Thirst Insights from Logue Ch. 3

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Questions and Answers

What is the relationship between high dietary sodium and health risks?

High sodium intake is beneficial for cardiovascular health.

High sodium levels reduce blood pressure and lower stroke risk.

High levels of dietary sodium increase blood pressure and stroke risk. (correct)

High sodium levels have no impact on blood pressure.

What triggers anticipatory drinking during food intake?

The act of chewing food stimulates thirst.

Increased physical activity related to eating.

Release of adrenaline upon seeing food.

Chemical changes such as histamine and insulin release. (correct)

What is schedule induced polydipsia (SIP)?

A condition where animals drink excessively regardless of thirst.

A normal regulatory behavior for thirst and hydration.

A displacement behavior that allows animals to switch between needs. (correct)

A method of controlling dietary intake of liquids.

Why is there pressure to reduce salt intake in many countries?

To lower hidden salt levels particularly in bread. Signup and view all the answers

How does thirst regulation work in animals and humans?

It involves both peripheral and central mechanisms responding to set point deviations. Signup and view all the answers

What is a key reason why writing a good Appetite report can be challenging?

It must be brief and require judgment about content. Signup and view all the answers

What is the concept of displacement in relation to thirst?

A primary activity can be temporarily replaced by another, such as drinking in the face of hunger. Signup and view all the answers

Which of the following components is NOT part of writing a report?

Background research Signup and view all the answers

What physiological change triggers thirst at the sight of food?

Release of histamine and insulin. Signup and view all the answers

What is emphasized as a critical skill when presenting information in a report?

The ability to be brief and include only important information. Signup and view all the answers

What is the impact of dietary salt on blood pressure over time?

It may contribute to increased blood pressure and stroke risk. Signup and view all the answers

What distinguishes human drinking behavior from that of other animals?

Human behavior is influenced by the consumption of various substances, including caffeine and alcohol. Signup and view all the answers

What should be included in the Method section of a report?

Chronological presentation of actions taken. Signup and view all the answers

What percentage of the Earth's water is fresh water?

3% Signup and view all the answers

What is a common error to avoid when writing a report?

Providing sweeping statements without clarification. Signup and view all the answers

What does the discussion section of a report typically address?

How the results relate to the original aim. Signup and view all the answers

What is the daily household water usage per person in the West?

400 liters Signup and view all the answers

What alarming prediction has been made regarding water resources?

Fresh water will be the basis for armed conflict Signup and view all the answers

What tally or statistical details should be included in a report?

Details of sample sizes, statistical values, and context. Signup and view all the answers

Which of the following is an important guideline regarding word count in a report?

Going over the word count should be avoided. Signup and view all the answers

How many people worldwide rely on standpipes for water access?

2.1 billion Signup and view all the answers

As of 2017, how many people lacked access to safe drinking water?

0.8 billion Signup and view all the answers

What significant event involved Egypt and the Nile River?

Threatened military action over damming Signup and view all the answers

What is the estimated number of deaths caused by waterborne diseases in 2017?

0.5 million Signup and view all the answers

What does fresh water constitute in terms of total water available on Earth?

A small fraction Signup and view all the answers

What is one consequence of unsustainable water usage habits?

Potential for resource shortages Signup and view all the answers

Which explorer documented his experience of thirst after crossing a desert?

Sven Hedin Signup and view all the answers

What is the primary function of homeostatic drinking?

To maintain water consumption when set points deviate Signup and view all the answers

Which body fluid compartment can trigger thirst when it experiences a loss of fluid?

Fluid outside cells Signup and view all the answers

What is anticipatory drinking?

Drinking in preparation for future fluid needs Signup and view all the answers

What behavior is associated with schedule induced polydipsia (SIP)?

Drinking significantly more water due to a feeding schedule Signup and view all the answers

What percentage of chronic psychiatric patients are reported to be polydipsic?

6-17% Signup and view all the answers

In which condition might a person drink excessively, potentially leading to fatal consequences?

Polydipsia in psychiatric patients Signup and view all the answers

What type of drinking behavior reflects an animal's preference for drinking mainly at night?

Non-homeostatic drinking Signup and view all the answers

How is the need for hydration related to food intake in the context of drinking behavior?

Food can create anticipatory needs for water without immediate thirst Signup and view all the answers

What ratio of water to food is needed for optimal digestion in the stomach?

1 part water to 1 part food Signup and view all the answers

What potential consequence does excessive water consumption have in psychiatric patients?

