Class 12 Nervous System MCQs AIIMS NEET

Multiple Choice questions

26.   The stimulation of the sympathetic nervous system–

          (a)    increases perspiration

          (b)    increases flow of tears

          (c)    decreases saliva secretion

          (d)    causes all of these

27.   Anaesthetics reduce pain by preventing conduction due to –

          (a)    blocking of neurotransmitter receptors

          (b)    blocking of Na+ channels

          (c)    blocking of Ka+ channels

          (d)    all the above              

28.   Which one is incorrect?

          (a)    conditioned reflex was discovered by Pavlov

          (b)    Brain ventricles are lined with ependymal cells

          (c)    Cerebrospinal fluid is formed by choroid plexus

          (d)    None of these.         

29.   Motor end-plates are –

          (a)    formed by a sensory neuron

          (b)    formed by dendrites

          (c)    areas of transmission

          (d)    modified cell bodies      

30.   Pacinian corpuscle is a –

          (a)    chemoreceptor        (b)    tangoreceptor

          (c)    gustatoreceptor       (d)    ganglion

31.   Pain is experienced by –

           (a)   algesireceptor          (b)    calcoreceptor

           (c)   hygroreceptor          (d)    proprioceptor

32.   Synaptic vesicles are –

          (a)    extracellular vesicles

          (b)    intracellular vesicles

          (c)    mitochondria         

          (d)    axon bulbs               

33.   What does not happen to the electrical impulse at the synapse ?

          (a)    The electrical impulse is transmitted through a neurotransmitter

          (b)    The electrical impulse passes directly from axon to dendrite

          (c)    The electrical potential stops at the axon bulb

          (d)    The action potential diminishes as it moves along.

34.   Polarised state of axon implies –

          (a)    +ve charge outside the membrane and -ve charged inside

          (b)    -ve charged outside the membrane and  +ve charge inside

          (c)    potassium ions outside the membrane

          (d)    sodium ions inside the membrane.         

35.   Sodium – potassium gates refer to –

          (a)    the gaps and pumps in the membrane which control their entry and exit

          (b)    ATP

          (c)    sodium and potassium

          (d)    dendrites                  

36.   Spike potential refers to the –

          (a)    the rise in +ve charge  inside the membrane

          (b)    immediate decrease  in +ve charges inside the membrane

          (c)    slow decrease in +ve charges

          (d)    resting potential.   

37.   The conduction of nerve impulse  –

          (a)    follow all -or – no law

          (b)    is dependent on the stimulus after the threshold value

          (c)    is independent on a threshold value

          (d)    is bidirectional.     

38.   Unmyelinated nerves –

          (a)    conduct impulse faster

          (b)    have no axon

          (c)    are found in invertebrates

          (d)    have small myelin sheath          

39.   The contraction of pupil in response to bright light is –

          (a)    a voluntary act       

          (b)    conditioned reflex

          (c)    unconditioned reflex

          (d)    controlled by optic lobes                             

40.   Condition reflex was shown by –

          (a)    Golgi                          (b)    Pavlov

          (c)    Oparin                       (d)    Dobzhansky     

41.   In the automatic nervous system –

          (a)    the message from the brain goes to automatic ganglia

          (b)    the nerve fibres are very small

          (c)    there is no electrical impulse

          (d)    there are no synaptic junctions  

42.   All pre-ganglionic fibres are –

          (a)    adrenergic               

          (b)    cholinergic

          (c)    without axons        

          (d)    without myelin sheath 

43.   The autonomic nervous system is –

          (a)    fully autonomic     

          (b)    partially  autonomic

          (c)    voluntary

          (d)    part of the peripheral nervous system.

44.   Cranial nerves belonging to the parasympathetic group are numbered  –

          (a)    II, III, IV                      (b)    III, VI, IX, X

          (c)    IV, V, VI                     (d)    IV, V, IX, X         

45.   Sympathetic nerves –

          (a)    dilate the pupils

          (b)    constrict the pupils

          (c)    decrease blood pressure

          (d)    increase salivary  secretion        

46.   Coronary arteries are dilated by –

          (a)    sympathetic nerves

          (b)    parasympathetic nerves

          (c)    acetylcholine

          (d)    decreased stimulation  

47.   Parasympathetic nerves –

          (a)    increase tear secretion

          (b)    decrease tear secretion

          (c)    cause ejaculation of seminal fluid

          (d)    decrease gastric secretion

48.   The adrenal gland secretes –

          (a)    more adrenaline due to parasympathetic nerves

          (b)    less adrenaline due to sympathetic nerves

          (c)    more adrenaline due to sympathetic  stimulation

          (d)    insulin                      

49.   Post-ganglionic parasympathetic fibre secretes –

          (a)    noradrenaline         (b)    adrenalin

          (c)    acetylcholine           (d)    sympathin         

50.   What is correct about the eye?

          (a)    Sclera and ciliary body make the outermost layer

          (b)    The colour of the eye is due to the cornea

          (c)    The colour of the eye is due to the lens

          (d)    The cornea is transparent.