All Free Physiology MCQs with Answers

• A. Dopamine
• B. Acetylcholine
• C. Nor epinephrine
• D. Epinephrine

Explanation: Somatic motor neurons release acetylcholine at the neuromuscular junction, where it activates nicotinic receptors on the muscle end plate.

• A. there is lack of acetyl choline
• B. There is isometric contraction
• C. Lack of acetyl choline receptors
• D. Muscles are rigid and tough

Explanation: Myasthenia gravis is an autoimmune disorder in which antibodies reduce functional acetylcholine receptors at the neuromuscular junction.

• A. EMG
• B. EEG
• C. Venn diagram
• D. ECG

Explanation: Electromyography, or EMG, records the electrical activity of skeletal muscle.

• A. Round electrode
• B. Surface electrode
• C. Hook electrode
• D. Needle electrode

Explanation: Surface electrodes detect muscle electrical activity through the skin and are painless because they do not enter the muscle.

• A. Less activity in the membrane
• B. There are no gaps between active sites
• C. There are gaps between tight junctions at the active sites
• D. Fibronectin provides a barrier for diffusion

Explanation: The blood-brain barrier is formed by continuous endothelial tight junctions, so gaps are not present between adjacent endothelial cells.

• A. Prefrontal cortex
• B. Neocortex
• C. Hippocampus
• D. Amygdala

Explanation: The hippocampus is important for consolidating newly acquired short-term memories into long-term memories.

• A. Sense muscle tension
• B. Involved in reciprocal innervation
• C. a- motor neuron stimulation
• D. Senses dynamic length of muscle

Explanation: Golgi tendon organs detect tension generated in a muscle and its tendon, especially during contraction.

• A. Somatostatin
• B. Glycine
• C. Substance P
• D. Calcitonin

Explanation: Glycine is a rapidly acting inhibitory neurotransmitter that opens chloride channels through ionotropic receptors.

• A. Plasma cell
• B. Mast cell
• C. Nerve terminal
• D. Vascular endothelium

Explanation: Substance P is a neuropeptide released mainly from peripheral sensory nerve terminals, especially nociceptors, where it contributes to…

• A. Structural changes in rhodopsin
• B. Activation of transducin
• C. Decreased intracellular cGMP
• D. Opening of Na+ channels

Explanation: Light activates rhodopsin and transducin, lowers cGMP, and closes cGMP-gated sodium channels, causing rod hyperpolarization.

• A. Impairment of both sensory and motor function
• B. Intact neural sheath is not present
• C. Wallerian degeneration
• D. Reversible loss, which will be regenerated i 6-8 wks

Explanation: In axonotmesis, the axon is interrupted but the surrounding neural connective-tissue sheath remains sufficiently intact to guide…

• A. Present in posterior part of temporal lobe
• B. Comprehends language not speaking
• C. Word formation
• D. Is the confluence of somatic , auditory and visceral areas

Explanation: Broca’s area in the dominant inferior frontal gyrus coordinates motor planning for speech, so it is associated with word formation and…

• A. They are metabolites of various neurogentic amines .Health
• B. They are acidic precursors of Brain amines
• C. They act as neuromodulators
• D. They cross Blood Brain Barriers

Explanation: DOPA and 5-hydroxytryptophan can cross the blood-brain barrier and are then converted to dopamine and serotonin, respectively, within the…

• A. GABA
• B. Glutamate
• C. Aspartic acid
• D. Lysin

Explanation: GABA is the principal inhibitory neurotransmitter in the brain, usually reducing neuronal excitability by increasing chloride or potassium…

• A. Vagus nerve
• B. Facial nerve
• C. Trigeminal nerve
• D. Glossopharyngeal nerve

Explanation: The afferent limb of the corneal reflex travels through the ophthalmic division of the trigeminal nerve, while the efferent blinking…

• A. Reticulospinal
• B. Vestibulospinal
• C. Rubrospinal
• D. Corticospinal

Explanation: The corticospinal tract is a pyramidal tract involved in voluntary skilled movement.

• A. Sympathetic nerves
• B. Parasympathetic nerves
• C. Sensory nerves
• D. Motor nerves

Explanation: Sweat glands receive sympathetic autonomic fibres, but unlike most sympathetic postganglionic fibres, these release acetylcholine rather…

• A. Deuteranopia
• B. Protanopia
• C. Protanomaly
• D. Deuteranomaly

Explanation: Protanopia is absence of the red-sensitive L cone and causes red colour blindness.

• A. Astrocytes
• B. Schwann cells
• C. Oligocytes
• D. Microglia

Explanation: Microglia are the resident macrophage-like cells of the CNS, so they remove cellular debris and phagocytose pathogens.

• A. Neuronal inhibition
• B. Neuronal activation
• C. Glial cell inhibition
• D. Glial cell activation

Explanation: GABA is the major inhibitory neurotransmitter in the CNS; it usually reduces neuronal excitability by increasing chloride entry or…