PHY104 Physiology MCQs PDF

PHY 104 Physiology MCQs For 1st Year Medical Students By Prof. Dr. Maged Haroun Professor of Physiology Head of Physiology Department Faculty of Medicine – MTI University ` ...

PHY 104 Physiology MCQs For 1st Year Medical Students By Prof. Dr. Maged Haroun Professor of Physiology Head of Physiology Department Faculty of Medicine – MTI University `  Introduction 1) Human cell membrane: a. Is a bilipid layer membrane b. Consists mainly of carbohydrate molecules c. Is impermeable to lipid soluble molecules d. Has integral proteins on the outer surface only 2) The main extracellular cation is: a. Sodium b. Magnesium c. Calcium d. Potassium 3) Proteins in the cell membrane act as: a- Carriers b- Channels c- Receptors d- All of the above 4) Isotonic saline is NaCl with one of the following concentration: a- 0.9% b- b -8% c- 12% d- 25% 5) Glucose transport across the cell membrane occurs by: a- Primary active transport b- Secondary active co-transport with sodium ions c- Simple diffusion through protein channels d- Simple diffusion through lipid bilayer 6) Sodium-potassium pump: a- Is an example of secondary active co-transport. b- Pumps 3 Na+ ion out of the nerve fiber and 2 K* ions into 2 c- Is the only cause of resting membrane potential. d- Is responsible for depolarization phase of the nerve action potential. 7) Concerning the integral proteins of the cell membrane: a- They act as carriers b- They act as receptors c- The function as enzymes d- All the above are correct 8) The rate of diffusion across the cell membrane is indirectly proportionate with: a. The concentration gradient across the cell membrane b. The surface area of the membrane c. Temperature d. Thickness of the membrane 9) Connexon is an important component of the: a- Sodium channels b- Sarcoplasmic reticulum c- Gap junction d- Synaptic vesicles 10) Most of the body weight is formed of: a. Proteins b. Water c. Fats d. Minerals 11) ICF differs from ECF, in that ICF has higher concentration of: a- Cl- b- K+ c- Phosphate d- Na+ 3 12) The following body fluid compartments can be measured directly by using substances, EXCEPT: a- extracellular fluid. b- total body water. c- intracellular fluid. d- plasma volume. 13) Voltage-gated channels are characterized by: a. They are non-gated b. They allow diffusion of large protein molecules c. They open or close by change in the membrane potential d. They are structural proteins 14) The rate of diffusion of a solute across a membrane depends on the: a- total cross-sectional area of the membrane. b- temperature of the solvent. c- concentration gradient of the solute across the membrane. d- all of the above. 15) Ligand-gated channels are characterized by: a. They are continuously opened b. They allow diffusion of large protein molecules c. They open or close when the cell membrane potential change d. They open when a hormone or neurotransmitter binds to the receptor 16) Active transport of a substance: a. Occurs according to concentration gradient b. Occurs against electrochemical gradient c. Does not need energy d. Is directly proportional to the molecular size of the molecules 17) Regarding the transport mechanisms across the cellular membrane: a- facilitated diffusion is an active process. b- ions pass freely through protein channels. c- Na+-K+ pump is an example of secondary active transport. 4 d- counter transport is transporting 2 molecules in the same direction. 18) Osmosis: a- Occurs against concentration gradient b- Needs a carrier c- Needs energy d- Is a passive process 19) Secondary active transport includes: a. Sodium-potassium pump b. Sodium- glucose co-transport c. Influx of sodium ions through protein -channels d. Movement of large protein molecules out of the cell 20) The rate of diffusion of a particle across a membrane will increase if: a. The area of the membrane decreases b. The thickness of the membrane increases c. The size of the particle increase d. The lipid solubility of the particle increases 21) One of the following is an example of facilitated diffusion: a. Na+ transport across cell membrane b. Glucose transport using a carrier specific for glucose c. Pumping of K* ions into the cell d. Movement of CO2 and O2 through the bilipid layer 22) Concerning osmosis across selectively permeable membrane, all are true, EXCEPT: a- it is the movement of solute across a semi-permeable membrane from area in which of low concentration to area in which of high concentration. b- it is caused by a concentration difference of water. c- osmotic pressure is the amount of pressure to stop osmosis completely. d- the osmotic pressure is determined by the number of particles per unit volume of fluid. 