HPhys Exam 1 Review PDF

Exam 1: Videos 1-21 Questions & Answers Lecture 1: Videos 1&2: Homeostasis & Passive Transport-Simple Diffusion Notes Questions 1) Define homeostasis a) The body’s ability to maintain a relatively stable “internal environment” through a variety of orchestrated...

Exam 1: Videos 1-21 Questions & Answers Lecture 1: Videos 1&2: Homeostasis & Passive Transport-Simple Diffusion Notes Questions 1) Define homeostasis a) The body’s ability to maintain a relatively stable “internal environment” through a variety of orchestrated physiologic responses 2) What is the goal of physiology? a) To understand processes involved in maintaining homeostasis 3) What does the process of maintaining homeostasis require? a) Receptors monitor any changes that cause imbalance and send info to the integrating center which then send the info to effector organs which bring about change to restore homeostasis. 4) What are the 3 ways our body responds to a change that causes a homeostasis imbalance? a) Get rid of the thing that causes imbalance b) Create another substance to counterbalance c) Combination of removing and adding something 5) Describe the cell membrane a) Phospholipid bilayer b) Primarily lipophilic c) Phospholipid heads with nonpolar hydrocarbon tails 6) What is the difference between passive and active transport? a) Passive does not require energy while active does 7) Define simple diffusion and explain what its rate of flux is influenced by. a) Unassisted movement of a molecule directly through the phospholipid bilayer of the plasma membrane b) Used to move lipophilic molecules c) The rate of flux (diffusion) is influenced by: i) Concentration gradient: concentrations of molecule on both sides of membrane ii) Partition coefficient: how lipid the molecule is iii) Diffusion coefficient: size of the molecule iv) Thickness of membrane v) Surface Area 8) How would you increase the rate of flux of simple diffusion? a) Increase concentration gradient b) Increase partition coefficient c) Increase diffusion coefficient (decrease size of molecule) d) Decrease thickness of membrane e) Increase the surface area 9) What surrounds the cell? a) Phospholipid bilayer 10) What environment do our cells live in? a) Extracellular fluid 11) Is a cell more concerned about stabilizing the external or internal environment? a) External Lecture 2: Videos 3,4,5 – Passive Transport – Simple Diffusion, Facilitated Diffusion, Osmosis In Class Questions 1. Define facilitated diffusion. Describe the two types. a. A passive form of diffusion that requires some type of helper to move hydrophilic molecules b. Either utilizes a channel protein (smaller hydrophilic molecules- ions) or a carrier protein (larger hydrophilic molecules) c. Both are transmembrane proteins that can move molecules either direction depending on the concentration gradient 2. Which direction can a channel protein carry molecules? What about carrier proteins? a. Either way depending on conc gradient b. Same 3. Describe a carrier protein a. Has a binding site which can bind to a hydrophilic molecule and will move it wherever the concentration gradient direction is b. Transmembrane protein 4. What 3 things are binding sites subject to? a. Specificity – how specific a binding site is to the ligand b. Saturation (aka transport max) – at a certain concentration of ligand, the binding site cant bind anymore because there are no more binding sites c. Affinity – attractive force a binding site has for a ligand i. Having higher affinity increases likelihood a binding site will bind to a ligand 5. What two models are used to describe a binding site’s specificity to a ligand? a. Lock and key – perfect fit b. Induced fit model – binding site conforms to target 6. Define a ligand. What may it be involved in? What is that influenced by? a. Generalized term used to describe a molecule that binds to a binding site b. Competition c. The concentration of respective ligands 7. Explain how affinity of a binding site changes. a. It changes based on the local environment – whether it is intracellular or extracellular b. It increases affinity to bind to the molecule but decreases to allow it to pass into the other side 8. How can we manipulate a binding site to bind to a certain ligand when two are present? How could we achieve this by changing the binding site? a. Increase the amount of the desired ligand b. Increasing the affinity of the binding site for the specific ligand 9. Is the concept of “saturation” seen in all types of transport? a. No, not in simple diffusion b. Only in carriers 10. Describe primary active transport. What are these transporters called? What is the most common transporter in our body called? Give one more example.  a. Directly utilizes hydrolysis of ATP to move a molecule against its concentration gradient b. Called a pump c. Sodium potassium pump d. Calcium pump 11. Describe secondary active transport a. Uses the sodium gradient caused by the sodium-potassium pump to power transport of a molecule against its gradient; b. SODIUM ALWAYS MOVES INTO CELL c. Na+ can either co transport (moving another molecule the same direction as sodium against its gradient) or counter transport (moving a molecule the opposite direction as sodium against its gradient) since it is moving passively down its concentration gradient d. By sodium moving into the cell, the potential energy lost is what powers the secondary transporter. 12. Where is sodium more concentrated? Potassium? Calcium? a. Extracellularly b. Intracellularly c. Extracellularly 13. What is osmosis? Why does this occur? a. Passive movement of water across a membrane b. Difference in solute concentration (osmotic pressure) 14. Since water is hydrophilic, how does it pass through the primarily lipophilic bilayer? a. Unrestricted movement due to the concentration of H2O, its small size, and there is such a large SA for it to diffuse over 15. What is an aquaporin? a. A channel that allows water to move through it 16. What determines which direction water will move through? a. Osmotic pressure aka solute concentration 17. What different types of solute particles are there, and do they cause osmosis? a. Penetrating – they can freely move through a membrane; no b. Non-penetrating – they cannot freely move through a membrane; yes 18. What equation is used to find osmotic pressure? How does it relate to the concentration of solute and the reflection coefficient? a. Van’t Hoff equation b. When conc of solute or reflection coefficient increases, so does the osmotic pressure 19. What symbol represents osmotic pressure? Concentration of solute? Reflection coefficient? a. Pi b. C c. (sigma symbol) 20. What is the reflection coefficient? What does a reflection coefficient of 0 and 1 mean? a. Unitless number between 0-1 that describes how much of a solute is reflected across a membrane b. 0: solute penetrates membrane without any being reflected (equally distributes)  c. 1: solute unable to penetrate membrane; 100% reflected 