muscarinic receptors). |
|
|
Term
| What is the effect of acetylcholine on smooth muscle tissue? |
|
Definition
| Inhibition (indirect-GPCR on endothelial cells). |
|
|
Term
| What is the effect of acetylcholine on smooth muscle cells? |
|
Definition
| Activation (direct-GPCR on smooth muscle cells). |
|
|
Term
| Which muscarinic receptors are coupled to Gq? |
|
Definition
|
|
Term
| Which muscarinic receptors are coupled to Gi? |
|
Definition
|
|
Term
| What G-protein is the alpha-1 adrenergic receptor coupled to? |
|
Definition
|
|
Term
| What G-protein is the alpha-2 adrenergic receptor coupled to? |
|
Definition
|
|
Term
| What G-protein are the beta-1 and beta-2 adrenergic receptors coupled to? |
|
Definition
|
|
Term
| What does cholera toxin do? |
|
Definition
| It stimulates G-alpha-s, which activates adenylyl cyclase and leads to the formation of cAMP. |
|
|
Term
| What does pertussis toxin do? |
|
Definition
| It inhibits G-alpha-i, leading to an increase in cAMP. |
|
|
Term
| How is arachidonic acid produced? |
|
Definition
| By the action of PLA2 on phosphatidylcholine. |
|
|
Term
| What are the ligands for particulate guanylyl cyclase? |
|
Definition
|
|
Term
| What is the ligand for soluble guanylyl cyclase? |
|
Definition
|
|
Term
| What are two mechanisms of termination of G-protein signaling? |
|
Definition
Phosphorylation of receptors uncouples receptor from G-protein (short-term process) and eventually leads to the binding of beta-arresting and internalization of the receptor.
GAPs (aka RGS) accelerate GTPase activity of the G-protein and inactivate the G-protein. |
|
|
Term
|
Definition
| GRK2 is a kinase that phosphorylates GPCRs, leading to receptor internalization. It is activated by G-beta-gamma. |
|
|
Term
| What phosphodiesterases are specific for cAMP? |
|
Definition
|
|
Term
| What phosphodiesterases are specific for cGMP? |
|
Definition
|
|
Term
| What does hematoxylin interact with? |
|
Definition
| Negative charges (nuclear chromatin, nucleolus, and rER) |
|
|
Term
| What does eosin interact with? |
|
Definition
| Positive charges (basically everything except the nucleus and rER). |
|
|
Term
| What is the largest type of muscle fiber? |
|
Definition
|
|
Term
| Are skeletal muscle fibers branched or unbranched? |
|
Definition
|
|
Term
| Which bands narrow and which remain unchanged during muscle contraction? |
|
Definition
| The I and H bands narrow, and the A band does not change length. |
|
|
Term
| Are cardiac muscle fibers branching or non-branching? |
|
Definition
|
|
Term
| Where is the nucleus of a cardiac muscle cell located? |
|
Definition
|
|
Term
| What type of muscle fiber has intercalated disks? |
|
Definition
|
|
Term
| List 2 types of junctions at intercalated disks. |
|
Definition
| Adherent junctions and gap junctions. |
|
|
Term
| What is the smallest type of muscle fiber? |
|
Definition
|
|
Term
| Where is the nucleus in smooth muscle cells? |
|
Definition
| There is a single central nucleus. |
|
|
Term
| Dense bodies are associated with which type of muscle fiber? |
|
Definition
|
|
Term
| What is the purpose of dense bodies? |
|
Definition
| Dense bodies anchor thin filaments in smooth muscle fibers. |
|
|
Term
| What is the main protein component of dense bodies discussed in class? |
|
Definition
|
|
Term
| What type of muscle undergoes both hypertrophy and hyperplasia? |
|
Definition
| Smooth muscle. The others only undergo hypertrophy. |
|
|
Term
| What is the effect of an impermeable solute on the hydrostatic pressure in a compartment? |
|
Definition
| An impermeable solute decreases the hydrostatic pressure in a compartment. |
|
|
Term
| Does water move to the compartment with higher or lower osmotic pressure? |
|
Definition
|
|
Term
| What is the difference between a hypertonic and a hypotonic solution? |
|
Definition
| A hypertonic solution causes cells to shrink. A hypotonic solution causes cells to swell. |
|
|
Term
