Human Physiology and Metabolism MCQ 04

Glucose in the blood is detected by four different methods (a, b, c and d). The sensitivity and range of detection of glucose by these four methods is shown below. Clinically relevant concentration of glucose in blood is between 80 – 250mg/dL

Which of the following method is most appropriate? (CSIR_2015_II)

Respiration can be inhibited voluntarily for some time. The point at which respiration cannot be voluntarily inhibited is known as breaking point. Following explanations are offered for the breaking point:

(A). J-receptors stimulate respiratory centers
(B). Hering-Breuer reflex operates
(C). The rise of arterial pCO2 stimulates the respiratory centre
(D). The fall of arterial pO2 stimulates the respiratory centere.

Which of the above combination is correct? (CSIR_2015_I)

A mechanical pressure was exerted on a specific location of a peripheral nerve of a mammal. The touch or pain receptors were stimulated from the skin surface innervated by the same nerve. The action potential generated by touch receptor stimulation was blocked beyond the point of mechanical pressure. But the action potential generated by pain receptors stimulation possess through the point of mechanical pressure.

The following explanations were offered for these observations:

(A). The large diameter ‘A’ fiber were affected by mechanical pressure
(B). The small diameter ‘C’ fibres were not affected by mechanical pressure
(C). The intermediate diameter ‘B’ fibres were affected by mechanical pressure
(D). The large diameter ‘A’ fibres were not affected by mechanical pressure

Which of the above combinations is correct? (CSIR_2015_I)

When a skeletal muscle with an intact nerve supply is stretched, the muscle contracts and the tone increases. The following explanations are offered for this observation:

(A). Golgi tendon organ was stimulated by the stretching of muscle
(B). γ-motor neurons were excited by the stimulated afferent nerve fibres from the stretched muscle
(C). Muscle spindle was stimulated by stretching of muscle
(D). α-motor neurons were excited by the stimulated afferent nerve fibres from the stretched muscle

Which of the combinations is correct? (CSIR_2015_I)

You are asked to identify the stage of estrus cycle in vaginal smear of a mouse containing large number of leukocytes and very few nucleated epithelial cells. Which one of the following will be the correct stage of estrous cycle? (CSIR_2015_II)

Which one of the following neurotrans- mitters is secreted by the pre-ganglionic neurons of sympathetic nervous system? (CSIR_2015_II)

After hemorrhage, a subject develops hypo-volemia and hypotension. Following are some of the statements regarding homeostatic measure taken by the body after hemorrhage.

(A). Increased release of vasopressin
(B). Increased water retention and reduced plasma osmolality
(C). Increased rate of afferent discharge from low-pressure receptors of vascular system
(D). Decreased rate of afferent discharge from high pressure receptors of vascular system

Which one of the following is NOT correct in this condition? (CSIR_2015_II)

Glycophorin of red blood cell (RBC) membrane spans the membrane only once and the N-terminal is projected extracellularly and the C-terminal is exposed to the cytosolic side. With the help of antibodies (labelled with fluorophors) against N-terminal and C-terminal peptides, orientation of glycophorin across membrane can be verified. Which one of the following statements is correct? (CSIR_2016_I)

A majority of humans with normal colour vision was found to be more sensitive to red light in Rayleigh match where the subject mixed variable amount of red and green light to match monochromatic orange. Which one of the following statements is NOT true to explain the observation? (CSIR_2016_I)

The membrane potential in a giant squid axon recorded intra-cellularly at the resting condition (-70 mV) was reversed at the peak of action potential (+35 mV) after stimulation of the nerve fibre with a threshold electrical stimulus. This overshoot of the membrane potential has been explained in the following proposed statements:

(A). The rapid increase in Na+-conductance during early phase of action potential causes membrane potential to move toward the equilibrium potential of Na+ (+45 mV).
(B). The Na+ -conductance quickly decreases toward resting level after peak in the early phase and Na+-ions are not able to attain its equilibrium potential within this short time.
(C). The conductance of K+ at the early phase of action potential is increased and that leads to the reversal of membrane potential.
(D). The increase of K+ - conductance due to stimulation of nerve occurs before the changes of Na+ - conductance is initiated and thus causes overshoot at the peak of action potential.

Which one of the following is correct? (CSIR_2016_I)