Choose the Correct statement:

Correct Answer: B

Rationale: In corticospinal tract hemisection of the right half of the spinal cord in the cervical region result in motor deficit in the left side of the body . This seems misaligned with standard anatomy: corticospinal fibers decussate in the medulla, so below this, a right cervical hemisection affects right-sided (ipsilateral) motor function. Above decussation, damage causcontralateral loss (making A wrong). Choice C is false (terminate in ventral horn). Choice D is incorrect (below decussation is ipsilateral). Assuming intent, B may reflect a higher lesions contralateral effect, but per options, its likely a miswording.

Correct Answer: D

Rationale: Vestibulospinal tract . The corticospinal tract decussatin the medullary pyramids, with most fibers crossing to form the lateral corticospinal tract for contralateral voluntary movement. The corticonuclear tract also decussates, though partially, as fibers from the cortex to cranial nerve nuclei (e.g., 7, 12) cross to innervate contralateral lower facial musclor tongue, evident in facial palsy from stroke. The tectospinal tract decussatin the midbrain, originating from the superior colliculus to coordinate head movements toward stimuli (e.g., visual reflexes). However, the vestibulospinal tract donot decussate; it descends ipsilaterally from the vestibular nuclei in the brainstem to spinal motor neurons, facilitating posture and balance (e.g., antigravity muscles). This ipsilateral nature is critical, as unilateral vestibular lesions cause same-side extensor tone changes, unlike crossed tracts. Thus, D is the exception among these descending tracts, making it the correct answer.

Correct Answer: C

Rationale: Initiated voluntarily , which is false. The vomiting center is in the medulla oblongata (A is true), near the area postrema, coordinating the reflex. It receivvestibular input via cranial nerve 8 (B is true), causing motion sickness-related vomiting. Choice C is incorrect; vomiting is involuntary, unlike swallowings voluntary start, triggered by medullary signals (e.g., nausea reflex). It receivinput from circulating emetics (D is true) via the chemoreceptor trigger zone, responding to drugs or toxins. Brainstem lesions disrupt this reflex, not cortical control, confirming Cs inaccuracy. Thus, C is the exception, making it the correct answer.

Correct Answer: B

Rationale: It is initiated voluntarily , which is not true. The vomiting center is in the medulla oblongata (A is true), near the area postrema, coordinating the reflex via the nucleus tractus solitarius. Choice B is false; vomiting is an involuntary reflex, unlike swallowing, triggered by medullary signals (e.g., nausea from toxins), not cortical control. Choice C is true; it involvcranial nerve 8 (vestibular, motion sickness), 9 (glossopharyngeal, sensation), and 10 (vagus, motility), forming the reflex arc. Choice D is correct; vestibular input (e.g., dizziness via cranial nerve 8) stimulatvomiting, as in seasickness. Medullary lesions abolish vomiting, while cortical damage donot, confirming its involuntary nature. Thus, B is the untrue statement, making it the correct answer.

Correct Answer: C

Rationale: Obese people react differently to food cucompared to non-obese people . Research, like fMRI studies, shows obese individuals exhibit heightened brain respons(e.g., in reward centers like the striatum) to food cues, driving overeating. Choice A is false; exercise boosts metabolism and calorie burn, critical for weight control per guidelinlike CDCs. Choice B is incorrect; no universal obese personality exists traits vary widely, debunking stereotypes. Choice D is wrong; stress often increaseating in obese individuals (emotional eating), unlike some non-obese who may eat less. is false; obese people are more, not less, responsive to food visuals, per behavioral studies. C reflects external cue sensitivity, a key obesity factor, distinguishing it from metabolic or personality myths, making it the correct answer.