Reading Comprehension

PT112 · S2 · P3 · Q17 Hormones

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Discussions of how hormones influence behavior have generally been limited to the effects of gonadal hormones on reproductive behavior and have emphasized the parsimonious arrangement whereby the same hormones involved in the biology of reproduction also influence sexual behavior.

Topic

Hormones and their role in both reproductive and homeostatic (fluid balance) behaviors

Framework

Old / New

Main Point

Previously, people mainly focused on how reproductive hormones affect sexual behavior, but now it’s clear that other hormones, specifically those involved in fluid balance (like vasopressin), also play an important role in controlling behaviors such as water and salt consumption. ( — middle of P1)

P1: Challenging the Narrow Focus on Hormones

Most research has looked at how reproductive (gonadal) hormones affect sexual behavior, but now scientists realize that hormones involved in regulating body fluids (homeostasis) also influence behavior, like thirst and salt appetite. Homeostasis keeps plasma osmolality (solute concentration) steady by tweaking water and sodium intake and output whenever even small changes arise.

P2: How Homeostatic Hormones Control Thirst and Water/Salt Balance

This paragraph explains how water and solute levels are managed in the body through both physiological and behavioral responses. For example, if you have too much water in your body, the hormone vasopressin gets suppressed so your body can get rid of the excess through urine and you stop feeling thirsty. If your blood is too salty, vasopressin gets released to conserve water and increase thirst, so you’ll drink more and dilute the salts. Thirst kicks in only after the body’s initial physiological measures (like vasopressin release) have already tried to fix the imbalance.

17.

It can be inferred from the passage that which one of the following is true of vasopressin?

The amount secreted depends on
Too Strong
Too Strong: depends Out of Support Window: steroid The concept of steroid hormones arises in the 1st paragraph, but our Support Window of text for 'vasopressin' is in the 2nd paragraph. That should make this answer very unappealing on a first pass. The passage never says that vasopressin depends on steroid levels. We are told in the 2nd paragraph that vasopressin secretion depends on whether our body has too much water or too little water in it.
1% picked this
Correct
The amount secreted is important
Why this is right
This answer doesn't trace to one specific sentence, but it reflects the Gist of the Paragraph. When we have too much water, our body wants less vasopressin in the system, so that we'll pee that water out. When we have too little water, our body wants more vasopressin in the system, so that we'll keep the water in. The idea of having "too much / too little" water is synonymous with "osmolality", so this answer is also using Callback Language to encode the concept of too much or too little water. Osmolality is the balance, the homeostasis, between body fluids, which is "achieved primarily through alternations in the intake and excretion of water and sodium". Prior to learning about vasopressin, we read: It is then that complementary physiological and behavioral responses come into play to restore plasma osmolality to normal (to equilibrium / homeostasis). So the whole discussion of vasopressin is framed by the idea that it's a physiological response that affects our behavior so that the body can restore osmolality to homeostasis.
Skill tested: Inference · how this choice captures the passage's function is the move to repeat next time.
79% picked this
It works in conjunction with
Out of Support Window: steroid
The concept of steroid hormones arises in the 1st paragraph but never in the 2nd. Meanwhile, our Support Window of text for 'vasopressin' is in the 2nd paragraph. The passage never says that vasopressin works in conjunction with steroid hormones.
2% picked this
It works in conjunction with
Out of Support Window: steroid
The concept of steroid hormones arises in the 1st paragraph but never in the 2nd. Meanwhile, our Support Window of text for 'vasopressin' is in the 2nd paragraph. The passage never says that vasopressin works in conjunction with steroid hormones.
3% picked this
It is secreted after an
Contradicted: after thirsty
This is what we learned at the end of the 2nd: The threshold for thirst appears to be slightly higher than for vasopressin secretion, so that thirst is stimulated only after vasopressin has been released.
15% picked this

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