5 23) Which of following structures is not component of a reflex arc? a. Afferent neuron b. Efferent ganglion c. Sensory receptor d. Effector organ 6  Nerve 1) The structural unit of a nerve is a: a- Nephron b- Neuron c- Myofibril d- Receptor 2) The myelinated nerve fiber has an outer layer of: a- Nerve cells b- Schwann cells c- Plasma cells d- Epithelial cells 3) The cause of resting membrane potential is: a- Equal distribution of ions in ICF and ECF b- Unequal distribution of ions in ICF and ECF c- Na+/Mg++ pump d- All of above 4) The absolute refractory period: a- Is due to hyperpolarization b- Refers to a normal or increased excitability state c- Is due to inactivation of Na+ channels d- Is equal in skeletal and cardiac muscles 5) The Na+-K+ pump: a) Is inactive at rest because the membrane is absolutely impermeable to sodium ions b) Enhanced by hypoxia c) Couples Na and K+ pump with a ratio 1:1 d) Causes continuous gain of positive charges outside the membrane 6) All the following statements are correct, except: 7 a- The selective permeability of the membrane is responsible for the polarized state b- The Na+-K+ pump maintains the normal distribution of ions. c- The Na+-K+ pump pumps Na+ into the nerve fiber. d- The Na+-K+ pump requires energy which is supplied by ATP 7) The local response: a- Is characterized by decreased excitability b- Jumps from one node of Ranvier to the next c- Obeys the all-or-none law d- Can be summated. 8) The firing level of a stimulated nerve fiber: a- Is reached at a membrane potential of -65 mV. b- Is reached at the end of the spike. c- Is the membrane permeability to K+ ions is increased, d- Is the time when repolarization starts 9) The relative refractory period: a- Occurs during depolarization. b- Is the inability of any stimulus to generate an action potential. c- Is due to inactivation of all voltage-gated Na+ channels, d- Is due to inactivation of some voltage-gated Na+ channels, while voltage- gated K+ channels are opened. 10) Saltatory conduction: a- Occurs in unmyelinated nerve fibers b- Is slower than nonsaltatory conduction c- Conserves energy for the axon d- The speed of propagation is inversely proportional to the diameter of the axon 11) The ascending limb of nerve action potential curve is: a) Represents repolarization b) Represents depolarization 8 c) Due to slow 1C outflow d) Due to Ca+ inflow 12) During the activation of a nerve cell membrane: a- CL ions flow outward b- K+ ions flow inward c- Na+ ions flow outward d- Na+ ions flow inward 13) During depolarization: a- K+ ions diffuse outside b- The membrane becomes impermeable to Na+ c- When membrane potential reaches -65mV, K+ channels open d- Activated voltage gated Na+ channels open 14) Repolarization of nerve is caused by opening of voltage gated: a) Sodium channels b) Calcium channels c) Chloride channels d) Potassium channels 15) Concerning the voltage gated sodium channels: a- The activation gate for sodium are closed at rest b- The inactivation gate for sodium are closed at rest c- At the firing level, the inactivation channels are closed d- None of the above 16) After release from the neuromuscular junction, acetylcholine: a- Activates presynaptic potassium channels b- Causes postsynaptic depolarization c- Enters the sarcoplasmic reticulum d- Is triggered by acetylcholinesterase 17) In muscle tissue, neurotransmitter receptors are located: a- In synaptic vesicles 9 b- On the motor neuron axon terminals c- In the synaptic cleft d- On the motor end plate 18) The action potential of skeletal muscle: a- Has a prolonged plateau phase b- Spreads inwards to all parts of the muscle via T tubules c- Is longer than the action potential of cardiac muscle d- Is not essential for muscle contraction 19) The curare blocks the ACh receptors on muscle tissue. This would result in: a- Increased stimulation of the muscle fiber b- Increased contractile strength of the muscle fiber c- Nonconsecutive eccentric contractions d- Inability of muscle to respond to the motor neuron stimulus 20) All about excitation contraction coupling of skeletal muscle fibers is correct, except: a- Excitation of the T-tubules results in the release of calcium from the sarcoplasmic reticulum b- Calcium binds to and activates tropomyosin c- Calcium is pumped into sarcoplasmic reticulum to initiate relaxation d- Acetylcholine is released at the motor end plate 21) Which of the following statements concerning cross bridges is not correct? a- Bind to actin during muscle contraction. b- Bend during muscle contraction. c- Are formed by the globular heads of the myosin molecules. d- Consist of troponin and tropomyosin protruding from the actin helix. 22) Synaptic transmission at the neuromuscular junction is: a- Enhanced by high levels of cholinesterase b- Caused by an influx of potassium ions through the muscle membrane 10 c- Depressed by abnormally low levels of magnesium d - Produced by the release of acetylcholine from the alpha motor neurons in skeletal muscle 23) Which of the following will increase the velocity of action potential propagation? a- Myelination of the axon b- Decrease in axon diameter c- Absence of myelin sheath d- Short inter nodal distances. 