Choose the wrong statement:

Correct Answer: D

Rationale: Knee jerk is an example on static stretch reflex . The knee jerk (patellar reflex) is a dynamic stretch reflex, triggered by a sudden stretch of the quadriceps muscle, detected by nuclear bag fibers (dynamic response), not a static stretch reflex (sustained stretch, nuclear chain). Choice A is correct (gamma fibers adjust spindle sensitivity indirectly). Choice B is true (secondary afferents connect to nuclear chain fibers). Choice C is accurate (primary afferents connect to nuclear bag fibers). Thus, D misclassifithe knee jerk reflex as static instead of dynamic, making it the wrong statement and the correct answer.

Correct Answer: B

Rationale: Cingulate gyrus . The cingulate gyrus, part of the limbic system, processthe emotional and motivational aspects of pain, integrating sensory input with affective responses. Choice A (occipital lobe) is incorrect as it handlvision. Choice C (insula) contributto pain perception and autonomic responses, but not primarily emotion. Choice D (midbrain) modulatpain via the periaqueductal gray, not emotional interpretation. Thus, B identifithe cingulate gyrus as the key structure for pains emotional aspect, making it correct.

Correct Answer: D

Rationale: A right hemisection in the spinal cord at the level of the C4 segment would spare (preserve) both sensations . Discriminative touch (left foot) travels via the dorsal column (ipsilateral, left side) and decussatin the medulla, while heat (right leg) crossimmediately via the spinothalamic tract to the left side. A right C4 hemisection sparleft-sided dorsal column (touch) and already-crossed left-sided spinothalamic (heat) fibers. Choice A is wrong (touch ascends left, heat left). Choice B is false (heat synapsin spinal cord, not gracilis). Choice C is incorrect (both go to parietal lobe, not frontal). Thus, D is correct.

Correct Answer: A

Rationale: pain and temperature . The dorsolateral tract of Lissauer is a small bundle of fibers in the spinal cord where first-order pain and temperature axons (from dorsal root ganglia) travel briefly before synapsing in the dorsal horn (e.g., substantia gelatinosa). These then cross to the lateral spinothalamic tract. Choice B (simple touch) and C (discriminative touch) are carried by dorsal columns. Choice D (conscious proprioception) is via dorsal columns too. Thus, A accurately describLissauers role, making it correct.

Correct Answer: A

Rationale: Slow pain is mostly arisfrom superficial structur, which is false. Slow pain, dull and poorly localized, often arisfrom deep structur(e.g., viscera, muscles), not just superficial ones, and is transmitted by C fibers . Choice B is true (referred pain, e.g., gallstonto shoulder). Choice D is correct (cingulate gyrus processemotional pain). Thus, A inaccurately limits slow pain to superficial origins, making it the exception and the correct answer.