Final Exam Physiology 1 PDF

Final exam physiology 1 1- What is the name of membrane depolarization which evoked in response of adequate stimulus of most sensory receptors? a- Local response; b- Action potential; c- Receptor potential; d- Junctional potential: e- En...

Final exam physiology 1 1- What is the name of membrane depolarization which evoked in response of adequate stimulus of most sensory receptors? a- Local response; b- Action potential; c- Receptor potential; d- Junctional potential: e- End-plate potential: 2- Which of the following statement concerning the generation of an action potential is correct? a- When the membrane potential in the soma-axon hillock dips below the "threshold", an action potential is initiated; b- The action potential is initiated in synaptic boutons: c- The fewest voltage-gated sodium channels in an axon are found near the node of Ranvier. d- Once an action potential is initiated, it always runs its course to completion: e- The action potential is propagated along dendrites until it reaches the cell body: 3- Which of the following anterior pituitary hormones plays a major role in the regulation of a nonendocrine target cells? a- Adrenocorticotropic hormone. b- Thyroid-stimulating hormone. c- Prolactin. d- Follicle-stimulating hormone. e- Luteinizing hormone. 4- Which of the following has the greatest effect of Na+ excretion? a- Progesterone: b- Cortisol: C- Vasopressin: d- Aldosterone; 5- What kind of fluid contain T tubules? a- Intracellular fluid; b- Extracellular fluid; c- Paracellular fluid; d- Special fluid of sarcoplasmic reticulum: 6- Neurotransmitter is stored and released from a- Axon terminals b- Dendritic spines c- Cell bodies d- Axon initial segment 7- The contractile response of skeletal muscle is triggered by a rise in intracellular Ca++, which occurs as follows: a- Action potential depolarizes the T tubules which causes Ca++ release from sarcoplasmic reticulum: b- Action potential triggers Ca++-influx which causes Ca++ release from sarcoplasmic reticulum; c- Almost all the Ca++ that cause contraction enter the cell from the extracellular fluid at the time of the action potential or other stimulus; d- Several stimuli close Na+ and Ca++ channels and inhibit muscle contraction; 8- A single action potential of motor nerve: a- Cannot elicit a contractile response in skeletal muscle; b- Gives rise to a skeletal muscle twitch; c- Is able to produce an incomplete tetanus; d- Is able to produce a fused tetanus; e- Give rise to a steady contracture; 9- The dorsolateral hypothalamus, in combination with the preoptic area, is involved in the control of which of the following functions? a- Cardiovascular functions involving blood pressure and heart rate; b- Regulation of thirst and water intake; c- Stimulation of uterine contractility and milk ejection from the breast; d- Signaling that food intake is sufficient (satiety); e- Secretion of hormones from the anterior lobe of the pituitary gland; 10- Which of the following statements concerning synaptic transmission is correct? a- When a specific population of synaptic terminals is spread over the considerable surface of a neuron, their collective effects cannot spatially summate and lead to initiation of an action potential; b- Even if the successive discharges of an excitatory synapse occur sufficiently close in time, they cannot temporally summate and initiate an action potential: c- A neuron is "facilitated" when its membrane potential is moved in the hyperpolarizing direction: d- Even when rapidly stimulated by excitatory synaptic input for a prolonged period, neurons typically do not exhibit synaptic fatigue: e- Dendrites cannot propagate action potentials, but they can transmit electrical potentials by electrotonic conduction 11- Which of the following statement concerning the blockade of the synaptic transmission by competitive antagonists is correct? a- Competitive antagonists block Ca++ entry in presynaptic terminals; b- Competitive antagonists breakdown the released neurotransmitter: c- Competitive antagonists inhibit the synthesis and axoplasmic transport of neurotransmitter: d- Competitive antagonists occupied the membrane receptor and thus prevent the transmitter receptor interaction: e- Competitive antagonists inactivate ionic channels on the postsynaptic membrane; 12- The resting membrane potential of a cell: a- is dependent on the permeability of the cell membrane to K+ being greater than the permeability to Na+: b- is usually equal to the equilibrium potential for K+ c- falls to zero immediately when Na+ - K+ ATP-ase in the membrane is inhibited. d- is usually equal to the equilibrium potential for Na+ e- is markedly altered if the extracellular Na+ concentration is increased. 