24) The rapid depolarization and overshoot of the axonal action potential is due to rapid: a- Increase in K+ conductance (permeability) b- Increase in Ca2+ conductance c- Opening of Na+ channels d- Opening of Cl- channels 25) Repolarization: a- Occurs at first gradual then becomes fast. b- Results from closure of sodium and opening of potassium channels c- Is represented by the ascending limb of the spike. d- Is followed by appearance of response. 26) The excitability of the nerve is zero during: a- Relative refractory period b- Catelectrotonus c- Local response d- Absolute refractory period 27) Relative refractory period: a) Is an increase in excitability b) Is a complete loss of excitability c) Coincides with the second 2/3 of descending limb of spike d) During it the nerve can't respond to any stimulus whatever it's strength 11 28) Nerve excitability is increased by: a) Hypercalcemia b) Increased potassium permeability c) Cooling d) Hypocalcaemia 29) Absolute refractory period of the nerve: a) Occurs after depolarization b) Is an increase in excitability c) comes before the relative refractory period d) Occurs after hyperpolarization 30) The local response: a- Is characterized by depressed excitability b- Can be summated c- Obeys all or none rule d- Is followed by an absolute refractory period 31) Conduction in the nerve: a) Is an active process b) In myelinated nerve is through myelin sheath c) In a living animal occurs in the antidromic direction only d) In unmyelinated nerves is called salutatory conduction 32) The function of tropomyosin in skeletal muscle includes: a) Sliding on actin to produce shortening b) Binding to myosin during contraction c) Binding Ca2+ at start of contraction d) Acting as a relaxing protein at rest by covering the active site on actin 33) The function of troponin C is: a- Binding with Ca2+ b- Binding with tropomyosin c- Binding with actin d- Covering active sites of actin 12 34) Relaxation of skeletal muscles: a) Readily occurs in absence of ATP b) Is completely passive process c) Results from simple diffusion of Ca to extracellular fluid d) None of the above 35) Starling's law states that there is: a- An inverse relation between tension and initial length b- A direct relation between tension and load moved. c- A direct relation between load moved And velocity of shortening. d- A direct relation between tension and initial length within limits. 36) The propagation of AP along the membrane of the T-tubules causes: a- The release of NE from the terminal cisternae b- Contraction of the T-tubules c- The release of Ach from the terminal cisternae d- The release of Ca2+ from the terminal cisternae. 37) Excitation-contraction coupling in the skeletal muscles involves: a- Binding of Ca2+ to tropomyosin. b- Binding of Ca2+ to myosin head. c- Release of Ca2+ from T-tubules. d- Attachment of myosin head to the active site of actin. 38) Fast skeletal muscle fibers differ from slow fibers in that they: a- Are adapted for short rapid muscle contractions. b- Have less glycolytic enzymes c- Have more extensive blood supply, d- Contain more mitochondria. 39) Red (slow) fibers are characterized by the following, except: a- Contains much blood capillaries. b- Glycogen stores are low. c- Contains high concentration of myoglobin. d- Depends on anaerobic oxidation 13 40) Causes of muscle fatigue include the following, EXCEPT: a) depletion of acetylcholine at the motor end plate. b) depletion of ATP, creatine P and glycogen stores in the muscle. c) decreased blood supply, d) decreased intracellular Ca2+. 41) All or non-law can be applied to: a) Whole skeletal muscle b) Nerve trunk c) Whole heart d) Single nerve fiber 42) The neurotransmitter at the motor end plate is: a) Adrenaline b) Noradrenalin c) Ca++ d) ACh 43) Neuromuscular transmission is: a) Inhibited by Ca++ b) Stimulated by prostigmine c) Stimulated by magnesium d) Inhibited by methacholine 44) Neuromuscular transmission is: a) Bi-directional b) Does not show fatigue c) Inhibited by calcium ions d) Blocked by curare 45) Neostigmine improves muscle weakness by: a- Blocks action of acetylcholine b- Interferes with action of mono-amine oxidase c- Enhances the action of Catecholamines d- Blocks the action of acetyl choline esterase 14 46) During isometric contraction: a) Tension is constant b) Tension is increased c) Muscle length decreases d) Tension is decreased 47) Isotonic contraction is characterized by: a) Constant length b) Very low mechanical efficiency. c) Decrease tension d) Decrease in muscle length 48) The myelin sheath of the nerve: a- Allows fast ionic movement b- Prevents ionic movements c- Behaves as a good conductor d- Contain nodes of Ranvier in between which prevents the ions flow 49) The chronaxie: a- Is the threshold stimulus