21. If the reflection coefficient of a solute is 1, how can you prevent osmosis? a. Apply a piston to the side with the osmotic pressure 22. Define osmotic pressure a. The magnitude of pressure necessary to prevent osmosis; the tendency of a solution to cause osmosis 23. How do you relate transport maximum to saturation a. Transport maximum is the rate of flux at saturation Lecture 3: Videos 6-7 For questions 1-2 imagine two compartments separated by a membrane 1) If we have two compartments filled with pure water separated by a membrane, there will be no net movement of water. Will there be any movement of water? a) Yes, random movement of water will still occur 2) If we have solute particle with a reflection coefficient of 1, will it pass through the membrane or reflect it? a) 100% will be reflected 3) Overall, is there more fluid inside or outside our cells? a) Inside 4) What are the two types of extracellular fluid? a) Blood plasma b) Interstitial fluid 5) What term describes the force/pressure which causes water to move? a) Osmotic pressure 6) If you infuse solute with a reflection coefficient of 0 into one of the compartments, will water move? Will solute move a) No b) Yes, since it has 0% reflection 7) If I place a cell in a hypertonic solution, what will the cell do? Where is stronger osmotic pressure? a) The cell will push water outside b) Outside the cell 8) If I place a cell in a isotonic solution, will water flow in or out? Where is stronger osmotic pressure? a) There will be no net movement of water b) They are equal 9) If I place a cell in a hypotonic solution, will water flow in or out? Where is stronger osmotic pressure? a) Water will flow in the cell b) Inside the cell 10) If a patient’s brain is swelling, what solution would we give them to reduce the swelling in their IV a) Hypertonic solution, for the cells to lose water and shrink 11) How does water move across a cell membrane even though the membrane is primarily lipophilic?  a) Mostly through aquaporins b) Simple diffusion, since the SA which water passes through is so large and the size of water is so small 12) What is TBW? What are the two divisions called? Which is larger? What separates the two compartments? Can water move across the membrane? Can ions? a) All of the water in our body b) Intracellular and extracellular c) Intracellular d) Plasma membrane e) Yes f) No 13) What compartments make up the extracellular fluid? What separates them? a) Blood plasma - Fluid located inside blood vessels b) Interstitial Fluid – the fluid between cells but not in the blood vessels c) Blood vessel wall 14) What are the tiny blood vessels called? a) Capillaries 15) If an isotonic fluid is infused into the body, TBW will increase. Will the volume of the ECF increase? What about the ICF? a) TBW increases b) Yes c) No, because water can only move if osmolarity is changed and in this case there is no change in osmolarity 16) If a hypertonic fluid is infused into the body. Where is it being infused? What is happening to the osmolarity? Where is the osmotic pressure greater? Where will water move? Will there be any volume changes? a) Into the ECF b) It is increasing c) The osmotic pressure is greater in the ECF d) Water will move from ICF into the ECF e) The TBW volume will increase, ECF volume will increase, ICF volume will decrease 17) Will a difference is osmolarity persist? a) No, it will always equal out 18) If a hypertonic fluid is infused into the body. Where is it being infused? What are we doing to the tonicity? What is happening to the osmolarity? Where is the osmotic pressure greater? Where will water move? Will there be any volume changes? a) Water will be infused into the ECF b) It is decreasing c) It is decreasing d) The osmotic pressure is greater in the ICF e) Water will move into the cell f) The TBW volume will increase, ECF volume will increase, ICF volume will increase 19) Explain the difference between osmotic pressure and osmolarity a) Osmotic pressure: the tendency of a solution to draw water b) Osmolarity: amount of solute in a solution 20) Define transduce  a) To convert from one form to another 21) What is the difference between an agonist and an antagonist? a) Agonist: chem messenger which activates a receptor b) Antagonist: aka blocker; chem messenger that binds to a receptor and doesn’t activate a receptor 22) Describe lipophilic messengers a) Function as transcription factors (so they interact with our DNA - intranuclear) b) Responses take relatively long to develop and effects persist for prolonged time c) The majority are bound to carrier molecules d) The messengers that are not bound are able to leave the blood vessel and go out to the cells are called free messengers. When a free messenger leaves the blood vessel, another one will unbind to become free – keeping a dynamic equilibrium of free messengers 23) Describe hydrophilic messengers a) Not bound to any carrier molecule b) Can easily move out of blood vessel but can’t enter into the cell by itself. It must bind to a membrane bound receptor to enter 24) What are the 3 types of membrane bound receptors? Describe them a) Enzyme linked receptor i) Has a receptor on the membrane linked to an enzyme. Many of these enzymes are kinases (which phosphorylate their substrate resulting in a response) b) Channel linked receptor i) Transmembrane protein w/ a binding site. When a chem messenger binds, a conformational change occurs opening up the channel. AKA fast channel; ionotropic channel c) G-protein linked receptor i) When a chem messenger binds, the alpha subunit dissociates & migrates along the membrane & interact w/ another structure which can be a channel (similar to channel linked receptor but it is slower. AKA slow channel; metabotropic channel) or it may activate an activator enzyme. This activator enzyme acts on a substrate, creating a second messenger 25) Explain the processes that occurs when a g-protein linked receptor is bound to a chemical messenger a) CHANNEL: When a chem messenger binds, the alpha subunit dissociates & migrates along the membrane & interact w/ another structure which can be a channel (similar to channel linked receptor but it is slower. AKA slow channel; metabotropic channel) b) ACTIVATOR ENZYME: An amplifier/activator enzyme acts on a substrate, creating a 2nd messenger which may do multiple things i) 2nd messenger (cAMP,cGMP,DAG) activate kinase ii) 2nd messenger (IP3) interacts with the smooth ER, creating a Ca++ channel allowing it to move into cytosol -> interact w/ Calmodulin then creating a complex which activates Kinase 26) What is a first messenger? a) Messengers used to signal between cells. These extracellular messengers bind to membrane bound receptors 27) What is a second messenger? Name the different types  a) Substances generated within (or enter the cytoplasm) as the result of action brought about by a 1st messenger. Theze eventually bring about a biological response of the target cell i) Ex: cAMP,cGMP,DAG (activate