Description : At resting stage permeability of `K^(+)` ion is more comparatively `Na^(+)` ion through axonal membrane
Last Answer : At resting stage permeability of `K^(+)` ion is more comparatively `Na^(+)` ion through axonal membrane
Description : When a neuron is in resting state i.e., not conducting any impulse, the axonal membrane is (a) comparatively more permeable to Na+ ions and nearly impermeable to K+ ions (b) equally permeable to both ... + and K+ ions (d) comparatively more permeable to K+ ions and nearly impermeable to Na+ ions.
Last Answer : (d) comparatively more permeable to K+ ions and nearly impermeable to Na+ ions.
Description : 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. falls to zero immediately when Na+ ... the equilibrium potential for Na+ e. is markedly altered if the extracellular Na+ concentration is increased
Last Answer : is dependent on the permeability of the cell membrane to K+ being greater than the permeability to Na+
Description : Consider the following statements: 1. When a nerve fibre is stimulated, a profound change is produced in the electrical properties of surface membrane and in steady potential. 2. Upon excitation, the resting potentialis suddenly changed. 3. It is due ... 1, 2, 3 (b) 2, 3 (c) 1, 2, 3, 4 (d) 1, 2, 4
Last Answer : Ans:(d)
Description : Consider the following statements: 1. In a resting neuron, there is difference in electrical charge on either side of surface membrane called potential difference. 2. It is due to unequal distribution of K+ ions and Na+ ions on either side if the ... ? (a) 1 only (b) 1, 2 (c) 1, 2, 3 (d) 1, 2, 3, 4
Last Answer : Ans:(b)
Description : The plasma membrane in resting condition is almost impermeable to a. K+ b. Na+ c. Cl d. HCo3
Last Answer : Na+
Description : In the resting state of the neural membrane, diffusion due to concentration gradients, if allowed, would drive (a) K+ into the cell (b) K+ and Na+ out of the cell (c) Na+ into the cell (d) Na+ out of the cell.
Last Answer : c) Na+ into the cell
Description : Which ion moves freely through the plasma membrane a. Na b. Cl c. k d. HCo3
Last Answer : Cl
Description : Binding of acetylcholine to its receptors increases the permeability of cell membrane to (A) Ca++ (B) Na+ (C) K+ (D) Na+ and K+
Last Answer : Answer : D
Description : Binding of gamma-aminobutyric acid to its receptors in brain increases the permeability of cell membrane to (A) Cl– (B) Na+ (C) K+ (D) Ca++
Last Answer : Answer : A
Description : There are two properties of the cell necessary to maintain nonequilibrium cellular composition; the first is selectivity and the second is energy conversion. Which of the following statement(s ... transported via secondary active transport include hydrogen ions, calcium, amino acids and glucose
Last Answer : Answer: c, d The selectivity of the plasma membrane, although impressive, cannot account for the nonequilibrium composition of living cells. A cell can be maintained in a nonequilibrium state only by ... to drive the transport of a second species such as protons, calcium, amino acids, or glucose
Description : Which ion is actively transported to the outside of cell membrane a. K b. Cl c. Na d. HCo3
Last Answer : Na
Description : The following is not true of local anaesthetics: A. The local anaesthetic is required in the unionized form for penetrating the neuronal membrane B. The local anaesthetic approaches its receptor ... the resting state D. The local anaesthetic combines with its receptor in the ionized cationic form
Last Answer : C. The local anaesthetic binds to its receptor mainly when the Na+ channel is in the resting state
Description : Actions of 5-HT2 receptor activation are primarily mediated by: A. Increased membrane permeability to Na+ ions B. Increased formation of cAMP C. Activation of guanylyl cyclase D. Generation of inositol trisphosphate and diacyl glycerols
Last Answer : D. Generation of inositol trisphosphate and diacyl glycerols
