Question at position 48 Soon after meeting with a car accident, Sally was rushed to the hospital. The doctors discovered that Sally's ventromedial hypothalamus had suffered some damage as a result of the accident. In the context of the biology of hunger, the doctor should expect that Sally willgain weight gradually.gain weight rapidly.lose weight gradually.lose weight rapidly.单项选择题
A
gain weight gradually.
B
gain weight rapidly.
C
lose weight gradually.
D
lose weight rapidly.

Question

Question at position 48 Soon after meeting with a car accident, Sally was rushed to the hospital. The doctors discovered that Sally's ventromedial hypothalamus had suffered some damage as a result of the accident. In the context of the biology of hunger, the doctor should expect that Sally willgain weight gradually.gain weight rapidly.lose weight gradually.lose weight rapidly.单项选择题

A

gain weight gradually.

B

gain weight rapidly.

C

lose weight gradually.

D

lose weight rapidly.

BlackTom AI · Accepted Answer

The ventromedial hypothalamus (VMH) functions as a major satiety center: when it is active, it signals that the body has eaten enough and suppresses further food intake. Damage to the VMH disrupts these satiety signals, producing hyperphagia (excessive eating) and consequent rapid obesity. In contrast, the lateral hypothalamus is the “hunger” center; its damage produces reduced eating and weight loss.

Step-by-step reasoning:
1. Identify the lesion: Sally’s ventromedial hypothalamus is damaged by the accident.  
2. Normal VMH role: VMH neurons respond to signals of energy sufficiency (glucose, leptin, insulin) and inhibit feeding behavior.  
3. Effect of VMH damage: Loss of satiety signaling removes the inhibitory control on eating, so meal size and meal frequency increase immediately. Experimental lesion studies (e.g., in rodents) show striking overeating within days.  
4. Metabolic consequences: Increased food intake plus shifts in autonomic and endocrine regulation (e.g., increased insulin-driven lipogenesis) accelerate fat storage.  
5. Time course: Because the behavioral drive to eat is disinhibited right away and metabolic pathways favor rapid fat deposition, weight gain occurs quickly rather than slowly.

Why the correct answer is correct:
- “Gain weight rapidly” matches the expected outcome of VMH lesions: immediate hyperphagia and fast accumulation of adipose tissue. Empirical animal studies and clinical observations support a relatively rapid onset of obesity after VMH damage.

Why the other options are incorrect:
- “Gain weight gradually”: underestimates the speed; the loss of satiety usually produces rapid overeating and faster weight gain.  
- “Lose weight gradually” and “Lose weight rapidly”: these would be expected after damage to the lateral hypothalamus (reduced hunger), not VMH damage.

Conclusion: Because VMH damage removes satiety control and produces immediate hyperphagia and accelerated fat deposition, the correct outcome is that Sally will gain weight rapidly. This matches the provided answer.