| What is the equation for effective osmotic pressure? |
|
Definition
| Effective osmotic pressure = (reflection coefficient)(R)(T)(osmotic coefficient)(n)(C) |
|
|
Term
| What is the value of the reflection coefficient when the membrane is completely impermeant to the solute? |
|
Definition
|
|
Term
| What is the value of sigma when the membrane is fully permeable? |
|
Definition
|
|
Term
| How does the speed of osmosis compare to the speed of diffusion? |
|
Definition
|
|
Term
| What is the effect of phosphorylating glycogen phosphorylase? |
|
Definition
| Phosphorylation activates glycogen phosphorylase and leads to the breakdown of glycogen into glucose. |
|
|
Term
| What is the effect of phosphorylating glycogen synthase? |
|
Definition
| Phosphorylation inhibits glycogen synthase. |
|
|
Term
| What is the function of AKAP? |
|
Definition
| It anchors PKA near its substrate. |
|
|
Term
| What lipid is required by all PKC isoforms? |
|
Definition
|
|
Term
| What PKC isoform is calcium/diacylglycerol-dependent? |
|
Definition
|
|
Term
| What PKC isoform is calcium-independent and diacylglycerol-dependent? |
|
Definition
|
|
Term
| What PKC isoform is calcium/diacylglycerol-independent? |
|
Definition
|
|
Term
| Which serine/threonine phosphatase is calcium-dependent? |
|
Definition
|
|
Term
| Are growth factor receptors receptor tyrosine kinases or non-receptor tyrosine kinases? |
|
Definition
| Receptor tyrosine kinases. |
|
|
Term
| Does cytokine signaling involve receptor tyrosine kinases or non-receptor tyrosine kinases? |
|
Definition
| Non-receptor tyrosine kinases. |
|
|
Term
| In the MAPK signaling pathway, what is the role of GRB2? |
|
Definition
| It has an SH2 domain that binds to phosphorylated tyrosine residues on the receptor. |
|
|
Term
| In the MAPK signaling pathway, what is the role of Sos? |
|
Definition
| Sos is a GEF that activates Ras. |
|
|
Term
| In the MAPK signaling pathway, what is the role of Ras? |
|
Definition
| Ras is a G-protein that activates Raf. |
|
|
Term
| Briefly describe insulin receptor signaling. |
|
Definition
Insulin binds to receptor.
Receptor dimerizes and autophosphorylates tyrosine residues.
IRS binds to phosphotyrosines.
PI3K binds to IRS.
PI3K forms PIP3. |
|
|
Term
| What does JAK do in the JAK-STAT pathway? |
|
Definition
|
|
Term
| What happens to phosphorylated STATs in the JAK-STAT pathway? |
|
Definition
| They dimerize and go to the nucleus to act as transcription factors. |
|
|
Term
| What is an isometric contraction? |
|
Definition
| A contraction in which muscle length remains constant. |
|
|
Term
|
Definition
| A single isometric contraction that results from a single stimulation. |
|
|
Term
| What is the relationship between twitch force and intensity of stimulation? |
|
Definition
| Twitch force increases with increasing intensity of stimulation (until a plateau is reached). |
|
|
Term
|
Definition
| Increasing voltage progressively activates all motor units. |
|
|
Term
|
Definition
| Increasing voltage progressively activates all motor units. |
|
|
Term
|
Definition
| A motor unit is one motor unit and all of the muscle fibers it innervates. |
|
|
Term
| What is the size principle? |
|
Definition
| Motor units are recruited in order of their size (small first). |
|
|
Term
| What is the lowest muscle stimulation frequency that shows summation? |
|
Definition
|
|
Term
| What is the effect of passive lengthening on muscle tension? |
|
Definition
| It increases tension non-linearly. |
|
|
Term
| What is the effect of muscle length on active tension? |
|
Definition
| Maximum active tension is reached at the resting length. |
|
|
Term
| What are the 3 ways to increase muscle force? |
|
Definition
Recruit more motor units.
Summation (increase frequency of stimulation).
Stretch muscle fibers (not so important). |
|
|
Term
| What are two ways that muscle force is augmented in the long-term? |
|
Definition
Increase in the cross-sectional area.