Description : Plasma membrane in resting condition is very permeable to a. K b. Cl c. Both d. None of them
Description : e primary mechanism by which general anaesthetics produce their action is: A. Affecting receptor operated ion channels in cerebral neurones B. Blocking voltage sensitive Na+ channels in neuronal ... activity of cerebral neurones D. Blocking production of high energy phosphates in the brain
Last Answer : A. Affecting receptor operated ion channels in cerebral neurones
Description : When a stimulus is applied on axonal membrane then generation of action potential is due to
Last Answer : When a stimulus is applied on axonal membrane then generation of action potential is due to
Description : Tyramine induces release of noradrenaline from adrenergic nerve endings (a) By depolarizing the axonal membrane (b) By mobilizing Ca2+ (c) By a nonexocytotic process (d) Only in the presence of MAO inhibitors
Last Answer : Ans: C
Description : Tyramine induces release of noradrenaline from adrenergic nerve endings: A. By depolarizing the axonal membrane B. By mobilizing Ca2+ C. By a nonexocytotic process D. Only in the presence of MAO inhibitors
Last Answer : C. By a nonexocytotic process
Description : Which ion is found in greater concentration inside the cell a. K b. Na c. Cl d. HCO3
Last Answer : K
Description : Which ion is found in greater concentration outside the cell a. K b. Na c. Cl d. HCO3
Description : Which is the must abundant major ion found in the cells. a. K+ b. HPO4 c. Mg d. Na
Last Answer : K+
Description : The 'new formula' WHO-ORS differs from the older 'standard formula' WHO-ORS in the following respect(s): A. It has lower Na+ ion and glucose concentration B. It has higher K+ ion concentration C. It has no basic salt D. Both 'B' and 'C' are correct
Last Answer : A. It has lower Na+ ion and glucose concentration
Description : Amiloride has the following effect on urinary cation excretion: A. Decreases both K+ and H+ ion excretion B. Decreases K+ excretion but increases H+ ion excretion C. Increases K+ but decreases Na+ excretion D. Decreases both Na+ and K+ excretion
Last Answer : A. Decreases both K+ and H+ ion excretion
Description : hat is/are the consequence(s) of myocardial Na+ K+ ATPase inhibition by digoxin: A. Increased intracellular Na+ ion concentration B. Increased cytosolic Ca2+ ion concentration C. Increased intracellular K+ ion concentration D. Both ‘A’ and ‘B’ are correct
Last Answer : D. Both ‘A’ and ‘B’ are correct
Description : Comparatively longer hair like out- growths of the plasma membrane is?
Last Answer : Flagella
Description : Consider the following statements: 1. Even when a nerve cell is not conducting an impulse, it is actively transporting K+ and Na+ ions in and out respectively against their concentration gradients at the expense of energy 2. As a ... is/are untrue? (a) 1 only (b) 1, 2, 4 (c) 2, 4 (d) 4 only
Description : 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 ... the cell membrane e. is not associated with any net movement of Na+ or K+ across the cell membrane
Last Answer : is terminated by efflux of K+
Description : The following processes depend on changes in membrane conductance to Na and K. a. Action potential b. depolarization c. repolarization d. all of them
Last Answer : all of them
Description : Chemiosmotic theory of ATP synthesis in the chloroplasts and mitochondria is based on (a) membrane potential (b) accumulation of Na+ ions (c) accumulation of K+ ions (d) proton gradient.
Last Answer : (d) proton gradient
Description : Select the correct statement from the following regarding cell membrane. (a) Na+ and K+ ions move across cell membrane by passive transport. (b) Proteins make up 60 to 70% of the cell ... towards the inner part. (d) Fluid mosaic model of cell membrane was proposed by Singer and Nicolson
Last Answer : (d) Fluid mosaic model of cell membrane was proposed by Singer and Nicolson.