Fluid overload leading to health complications Signup and view all the answers

What was one of the main social issues associated with gin during the time of Hogarth?

Significant social problems Signup and view all the answers

From which language does the word 'alcohol' derive?

Arabic Signup and view all the answers

What is noted about the evidence of brewing in relation to its historical origins?

It dates back to the Neolithic period. Signup and view all the answers

What gave rise to the image of heavy drinking in Australian national identity?

Rum issued to the first fleet during colonization. Signup and view all the answers

When did the practice of distillation spread throughout Europe?

By the middle ages Signup and view all the answers

What does the discussion about alcohol consumption include with regard to human behavior?

It considers psychoactive effects. Signup and view all the answers

What effect did alcohol consumption reportedly have on Australians when evaluated historically?

It contributed to a national identity based on heavy drinking. Signup and view all the answers

What is implied by the statement about contemporary accounts of alcohol consumption in Australia?

Australians are among the highest consumers of alcohol per capita. Signup and view all the answers

What is a key consideration when writing a discussion section of a report?

To interpret the findings relative to the aim. Signup and view all the answers

Which of the following should be avoided when describing research results?

Describing non-significant results as 'insignificant'. Signup and view all the answers

What aspect is essential when discussing meaningful limitations in research?

Determining if an educated person would consider the limitation significant. Signup and view all the answers

How should the findings of a report be addressed in relation to previous research?

By examining how they fit with previous research. Signup and view all the answers

Which of the following improves the clarity of a report?

Shortening sentences and removing unnecessary details. Signup and view all the answers

What should be considered when determining the next steps in research?

Considering where the line of research might go next. Signup and view all the answers

Which factor is critical when interpreting research findings?

Examining alternative explanations for findings. Signup and view all the answers

What is the significance of defining acronyms in a report?

To ensure clarity for all readers. Signup and view all the answers

Study Notes

Thirst Based on Logue Ch. 3

97% of Earth's water is in the ocean, with only 3% fresh water.
Only 0.7% of fresh water is accessible for drinking, food, and industrial use.
It takes ~3000 liters of water to produce the food an average Westerner consumes daily (~400 liters per person for household use).
This is unsustainable if everyone uses water resources at current rates.

Water

Fresh water is becoming a scarce resource.
Political figures anticipate conflict over water and food.
Access to clean fresh water is a luxury for many.
Extreme thirst is hard to imagine.
A 19th-century explorer, Sven Hedin, described crossing the Taklamakan Desert and experiencing severe dehydration.

Thirst

People can endure more time without food than water.
Death rapidly occurs with ~15-25% of body weight loss of water.
~2% loss of body water triggers severe thirst.
~5-8% loss of body water causes severe fatigue and apathy.
A loss of >10% body water can lead to delirium, coma, and death.
Dehydration is a serious problem for children and the elderly.
Some elderly people don't feel the need to drink as much.

So What is Thirst?

Two kinds of thirst:
- Homeostatic: Body maintains a set point for water intake.
- Non-homeostatic: Anticipating future water needs.

Homeostatic Drinking

There are two main types of homeostasis:
- Eating (water depletion impacts eating habits)
- Water (a ratio of 1 part water to 1 part food for stomach, and 3 parts of water to 1 part food for the intestines is needed for digestive purposes).

Homeostatic Drinking Types

Fluid inside cells.
Fluid outside cells (blood and plasma).
Loss of fluid from cells (increased salt levels).
Loss of fluid from outside cells (blood loss).

Non-Homeostatic Drinking

Animals drink more at night than day.
Humans sometimes drink while they eat.

Schedule-Induced Polydipsia (SIP)

Rats drink excessively when given food at frequent intervals.
This can also be seen in people playing slot machines.

Explaining Thirst

Three types of explanation for thirst:
- Peripheral mechanisms
- Central mechanisms
- Combined mechanisms

Dry Mouth Theory

Proposed by Walter Cannon, suggests thirst is driven by dryness in the mouth.
Saliva levels and the need for water are correlated.
When the mouth is anesthetized, thirsty dogs and humans experience reduced thirst levels.

Evidence Against Dry Mouth Theory

Even with an empty stomach, thirst is still triggered by water placed directly into the stomach.
People and animals can drink normally with dry mouths.

Central Mechanisms

The hypothalamus, specifically the median preoptic nucleus, is a possible area responsible for thirst.
It detects water deficit and signals for water intake.
It reacts to variations in salt levels, blood pressure, and other signals.