b- Is twice the rheobase c- Can be used as a measure of excitability d- Is the time needed to excite a nerve by a current strength equal to the rheobase 50) From the strength duration curve, one can observe that: a) Stimuli of extreme short duration will not excite b) Within limits, the stronger the current the longer duration required to produce its effect c) The threshold intensity of galvanic current which excite is Chronaxie d) The utilization time is a common measure of excitability 51) The strength-duration curve: a- Is the relationship between the duration of the stimulus and amplitude of response 15 b- Has a rheobase which is 2 times chronaxie c- Has a chronaxie which is the time needed by double the rheobase strength to stimulate the nerve d- Strong stimuli of extreme short duration can excite the nerve 52) All the following statements are correct, except: a- The selective permeability of the membrane is responsible for resting state b- Na+-K+ pump requires energy which is taken from ATP c- The Na+-K+ pump keeps the normal distribution of ions d- Na+-K+ pump is responsible for the pumping of Na to inside the nerve fibers 53) The resting membrane potential of a cell: a- Is dependent on the permeability of the cell membrane to K+ being greater than to Na b- Falls to zero if Na4/K+ ATPase in membrane is inhibited c- Is equal to the equilibrium potential for K+ d- Is equal to the equilibrium potential of Na+ 54) Chronaxie is: a- The utilization time b- The minimal duration of a stimulus that can excite the nerve c- The time needed by the rheobase to stimulate the nerve d- The time needed by current twice the rheobase to stimulate the nerve 55) The local response: a- Is characterized by depressed excitability b- Can be summated c- Obeys all or none rule d- Is followed by an absolute refractory period 56) The absolute refractory period: a- Is due to hyperpolarization b- Refers to a normal or increased excitability state c- Is due to inactivation of Na+ channels d- Is equal in skeletal and cardiac muscles 16 57) Concerning nerve excitability: a- During rest, the nerve membrane is depolarized b- Chronaxie means the intensity of the stimulus that produces the response c- An anelectrotonic response decreases the membrane potential and increases the nerve excitability d- The resting potential becomes less negative if the K+ concentration outside the nerve membrane is doubled 58) Concerning the sodium pump, it: a- Requires high energy phosphate bond b- Is the pumping of Na+ from outside to inside the cell c- Is an example of facilitated diffusion d- Is independent of K* influx 59) The local response in a single nerve fiber: a- Is produced by a cathode current of threshold intensity b- Is associated with increased K+ permeability c- Is not dependent on the intensity of the stimulus d- Can produce action potential if the membrane potential reaches -65mV 60) Concerning the nerve resting membrane potential: a- The extracellular sodium concentration is less than its intracellular concentration. b- The concentration of chloride is greatest inside the cell. c- If the resting potential is moved to a more negative value, the cell becomes more excitable. d- The concentration gradient for potassium tends to move potassium out of the cell. 61) Which of the following would occur as a result of inhibition of Na+-K+ pump? a- Decreased intracellular Na+ concentration b- Increased intracellular K+ concentration c- Decreased extracellular K+ concentration d- Increased intracellular Ma+ concentration 17 62) All the following statements are correct, except: a- The selective permeability of the membrane is responsible for the polarized state b- The Na+-K+ pump maintains the normal distribution of ions. c- The Na+-K+ pump pumps Na+ into the nerve fiber. d- The Na+-K+ pump requires energy which is supplied by ATP 63) The local response: a- Is characterized by decreased excitability b- Jumps from one node of Ranvier to the next c- Obeys the all-or-none law d- Can be summated. 64) The firing level of a stimulated nerve fiber: a- Is reached at a membrane potential of -65 mV. b- Is reached at the end of the spike. c- Is membrane potential when membrane permeability to K+ increased. d- Is the time when repolarization starts 65) The relative refractory period: a- Occurs during depolarization. b- Is characterized by the inability of any stimulus to generate an action potential. c- Is due to inactivation of all voltage-gated Na+ channels, d- Is due to inactivation of some voltage-gated Na+ channels, while voltage- gated. 