13- Which of the following is characteristic of the events occurring at an inhibitory synapse? a- There is a massive efflux of calcium from the presynaptic terminal: b- Synaptic vesicles bind to the presynaptic membrane: c- Voltage-gated potassium channels are closed: d- Ligand-gated channels are opened to allow chloride to enter the postsynaptic neuron: e- Electrical changes occurring at the postsynaptic membrane have no effect on other parts of the postsynaptic neuron; 14- Quantitatively, the major anion in the ECF compartment is: a- Bicarbonate; b- Chloride; c- Phosphate: d- Protein: e- Sulfate: 15- Tetanic contraction of a skeletal muscle fiber results from a cumulative increase in the intracellular concentration of which of the following? a- Sodium: b- Potassium: c- Troponin: d- ATP: e- Calcium; 16- The resting potential of a myelinated nerve fiber is primarily dependent on the concentration gradient of which ion? a- K+ b- Na+ c- Ca++ d- Cl- e- HCO3- 17- Match the Ouabain-sensitive transport of Na+ ions from the cytosol to the extracellular fluid with the correct type of transport listed below: a- Simple diffusion: b- Facilitated diffusion; c- Primary active transport; d- Co-transport; e- Counter-transport 18- A cross-sectional view of a skeletal muscle fiber through the H zone would reveal the presence of what? a- Actin, but not myosin; b- Actin and myosin; c- Myosin, but not actin; d- Actin and titin; 19- What is meant by the internal environment of the body? a- Intracellular fluid; b- Extracellular fluid; C- Paracellular Fluid; d- Body water; 20- The excitatory or inhibitory action of a neurotransmitter is determined by which of the following? a- Function of its postsynaptic receptor; b- Its molecular composition; c- Shape of the synaptic vesicle in which it is contained; d- Distance between the pre- and postsynaptic membranes; e- Influx of chloride ions into the synaptic terminal; 21- A pure phospholipids bilayer is most permeable to which of the following? a- Sodium: b- Calcium: c- Chloride; d- Water; e- Oxygen: 22- The delayed onset and prolonged duration of smooth muscle contraction, as well as the greater force generated by smooth muscle compared with skeletal muscle, are all consequences of which of the following? a- Higher energy requirement of smooth muscle; b- Slower cycling rate of the smooth muscle myosin cross-bridges: c- Slower uptake of Ca++ ions following contractions: d- Physical arrangement of actin and myosin filaments: e- Greater amount of myosin filaments present in smooth muscle: 23- Where does fertilization normally take place? a- Uterus: b- Cervix: c- Ovary; d- Ampulla of the fallopian tube; 24- In what way does single end-plate potential of neuromuscular junction differ from a single excitatory post-synaptic potential of neuron? a- The single end-plate potential propagates with decrement; b- The single end-plate potential is graded in intensity: c- The single end-plate potential trigger the action potential in the skeletal muscle membrane; d- The single end-plate potential greatly outlasts the action potential that is initiated it; e- The single end-plate potential is not accompanied by refractory period; 25- Which of the following metabolic substrates is preferentially metabolized by growth hormone? a- Fats; b- Proteins: c- Glycogen: d- Glucose 26- The spread of current along an axon from an active region to an inactive region mainly depends on the following factors except one. Which factor is not correct? a- The internal electrical resistance of the axon; b- The electrical resistance of the axon membrane; c- The electrical capacitance of the axon membrane; d- The internal electrical capacitance of the axon: 27- Which of following propagates without decrement? a- Postsynaptic potentials; b- End-plate potentials; c- Junctional potentials: d- Action potentials; e- Receptor potentials; 28- Which of the following is primarily responsible for the repolarization during an action potential? a- Movement of Na+ into the cell; b- Movement of Na+ out of the cell: c- Movement of K+ into the cell; d- Movement of K+ out of the cell: e- Inhibition of the Na+, K+-ATPase; 29- What is the name of pharmacological substance which occupies membrane