Interconversion between slow-twitch and fast-twitch fibers. |
|
|
Term
| What is the effect of increasing the afterload on the isometric phase and the isotonic force? |
|
Definition
| Increased duration of isometric phase and increased isotonic force. |
|
|
Term
| What is an isotonic contraction? |
|
Definition
| A contraction with constant force. |
|
|
Term
| What is the relationship between force and velocity of muscle contraction? |
|
Definition
| The velocity of muscle contraction varies inversely with force. |
|
|
Term
| What is the formula for power of a muscle? |
|
Definition
| Power = (force)(velocity) |
|
|
Term
| At what force does muscle power reach its peak? |
|
Definition
|
|
Term
| Which type of muscle fiber produces greater maximal power (slow twitch or fast twitch)? |
|
Definition
|
|
Term
| What is a concentric contraction? |
|
Definition
| A contraction that involves muscle shortening. |
|
|
Term
| What is an eccentric contraction? |
|
Definition
| A contraction that involves muscle lengthening. |
|
|
Term
| What is the sign of the work in a concentric contraction? |
|
Definition
|
|
Term
| What is the sign of the work in an eccentric contraction? |
|
Definition
|
|
Term
| What type of contraction can produce the greatest force? |
|
Definition
|
|
Term
| What is the effect of pinnation? |
|
Definition
| Pinnation increases muscle strength at the expense of muscle speed. |
|
|
Term
| Which type of muscle fibers fatigue more easily (fast twitch or slow twitch)? |
|
Definition
|
|
Term
| What is the relationship between muscle force and muscle area? |
|
Definition
|
|
Term
| What is the equation for the amount of charge stored on a capacitor? |
|
Definition
|
|
Term
| Define the Nernst equilibrium potential. |
|
Definition
| Potential difference across the membrane when the concentration and electrical gradients are equal and opposite. |
|
|
Term
| What is the equation for driving force? |
|
Definition
| Driving force = Em - ENernst |
|
|
Term
| What is the formula for the current of a specific ion? |
|
Definition
|
|
Term
| What is the current at resting membrane potential? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| What surrounds fascicles? |
|
Definition
|
|
Term
| What surrounds skeletal muscle cells? |
|
Definition
| Endomysium or basal lamina. |
|
|
Term
| What surrounds myofibrils? |
|
Definition
|
|
Term
| What is the length of the A band? |
|
Definition
| 1.6 micrometers (always). |
|
|
Term
| What is the length of the sarcomere at rest? |
|
Definition
|
|
Term
| Where do thick filaments crosslink? |
|
Definition
|
|
Term
| Where do think filaments crosslink? |
|
Definition
|
|
Term
| What makes up the I band? |
|
Definition
| Thin filaments made of actin. |
|
|
Term
| What makes up the A-band outside the H-band? |
|
Definition
| Overlap of thin (actin) and thick (myosin) filaments. |
|
|
Term
| What makes up the H band? |
|
Definition
| Thick filaments made of myosin. |
|
|
Term
| Where is the ATPase activity of myosin? |
|
Definition
|
|
Term
|
Definition
| The region in the center of the A band where myosin tails interact and there are no heads. |
|
|
Term
|
Definition
| The region in the center of the A band where myosin tails interact and there are no heads. |
|
|
Term
| What is the function of titin? |
|
Definition
| It provides elasticity and guides myosin. |
|
|
Term
| How many titin molecules are in each thick filament? |
|
Definition
|
|
Term
| What is the approximate length of actin? |
|
Definition
|
|
Term
| What is the function of nebulin? |
|
Definition
| Nebulin is a filamentous protein that binds actin and sets the length of the thin filaments. |
|
|
Term
| What causes the power stroke? |
|
Definition
| Release of ADP and Pi causes the myosin head to tilt 45 degrees. |
|
|
Term
| Is the length of the I-band variable or constant during contraction? |
|
Definition
|
|
Term
| List the speed, metabolism, and fatigue response of type I, IIA, and IIB muscle fibers. |
|
Definition
Type I - slow, oxidative, fatigue-resistant
Type IIA - fast, oxidative, fatigue-resistant
Type IIB - fast, glycolytic, fatigable |
|
|
Term
| What determines muscle velocity? |
|
Definition
|
|
Term
| What is the function of costameres? |
|
Definition
| Costameres transfer the force from inside to outside the muscle fiber. |
|
|
Term
| What happens to sodium channels upon depolarization? |
|
Definition
| They open very rapidly and deactivate rapidly upon continued depolarization. |
|
|
Term
| What does tetraethylammonium (TEA) do? |
|
Definition
| It blocks potassium current. |
|
|
Term
| What do tetrodotoxin and saxitoxin do? |
|
Definition
| They block sodium current. |
|
|
Term
| At resting membrane potential, how does the inward current compare to outward current? |
|
Definition
|
|
Term
| What 2 factors prevent the upstroke from continuing indefinitely in an action potential? |
|
Definition
Decrease in sodium driving force
Inactivation of sodium channels |
|
|
Term
| What causes the absolute refractory period? |
|
Definition
| Sodium channels inactivate upon depolarization, making it impossible to initiate another action potential during the absolute refractory period. |
|
|
Term
| What causes the relative refractory period? |
|
Definition
Some sodium channels are inactivated.
Potassium conductance is higher than at rest. |
|
|
Term
| What is the effect of the relative refractory period on the threshold potential? |
|
Definition
|
|
Term
|
Definition
| Decreased firing of action potentials in response to constant stimulus in nerve or muscle. |
|
|
Term
| What is the effect of increased serum potassium? |
|
Definition
| Depolarization and accommodation. |
|
|
Term
| What are 4 mechanisms of accommodation? |
|
Definition
Accumulation of sodium channels in inactivated state.
Incomplete recovery of sodium channels from inactivation.
Fewer sodium channels in closed (but available) state.
