This set of Human Physiology Multiple Choice Questions & Answers (MCQs) focuses on “Reflex Actions”.
1. Which part of nervous system controls reflex actions?
c) Spinal cord
d) Corpus callosum
Explanation: Corpus callosum is present in the cerebral cortex. It is about 10cm long. Reflex actions are controlled by Corpus callosum.
2. The electrical potential difference between outside and inside of a nerve axon before excitation is known as _______
a) Resting potential
b) Action potential
c) Spike potential
d) Reaction potential
Explanation: The resting potential of a neuron is about -70 Milli volts. At rest, there are relatively more sodium ions outside the neurons and more potassium ions inside the neurons.
3. Which set of ions are necessary for the nerve impulse conduction?
a) Sodium and potassium ions
b) Sodium and calcium ions
c) Calcium and potassium ions
d) Sodium and magnesium ions
Explanation: Sodium and potassium ions are necessary for the nerve impulse conduction. The process of moving sodium and potassium ions across the cell membrane is an active transport process involving the hydrolysis of ATP to provide the necessary energy.
4. Reflex arc consists of ________
a) Motor nerve
b) Sensory nerve
c) Both motor and sensory nerve
d) Mixed nerve
Explanation: Reflex arc is a neural pathway that controls the reflux. It includes sensory nerve and a motor nerve with a synapse between.
5. Dorsal root of spinal nerves contains ________
a) Effectors neurons
c) Detector neurons
d) Receptor neurons
Explanation: Dorsal root of spinal nerve emerges from the spinal cord. Dorsal root of spinal nerves contains receptor neurons. Receptors neurons receive the stimuli and send the signals.
6. Reflex action is simplest form of response in _______
a) Simple animals
b) Higher animals
c) Smaller animals
d) Lowest animals
Explanation: Reflex action is an involuntary response to the stimulus. Reflex action is the simplest form of response in higher animals.
7. Which of the following is not involved in voluntary actions?
a) Math neuron
b) Relay neuron
c) Sensory neuron
Explanation: Sensory neuron is nerve cells within the nervous system responsible for converting external stimuli into internal electrical impulses. It is also known as afferent neurons.
8. Nerve impulse is conducted toward the cell body through ______
a) Motor neurons
b) Nerve fibers
Explanation: Nerve impulse is conducted towards cell body through dendrons. Dendron is a postsynaptic branch of neuron that carries postsynaptic potentials towards the cell body.
9. Stimuli are also known as _______
b) Nerve impulse
Explanation: Stimuli is something that can elicit or evoke a physiological response in a cell, tissue or an organism. It can be internal or external. Stimuli are also known as Receptors.
10. Blinking of an eye is an example of _______
a) Spinal reflux
b) Cranial refluxes
c) Relay neurons
d) Spinal refluxes
Explanation: Cranial refluxes are mediated by pathways in the cranial nerves and brain. Blinking and swallowing are cranial refluxes.
Sanfoundry Global Education & Learning Series – Human Anatomy and Physiology.
To practice all areas of Human Anatomy and Physiology, here is complete set of 1000+ Multiple Choice Questions and Answers.