receptor on the postsynaptic cell and prevent neurotransmitter-receptor interaction? a- Noncompetitive antagonist: b- Competitive antagonist; c- Noncompetitive agonist; d- Competitive agonist: e- Protagonist; 30- Which of the following statements about smooth muscle contraction is most accurate? a- It requires more energy than skeletal muscle contraction; b- It can occur without the generation of an action potential: c- It is increased under conditions the stimulate adenylate cyclase; d- It is shorter in duration than skeletal muscle contraction: e- It is Ca++ independent 31- Which of the following statements about peptide or protein hormones is usually true? a- They have longer half-lives than steroid hormones; b- They have receptors on the cell membrane; c- They have a slower onset of action than both steroid and thyroid hormones; d- They are not stored in endocrine-producing glands; 32- Quantitatively, the major cation in the ECF compartment is: a- Potassium: b- Sodium: c- Calcium: d- Protein; e- Magnium: 33- The synaptic transmission of excitation involves all of the following character features except one. Which one is not involved? a- One way propagation; b- Delay of transmission: c- Rhythm transformation; d- Release of neurotransmitter is not depended upon the presynaptic excitation; e- Fatiguable transmission; 34- What is the name of synapse when the activity of presynaptic neuron leads to an increase of the activity of the postsynaptic cell? a- Axo-somatic synapse: b- Axo-dendritic synapse; c- Axo-axonal synapse: d- Excitatory synapse; 35- Which of the following statements about antidiuretic hormone is true? a- It is synthesized in the posterior pituitary gland: b- It increases salt and water reabsorption in the collecting tubules and ducts: c- It stimulates thirst: d- It has opposite effects on urine and plasma osmolality; 36- Which substance activates alpha- and beta-adrenergic receptors equally well? a- Acetylcholine; b- Norepinephrine: c- Epinephrine; d- Serotonin: e- Dopamine: 37- Skeletal muscle is made up which of following? a- Individual fibers containing sarcomeric myofibrils: b- Linked together cells containing sarcomeric myofibrils; c- Linked together spindle-shaped cells containing actin and myosin: d- Myoepithelial cells; 38- Which of the following has the fastest conduction velocity? a- A-alpha fibers: b- A-beta fibers: c- A-gamma fibers; d- B fibers; 39- The contractile response of smooth muscle is triggered by a rise in intracellular Ca++, which occurs as follows: a- Action potential depolarizes the T tubules which causes Ca++ release from sarcoplasmic reticulum: b- Action potential triggers Ca++-influx which causes Ca++ release from sarcoplasmic reticulum: c- Almost all the Ca++ that cause contraction enter the cell from the extracellular fluid at the time of the action potential or other stimulus; d- Several stimuli close Na+ and Ca++ channels and inhibit muscle contraction; 40- End-plate potentials can be prolonged by: a- Drugs that inhibit acetylcholine: b- Drugs that inhibit acetylcholinesterase; c- Muscarinic antagonists: d- Nicotinic antagonists; e- Drugs that inhibit norepinephrine; 41- The function of which of the following is increased by an elevated parathyroid hormone concentration? a- Osteoclasts; b- Hepatic formation of 25-hydroxycholecalciferol; c- Phosphate reabsorptive pathways in the renal tubules; d- All of the above; 42- In response to an action potential the nerve terminal secretes a neurotransmitter into the synaptic cleft by which of following process? a- Na-dependent exocytosis of synaptic vesicles; b- Ca-dependent exocytosis of synaptic vesicles; c- Cl-dependent exocytosis of synaptic vesicles; d- K-dependent exocytosis of synaptic vesicles: e- Mg-dependent exocytosis of synaptic vesicles; 43- In myelinated nerve fiber the action potentials are conducted from node to node. This is called: a- Antidromic conduction; b- Orthodromic conduction: c- Saltatory conduction: d- Continuous conduction; e- One way propagation: 44- The sodium pump is primarily responsible for maintaining the transmembrane concentration difference of which ions? a- Sodium and potassium; b- Sodium and Calcium; c- Sodium and Chloride; d- Sodium and Magnium; 45- Some organs only have a sympathetic supply. Which of following has both supply? a- Adrenal medulla; b- Pilomotor muscles of the skin hairs; c- Sweet glands: d- Salivary glands; e- Most blood vessels; 46- Which of the following is not essential for