Accumulation of potassium channels in open state. |
|
|
Term
| How is force generated in an eccentric contraction? |
|
Definition
| By breaking acto-myosin bridges. |
|
|
Term
| When does the calcium transient occur relative to the action potential and force development? |
|
Definition
| After the action potential and before force development. |
|
|
Term
| What senses skeletal muscle membrane depolarization and opens RyR channel on the SR? |
|
Definition
|
|
Term
| What shuts off the calcium transient? |
|
Definition
| Calcium reuptake into the SR by SERCA. |
|
|
Term
| What is the function of calsequestrin? |
|
Definition
| It binds calcium in the SR lumen to increase calcium content at the same free calcium concentration. |
|
|
Term
| What is the difference between the role of DHPR in skeletal and cardiac muscle? |
|
Definition
| In skeletal muscle, calcium entry through DHPR is not important. In cardiac muscle, calcium entry through DHPR is required for excitation-contraction coupling. |
|
|
Term
| How does signal amplification occur during excitation-contraction coupling? |
|
Definition
| 2 calcium ions bind to 1 troponin C and expose 7 actin binding sites for myosin. |
|
|
Term
| When does maximum occupancy of troponin C occur in relation to the calcium transient and peak force development? |
|
Definition
| Maximum occupancy of troponin C occurs after the calcium transient and before peak force development. |
|
|
Term
| What causes the delay between maximum troponin C occupation and peak force? |
|
Definition
| The series elastic elements must stretch before force is transmitted outside of muscle. |
|
|
Term
| What causes the delay in the fall of force after cross-bridge cycling has stopped? |
|
Definition
| Internal viscous elements. |
|
|
Term
| What is the purpose of parallel elastic elements? |
|
Definition
| Stretching parallel elastic elements helps set sarcomere length at rest. |
|
|
Term
| How does the internal resistance compare to the external resistance in an axon? |
|
Definition
| Internal resistance is much greater than external resistance. |
|
|
Term
| What are the 3 determinants of conduction velocity? |
|
Definition
Amplitude of inward current
Passive membrane properties
Excitability of membrane |
|
|
Term
| Which has greater internal resistance, a large-diameter axon or a small-diameter axon? |
|
Definition
|
|
Term
| Which has a greater length constant, a large-diameter axon or a small-diameter axon? |
|
Definition
|
|
Term
| How does an increased length constant affect the conduction velocity? |
|
Definition
|
|
Term
| What is the formula for length constant in terms of internal resistance and membrane resistance? |
|
Definition
| Length constant = sqrt(membrane resistance/internal resistance) |
|
|
Term
| What is the relationship between conduction velocity and axon diameter? |
|
Definition
| Conduction velocity is proportional to the square root of the diameter. |
|
|
Term
| What is the equation for the time constant? |
|
Definition
| Time constant = (membrane resistance)(membrane capacitance) |
|
|
Term
| What is the equation for the time constant? |
|
Definition
| Time constant = (membrane resistance)(membrane capacitance) |
|
|
Term
| What is the equation for the time constant? |
|
Definition
| Time constant = (membrane resistance)(membrane capacitance) |
|
|
Term
| How does increasing the time constant affect the conduction velocity? |
|
Definition
| Increasing the time constant decreases the conduction velocity. |
|
|
Term
| What is the effect of increasing axon diameter on the time constant? |
|
Definition
|
|
Term
| What is the relationship between conduction velocity and diameter in a myelinated axon? |
|
Definition
| Conduction velocity is proportional to diameter. |
|
|
Term
| What is the effect of myelination on membrane resistance and length constant? |
|
Definition
|
|
Term
| What is the effect of myelination on membrane capacitance and time constant? |
|
Definition
|
|
Term
| What is the effect of myelination on membrane capacitance and time constant? |
|
Definition
|
|
Term
| What is the safety factor? |
|
Definition
| The inward current is large enough for conduction to continue even if excitation at a few nodes is blocked. |
|
|
Term
| List three reasons that ATP hydrolysis is greatly increased during muscle contraction. List these in order from greatest to least ATP expenditure. |
|
Definition
Acto-myosin cross bridge cycle.
Calcium re-accumulation by SR.
Maintenance of sarcolemmal ionic gradients by sodium-potassium pump. |
|
|
Term
|
Definition
| Duty cycle is the fraction of time that a muscle is active. |
|
|
Term
| List the three systems that muscles use for regenerating ATP, from fastest to slowest. |
|
Definition
Phosphogen system.
Glycolysis.
Oxidative phosphorylation. |
|
|
Term
| List the three systems that muscles use to regenerate ATP, from highest capacity to lowest capacity. |
|
Definition
Oxidative phosphorylation.
Glycolysis.