kinase), IP3(interacts w/smooth ER releasing Ca++), Ca++ (some cells have calcium channels that can respond to 1 st messengers and open up. When Ca++ is in the cell, it binds to calmodulin, forms complex, then activates kinase. Lecture 4: Videos 8-11: Membrane Potentials 1-4 Review questions: (ch 7: questions 1-7 1) How do hydrophilic messengers interact with the cell? a) Hydrophilic messengers cannot go through the membrane alone. They can either enter through an enzyme linked receptor, channel linked receptor, or G protein linked receptor 2) What types of membrane bound receptors can hydrophilic messengers bind to? Describe them. a) Enzyme linked receptor i) Has a receptor on the membrane linked to an enzyme ii) Many of these enzymes are kinases which phosphorylate their substrate resulting in a response b) Channel linked receptor (AKA Ionotropic channel; fast channel) i) Chem messenger binds resulting in a conformational change which opens up a channel c) G-protein linked receptor i) When a chem messenger binds, the alpha subunit to dissociate and migrate along the membrane and interact with various structures such as” (1) Channel (AKA metabotropic channel; slow channel) (a) Slower channel than the channel linked receptor (2) Activator enzyme (a) Turns a substrate into a 2nd messenger (i) cAMP, cGMP, DAG – activates kinase (ii) IP(sub 3) – interact with smooth ER releasing Calcium which then binds to calmodulin creating a complex. The complex then activates kinase (iii)Calcium – since Ca++ is more conc outside the cell, it can enter the cell then bind to calmodulin then form complex then activate kinase 3) What is a first messenger? What is a second messenger? a) Messengers used to signal between cells. These extracellular messengers bind to membrane bound receptor b) Second – substances generated within (or enter the cytoplasm) as the result of action brought about by a 1st messenger. These eventually bring about a biological response of the target cell. 4) How do lipophilic messengers enter the cell? How does it bring about a response in the nucleus? a) They readily enter without needing a receptor and then into the nucleus b) Affect transcription of DNA 5) What is another name for lipophilic messengers? a) Transcription factors 6) What is the difference between lipophilic and hydrophilic a) Hydrophilic – see actions and effects very quickly b) Lipophilic – takes a while for an effect to occur but effects persist longer 7) Since hydrophilic messengers are all throughout our body, why do they only interact with certain cells? a) The cell must have a specific receptor to bind to the hydrophilic messenger 8) What is sodium’s chemical gradient? a) To move into the cell 9) Imagine the cell is negatively charged, what is sodium’s electrical gradient? a) To move inside the cell 10) The direction of movement of uncharged molecules is determined by what 2 things? a) Concentration gradient b) Membrane permeability 11) What is the electrochemical gradient? a) The net effect of the chemical gradient and diffusion potential which then determines the direction an ion will move 12) Is chemical gradient or electrical gradient more important? a) Neither the net effect is what matters 13) What is equilibrium potential describing? What equation finds it? What is the fundamental part of the equation? a) Represents the diffusion potential that exactly counterbalance the chemical gradient on a specific ion b) Describes the ELECTRICAL FORCE @ a point on ONE ION c) Nernst equation d) Equilibrium potential and concentrations of ions outside to inside the cell 14) What does polarity of the equilibrium potential describe? (describes inside of the cell) a) Is it positive or negative 15) If you have an anion more conc outside the cell, where is the chem gradient? What is the direction of the equilibrium potential? What is the polarity? a) Inside b) Outside c) Negative 16) What is a diffusion potential? a) An electrical potential that develops as a result of ions diffuse 17) How do you relate diffusion potential and equilibrium potential? What do we need to calculate equilibrium potential? What can change equilibrium potential for an ion? a) Equilibrium potential is the magnitude of diffusion potential needed to counterbalance the chemical gradient b) Equilibrium potential is a VERY specific diffusion potential c) Conc outside and inside the cell d) Changing the conc either inside or outside the cell 18) What is the equilibrium potential of sodium? Potassium? a) +60mV b) -90mV 19) What is a resting membrane potential? How would you find it in a neuron? What is the measured voltage of a typical neuron?  a) Determined by the combined b) Sticking an electrode in a nerve c) -70mV 20) What two factors of each ion present plays a role in determining the resting membrane potential? a) The equilibrium potential of each ion b) Relative permeability of the membrane to each individual ion 21) What equation is used to find resting membrane potential? What factors does the equation rely on? a) Goldman-Hodgkin-Katz Equation (GHK Equation) b) The equilibrium potential and membrane permeability for each ion 22) Is the resting membrane potential of a neuron (-70mV) impacted greater by potassium (- 90mV) or sodium (+60mV)? Why? a) Potassium b) K+ is more permeable a membrane is to an ion the greater impact the ion has on a potential Lecture 5: Video 12 -> stop before skeletal muscle (Graded Potentials, 1) What is the typical membrane potential for a neuron? a) -70mV 2) Can membrane potentials change? If so, how? a) Yes, in response to temporary changes in membrane permeability b) Through opening/closing “gated” membrane channels 3) Ions move through the membrane using two types of channels, describe them. a) Passive – non-gated channels; always open i) Ex: “K” leak channels b) Active – gated channels; can be opened or closed i) Ligand (chemically) gated, mechanically gated, voltage gated 4) As a membrane is made more permeable to an ion, the membrane potential will move towards what? a) The ion’s equilibrium potential 5) At resting membrane potential, the cell is said to be polarized. What does this mean? a) There is a separation of charge across the membrane 6) Describe the changes in polarized states of a membrane potential a) Depolarized: anything less negative than -70mV b) Hyperpolarized: anything more negative than -70mV c) Repolarization: the period in which a depolarized state travels back to -70mV after being depolarized 7) What two types of signals have been classified as the result of net ion movement? a) Graded potential b) Action potential 8) Define and describe a graded potential a) It is a diffusion potential that results from ion movemtn theough a ligand gated or mechanically gated ion channel  b) Referred to as graded because they vary in magnitude and polarity (depolarize/hyperpolarize) 9) What happens to the resting membrane potential is you open a sodium channel? Why? a) The potential will rise above -70mV (depolarize) b) Because sodium’s equilibrium potential is +60, so it moves towards sodiums equil potential 10) What will happen if we have three excitatory stimuli opening sodium channels? What is this an example of? a) There will be an even larger graded potential b) Summation 11) Do excitatory stimuli depolarize or repolarize? What about inhibitory stimuli? What happens if you have one of each with equal magnitude? a) Depolarize b) Repolarize c) They will summate, having no net affect 12) As graded potentials travel down a nerve, what happens? What is this called? Which way does it travel if it begins in the middle of a nerve? a) The potential gets weaker as they travel b) Decremental conduction c) Both directions 13) Can a synapse involve different messengers or receptors? Can you predict whether or not a response will be excitatory or inhibitory? a) No b) Yes 14) What does EPSP stand for? IPSP? a) Excitatory post synaptic potential b) Inhibitory post synaptic potential 15) What is the point of a graded potential? a) To get to an action potential 16) How does a graded potential get us to an action potential? a) An excitatory stimulus must make a graded potential reach the threshold 17) What happens at threshold? What is threshold? a) Voltage gated Sodium channels are opened and the potential will move towards sodium’s equilibrium potential, then it will move towards potassium’s equilibrium potential b) A particular voltage that will cause the opening of a voltage gated channel 18) At threshold, what is happening to the membrane permeability for sodium and potassium? a) It is becoming more permeable to both due to the voltage gated channels opening 19) What are the 3 conformations of a Voltage gated channel? What are the 2 gates called? What causes the gates to open? What happens to cause the 3 rd conformation? What happens when we get back to resting membrane potential? a) Closed – Capable of Opening, open, Closed – Incapable of Opening b) Activation & inactivation gates c) The activation & inactivation gate open at threshold d) Inactivation gate closes after 1 millisecond e) Inactivation gate opens, Activation gate closes 20) What channel allows potassium to move in ? When is it stimulated to open? Compare its effects to sodium. a) Voltage gated potassium channel b) At threshold (along with Na Gate) c) Its slow to open, so its affects are seen later. It is also slow to close, so this is why we see the repolarization 21) After the repolarization period of the action potential, how does potassium get back into the cell? a) Sodium potassium pump 22) What is the only thing that can open the “Closed – Incapable of Opening” conformation? a) When we get back to resting membrane potential 23) What is the difference between action potentials and graded potentials? a) Action potential i) Larger size ii) Cannot vary in size iii) Always excitatory iv) Cannot summate v) Unidirectional vi) Does not get weaker as it propagates b) Graded potential i) Smaller size ii) Size can in vary iii) Excitatory or inhibitory iv) Can summate v) Travel in both directions vi) Gets weaker as it propagates 24) What phrase is used to describe the inability of action potentials to vary in size? a) “all or none” 25) Why can’t we summate action potentials? a) In order to summate, we would have to let more sodium into the cell. The voltage gated channels cannot let any more in during the first two conformations 26) Describe the absolute refractory period a) There is nothing we can do during this phase of the action potential that will cause another action potential b) The first two conformations of the voltage gated channels: Open & Closed/Incapable 27) Describe the absolute refractory period a) Includes the period of hyperpolarization b) Includes the conformation – closed/capable c) A stronger than normal stimulus may result in an action potential d) Results in unidirectional propogation of action potentials 28) What is the area right after the cell body (axon)? What is special about it? a) Axon hilac? b) Contains several voltage gated Na+ channels; this is where we see an action potential 29) Why does the action potential only travel in one direction? a) The voltage runs into the absolute refractory period which blocks it 30) What happens when an action potential reaches an axon terminal?  a) Voltage gated Ca++ channels open (the action potential provides the energy to move Ca++ inside) b) Ca++ inside the cell interacts with synaptic vessels c) The synaptic vesicles move to front of cell, releasing a chemical messenger d) The chem messenger opens a ligand gated channel of the post synaptic cell membrane e) Another graded potential may be caused reaching threshold and resulting in another action potential 31) What is the space between two nerves? a) Synapse; synaptic cleft 32) Where is calcium more concentrated? a) Outside the cell 33) The Central Nervous System is composed of what organs? a) Brain & spinal cord 34) The afferent division transmits what information? Direction of travel? a) Sensory information b) From PNS to CNS 35) What makes up the Peripheral Nervous System? a) Everything besides brain & spinal cord 36) The efferent division transmits what information? Direction of travel? a) Somatic NS -> skeletal muscle b) Autonomic NS -> i) Sympathetic (1) Smooth muscle (2) Cardiac muscle (3) Visceral tissues/glands ii) Parasympathetic c) From CNS to effectors 37) Which type of autonomic NS controls voluntary muscles? Involuntary? a) Somatic b) Autonomic 38) What does the sympathetic NS do? Parasympathetic? Is there any overlap in where they both innervate? If they both innervate, what do they do? a) Fight or flight – do things that gets us ready to fight, run, do physical activity b) Rest & digest – slows things down, gets us ready for resting and storing things away c) Yes! Most organs are innervated by both (DUAL INNERVATION) d) They tend to balance each other out 39) What is a schwann cell? Where are they found? What are the spaces in between called? Are these spaces found anywhere else? a) They wrap around the peripheral neuron creating a sheath and facilitate the rapid transmission of action potential by allowing the action potential to jump from node to node b) Only in PNS c) Nodes of Ranvier d) Between myelin sheaths in the CNS 40) Define Saltatory conduction a) The rapid transmission of action potentials between nodes 41) What is the function of myelin? a) To speed up transmission; NOT to protect it b) It works as an insulator 42) Describe the matter of the spinal cord a) Gray matter: located in center of spinal cord; it is the location of cell bodies b) White matter: surrounds the gray matter; where the myelinated axons are found 43) What roles do the dorsal and ventral root of the spinal cord play? a) Ventral root: takes info away from the CNS and out to effector organs; sends out motor and efferent information b) Dorsal root: brings information to the CNS i) Contains the dorsal root ganglion which is a swelling on the dorsal root (1) Location of afferent neuron cell bodies (2) Sensory information 44) What surrounds the spinal cord? What is in between them? a) Bony vertebral bodies b) At each level between them a spinal nerve is present 45) What do you call the messengers that are released at the end of a nerve by the arrival of a nerve impulse, which diffuses across a synapse? a) Neurotransmitter 46) Describe ACH a) Acetylcholine b) Hydrophilic messenger c) Broken down by acetyl cholinersterase 47) How does ACH bring about a response? a) Bind to a channel linked protein – Nicotinic Cholinergic Receptor b) Bind to a g-protein linked receptor (which opens up a channel)– Muscarinic Cholinergic Receptor 48) Describe NE/Epi. Explain differences in understanding in UK. a) Nor-epinephrine and epinephrine b) Can be broken down by mono amine oxidase c) They are both known as adrenaline 49) How does NE/Epi bring about a response? a) G protein linked response – Adrenergic Receptor which can be alpha or beta 50) Where is ACH, NE, and Epi originally found? a) ACH & NE: axon terminal b) Epi: Adrenal medulla (center of adrenal gland) 51) If we have a nerve innervating a skeletal muscle: What NS is being used? What neurotransmitter is being transmitted? What receptor is present? a) CNS -> Efferent -> Somatic b) Ach c) Nicotinic cholinergic receptor 52) In the autonomic sympathetic system, where does the pre-ganglionic neuron synapse with? What specific part of the adrenal gland? What type of cell does it synapse with? What type of receptor is on this cell? a) Adrenal gland b) Adrenal medulla  c) Chromaphin cell d) Nicotinic cholinergic receptor 53) Draw the various ways our nerves are set up in the nervous system (4) Lecture 6: Video 16-(supposed to be 19) 1) What is the functional unit of skeletal muscle? What composes them? a) Sarcomeres b) Actin (Thin Filament) & Myosin (Thick Filament) 2) What composes the thin filaments? a) Actin globules strung together into two strands i) Actin has myosin binding sites b) Tropomyosin – long filament which lays along the strand of actin and covers up myosin binding sites on actin globules i) Has binding sites for troponin and actin c) Troponin i) Has binding sites for tropomyosin, actin and calcium 3) What composes the thick filaments? a) Myosin i) Has 2 binding sites on crossbridge/head (1) ATP binding site called ATPase (2) Actin binding site 4) Describe the shapes of actin and myosin a) Actin is composed of individual spheres combining into long strands which then wind around each other creating a double strand b) Myosin is shaped like a hockey stick with a handle and a head pointing outward 5) What is a myofibril? a) Actin and myosin in a repeating pattern 6) What makes up a muscle fiber? What is it also called? a) It is a collection of myofibrils wrapped together and surrounded by a cell membrane b) Aka muscle cell 7) Describe the size of a skeletal muscle cell.  a) Very large b) May extend the entire length of muscle 8) What makes up a skeletal muscle? Describe it a) Muscle fibers(cells) wrapped together b) Each of the cells are multinucleated and can extend the entire length of the muscle c) They are innervated by somatic motor neurons (efferent) d) Also known as voluntary muscles since there is voluntary/conscious control of when the muscle contracts 9) Explain the pathway of the efferent neuron to skeletal muscle a) Its cell body originates in the ventral horn (gray matter of spinal cord) and innervates skeletal muscle. The efferent axon is within the ventral root. 10) What organelle is important when thinking of skeletal muscles? a) Smooth ER 11) What is a sarcomere? How do you measure length of it? a) The arrangement of thick and thin filaments b) From z disk to z disk 12) Describe “titan” a) Located at the ends of myosin b) Helps keep proteins organized properly and plays a role in elastic properties of skeletal muscle 13) How do we describe skeletal muscle due to the repeated pattern of sarcomeres? a) Striated 14) Explain the entire crossbridge cycle starting at a myosin head bound to an actin filament. a) ATP binds to myosin head, dislodging the bond between actin & myosin b) ATP is hydrolyzed into ADP and an inorganic phosphate c) If calcium is present, it will bind t troponin causing a conformational change, causing tropomyosin to shift off and expose the binding sites on myosin d) The activated myosin head now binds to actin. This is called crossbridge formation. e) The inorganic phosphate is released and the myosin head swivels performing a power stroke in which the myosin head pulls actin towards the center of the sarcomere and therefore shortening it 15) What must be available for the crossbridge cycle to occur? a) ATP and calcium 16) What is required for myosin to be considered activated? What does activated mean? a) ATP is hydrolyzed and the ADP and inorganic phosphate are bound to myosin head b) Myosin can now potentially bind to actin 17) Explain the Sliding Filament Theory of Muscle Contraction a) When crossbridges form and the myosin pulls actin towards the center of the sarcomere the muscle shortens and tension is created b) When this muscle contraction occurs, actin and myosin molecules do not coil up but instead they slide by each other 18) What type of nerve innervates skeletal muscle fiber? a) Somatic motor neuron 19) What do we call the site of innervation of a somatic motor neuron and a muscle? What type of receptor is present? a) Neuromuscular junction  b) Motor end plate c) Nicotinic cholinergic receptor 20) In the case of a neuromuscular junction, what type of neurotransmitter is stored in the axon terminal? a) ACH is stored in the axon terminal’s synaptic vesicles 21) When the receptors at a neuromuscular junction open, what occurs? a) Sodium moves in and potassium moves out (sodium at a faster rate) b) This results in an excitatory post-synaptic potential, reaching threshold, and creating an action potential 22) What is special to know about when a somatic nerve synapses with a receptor? a) When a nerve is stimulated, The diffusion potential @ the motor end plate is always excitatory and always reaches threshold and always creates an action potential 23) Can inhibitory action potentials reach a Neuromuscular junction? a) No, since it always reaches an action potential (requiring excitatory stimuli) 24) What is a t-tubule? a) Invagination of cell membrane of the muscle. It allows a way for the electrical signal to travel deep into the depths of the very large skeletal muscle fibers 25) Explain the process of how an action potential reaches the muscle fiber a) ACH is released @ neuromuscular junction b) Binds to Nicotinic cholinergic receptors c) End plate potential leads to action potential d) Action potential travels down t tubule into the depths of the muscle fiber 26) What receptors are found in the t tubule? a) DHP receptor: voltage sensitive receptor b) Ryanodine receptor: Calcium channel in smooth ER c) They are attached to each other 27) Explain what happens