66) Unmyelinated nerves differ from myelinated nerves in that they: a- Are more excitable b- Conduct impulses by saltatory conduction c- Have no nodes of Ranvier d- Are not capable of regeneration 67) Concerning the strength-duration curve all is true, except: a- Stimuli of extremely short duration fail to excite the nerve 18 b- Within limits, the stronger the current the shorter the duration required to excite c- The threshold galvanic current which can excite the nerve is called the rheobase d- The subthreshold stimulus has no effect on the nerve 68) Saltatory conduction: a- Occurs in unmyelinated nerve fibers b- Is slower than non-saltatory conduction c- Conserves energy for the axon d- The speed of propagation is inversely proportional to the diameter of the axon 69) Concerning action potentials: a- Saltatory conduction occurs in unmyelinated nerves b- There is an absolute and a relative refractory period c- Conduction of impulses is the same in the myelinated and unmyelinated nerves d- Repolarization is caused by increased permeability to Na+ 70) All the following statements are correct, except: a- The RMP is caused by selective permeability of the nerve membrane and Na+/K+ pump b- Chronaxie is the time needed by a current which is double the rheobase to excite c- During the descending limb of the spike there is increased permeability of the nerve fiber to Na+ d-The absolute refractory period of the nerve coincide with the ascending limb of the spike and the 13) third of the descending limb 71) During the activation of a nerve cell membrane: a- CL ions flow outward b- K+ ions flow inward c- Na+ ions flow outward d- Na+ ions flow inward 19 72) The resting membrane potential of a nerve fiber: a- Includes all the changes in membrane potential during conduction of the nerve impulse. b- Is the potential difference between the inside and outside of the resting membrane. c- Is always around zero, d- Is due to the presence of negative ions on the outer surface of the membrane in relation to its inner surface 73) Resting membrane potential of the nerve fiber is: a) A constant potential difference between the outer and inner surfaces of the membrane of the nerve fiber b) Caused only by Na+-K+ pump c) The cause of excitability of the nerve d) +70 Mv 74) Repolarization of nerve is caused by opening of voltage gated: a) Sodium channels b) Calcium channels c) Chloride channels d) Potassium channels 75) Concerning the voltage gated sodium channels: a- The activation gate for sodium are closed at rest b- The inactivation gate for sodium are closed at rest c- At the firing level, the conformational changes in the membrane open the inactivation channels d- None of the above 76) Action potential: a- Has magnitude dependent on the stimulus intensity b- Is accompanied by increasing nerve excitability c- Velocity is decreased with myelination d- Is caused by transient increase in Na permeability followed by a prolonged increase in K permeability 20 77) Na+ influx into a nerve fiber during stimulation: a) Decreases the membrane potential making RMP less negative b) Increases the membrane potentials making RMP more negative c) Increases at the firing level of about -70 mV d) Is responsible for repolarization of the nerve fiber 78) The action potential of a neuron: a) Is initiated by efflux of Na+ b) Is terminated by efflux of K+ c) Declines in amplitude as it moves along the axon d) Results in a transient reversal of the concentration gradient of Na across the cell membrane 79) The ascending limb of nerve action potential curve is: a) Represents repolarization b) Represents depolarization c) Due to slow 1C outflow d) Due to Ca+ inflow 80) The firing level of a stimulated large nerve fiber: a) Is reached when the membrane potential reaches -65 mV b) Is reached at the end of the spike potential c) At which the permeability to K+ increases d) None of the above 81) Action potential in a mixed nerve: a) Obeys all or non-law b) Can't be graded c) Can't be summated d) Has multiple peaks 82) Nerve excitability is increased by: a) Hypercalcemia b) Increased potassium permeability c) Cooling 21 d) Hypocalcaemia 83) Which of the following is correct for nerve fibers: a) C fibers are myelinated b) B fibers are faster than A fibers c) Postganglionic nerve fibers are of B type d) Deep pressure decreases conduction mainly in A type 84) Which of the following has the slowest conduction velocity? a) A alpha fibers b) Aβ fibers c) A gamma fibers d) C fibers 85) During depolarization: a- K+ ions diffuse outside b- The membrane becomes impermeable to Na+ c- When the membrane potential reaches -65mV, Na+ and K+ channels open at the same time d- Activated voltage gated Na+ channels open 86) Regarding the relative refractory period: a- During it the nerve excitability is increased b- A stimulus stronger than threshold is required to generate an action potential c- It occupies all the descending limb of action potential d- During it all voltage gated K+ channels are closed 87) Excitability of the nerve is: a- Increased if the membrane potential becomes more negative b- Increased by increased K+ efflux c- Increased during the relative refractory period d- Completely lost by local anesthetic drugs 88) To measure resting membrane potential: a- We use a special voltmeter or CRO. 22 b- We put the two electrodes outside the nerve fiber. ' c- We stimulate the nerve by an effective stimulus. d- We put the two electrodes inside the nerve fiber. 