Phosphogen system. |
|
|
Term
| What two enzymes are used in the phosphogen system? |
|
Definition
|
|
Term
| What is the function of the Cori Cycle? |
|
Definition
| The Cori Cycle recycles lactate into glucose and regenerates NAD+. |
|
|
Term
| Rank Type I, IIA, and IIB muscle in based on the number of mitochondria (in increasing order). |
|
Definition
| Type IIB < Type I < Type IIA. |
|
|
Term
| Ranke Type I, Type IIA, and Type IIB muscle based on the amount of glycogen (in increasing order). |
|
Definition
| Type I < Type IIA < Type IIB. |
|
|
Term
| What RyR isoform is in Type I, Type IIA, and Type IIB skeletal muscle? |
|
Definition
|
|
Term
| What causes fatigue in maximum effort, short duration exercise? |
|
Definition
| Increased cytoplasmic organic phosphate and decreased cytoplasmic pH. |
|
|
Term
| What causes fatigue in endurance events? |
|
Definition
| Depletion of glycogen stores. |
|
|
Term
| What is the anaerobic threshold? |
|
Definition
| Anaerobic threshold is the relative work load at which blood lactate concentration begins to increase quickly. |
|
|
Term
| List the three lactic acid shuttles. |
|
Definition
1. to the mitochondria
2. to oxidative fibers
3. to the liver. |
|
|
Term
| What is the effect of exercise on glucose uptake by muscle cells? |
|
Definition
| Exercise increases GLUT4 on muscle membranes and increases glucose uptake independently of insulin. |
|
|
Term
| During exercise, what two mechanisms lead to increased localization of GLUT4 on the muscle cell membrane? |
|
Definition
Calcium/calmodulin activates CAMK, which increases GLUT4 localization on membrane.
AMP increases GLUT4 localization on membrane. |
|
|
Term
| Why does the diameter of muscle fibers increase during hypertrophy? |
|
Definition
| The muscle fibers make more myofibrils, and satellite cells fuse to contribute cytoplasm. |
|
|
Term
| List 3 muscle growth activators. |
|
Definition
| Increased intracellular calcium, stretch, and hormones. |
|
|
Term
| What is the function of myostatin? |
|
Definition
| Myostatin inhibits muscle growth. |
|
|
Term
| How does exercise that creates chronic low fiber stimulation affect the fiber type? |
|
Definition
| Fast twitch switches to slow twitch. |
|
|
Term
| List the steps of the biochemical pathway that switches fast twitch to slow twitch fibers. |
|
Definition
Exercise leads to an increase in intracellular calcium.
Calcium activates calcineurin, a phosphatase.
Calcineurin dephosphorylates NFAT, activating the transcription factor.
NFAT increases transcription for MHCI and decreases transcription for MHCII.
Fast twitch fibers convert to slow twitch fibers. |
|
|
Term
| What biochemical defect causes McCardle Disease? |
|
Definition
| Glycogen phosphorylase deficiency. |
|
|
Term
| What two main metabolic fuels does the McCardle muscle fiber use? |
|
Definition
Glucose uptake from blood by insulin-dependent GLUT4.
Fatty acids. |
|
|
Term
| What causes synaptic delay? |
|
Definition
| Diffusion time across the synaptic cleft. |
|
|
Term
| List 3 rapid mechanisms of termination of signals at synapses. |
|
Definition
Degradation of transmitter.
Diffusion out of synaptic cleft.
Reuptake into presynaptic nerve terminal. |
|
|
Term
| List two slow mechanisms for termination of signaling at a synapse. |
|
Definition
Desensitization of receptor.
Autoreceptors (reduced release). |
|
|
Term
| How is acetylcholine taken up into vesicles? |
|
Definition
| ACh-H+ exchanger (secondary active transport powered by H+ pump. |
|
|
Term
| What is stored and released with acetylcholine? |
|
Definition
|
|
Term
| How is acetylcholine signaling terminated at the neuromuscular junction? |
|
Definition
| Acetylcholine is degraded by acetylcholinesterase. |
|
|
Term
| What is the acetylcholine receptor permeant towards? |
|
Definition
|
|
Term
| What value does Em move towards when the acetylcholine receptors open? |
|
Definition
| 0 mV (the reversal potential) |
|
|
Term
| What happens to the magnitude of the EPP with increasing rate of stimulation? |
|
Definition
|
|
Term
|
Definition
| Sodium-choline cotransporter in nerve terminal. |
|
|
Term
| What does botulinum toxin do? |
|
Definition
| It blocks acetylcholine release. |
|
|
Term
| What does tetanus toxin do? |
|
Definition
| It blocks GABA release at interneurons and removes inhibition of motor neurons, causing spasms. |
|
|
Term
| What does d-tubocurarine do? |
|
Definition