normal biosynthesis of thyroid hormones? a- Iodine: b- Ferritin; c- Thyroglobulin; d- Protein synthesis; e- TSH 47- Cells of the adrenal medulla receive synaptic input from which of the following types of neurons? a- Preganglionic sympathetic neurons; b- Postganglionic sympathetic neurons: c- Preganglionic parasympathetic neurons: d- Postganglionic parasympathetic neurons; e- Presynaptic parasympathetic neurons; 48- Release of which of the following hormones is an example of neuroendocrine secretion? a- Growth hormone: b- Cortisol: c- Oxytocin: d- Prolactin: e- Adrenocorticotropin hormone; 49- The principal intracellular cation is: a- Sodium; b- Calcium: C- Potassium: d- Magnium: 50- Skeletal muscle contraction is terminated by which action? a- Removal of acetylcholine from the neuromuscular junction: b- Removal of Ca++ from the terminal of the motor neuron: c- Closure of the postsynaptic nicotinic acetylcholine receptor; d- Removal of sarcoplasmic Ca++: e- Return of the dihydropyridine receptor to its resting conformation: 51- In a normal, healthy muscle, what occurs as a result of propagation of an action potential to the axon terminal membrane of a motor neuron? a- Opening of voltage-gated Ca++ channels in the presynaptic membrane: b- Depolarization of the T tubule membrane follows: c- Always results in muscle contraction: d- Increase in intracellular Ca++ concentration in the motor neuron terminal; e- All of the above are correct; 52- Which of the following increases the rate of excretion of calcium ions by the kidney? a- Decrease in calcitonin concentration in the plasma: b- Increase in phosphate ion concentration in the plasma; c- Decrease in the plasma level of parathyroid hormone; d- Metabolic alkalosis; 53- The force developed by a skeletal muscle depends on the following factors except one. Which one does not depend? a- Number of active motor units: b- Stimulation by catecholamines: c- Skeletal muscle's cross-sectioned area; d- The frequency of stimulation 54- Which of the following decreases in length during the contraction of a skeletal muscle fiber? a- Thin filaments: b- Thick filaments; c- Z discs of the sarcomere; d- A band of the sarcomere; e- I band of the sarcomere; 55- Smooth muscle that exhibits rhythmical contraction in the absence of external stimuli also necessarily exhibits which of the following? a- "Slow" voltage-sensitive Ca++ channels; b- Intrinsic pacemaker wave activity; c- Higher resting cytosolic Ca++ concentration; d- Hyperpolarized membrane potential; e- Action potentials with "plateaus": 56- The function of which of the following is dominated by the sympathetic nervous system? a- Systemic blood vessels; b- Heart; c- Gastrointestinal gland secretion: d- Salivary glands: e- Gastrointestinal motility; 57- Why do children who are not exposed to ultraviolet light develop rickets? a- They cannot absorb calcium from the gastrointestinal tract; b- They cannot synthesize parathyroid hormone; c- The metabolism of all the cell in bone is suppressed; d- They can form adequate amounts of 25-hydroxycholecalciferol but are unable to convert it to the active form, 1.25-dihydroxycholecalciferol: 58- Refractory period is a characteristic feature for: a- Postsynaptic potentials; b- End-plate potentials: c- Junctional potentials; d- Action potentials: e- Receptor potentials: 59- The concept of "autonomic tone" is quite advantageous because it allows the nervous system to have fine control over the function of an organ or organ system. This is exemplified in the control of systemic arterioles. Which of the following actions would lead to vasodilatation of systemic arterioles? a-Increased activity of preganglionic parasympathetic neurons; b- Decreased activity of postganglionic parasympathetic neurons; c- Increased activity of postganglionic sympathetic neurons; d- Decreased activity of postganglionic sympathetic neurons; e- Increased activity of preganglionic sympathetic neurons; 60- The process by which an environmental stimulus becomes encoded as a sequence of nerve impulses in an afferent nerve fiber is called sensory: a- Adaptation; b- Accommodation; c- Transduction; d- Propagation: 61- Which of the following has the slowest conduction velocity? a- A-alpha fibers; b- A-beta fibers: c- A-gamma fibers; d- B fibers; e- C fibers; 62- The force produced by a single skeletal muscle fiber can be increased by what means? a- Increasing the frequency of stimulation of the fiber: b- Increasing the amplitude of the