PYQ (Previous Year Questions)

Important Points for NEET Exam

The Pump & Potential Concepts

• Resting Potential: High $K^+$ inside, High $Na^+$ outside. Outer surface is positive, inner is negative.
• Sodium-Potassium Pump: Transports 3 $Na^+$ OUT for every 2 $K^+$ IN using active transport (ATP).
• Depolarization: Triggered by rapid influx of $Na^+$.
• Repolarization: Triggered by efflux of $K^+$.

Brain Centre Master List

• Hypothalamus: The "Thermostat" (Body temperature, Hunger, Thirst).
• Medulla Oblongata: The "Survivor" (Respiration, Cardiovascular reflexes, Gastric secretions).
• Cerebellum: The "Balancer" (Coordination, Posture).
• Corpus Callosum: The "Bridge" (Connects left and right cerebral hemispheres).
• Limbic System: The "Emotional Brain" (Excitement, pleasure, fear, rage).

3. Sensory Systems Breakdown

• Eye Neural Layers (Inside $\rightarrow$ Out): Ganglion cells $\rightarrow$ Bipolar cells $\rightarrow$ Photoreceptors.
• Blind Spot vs. Fovea: Blind spot has NO photoreceptor cells; Fovea has ONLY cones (highest resolution).
• Rods vs. Cones: Rods = Rhodopsin (Night/Scotopic vision); Cones = Iodopsin (Colour/Daylight/Photopic vision).
• Ear Ossicles (Outside $\rightarrow$ In): Malleus $\rightarrow$ Incus $\rightarrow$ Stapes (MIS).
• Ear Fluids: Perilymph surrounds the membranous labyrinth; Endolymph is inside it.