| It competes with acetylcholine at the acetylcholine receptor, thus decreasing the EPP. |
|
|
Term
| What do neostigmine and physostigmine do? |
|
Definition
| They are acetylcholinesterase inhibitors. |
|
|
Term
| What does hemicholinium do? |
|
Definition
| It blocks the re-uptake of choline into the presynaptic terminal. |
|
|
Term
|
Definition
| Constriction of the pupil in bright light. |
|
|
Term
|
Definition
| Dilation of the pupil in low light. |
|
|
Term
| What is the approximate speed of onset of autonomic responses? |
|
Definition
|
|
Term
| What is tonic activity in the ANS? |
|
Definition
| Basal rate of neuronal firing (about 1 Hz) that sets a baseline for effector organ activity. |
|
|
Term
| How do the width, speed, and frequency of conduction in autonomic neurons compare with somatic motor neurons? |
|
Definition
| Width, speed, and frequency of conduction are all lower in autonomic neurons. |
|
|
Term
| What division of the ANS causes contraction of the piloerector muscles? |
|
Definition
|
|
Term
| Are preganglionic axons in the sympathetic nervous system myelinated? |
|
Definition
|
|
Term
| Are preganglionic axons in the parasympathetic nervous system myelinated? |
|
Definition
|
|
Term
| What part of the adrenal gland is innervated by preganglionic sympathetic fibers? |
|
Definition
| Adrenal medullary chromaffin cells. |
|
|
Term
| In which division of the ANS are divergence and convergence observed? |
|
Definition
|
|
Term
| Which division of the ANS has a distinct ganglion system? |
|
Definition
|
|
Term
| Describe the length of the preganglionic and postganglionic axons in the sympathetic and parasympathetic nervous system. |
|
Definition
Sympathetic has short preganglionic and long postganglionic axons.
Parasympathetic has long preganglionic and short postganglionic axons. |
|
|
Term
| Which division of the ANS is more like a relay system, with a 1:1 or 1:2 ratio of pre to postganglionic neurons? |
|
Definition
|
|
Term
| What type of receptors mediate signaling in the ANS? |
|
Definition
|
|
Term
| What neurotransmitter is released by postganglionic neurons in the sympathetic nervous system? |
|
Definition
| Norepinephrine (except in generalized sweat glands, which use acetylcholine). |
|
|
Term
| Is the second neuron myelinated in the ANS? |
|
Definition
|
|
Term
| What is the NMDA receptor selective for? |
|
Definition
| Sodium, potassium, and calcium. |
|
|
Term
| Is glutamate excitatory or inhibitory? |
|
Definition
|
|
Term
| What is the ionotropic receptor for serotonin? |
|
Definition
|
|
Term
| What is 5HT3 selective for? |
|
Definition
|
|
Term
| What is the GABA-a receptor selective for? |
|
Definition
|
|
Term
| Is GABA excitatory or inhibitory? |
|
Definition
|
|
Term
| List 3 types of rapid up-regulation of synaptic function in response to high synaptic activity. |
|
Definition
Post-tetanic potentiation.
Facilitation.
Augmentation. |
|
|
Term
| List three types of rapid downregulation of synaptic transmission in response to high synaptic activity. |
|
Definition
Fatigue.
Depression.
Desensitization. |
|
|
Term
| List three mechanisms of long-term potentiation that occur due to simultaneous stimulation of weak and strong synapses. |
|
Definition
Postsynaptic calcium influx increases CAMK signaling.
Presynaptic signaling leads to increased NO.
Increasing number of dendritic spines and synapses per spine. |
|
|
Term
| How does the source of calcium for smooth muscle contraction differ from the source for skeletal muscle contraction? |
|
Definition
| Smooth muscles get calcium from both influx and SR release, whereas skeletal muscles only increase cytoplasmic calcium via SR release. |
|
|
Term
| What is the function of dense bands and dense bodies in smooth muscle? |
|
Definition
| Dense bands and dense bodies anchor actin at the membrane and in the cytoplasm, respectively. |
|
|
Term
| What is the inhibitory neurotransmitter for smooth muscle? |
|
Definition
|
|
Term
| What is the excitatory ion channel in smooth muscle cell membranes? |
|
Definition
| L-type calcium channels (dihydropyridine sensitive voltage-dependent calcium channels) |
|
|
Term
| What is the inhibitory ion channel in smooth muscles? |
|
Definition
|
|
Term
| List four functions of interstitial cells of Cajal. |
|
Definition
Generation of electrical slow wave activity.
Coordination of pacemaker activity and active propagation of slow waves.
Transduction of motor neural inputs from the enteric nervous system.