depolarizing stimulus; c- Decreasing extracellular K+ concentration; d- Increasing the permeability of the sarcolemma to K+; e- Increasing the number of voltage-gated Na+ channels in the sarcolemma; 63- The excitatory or inhibitory effect of a postganglionic sympathetic fiber is determined by which of the following features or structures? a- The function of the postsynaptic receptor to which it binds: b- The specific organ innervated; C- The ganglion where the postganglionic fiber originates: d- The ganglion containing the preganglionic fiber; e- The emotional state of the individual; 64- What is meant by motor unit? a- Muscle fibers in fasciculus: b- All fibers in muscle: c- Individual muscle fiber; d- Muscle fibers innervated by a single nerve fiber; e- Muscle fibers innervated by a appropriate pool of motoneurons; 65- In order for milk to flow from the nipple of the mother into the mouth of the nursing infant, which of the following must occur? a- Myoepithelial cells must relax; b- Prolactin levels must fall; c- Oxytocin secretion from the posterior pituitary must take place; d- The baby's mouth must develop a strong negative pressure over the nipple: e- All of the above; 66- The release of a neurotransmitter at a chemical synapse is dependent on which of the following? a- Synthesis of acetylcholinesterase: b- Hyperpolarization of the synaptic terminal; c- Fusion of synaptic vesicles with the postsynaptic membrane; d- Opening of ligand-gated calcium ion channels: e- Influx of calcium into the synaptic terminal: 67- Which endocrine gland is under direct nervous control? a- Thyroid: b- Parathyroid: c- Adrenal cortex: d- Adrenal medulla; 68- Nerve cells propagate signals along their axons by means of: a- Electrotonic potentials; b- Local response; c- Action potentials: d- Postsynaptic potentials; e- Receptor potentials: 69- Which of the following findings is most likely in a patient who has myxedema? a- Somnolence; b- Palpitations: c- Increased respiratory rate: d- Increased cardiac output: e- Weight loss: 70- Which of the following statements concerning milk production by the breast is true? a- It is stimulated by prolactin: b- It takes place in myoepithelial cells; с- It begins during the last month of pregnancy: d- It is not responsive to changes in demand for milk from the breast; 71- The anticholinesteratic drug: a- Inhibit acetylcholine synthesis; b- Block acetylcholine axoplasmic transport c- Inhibit acetylcholinesterase; d- Breakdown released acetylcholine; e- Block the action of acetylcholine on cholinergic receptor; 72- Which of the following is primarily responsible for the depolarization during an action potential? a- Movement of Na+ into the cell; b- Movement of Na+ out of the cell; c- Movement of K+ into the cell; d- Movement of K+ out of the cell: e- Inhibition of the Na+, K+-ATPase: 73- A new action potential cannot be elicited in an excitable fiber as long as the membrane is still depolarized from the preceding action potential. This unexcitability is called: a- Safety factor, b- All or none principle; c- Refractoriness: d- Accommodation: e- Adaptation; 74- Excitation-contraction coupling in skeletal muscle involves all of the following events except one. Which one is not involved? a- Increase in the permeability of the muscle fiber to Na+; b- Binding of Ca++ to calmodulin: c- Conformational change in the dihydropyridine receptor; d- Depolarization of the transverse tubule (T tubule) membrane: e- ATP hydrolysis; 75- Excitation-contraction coupling in smooth muscle involves all of the following events except one. Which one is not involved? a- Increase in the permeability of the muscle fiber to Na+: b- Binding of Ca++ to calmodulin: c- Depolarization of the transverse tubule (T tubule) membrane; d- ATP hydrolysis; 76- Which of the following hormones exerts the least effect on growth? a- Growth hormone; b- Testosterone; c-T4: d- Insulin: e- Vasopressin: 77- Which of the following is most likely to produce the greatest increase in insulin secretion? a- Amino acids; b- Amino acids and glucose; c- Amino acids and somatostatin; d- Glucose and somatostatin: 78- Sympathetic division of autonomic nervous system acts as follows: a- Prepare the body for activity ("flight or fight"); b- Promote restorative function of body ("rest and digest"); c- Plays an important part in the regulation of the motility and secretory activity of the digestive system: d- Plays an important part in the trophic function of skeletal muscles: 