when an action potential travels down the t-tubule a) It causes DHP to change conformation opening up the Ryanodine receptor which then opens up its calcium channel in the smooth ER, allowing calcium to move from an area of high conc in the ER out the cytosol to bind to troponin and continue in the crossbridge cycle 28) Explain the general sequence and timeframe of how tension occurs a) Action potential occurs @ a motor plate (brief) b) Intracellular calcium increases (brief) c) Tension is formed (Longer) 29) What is another term used for the ER surrounding the myofibrils? a) Sarcoplasmic reticulum 30) In order to get skeletal muscle to contract, what has to be released into the cell? What causes it to be released? a) Calcium b) The action potential 31) What are the 3 phases of a muscle contraction? What occurs during each? a) Latent phase: right after muscle fiber is stimulated; no tension develops b) Contraction phase: develops tension i) Ca++ bound to troponin  tension develops c) Relaxation phase: Muscle can no longer create tension  i) Ca++ no longer released and has re-entered the smooth ER; bidning sites are recovered 32) What is a motor unit? Where does it come from? a) One motor neuron and all of the muscle fibers it innervates b) It comes out of the ventral root in the spinal cord gray matter ventral horn 33) Motor neuron 1 innervates muscle fibers 1,2,3. Motor neuron 2 innervates muscle fibers 4,5,6. Is it possible that motor neuron 2 also innervates muscle fiber 2? If we stimulate motor neuron 1, will all fibers be stimulated? a) No, they do not cross b) Yes 34) What is the response to a single stimulus called? a) Twitch 35) Why do we always get the same amount of tension within a certain muscle fiber when it is stimulated? a) The same stimulus, same amount of calcium is released which binds to the same amount of troponin which exposes the same amount of binding sites and same amount of cross bridges forming 36) Compare the duration of an action potential to a muscle twitch a) A twitch is MUCH longer (100x) 37) What is tetanus? a) The max tension a muscle fiber can develop 38) How does summation of tension occur? If we keep stimulating a motor neuron, eventually the amount of tension levels out. Why does this occur? a) More calcium is released b) Once it has been stimulated several times, the number of binding sites for actin and myosin are completely full, and therefore tension can no longer increase 39) Where would you like to have smaller muscle motor units (smaller number of muscle fibers) in your body? Why? Where do you want larger muscle motor units? Why? a) Eyes b) We want really fine control in these areas c) Legs, arms d) More fibers = more tension = more strength to these areas 40) If 1 motor unit isn’t enough, what does a motor unit do? Describe this a) Recruitment of motor units b) If we are lifting a sub maximal load, the body will asynchronously recruit motor units to reduce fatigue 41) If we are lifting a maximal load, how many motor neurons will be recruited? a) All of them 42) What affects the amount of tension an individual muscle fiber can create? a) Thickness of the fiber i) Thicker fibers have more actin and myosin and can create more cross bridges b) Frequency of stimulation (summation can increase tension) c) Length of the sarcomere (muscle fiber) prior to stimulation i) Shortened before: decreased tension (too much IN CLASS HE SAID IT CANNOT OCCUR ii) Lengthened before: tension cannot occur (no overlap; nothing happens) 43) What is the perfect overlap of actin and myosin in sarcomeres called? When we activate skeletal muscles, what % of tension can we reach when they are at this length? a) Optimal length b) 100% maximal tension 44) When a somatic motor neuron is activated, does every fiber become activated as well every time? a) Yes 45) Describe recruitment of motor units a) One motor unit can recruit other motor units to increase tension 46) When lifting a submaximal load, does the nervous system activate all motor units in a muscle? What do the motor units do to decrease fatigue? a) No, only the requisite number needed b) They rotate activation called asynchronous activation resulting in a smooth contraction 47) When lifting a maximal load, describe the motor units. a) All are recruited and stimulated to tetanus b) Fatigues occurs relatively soon 48) Define fatigue in reference to muscles a) Inability of muscle fibers to maintain tension 49) How is the size of a motor unit related to preciseness of a movement? a) The smaller (fewer fibers) the motor unit, the greater ability to precisely control movement 50) What are the two functional components of muscle? What composes them? a) Contractile elements i) sarcomeres b) Series elastic tendons i) Tendons and other proteins (ex: titan) 51) When we first stimulate a muscle, our contractile elements and series elastic elements do what? a) Contractile elements lengthen & series elastic elements shorten 52) Does the measurement of a muscle length, include both the series elastic element and contractile element? a) Yes 53) What happens to the overall length of the muscle during this initial stimulus? a) It stays the same 54) Describe Isometric Contraction a) We are creating tension, our muscle is contracting but the overall muscle length stays the same (due to the load being greater than the force) 55) Describe Isotonic Contraction a) Occurs when the force is greater than or equal to the load. b) The contractile elements are shortened, series elastic elements lengthen but if we keep stimulating it we can continue to shorten the contractile elements c) Muscle length is shortened 56) A muscle is strong enough to hold 20 lbs. If the load is greater than 20 lbs, describe what happens. If the load is less than 20 lbs, describe what happens a) Isometric: the muscle length stays the same, and is unable to lift the load b) Isotonic: the muscle shortens so we are able to lift the load 57) What provides energy for muscle contraction? How long can it provide energy? What replenishes this energy? Where is it originally located and what does it do to replenish the energy? a) ATP b) A few seconds c) Creatine phosphate d) Stored in skeletal muscle and then donates a phosphate to ADP 58) Draw out the mechanism of this “replenishing of energy” a) Creatine phosphate + ADP > ATP + creatine 59) How long does creatine phosphate provide ATP for? Glycolysis? Oxidative phosphorylation? a) 10 sec b) Several minutes c) As long as nutritional stores are present 60) Which is faster: glycolysis or oxidative phosphorylation? More efficient? a) Glycolysis b) Oxidative phosphorylation 61) The type of skeletal muscle is classified based on what? a) Speed of contraction b) Primary means of producing ATP 62) What determines the speed of contraction? a) Activity of myosin ATPase (present on myosin head i) There are fast fibers with fast myosin ATPase and there are slow fibers with slow ATPase 63) What are the 3 ways of producing ATP? Describe each one. a) ATP