Mechanosensation to stretch in GI muscles. |
|
|
Term
| List two excitatory agents that modulate slow waves. |
|
Definition
| Acetylcholine and substance P. |
|
|
Term
| List two inhibitory agents that modulate slow wave activity. |
|
Definition
| Vasoactive intestinal peptide and NO. |
|
|
Term
| What is the effect of sympathetic activity on the blood vessels that supply the skeletal muscles? |
|
Definition
|
|
Term
| What do large dense core vesicles in cholinergic neurons contain? |
|
Definition
|
|
Term
| How is catecholamine signaling terminated? |
|
Definition
|
|
Term
| What is stored in small dense-cored vesicles in postganglionic sympathetic varicosities? |
|
Definition
| Norepinephrine, ATP, and dopamine-beta-hydroxylase. |
|
|
Term
| What is stored in large dense-cored vesicles in postganglionic sympathetic varicosities? |
|
Definition
|
|
Term
| How many quanta are released at an autonomic NEJ (approximately)? |
|
Definition
|
|
Term
| How does catecholamine synthesis increase with increased nerve activity? |
|
Definition
Tyrosine hydroxylase is activated over PKA, which causes loss of feedback inhibition.
Induces new TH. |
|
|
Term
| What is the role of the adrenal cortex in epinephrine synthesis? |
|
Definition
| It releases glucocorticoid. |
|
|
Term
| List the 5 steps of activation of smooth muscle contraction according to the phosphorylation theory. |
|
Definition
Increase in intracellular calcium.
Formation of calcium/calmodulin complex.
Activation of MLCK by calcium/calmodulin.
Phosphorylation of MLC.
Activation of actin-activated myosin ATPase. |
|
|
Term
| What receptor on the SR is involved in electromechanical coupling in smooth muscle? |
|
Definition
|
|
Term
| What protein on the cell membrane is responsible for increased intracellular calcium in the electromechanical coupling mechanism in smooth muscle? |
|
Definition
| L-type voltage-gated calcium channel. |
|
|
Term
| What receptor on the SR is involved in pharmacomechanical coupling? |
|
Definition
|
|
Term
|
Definition
| It phosphorylates the regulatory subunit of MLC phosphatase and inactivates it. |
|
|
Term
|
Definition
| It inhibits MLC phosphatase. |
|
|
Term
|
Definition
|
|
Term
| What is the effect of phosphorylating caldesmon and calponin? |
|
Definition
| It removes the inhibition of actin/myosin interaction in smooth muscle. |
|
|
Term
| List 6 pathways involved in PKA- and PKG-mediated smooth muscle relaxation. |
|
Definition
1. Activation of potassium channel.
2. Inhibition of membrane calcium channel.
3. Activation of SERCA.
4. Inhibition of IP3 generation.
5. Inhibition of IP3 receptor function.
6. Stimulation of MLCP activity. |
|
|
Term
| How does the innervation of unitary smooth muscle compare with the innervation of multiunit smooth muscle? |
|
Definition
| Unitary smooth muscle is more sparsely innervated. |
|
|
Term
| What type of receptor is present on all postganglionic neurons? |
|
Definition
|
|
Term
| What type of receptor is present on the adrenal medulla? |
|
Definition
|
|
Term
| What type of receptor is on effector tissues innervated by parasympathetic postganglionic neurons? |
|
Definition
|
|
Term
| What type of receptor is on the generalized sweat glands that receive sympathetic innervation? |
|
Definition
|
|
Term
| What causes SLUDE syndrome? |
|
Definition
| Over-activation of the muscarinic receptors. |
|
|
Term
|
Definition
| It is a competitive antagonist at the muscarinic receptors and decreases parasympathetic activity. |
|
|
Term
| Are muscarinic receptors on the heart excitatory or inhibitory? |
|
Definition
|
|
Term
| Are muscarinic receptors on smooth muscle excitatory or inhibitory? |
|
Definition
|
|
Term
| Are muscarinic receptors on glands excitatory or inhibitory? |
|
Definition
|
|
Term
| What is the mechanism of parasympathetic inhibition of the heart muscle? |
|
Definition
| Activated muscarinic receptor activates a GPCR, which opens a potassium channel and inhibits beta-1 receptor action. |
|
|
Term
| Are alpha receptors more sensitive to epinephrine or isoproterenol? |
|
Definition
|
|
Term
| What is the most important location of alpha-1 receptors? |
|
Definition
| Smooth muscle of blood vessels. |
|
|
Term
| Are alpha-1 receptors excitatory or inhibitory? |
|
Definition
|
|
Term
| What ligand activates alpha-1 receptors under physiological conditions? |
|
Definition
|
|
Term
| What second messenger mediates the effects of the alpha-1 receptor? |
|
Definition
|
|
Term
| Where are alpha-2 receptors located? |
|
Definition
| On pre-synaptic nerve terminals. |
|
|
Term
| What ligand activates alpha-2 receptors? |
|
Definition
| Norepinephrine released by sympathetic nerves. |
|
|
Term
| What is the function of alpha-2 receptors? |
|
Definition
| They inhibit evoked release of transmitter by decreasing calcium entry into the presynaptic terminal; they act both as autoreceptors and as hetero-receptors on the parasympathetic nerves of the GI tract. |
|
|
Term
| Which is more sensitive, alpha receptors or beta receptors? |
|
Definition
|
|
Term
| What is the location and effect (excitatory or inhibitory) of beta-1 receptors? |
|
Definition
|
|
Term
| What second messenger mediates the response to activation of all beta receptors? |
|
Definition
|
|
Term
| What are the physiological ligands for the beta-1 receptor? |
|
Definition
|
|
Term
| Are beta-2 receptors excitatory or inhibitory? |
|
Definition
|
|
Term
| What is the ligand for beta-2 receptors? |
|
Definition
|
|
Term
| List 3 locations of beta-2 receptors. |
|
Definition
Smooth muscle of airways.