Description : The following diuretic acts on the luminal membrane of distal tubule and collecting ducts to inhibit electrogenic Na+ reabsorption so that K+ excretion is diminished and bicarbonate excretion is enhanced: A. Xipamide B. Isosorbide C. Triamterene D. Spironolactone
Last Answer : C. Triamterene
Description : Aldosterone increases Na+ reabsorption and K+ excretion in the renal collecting duct cells by: A. Inducing synthesis of Na+K+ATPase B. Inducing synthesis of amiloride sensitive Na+ channels C. Translocating Na+ channels from cytosolic site to luminal membrane D. All of the above
Last Answer : D. All of the above
Description : Select the correct statement from the following regarding cell membrane (1) Fluid mosaic model of cell membrane was proposed by Singer and Nicolson (2) Na+ and K+ ions move across cell membrane by ... of the cell membrane (4) Lipids are arranged in a bilayer with polar heads towards the inner part
Last Answer : (1) Fluid mosaic model of cell membrane was proposed by Singer and Nicolson
Description : A resting nerve is relatively resistant to blockade by lignocaine compared to one which is repeatedly stimulated because: A. Lignocaine penetrates resting nerve membrane poorly B. Lignocaine binds ... promotes ionization of lignocaine D. Nodes of Ranvier are inaccessible in the resting state
Last Answer : B. Lignocaine binds more avidly to the inactivated Na+ chan
Description : Insulin increases the permeability of glucose across the plasma membrane of muscle cells by (A) Acting on adenylate cycle (B) By loosening the integrity of the membrane (C) Through Ca2 ... membrane cruting the hexose carries of intracellular organelles and making them fuse with the plasma membrane
Description : The potential difference across the membrane of a relaxed muscle fiber is called resting potential. It amounts to about
Last Answer : The potential difference across the membrane of a relaxed muscle fiber is called resting potential. It amounts to ... C. `100m V` D. `50- 100mV`
Description : The neuronal resting membrane of the human brain is : a. maintained by the sodium pump b. around -70mV c. maintained by using ATP for energy d. all above
Last Answer : all above
Description : The electrophysiological effects of digitalis on Purkinje fibres include the following except: A. Enhancement of resting membrane potential B. Decrease in the slope of phase-0 depolarization C. Increase in the rate of phase-4 depolarization D. Abbreviation of action potential duration
Last Answer : A. Enhancement of resting membrane potential
Description : Concentration gradient of axoplasm at resting stage is maintained by
Last Answer : Concentration gradient of axoplasm at resting stage is maintained by
Description : At resting stage charge of inner surface is due to presence of
Last Answer : At resting stage charge of inner surface is due to presence of
Description : In cell cycle, which stage is misnomerly called resting -I is called:-
Last Answer : In cell cycle, which stage is misnomerly called resting -I is called:- A. S-phase B. Telophase C. Cytokinesis D. Interphase
Description : `XeO_(3)` forms xenate ion in alkaline medium. `XeO_(3) +NaOH rarr Na[HXeO_(4)]` But the xenate ions slowly disproportionate in alkaline solution as `
Last Answer : `XeO_(3)` forms xenate ion in alkaline medium. `XeO_(3) +NaOH rarr Na[HXeO_(4)]` But the xenate ions slowly ... `Na_(4)XeO_(6)` D. `Na_(4)XeO_(4)`
Description : What is the coordination number of an ion what is the coordination number of the cation (a) Na Cl structure and (b) Cs Cl structure explain the reason for this difference?
Last Answer : The coordination number is six for Na in NaCl.The coordination number is eight for Cs in CsCl. The accepted explanation is that the ionic radii of cesium and chloride are very similar.
Description : Muscarinic cholinergic receptors (a) Are located only on parasympathetically innervated effector cells (b) Mediate responses by opening an instrinsic Na+ ion channel (c) Are present on vascular endothelium which has no cholinergic nerve supply (d) Predominate in the autonomic ganglia
Description : Most bacteria do not require the ion a. Mg2+ b. Ca2+ c. Na+ d. Fe+2