i) All cells have ATP & creatine b) Glycolysis i) Glycolytic fibers – larger fibers ii) Do not have much vascular supply (do not need as much oxygen) iii) Low resistance to fatigue (1) Produce large amounts of ATP but only for a brief time bc of fatigue c) Oxidative phosphorylation i) Oxidative fibers – smaller fibers ii) Have a good vascular supply (aerobic process) iii) Contain myoglobin iv) High resistance to fatigue 64) Describe myoglobin a) Protein which binds to oxygen b) Higher affinity than hemoglobin 65) Combining the speed of myosin ATPase w/ metabolic characteristics yield the following fiber types: a) Slow oxidative fibers b) Fast Oxidative fibers c) Fast glycolytic fibers 66) Explain the size principle of recruitment  a) The 3 different types of motor units are recruited at different times based on the size of their neuron axon b) Slow oxidative fibers: thinner fibers which are recruited first, less likely to fatigue (resistant to fatigue) c) Fast oxidative: middle of the two types above and below d) Fast glycolytic fibers: thicker fibers are recruited last 67) How does having thicker fibers allow us to have more tension? a) More cross bridges potentially can form 68) Why does slow oxidative fibers contain myoglobin? a) Myoglobin has a higher affinity than hemoglobin 69) What muscles are primarily slow oxidative fibers? Fast glycolytic? a) Core muscles, like your thighs, maintaining posture b) Biceps, calf muscle (jumping motion) 70) What is a motor unit? How many of those fibers are activated when it is stimulated? Can the fibers be a mix of slow oxidative and fast glycolytic a) One motor nerve and all of the fibers it innervates b) All of them c) No they are always the same size and type of fiber 71) Every time a muscle contracts, if we have different groups of motor units (some slow ox and some fast glyc), which groups are activated first? a) Slow oxidative 72) What are 3 different ways that ATP is used in skeletal muscles? a) ATP knocks the myosin off of the actin binding site b) Powers the sodium potassium pump to restore the resting membrane potential c) ATP powers the calcium pump which is necessary to put Calcium back into the smooth ER d) It activates myosin when it is hydrolyzed Lecture 7: Video 20-21 1) What is the primary purpose of the immune system? What if it fails? a) To prevent pathogens from entering the body b) Identify when pathogen is present, initiate a response to eliminate or neutralize pathogen, create a memory of pathogen which facilitates a quicker more robust response if future infections occur 2) What is the difference between an innate immune response and an adaptive immune response? a) Innate: we are born with it, immediate response to pathogen, nonspecific, no memory associated w/ it b) Adaptive: Takes time to develop, highly specific, can recognize an infinite # of pathogens, requires exposure to “prime” cells, involves memory 3) List the different types of leukocytes (white blood cells) a) Neutrophils b) Macrophage (M phi) c) Dendritic cell d) Eosinophils, Basophils, Mast Cell 4) Describe neutrophils a) Most abundant white blood cell b) Circulates through bloodstream then goes out into tissues (diapedesis) c) Have pathogen recognition receptors (PRR) d) Involved in the innate response e) Phagocytosis f) Release cytokines and chemokines 5) What is the role of cytokines/chemokines? a) They are chemical messengers that call in other cells/responses 6) Describe macrophages a) Masters at phagocytosis b) Remove dead cells from tissue c) Stimulate other immune cells by releasing cytokines d) Present antigens to lymphocytes to initiate adaptive response 7) Describe dendritic cells a) Present in skin and GI mucosa & airways (first line of defense areas) b) Phagocytosis then they Travel to lymph nodes c) Present antigens to lymphocytes to initiate adaptive response 8) Describe the granulocytes: eosinophils, basophils, mast cells. Why are they called granulocytes? a) Various roles in “allergic” rxns b) Release histamine (important in inflammation response) c) Release “pro-inflammatory cytokines” which help drive the inflammatory response further d) They have prominent granules in their cytoplasm 9) List the different types of lymphocytes and describe each a) Natural killer cells: i) Part of the innate immune system ii) Recognize and kills virus infected cells iii) May recognize and kill cancer cells b) B-lymphocytes: i) Part of the adaptive immune system ii) Presents antigen to T-cell iii) Matures into plasma cells and produces antibodies which then will circulate in the blood, bind to pathogens and mark for destruction (humoral immunity) iv) Provides memory c) T-lymphocytes: i) Part of the adaptive immune system ii) Become “primed” by interaction with antigen presenting cells iii) After they’re primed, they either produce: (1) T helper cells: Help B-lymphocytes by secreting cytokines which corrdinate B- cell and macrophage activity (2) Cytotoxic T cells(Killer T cells): kills pathogens; kill specific cells identified with specific antigens and provide memory 10) Which types of lymphocytes are related to the adaptive immune system? a) B lymphocytes and t lymphocytes 11) What 3 things of the innate immune system prevent pathogens from entering the body? a) Barrier surfaces b) Protective surface of commensal bacteria (non-harmful; limits survival of pathogenic bacteria) c) Various chemical defenses 12) What are barrier surfaces? What immune system are they related to? a) They are the epithelial surfaces with tight junctions that limits materials going between cells b) They are covers in anti-microbial peptides c) The innate immune response 13) List examples of the chemical defenses our innate immune system has i) Gastric acid: its low pH destroys ingested pathogens ii) Mucous lining our nose & airways: traps pathogens; its ciliated cells help sweep pathogens iii) Lysozymes in our tears: can destroy bacteria iv) Sebaceous glands on our skin: secretes substances that can kill bacteria 14) Describe the “complement” system of our innate immune response. How does it help the body get rid of bacteria if the complement binds? a) Group of proteins circle in our plasma surveying for pathogens b) If a pathogen enters, there are different processes the complement system activates such as Opsomization, activates the membrane attack complex, enhances inflammation, (increases vascular permeability) vasodilation, attracts leukocytes 15) What occurs when the “complement cascade” is activated? a) The cascade produces active molecules which can: i) perform opsomization ii) form membrane attack complex iii) enhance inflammation (1) Increase vascular permeability which makes it easier for substances to go from circulatory system into interstitial tissue (where the infection may be) (2) Vasodilation: blood vessels dilate, increasing blood flow (3) Attract leukocytes: WBC which play a role in fighting 16) Define opsomization a) Complement attaches to surface pathogens, which makes