Smooth muscle of GI tract.
Smooth muscle of blood vessels supplying skeletal muscles. |
|
|
Term
| Are beta-3 receptors excitatory or inhibitory? |
|
Definition
|
|
Term
| List 2 locations of beta-3 receptors. |
|
Definition
|
|
Term
| What is the ligand for beta-3 receptors? |
|
Definition
|
|
Term
| What effect does the sympathetic nervous system have on the pupil, and via what receptor? |
|
Definition
| Dilates pupil by contraction of the radial muscle; alpha-1. |
|
|
Term
| What effect does the sympathetic nervous system have on the ciliary muscle, and via which receptor? |
|
Definition
| Relaxes (far vision); beta-2. |
|
|
Term
| What receptor causes relaxation of the gallbladder and bile ducts in response to sympathetic stimulation? |
|
Definition
|
|
Term
| What receptor activates sweat glands in the palms in response to sympathetic stimulation? |
|
Definition
|
|
Term
| Are autonomic reflexes monosynaptic? |
|
Definition
| No; a ganglionic synapse is always present. |
|
|
Term
| What part of the brain is involved in cognitive processing in autonomic reflexes? |
|
Definition
|
|
Term
| What part of the brain is involved in emotional effects on autonomic reflexes? |
|
Definition
|
|
Term
| What are the afferents for the baroreceptor reflex? |
|
Definition
| Glossopharyngeal (IX) and vagus (X) cranial nerves. |
|
|
Term
| What is the integration for the baroreceptor reflex? |
|
Definition
| Medullary vasomotor center. |
|
|
Term
| What is the integration center for the pupillary light reflex? |
|
Definition
|
|
Term
| What is the integration center for bladder emptying? |
|
Definition
| Pontine filling and micturition center. |
|
|
Term
| What conveys information on touch, temperature, proprioception, and pain to the CNS? |
|
Definition
| Spinal afferents in the spinal cord. |
|
|
Term
| What carries the efferent output in the pupillary light reflex? |
|
Definition
| Cranial nerve III carries parasympathetic output to the sphincter muscle, leading to constriction of the pupil. |
|
|
Term
| What happens if the parasympathetic innervation to the left eye is damaged? |
|
Definition
| The left eye is unresponsive to light shone into the left eye or right eye, while the right eye remains responsive to light shone into either eye. |
|
|
Term
| What happens if the left optic nerve is damaged? |
|
Definition
| Neither pupil constricts when light is shone into the left eye. Both pupils constrict when light is shone into the right eye. |
|
|
Term
| What effect does a hot temperature have on the sympathetic firing to the skin arterioles? |
|
Definition
|
|
Term
| What effect does a hot temperature have on the sympathetic firing to the sweat glands? |
|
Definition
|
|
Term
| What effect do cold temperatures have on sympathetic firing to the skin arterioles? |
|
Definition
|
|
Term
| What effect do cold temperatures have on the sympathetic firing to the sweat glands? |
|
Definition
|
|
Term
| Where are the high pressure baroreceptors of the baroreceptor reflex? |
|
Definition
| Wall of carotid sinus and aorta. |
|
|
Term
| What is the effect of increased baroreceptor firing on sympathetic and parasympathetic activity? |
|
Definition
| Decreased sympathetic and increased parasympathetic activity. |
|
|
Term
| List the 3 physiological stressors that cause reflex release of adrenal medullary catecholamines. |
|
Definition
Fear.
Low blood sugar.
Severe hypothermia. |
|
|
Term
| What is the most potent stimulus for the adrenal medulla? |
|
Definition
|
|
Term
| What is vago-vagal activation of the stomach? |
|
Definition
| Food in the stomach activates the stomach (CNS reflex). |
|
|
Term
| What is the gastrocolic reflex? |
|
Definition
| Food in the stomach or upper part of the small intestine leads to evacuation of the bowel. |
|
|
Term
| List 4 mechanisms by which the sympathetic nervous system causes global inhibition of GI function. |
|
Definition
1. Alpha-2 heteroreceptors on postganglionic parasympathetic nerves.
2. Closing of sphincters (NE activates alpha-1 receptors).
3. Reduced blood flow due to alpha-1 receptor activation.
4. Adrenal epinephrine inhibits motility by activating beta-2 receptors. |
|
|
