The conduction velocity of action potential in a myelinated nerve fibre was much greater than that of an unmyelinated fibre of the same diameter. The following statements were proposed to […]
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CSIR NET Life Science Previous Year Questions and Solution on Animal Physiology
Direction of Nerve Impulse Propagation When Stimulated at the Middle of an Axon
An experimentalist stimulates a nerve fibre in the middle of an axon and records the following observations. Which one of the observation is correct? (1) Nerve impulse is travelling in […]
CSIR NET Life Science Previous Year Questions and Solution on Animal Physiology
Impact of External Sodium Ion Concentration on Action Potential in Squid Giant Axons
The action potential was recorded intracellularly from a squid giant axon bathed in two types of fluid such as sea water and artificial sea water having lower concentration of sodium […]
CSIR NET Life Science Previous Year Questions and Solution on Animal Physiology
Physico-Chemical and Biological Basis of Resting Membrane Potential in Neurons
A potential difference of about -70 mV between inside and outside of a single axonal membrane in resting condition may be recorded by suitable electrodes and amplifier. The physico-chemical and […]
CSIR NET Life Science Previous Year Questions and Solution on Animal Physiology
Mechanism of After-Hyperpolarization in Nerve Fiber Action Potentials: The Role of Potassium Conductance
An action potential of a nerve fibre is described by different components including after-hyperpolarization. The mechanism of generation of this after- hyperpolarization has been proposed in the following statements: A. […]
CSIR NET Life Science Previous Year Questions and Solution on Animal Physiology
Why a Nerve Fiber Cannot Generate a Second Action Potential During the Absolute Refractory Period
An action potential was generated on a nerve fibre by a threshold electrical stimulus. When a second stimulus was applied, no matter how strong it was, during the absolute refractory […]
CSIR NET Life Science Previous Year Questions and Solution on Animal Physiology
Why a Nerve Fiber Cannot Be Stimulated During the Absolute Refractory Period
A nerve fibre cannot be stimulated during the absolute refractory period of a previous stimulation because (1) Sodium permeability remains high. (2) Sodium-potassium pump does not operate. (3) Voltage-gated calcium […]
CSIR NET Life Science Previous Year Questions and Solution on Animal Physiology
Understanding Nerve Fiber Accommodation: Why Action Potentials Fail Despite Threshold Stimulus
When a nerve fiber is stimulated with increasing strength of stimulus, the action potential fails to generate even though the threshold level may be passed. The following statements may explain […]
CSIR NET Life Science Previous Year Questions and Solution on Animal Physiology
Explaining the Overshoot Phase in Action Potential of Giant Squid Axon: Roles of Sodium and Potassium Conductance
The membrane potential in a giant squid axon recorded intracellularly at the resting condition (-70 mV) was reversed at the peak of action potential (+35 mV) after stimulation of the […]
CSIR NET Life Science Previous Year Questions and Solution on Animal Physiology
Understanding Action Potential Initiation at the Axon Hillock and Directional Conduction in Neurons
In the nervous system, the action potential is generated at the axon hillock in physiological conditions and it is conducted to the terminal end of axon. The location specific origin […]