79- Which of the following is a characteristic feature for the action potential of skeletal muscle? a- Has a prolonged plateau phase: b- Spreads inward to all parts of the muscle via the T tubules: c- Causes the immediate uptake of Ca++ into the lateral sacs of the sarcoplasmic reticulum: d- Is longer than the action potential of cardiac muscle; e- Is not essential for contraction: 80- What is the type of inhibition which occurs at the synaptic terminals before the signal ever reaches the synapse is called: a- Presynaptic inhibition; b- Postsynaptic inhibition: c- Reccurrent inhibition; 1) increasing the frequency of stimulation causes the force of skeletal muscle contraction to be increased due to an increase in which of following? a- Intracellular Ca++ concentration; b- Number of cross-bridges binding to actin; c- Duration of the active state; d- Activity of myosin ATPase; e- Number of muscle fibers contracting; 2) Cells respond to chemical signals by initiating an appropriate physiological response. This process is called: a- Conduction; b- Transduction; c- Transmission; d- Inhibition; e- Transformation; 3) Troponin-tropomyosin complex is activated by which of following ions? a- Sodium; b- Potassium; C- Calcium; d- Chloride; 4) Which of the following hormones is largely unbound to plasma proteins? a- Cortisol; b- Thyroxine: c- Antodiuretic hormone; d- Estradiol; e- Progesterone; 5) Which of the following is a consequence of myelination in large nerve fibers? a- Increase in the nonselective diffusion of ions across the axon membrane; b- Decrease in the velocity of nerve impulses along the axon; c- Increase in the energy required to maintain ion gradients across the membrane; d- Generation of action potentials only at the nodes of Ranvier; e- Increase in the membrane capacitance of the axon; 6) some cells secrete chemicals into the extracellular fluid that act on cells in the same tissue. Which of the following refers to this type of regulation? a- Neural; b- Endocrine; c- Neuroendocrine; d- Paracrine; e- Autocrine; 7) Type of cellular contact which operates by transmitting the electric current generated by the actio n potential to the neighbor cell via gap-junctions is called: a- Chemical synapse; b- Electric synapse; c- Tight-junction; d- Neuromuscular junction; e- Syncytium; 8) The cross-bridges of the sarcomere in skeletal muscle are made up of: a- Actin; b- Myosin; c- Troponin; d- Tropomyosin; e- Myelin; 9) In what way does visceral smooth muscle differ from skeletal muscle? a- Visceral smooth muscle can contract in response to stretch; b- Visceral smooth muscle does not contain actin filaments; c- Visceral smooth muscle is capable of generating only about half the maximal force of contraction: d- Contraction of visceral smooth muscle is ATP dependent; e- The rate of cross-bridge cycling in visceral smooth muscle is approximately 100 times faster than in skeletal muscle 10) Match the movement of Na+ ions into a nerve cell during the upstroke of an action potential with th e correct type of transport listed below: a- Simple diffusion; b- Facilitated diffusion: c- Primary active transport; d- Co-transport; e- Counter-transport; 11) What is the name of synapse when the activity of presynaptic neuron leads to a decrease of the activity of the postsynaptic cell? a- Axo-somatic synapse: b- Axo-dendritic synapse; c- Axo-axonal synapse: d- Excitatory synapse; e- inhibitory synapse; 12) A stimulus that is below the threshold will not elicit an action potential while a stimulus that is above the threshold will do so, and each action potential has approximately the same magnitude and duratio n irrespective of the strength of the stimulus. This is known as: a- Safety factor; b- All or none principle; c- Refractoriness; d- Accomodation; e- Transmission; 13) Which of following submitted the all-or-none principle? a- Postsynaptic potentials; b- End-plate potentials; C- Junctional potentials; d- Action potentials; 14) Which of the following stimulates the secretion of parathyroid hormone (PTH)? a- Decrease in extracellular calcium ion activity below the normal value; b- Calcitonin; c- Respiratory acidosis; d- PTH-releasing hormone from the hypothalamus; 15) Both active transport and facilitated diffusion have which characteristic? a- Display saturation kinetics; b- Require some type carrier mechanism for transport; c- Can work in the absence of adenosine triphosphate (ATP); d- Can transport materials against a concentration gradient;