89) Repolarization: a- Occurs at first gradual then becomes fast. b- Results from closure of sodium and opening of potassium channels c- Is represented by the ascending limb of the spike. d- Is followed by appearance of response. 90) In saltatory conduction, the nerve impulse: a- jumps from one node to another node b- Jumps from one inter-node to another inter-node. c- Shows continuous conduction. d- Velocity is slower than that of the unmyelinated nerve fiber. 91) The excitability of the nerve is zero during: a- Relative refractory period b- Catelectrotonus c- Local response d- Absolute refractory period 92) During a nerve action potential, the opening of outer gates of Na+ channels is responsible for: a- The absolute refractory period b- The relative refractory period, c- Rapid Hyperpolarization d- Rapid depolarization 93) Which of the following will increase the velocity of action potential propagation? a- Myelination of the axon b- Decrease in axon diameter c- Absence of myelin sheath d- Short inter nodal distances. 23  Metabolism 1) The metabolic rate decreases in all the following, except: a- Prolonged fasting b- During sleep c- During pregnancy d- Old age 2) Regarding basal metabolic rate (BMR): a- BMR is defined as metabolic rate that occurs in any 24 hour period b- BMR is increased in people suffering from hypothyroidism c- BMR increases with age d- Adult males have a higher BMR than adult females 3) In the body, metabolism of 100 g of protein would produce approximately: 1. 1 kcal 2. 41 kcal 3. 410 kcal 4. 4100 kcal 4) Concerning the energy equivalent of oxygen, which of the following values is correct? a- For fats it is 4.1 Kcal/L b- For proteins it is 4.7 Kcal/L c- For carbohydrate it is 5 Kcal/L d- For a mixed diet it is 4.2 Kcal/L 5) The physical heat value of: a- Food is measured by indirect calorimetry b- Fats is equal to its physiological heat value c- Protein equals 4.1 Kcal/gm d- Carbohydrate equals 5.6 Kcal/gm 6) All about BMR is correct, except: a- It is expressed in Kcal/square meter/hour 24 b- Normally it is about 40 Kcal/hour/m2 in an average size adult male c- It represents the energy expenditure needed for activity of vital organs d- It is measured immediately after dinner 7) All about SDA of food is true, except: a- It is an increase in the metabolic rate after food intake b- SDA of proteins is about 30% & is due mainly to its metabolism in liver c- It is due to the work done during digestion and absorption of food d- It lasts up to 6 hours 8) The specific dynamic action: a- Results from absorption of the ingested food b- Reaches its maximum 3-4 hours after meal c- Is 10% of the BMR when the subject consumes proteins d- Is caused by increased secretion of gastrointestinal hormones 9) The metabolic rate increases after the following, except: a- Injection of adrenaline b- Food intake c- Decrease atmospheric temperature d- Decrease body temperature 10) About the basal metabolic rate: all are correct, except: a- In adult, under normal conditions is equal to 40 Kcal/hour/m2 b- It decreases in myxedema and shock c- It decreases in diabetes insipidus d- It increases with heart failure 11) The basal metabolic rate: a- Is usually measured 12-14 hours after the last meal b- Is maximal at old age c- Is equal in both males and females of the same age d- Is usually measured, at an atmospheric temperature below 10°C 12) The respiratory quotient (RQ): 25 a- Is the ratio of the volume of O2 consumed to that of CO2 produced b- Rises in the second week of starvation c- Is 0.7 when glucose is the metabolized substrate d- Is about 1 in the brain 13) The respiratory exchange ratio: a- For the brain is 1 b- Is the ratio between O2 consumed to the CO2 produced c- Equal 0.9 in starvation d- All of the above 14) RQ decreases in all the following, except: a-Transformation of fat into carbohydrate b- Carbohydrates are stored as lipids c- Diabetes mellitus and starvation d- Metabolic alkalosis 15) A man with a respiratory quotient (RQ) of 0.7: a- Has been eating a high-fat diet b- Has been eating a high-protein diet c- Has eaten nothing but carbohydrates for 24 hours d- Is dehydrated 16) Regarding Sweating and heat loss: a- Heat loss through sweating is controlled by parasympathetic system b- The efficacy of sweating is increased in humid atmosphere c- Profuse sweating can lead to heat stroke d- Sweat is a passive process 17) Heat loss: a- By radiation increases with rise of atmospheric temperature b- Is mainly by conduction c- By convection is helped by air currents d- By evaporation increased with humidity of the air 26 18) On exposure to cold: a- The muscle tone increases and