A neuroscientist observes a neuron where the electrical potential difference shifts from $-70\ mV$ to $+30\ mV$. This phase is characterized by:

B) Rapid influx of $Na^+$ ions through voltage-gated channels.

A) Efflux of $K^+$ ions through voltage-gated channels.

B) Rapid influx of $Na^+$ ions through voltage-gated channels.

C) Activation of the Calcium-calmodulin complex.

D) Closing of all leak channels.

In a clinical reflex test, a doctor taps the patellar tendon. Which of the following correctly describes the pathway of this monosynaptic reflex?

D) Receptor $\rightarrow$ Afferent neuron $\rightarrow$ Dorsal root ganglion $\rightarrow$ Efferent neuron $\rightarrow$ Effector.

A) Receptor $\rightarrow$ Efferent neuron $\rightarrow$ CNS $\rightarrow$ Afferent neuron $\rightarrow$ Effector.

B) Effector $\rightarrow$ Afferent neuron $\rightarrow$ Ventral root $\rightarrow$ Efferent neuron.

C) Receptor $\rightarrow$ Ventral root $\rightarrow$ Spinal Cord $\rightarrow$ Dorsal root $\rightarrow$ Muscle.

D) Receptor $\rightarrow$ Afferent neuron $\rightarrow$ Dorsal root ganglion $\rightarrow$ Efferent neuron $\rightarrow$ Effector.

If the Vagus nerve (Cranial Nerve X) is stimulated, what is the expected physiological effect on the heart?

B) Decreased heart rate due to Parasympathetic activation.

A) Increased heart rate due to Sympathetic activation.

B) Decreased heart rate due to Parasympathetic activation.

C) No effect on heart rate, only affects digestion.

Grade 11 Biology Quiz: Neural Control & Coordination (Set 6)

Grade 11 : Biology - Neural (Set 6) | Concept of Maths

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During the resting state of a neuron, the axonal membrane is comparatively more permeable to $K^+$ ions and nearly impermeable to $Na^+$ ions. If a toxin selectively blocks the $Na^+-K^+$ ATPase pump, what is the most immediate consequence?

The resting potential becomes more negative immediately.

Rapid depolarization occurs due to $Na^+$ influx.

The ionic gradients across the membrane will gradually disappear.

The membrane becomes permeable to large negatively charged proteins.

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