All Free Physiology MCQs with Answers

• A. Less than 3.5 cycles per second
• B. Between 8 and 13 cycles per second
• C. More than 14 cycles per second
• D. Between 4 and 7 cycles per second

Explanation: Delta waves are the slowest EEG waves, typically about 0.5 to 3.5 cycles per second and prominent in deep sleep.

• A. Pacinian corpuscles
• B. Free nerve endings
• C. End bulbs of Krause
• D. End organs of Ruffini

Explanation: Pain receptors are free nerve endings, usually carried by A-delta or C fibres and activated by damaging mechanical, thermal, or chemical…

• A. Proprioception
• B. Melanophage
• C. Chemoreceptor
• D. Tactile sensation

Explanation: Merkel cells are slowly adapting cutaneous mechanoreceptors that detect sustained light touch, pressure and texture.

• A. Decibels
• B. Daltons
• C. Diopters
• D. Pounds

Explanation: Sound intensity is expressed in decibels, a logarithmic unit comparing sound power or pressure.

• A. Pain
• B. Pressure
• C. Touch
• D. Temperature

Explanation: Pacinian corpuscles are rapidly adapting receptors for deep pressure and high-frequency vibration.

• A. -55 mv
• B. -90 mv
• C. -70 mv
• D. + 35 mv

Explanation: A typical nerve fibre has a resting membrane potential of about −70 mV, maintained mainly by potassium leak and the sodium-potassium pump.

• A. MIdbrain
• B. Pons
• C. Cerebellum
• D. Medulla

Explanation: The swallowing centre is a medullary pattern-generating network that coordinates the sequential phases of swallowing, with related…

• A. Distal cut end of nerve without cell body
• B. Proximal cut end of nerve with cell body
• C. Both the free ends of the cut nerve
• D. All are true

Explanation: Wallerian degeneration occurs in the distal part of a severed axon, which is disconnected from its cell body and therefore loses trophic…

• A. Myelin degeneration
• B. Axonal degeneration
• C. Mitosis of schwann cell
• D. Sprouting

Explanation: The axon in the distal segment degenerates first after nerve severance, followed by breakdown of its myelin sheath and later Schwann-cell…

• A. Acetyl choline
• B. GABA
• C. Dopamine
• D. Nor epinephrine

Explanation: The nigrostriatal pathway carries dopaminergic projections from the substantia nigra to the striatum and helps regulate movement.

• A. Near sightedness
• B. Far sightedness
• C. Constriction of the pupil
• D. Dilation of the pupil

Explanation: Myopia is short-sightedness: nearby objects are seen clearly, but distant images focus in front of the retina.

• A. Sensory area
• B. Broca's area
• C. Primary motor area
• D. Visual area

Explanation: Broca's area is the dominant frontal speech area, and its lesion causes expressive or motor aphasia with impaired speech production.

• A. fibers
• B. fibers
• C. Sympathetic fibers
• D. Parasympathetic fibers

Explanation: Visceral pain from abdominal organs generally travels with sympathetic afferent fibers, entering the spinal cord through dorsal roots and…

• A. Exteroceptors
• B. Nociceptors
• C. Proprioceptors
• D. Chemo receptors

Explanation: Muscle spindles, which initiate the stretch reflex, detect muscle length and its rate of change, so they are proprioceptors.

• A. Basal ganglia
• B. Pain pathway
• C. Pyramidal tract
• D. Parathyroid gland

Explanation: Tremor is a common movement disorder involving basal ganglia circuits, as seen in Parkinson disease and other extrapyramidal disorders.

• A. Somatic only
• B. Cholinergic
• C. Sympathetic
• D. Parasympathetic

Explanation: All autonomic preganglionic neurons release acetylcholine, so preganglionic parasympathetic fibers are cholinergic.

• A. Corticospinal tract
• B. Dorsal column
• C. Spino thalmamic tract
• D. Spinocerebellar tract

Explanation: Pain and temperature sensations from the limbs and trunk ascend mainly in the anterolateral system, especially the lateral spinothalamic…

• A. Osmoreceptors in the hypothalamus
• B. Afferent arterioles of the glomeruli
• C. Thirst center in the hypothalamus
• D. Distal tubules and collecting ducts in the kidney

Explanation: ADH acts mainly on V2 receptors in the late distal tubules and collecting ducts, inserting aquaporin-2 channels and increasing water…

• A. Adrenaline
• B. Aldosterone
• C. A.D.H. and vasopressin
• D. All of the above

Explanation: Aldosterone increases sodium reabsorption in the distal nephron, with accompanying water retention and increased potassium secretion.

• A. Loop of henle
• B. DCT
• C. PCT
• D. Vasa recta

Explanation: About 65% of filtered sodium is reabsorbed in the proximal convoluted tubule through coupled transport with glucose, amino acids…