shivering may occur b- There is excessive secretion of catecholamines c- The sympathetic is activated causing vasoconstriction & piloerection d- All of the above 19) Which of the following is correct? a- Increase in body temperature leads to increased cutaneous blood flow b- A decrease in body temperature leads to increased cutaneous blood flow c- During exercise renal blood flow increases d- During exercise TPR increases 20) On exposure to cold: a- The sympathetic nervous system is activated b- Shivering may occur c- Excessive secretion of thyroid hormones occurs d- All of the above 21) On exposure to a hot humid atmosphere: a- Sweat secretion is inhibited b- Vasodilatation occurs in the skin blood vessels c- Sweat evaporation increases d- Na+ is retained in the body 22) About the body temperature: a- In females decreases by 0.5°C in the second half of menstrual cycle b- Atropine decrease it c- Each 1 ml of sweat evaporated remove 0.6 k calorie d- Curare increases it 23) In heat stroke: a- There is shivering b- Tachycardia occurs c- Core body temperature is less than 30°C d- Intravascular fluid content increases 27 24) Obesity: a- Is usually caused by hyperphagia b- Is predisposes to gall bladder diseases c- In childhood is a severe type of obesity and difficult to treat d- All of the above 25) All about obesity is correct, except: a- It is associated with increased body mass index above 30 b- Is one cause of diabetes mellitus c- In parents is associated with obesity in their children d- Is usually due to endocrinal disorder, mainly hyperthyroidism 26) Feeding : a- Is inhibited if the satiety center is damaged b- Is promoted if the hunger center is damaged c- Is inhibited by leptin secreted by muscle cells d- Is inhibited by leptin secreted by adipocytes 27) The following factors leads to decrease food intake, except: a- Receptors in the mouth and esophagus which monitor food intake b- Receptors which are stimulated by distension of the stomach c- GIT hormones d- Cold receptors 28  Biophysics 1- The average hydrostatic pressure in the systemic capillaries is: a- 35 mmHg b- 18 mmHg c- 60 mmHg d- 28 mmHg 2- The oncotic pressure is exerted by: a- Blood electrolytes mainly Na b- Plasma proteins c- Plasma lipids d- Plasma bicarbonate 3- The capillary membrane is nearly impermeable to: a- Na+ b- K+ c- Proteins d- Lipids 4- The capillary membrane is freely permeable to: a- Ions b- Proteins c- Hormones d- RBCs 5- Obstruction of the lymphatic capillaries will decrease: a- The hydrostatic capillary pressure b- The interstitial fluid volume c- The oncotic pressure d- The absorption force at the capillary end 6-Normal value of lung compliance is about …… : a- 200 ml /cmH2O b- 2 L//cmH2O c- 0.02 L//cmH2O d- 20 ml//cmH2O 29 7- The resistance of the lungs to inflation is increase by: a- Increase the elastic forces of the lung tissues b- Decrease the surface tension of the fluid lining the alveoli c- Increase surfactant concentration d- Decrease collagen and elastic fibers 8- If the lungs experimentally filled completely with saline, so the surface tension of fluid lining alveoli is : a- Increased slightly with increase lung compliance b- Decreased slightly with decrease lung compliance c- Remains constant with no change in lung compliance d- Completely lost with increase in lung compliance 9- Which disease increase lung compliance: a- Emphysema b- Lung fibrosis c- Lung congestion d- Pulmonary edema 10- Which disorder decreases the chest compliance: a- Scoliosis b- Fracture ribs c- Paralysis of respiratory muscles d- All are true 11- Which disorder represents curve A: a- Lung fibrosis b- Pulmonary edema c- Fracture ribs d- Emphysema 30  A Normal B 12- The recoil tendency of the lungs : a- Results from tendency of the lungs to expands b- It is due to surface tension of the fluid lining the alveoli c- It increases in lung emphysema d- It decreases in lung fibrosis 13- Concerning compliance of large arterial blood vessels, one is true: a- The initial linear relationship between volume and pressure is due to stretching of the elastic fibers in the wall of the artery b- The steeper part of the pressure-volume curve is due to stretching of the elastic fibers in the wall of the artery c- The compliance is increased by more stretching of the elastic fibers in arterial wall d- The compliance becomes higher by stretching the collagen fibers 14- Compliance of large veins is more that of arteries by: a- 100 times b- 60 times c- 40 times d- 20 times 31 15- The pressure-volume curve of veins has the following criteria: a- Large increase in volume is associated with very little change in pressure b- Veins can accommodate large volume of blood with large change in pressure c- At excessive volume, the ΔV / ΔP is very high due to the poor elasticity of the wall of veins d- The diameter of blood vessels remains constant as the internal pressure increases 