Physiology

Conduction velocity is maximum in

• Ia nerve fibre
• Ib nerve fibre
• II nerve fibre
• IV nerve fibre

Blood-brain barrier is formed by

• Astrocytes
• Schwann cells
• Oligodendrocytes
• Microglia

Hyperpolarization during action potential can be explained by

• Opening of Na+ channel
• Closure of Na+ channel
• Opening of K+ channel
• Slow closure of K+ channel

All of the following are associated with thin filament except

• Tropomyosin
• Troponin – C
• Troponin – T
• Titin

Interaction between actin and myosin is prevented by

• troponin I
• troponin T
• troponin C
• tropomyosin

A stimulus in the form of slowly rising current will not generate action potential. This is known as

• adaptation
• accomodation
• refractoriness
• tetanus

Botulinum toxin will

• Inhibit the binding of acetylcholine to post- synaptic receptor
• Inhibit the release of acetylcholine from pre-synaptic nerve terminal
• Inhibit the entry of Ca++ in pre-synaptic nerve terminal
• Inhibit acetylcolinestrase

SGLT is an example of

• facilitated diffusion
• ion channel
• primary active transport
• secondary active transport

4th heart sound is because of

• Opening of aortic and pulmonary valve
• Opening of mitral and tricuspid valve
• Atrial contraction
• Ventricular contraction

‘A’ wave of JVP is because of

• atrial contraction
• bulging of tricusptd valve durinf ventricular contraction
• ventricular ejection
• opening of tricuspid valve