them much more likely to be destroyed by phagocytosis b) Coats substances making them more likely 17) What is the membrane attack complex? a) Several complement proteins coalesce then can perforate the cell membrane and cause destruction of invading cells 18) What are the signal molecules released to cause complement system to occur? a) Cytokines b) Chemokines (cytokine involved in calling other cells) 19) When does the innate immunity initiate an inflammatory response? a) When immune cells recognize pathogens or damaged cells by the things they release (PAMPs and DAMPs) 20) How does the innate immunity destroy invading pathogens? a) Phagocytes (neutrophils, macrophages, dendritic cells)  b) Natural killer cells 21) Why does the innate immune system increase blood flow and enhance clotting mechanisms in response to an infection? a) The clotting helps “wall off” the infected area 22) Define PAMPs and DAMPs a) Pathogen associated membrane proteins b) Damage associated membrane proteins 23) What activates the complement system? a) Pathogens traverse (travel through) the epithelial cells, get into body and then replicate. Their presence activates it. 24) Describe what occurs when the complement system is activated a) It will either create membrane attack complexes or perform opsomization b) Some pathogens will be lysed by membrane attack systems and then disappear c) Other pathogens which were coated with the complement will be phagocytosed and processed by a macrophage. d) Next the macrophage will release cytokines and chemokines which call in additional inflammatory cells. Some that are called in are leukocytes (neutrophils and granulocytes) which can also release cytokinins furthering the inflammatory response e) The innate immune response will continue until the pathogen is completely eradicated. If unable to completely eradicate this infection, it may require adaptive immune system help. 25) As a result of innate immune response, what do cytokines and bradykinins do? a) Cytokines increase blood flow and permeability of vessels locally b) Endogenous cytokines and pyrogens (from bacteria) cause fever c) Bradykinins ( a type of cytokinin) sensitizes local nerve receptors 26) As a result of the acute inflammatory response (and cytokines and bradykinins being released), what 4 things occur? a) Rubor (redness) i) Due to increased blood flow b) Calor (heat) i) Due to increased metabolic activity c) Tumor (swelling) i) Due to increased blood flow and interstitial fluid d) Dulor (pain) i) Brought on by sensitivity of nerves due to bradykinin release 27) Is the innate immune response enough to fight off an infection? a) Sometimes depending on the pathogen 28) What substances are on pathogens that allow our immune system to recognize them? a) PAMPs: pathogen associated membrane proteins 29) What substances are on damaged cells that allow our immune system to recognize them? a) DAMPs: damage associated membrane proteins 30) How does the innate immune system activate the adaptive immune system? a) Antigen presenting cells (ex: macrophages, dendritic cells) of the innate response interact with and “prime” naïve lymphocytes 31) What cells are associated with the adaptive immune response? a) Lymphocytes  i) B cells ii) T cells 32) What does it mean when we say a lymphocyte is “naïve” a) It has never been exposed to a particular pathogen 33) What communication occurs between the innate immune system and the adaptive immune system? a) The dendritic cells (which phagocytosed a pathogen, processed it, and created antigens (markers on the dendritic cell which recognize the pathogen)) present these antigens to lymphocytes 34) What are the two general types of adaptive immunity called? a) Humoral immunity b) Cell mediated immunity 35) What is present on the surface of a B cell? a) Very specific receptors which can bind to a pathogen 36) What can a B cell turn into? a) Plasma cells i) Produce large number of specific antibodies for the pathogen. The antibodies circulate in plasma and help fight infection. b) Memory B cell i) Insures rapid and robust response to future exposures ii) Produces antibodies faster 37) How do antibodies help fight an infection? a) They circulate in our plasma b) They surround the pathogens, blocking any binding sites they have to enter our cells c) They perform opsomization d) They perform agglutination 38) Describe agglutination a) Antibodies bind to pathogen surface and bind to each other creating clumps of pathogen and then the pathogen will not be able to enter the cell 39) What type of immunity does B cells give us? Why is it called that? a) Humoral immunity b) It refers to our blood plasma, a humor, because the antibodies created circulate in plasma and have their effects in this method 40) The receptors on these B cells (same as T cells), have the ability to recognize what type of pathogens? a) ALL types; infinite number 41) Describe the cell mediated immunity between a dendritic cell and a Naïve T-cell a) The dendritic cell phagocytoses & processes a pathogen, and then presents different antigens on its surface becoming an antigen presenting cell b) Next, it migrates to the lymph node and it interacts w/ naïve t cells c) The t cells then differentiate 42) What are the 3 things a naïve t cell can differentiate into? a) T Killer Cell (Cytotoxic Cell): kill infected cells b) T Helper Cell: activate macrophages, B-cells and recruit & activate granulocytes which: i) Phagocytosis and cytokinin release ii) More antibodies produced  iii) Further immune response Memory T-Cell: activated by either macrophages, B-cells, and dendritic cells (1) Not restricted to lymph node like naïve T-cells 43) What two types of cells allow us to have a more rapid and robust response the second time a pathogen is presented? a) Memory B cells b) Memory T cells 44) How long does it take our innate immune system to take effect? a) Starts working immediately TONICITY 1) What does osmolarity describe? a) The solute concentration of a solution 2) What number do we use to describe “normal osmolarity of our extracellular and intracellular fluids? a) 300 mOsm 3) Which way will water move? To an area of lower/higher osmolarity? To an area of lower/higher osmotic pressure? a) Higher osmolarity b) Higher osmotic pressure 4) What does tonicity describe? a) Solutions regarding the effect a solution will have on cell size 5) Describe an isotonic solution a) It has the same amount of nonpenetrating solute as a cell (300 mOsm) b) Osmotic pressure is equal on both sides of membrane and no net movement of water c) They do not result in a change in cell size 6) Describe an hypotonic solution a) It has less nonpenetrating solute (300mOsm) as a cell (300 mOsm) b) Osmotic pressure within the cell is less than the surrounding fluid and water will move outside the cell. c) If a cell is placed in a hypertonic solution, the cell will shrink 8) When determining the tonicity of a solution, we only consider what type of solute? a) Non-penetrating