16- Which one can increases the compliance of blood vessels a- Activation of sympathetic nervous input. b- Estrogen hormone c- Aging d- Atherosclerosis 17- The distensibility of the veins is more than the of arteries by : a- 10 times b- 20 times c- 30 times d- 40 times 18- Concerning the stress relaxation of the blood vessel, one is correct: a- It is the reciprocal of delayed compliance b- It occurs slightly in the veins but to a much greater extent in the arteries c- It allows vascular system to accommodate much extra blood transfusion d- It allows the circulation automatically adjusts itself immediately to diminished volume after serious hemorrhage 19- The plasticity of the urinary bladder is explained by: a- Laplace law b- Starling law c- Poiseuille law d- Reynold number 20- Concerning compliance of the stomach, one is true: a- Normally the body of the stomach accommodating greater quantities of food up to 10L b- The smooth muscle in stomach wall exhibits a quality of plasticity 32 c- The radius of stomach curvature is indirectly proportion to the stretching force on the walls d- The vagal reflex stimulates muscle activity in the body of the stomach 21- Which statement is true about ventricular preload: a- Preload represents the load- velocity relationship b- It is represented by aortic pressure c- It means the blood remains in the ventricle at the end of systole d- It represents the length-tension relationship 22- Which of the following is not example of ventricular afterload: a- End systolic volume b- End diastolic volume c- Aortic pressure d- Vascular resistance 23- One statement is true about Starling law in cardiac muscle: a- The degree of contraction is inversely proportionate to the degree of stretching b- The more the ventricular filling, the less blood pumped from the ventricle c- It describes the load-velocity relationship d- the degree of contraction is proportion to degree of ventricular filling 24- The following curves represent the relation between end diastolic volume and the force of contraction. The middle curve is the normal contraction. Which one of the following factors shifts the normal curve down and to the right? a- Hypocalcemia b- Xanthines c- Digitalis d- Exercise 33 25- Regarding the force-velocity relationships of cardiac muscle, one is not true: a- Increase the afterload resulted in a reduced velocity of contraction b- During the isometric contraction, the shortening velocity is zero c- In skeletal muscle, Vmax is constant d- In cardiac muscle, Vmax is constant 26- The following curve represents the force-velocity relationship in skeletal muscle, which of the following is true about point 3 on the curve: a- The velocity of contraction is the maximum b- The shortening of contraction is maximum c- The contraction is isotonic d- The contraction is isometric 27- One of the following doesn’t affect the Vmax of force –velocity curve of the heart: a- End diastolic volume b- Sympathetic stimulation c- Exercise d- Tachycardia 28- Concerning laminar blood flow, one is incorrect: a- Blood flow occurs in layers b- Blood flow is silent 34 c- Re below 400 d- Re above 2000 29- Turbulent blood flow has the following criteria: a- It is silent flow b- Occurs when diameters of blood vessels become wider c- Occurs when viscosity of the blood is decreased d- Occurs normally at all blood vessels 30- Murmur appears in the following condition: a- Mild anemia b- Stenosis of cardiac valves c- During sleep d- Decrease cardiac output 31- The Poiseuille law is concerned with which of the following factors: a- The vascular resistance b- The end diastolic volume c- The preload and after load d- The plasticity of smooth muscle 32- The main site of resistance in the systemic circulation is: a- Aorta b- The big arteries c- The arterioles d- The capillaries 35  INTRODUCION Key Answers of MCQ No Answer 1 A 2 D 3 A 4 A 5 B 6 B 7 C 8 D 9 B 10 B 11 D 12 C 13 C 14 D 15 D 16 B 17 B 18 A 19 D 20 D 21 B 22 A 23 B 36  Nerve Key Answers of MCQ No. Answer No. Answer No. Answer No. Answer 1 D 27 D 57 D 87 D 2 B 28 C 58 A 88 A 3 B 29 C 59 D 89 B 4 C 30 B 60 D 90 A 5 D 31 A 61 D 91 D 6 C 32 D 62 C 92 D 7 D 33 A 63 D 93 A 8 A 34 D 64 A 9 D 35 D 65 D 10 C 36 D 66 C 11 B 37 D 67 D 12 D 38 A 68 C 13 D 39 D 69 B 14 D 40 D 70 C 15 A 41 D 71 D 16 B 42 D 72 B 17 D 43 B 73 A 18 B 44 D 74 D 15 D 45 D 75 A 16 B 46 B 76 D 17 D 47 D 77 A 18 A 48 B 78 B 19 D 49 C 79 B 20 B 50 A 80 A 37 21 B 51 C 81 A 22 D 52 D 82 D 23 D 53 A 83 D 24 A 54 D 84 D 25 C 55 B 85 D 26 D 56 C 86 B Metabolism Key Answers of MCQ No Answer No Answer 1 C 20 D 2 D 21 A 3 C 22 C 4 C 23 B 5 B 24 D 6 D 25 D 7 C 26 D 8 B 27 D 9 D 10 C 11 A 12 D 13 A 14 C 15 A 16 C 17 C 18 D 19 A 38  Biophysics Key Answers of MCQ No. Answer No. Answer 1 A 25 D 2 B 26 D 3 C 27 A 4 A 28 D 5 D 29 C 6 A 30 B 7 A 31 A 8 D 32 C 9 A 10 D 11 D 12 B 13 A 14 D 15 A 16 B 17 A 18 C 19 A 20 B 21 D 22 B 23 D 24 A 39