Top 550+ Solved Physiology MCQ Questions Answer
Q. Inhibitory post synaptic potentials involve:
a. localised increase in membrane permeability to Na+
b. localised decrease in membrane permeability to Cl-
c. localised increase in membrane permeability to PO4
d. localised increase in membrane permeability to Cl-
e. localised decrease in membrane permeability to K+
Q. In skeletal muscle relaxation:
a. there is a spread of depolarisation along T tubules
b. Ca2+ is released from troponin
c. there is increase Na+ and K+ conduction in the end plate membranes
d. a resting membrane potential of -65mV is finally reached
e. Mg2+ has a crucial role
Q. Regarding synapses:
a. the synaptic cleft is 30-50mm wide
b. transmitters are released from synaptic knobs secondary to Na+ triggers
c. the amount of transmitter released is proportionate to Ca2+ efflux
d. acetylcholine is present in granulated vesicles in synaptic knob
e. the EPSP is caused by Na+ influx
Q. Which of the following is inhibitory neurotransmitter?
a. gallamine
b. acetylcholine
c. glutamate
d. glycine
e. aspartate
Q. Which of the following nerves is NOT of fibre type A?
a. proprioception
b. touch
c. motor to muscle spindles
d. somatic motor
e. dorsal root pain and temperature
Q. Which nerve fibre is MOST susceptible to local anaesthetics?
a. proprioception
b. touch
c. motor to muscle spindles
d. somatic motor
e. dorsal root pain and temperature
Q. Which nerves have the biggest diameter and faster conduction velocity?
a. group A alpha
b. group A beta
c. group A gamma
d. group A delta
e. group C
Q. In excitation-contraction of skeletal muscle, calcium binds to:
a. tropomyosin
b. myosin
c. troponin I
d. troponin C
e. troponin T
Q. Myosin binding sites on actin are normally covered by:
a. troponin I
b. troponin C
c. troponin T
d. tropomyosin
e. ryanodine molecule
Q. With regard to skeletal muscle, which is INCORRECT?
a. the terminal cisterns of sarcoplasmic reticulum lie in contact with T tubules
b. the T tubules surround the muscle at its Z lines
c. the Z line lies within the I band
d. the M line is due to a central bulge in each of the thick filaments
e. the area between two adjacent Z lines is called a sarcomere
Q. Noradrenaline:
a. is the main neurotransmitter of the parasympathetic nervous system
b. acts as sympathetic neuromuscular junctions in skeletal muscle and vascular smooth muscle
c. is secreted by the adrenal medulla
d. causes pupillary constriction
e. reduces blood pressure
Q. Acetylcholine:
a. is a major neurotransmitter in the spinal cord
b. is degraded within the neuromuscular end-plate by dehydration
c. is important in the stimulation of pancreatic function
d. is the neurotransmitter involved in vagal stimulation of the heart
e. is antagonised by neostigmine
Q. The functions of tropomyosin in skeletal muscle include:
a. releasing Ca2+ after an action potential
b. sliding on actin to produce shortening
c. binding to myosin during contraction
d. acting as a “releasing protein” at rest by covering up the sites where myosin binds to actin
e. generating ATP which passes to the contractile mechanism
Q. Membrane potential:
a. is only found in nervous tissue
b. is not contributed to by the Na+ /K+ pump
c. magnitude does not change from tissue to tissue
d. is negative inside in relation to the outside
e. is mainly caused by leaking Na+ / K+ channels
Q. Gamma amino butyric acid:
a. is an excitatory mediator in the brain
b. is formed by decarboxylation of glutamate
c. acts at three different classes of GABA receptors
d. is mostly secreted unchanged in the urine
e. is the main mediator in glutamate