Hypothalamus and Thirst

The hypothalamus controls thirst via ADH release (antidiuretic hormone).
ADH increases water retention and blood pressure.
ADH is triggered by fluid loss within the cells or blood/plasma.

Problems

Peripheral systems also play a role in drinking behavior, working cooperatively with but independently from the hypothalamus.
The kidney is another important part to consider in this pathway.

The Kidney

Falling blood pressure triggers renal hormone release (renin).
Renin triggers the release of angiotensin.
Angiotensin affects the CNS to trigger drinking behavior and constricts blood vessels to increase blood pressure.

Summary So Far

Thirst results from an interaction of peripheral and central mechanisms.
Related systems regulate thirst and drinking.
Non-homeostatic drinking still needs further explanation.

Explaining NHD

Schedule-induced polydipsia (SIP) is not always maladaptive.
Disruption in appetite-related drive states can displace drink intake activity.

Anticipatory Drinking

Thirst triggers can be chemical changes from smelling or seeing food.
Histamine and insulin factors play a role in triggering thirst.

Conclusion

Thirst mechanisms are more complex than thought.
Peripheral and central systems interact to regulate thirst.

Drugs and Food

Logue Chapter 11 outlines the psychology of eating and drinking.
Examples like alcohol and caffeine highlight their effect on our daily intake choices.

Alcohol - Overview

Alcohol consumption has a long history.
Consumption varies by culture and time period.

Drinking - The Australian Context

The Australian national identity is linked to drinking.

Drinking- Australian Context: Today

~90% of adults have consumed alcohol.
Per-capita consumption is moderately high (comparatively).

Alcohol - Impact

Positive impacts include tax revenue, reduction of cardiovascular deaths, and prevention of hospitalizations due to kidney or gallstones, and increased bone density.
Negative impacts include harms arising from excessive consumption such as cirrhosis, heart disease, brain damage, road trauma, violence, relationship breakdown, lost productivity, or the increased rate of consumption in Indigenous populations.

Alcohol - Impact (Statistics)

Average tax revenue is $6 billion per year.
Alcohol abuse costs about $15 billion yearly.
About 35% of violent crimes occur while under the influence of alcohol.

Alcohol - The effects of Alcohol

Metabolism differs between sexes.
Women metabolise alcohol more slowly than men.
The average alcohol absorption rate is ~6-8g per hour.

Alcohol - Effect on the Brain

Alcohol acts on multiple brain systems.
Effects vary by dose.
It acts like an anesthetic by increasing nerve cell membrane permeability.
It alters brain dopamine and endogenous opioid levels.

Tolerance

Alcohol's behavioral and pharmacological effects change with exposure.
Tolerance leads to disconnect between alcohol level and behavior.
Chronic tolerance happens with consistent consumption and is lost with abstinence.

Addiction to Alcohol

It is a significant problem impacting ~10% of regular drinkers.
Symptoms and criteria are covered in Logue.
Chronic abuse is connected to various neurological issues.

Disorders like Marchiafava-Bignami disease affect the corpus callosum, while others (haematoma) are due to head trauma.
Hepatic encephalopathy is another issue, as are cerebellar degeneration and alcoholic dementia.

Alcohol- Withdrawal symptoms

Range from mild (tremors and anxiety) to severe, including delirium tremens (high mortality if left untreated).

Risk Factors for Alcoholism

Genetic susceptibility, higher risk in offspring of alcoholics, higher concordances in identical than fraternal twins, less sensitivity to low alcohol levels, irregularities associated with dopamine receptors and 5-hydroxytryptamine (serotonin) metabolism

Caffeine

Caffeine is a widely consumed psychoactive drug.
Present in coffee, energy drinks, tea, and chocolate.

Caffeine Psychological & Physiological effects

Increased alertness, mood, subjective wellbeing, and various cognitive functions (such as attention)
Mild diuretic effects, elevated blood pressure/rate, and tremors/anxiety are seen at larger doses.
Potential issues for people who don't regularly consume and sudden abstinence (which can result in a withdrawal syndrome)

Is Caffeine Addictive?

Are such foods addictive?

US courts have historically not ruled food overly addictive.
More modern science suggests a possible connection between specific food characteristics and behavioral addictive patterns.

Conclusion

Caffeine has generally few or no significant negative effects.
The main issues surrounding the use of alcohol and/or addictive foods involve societal costs, choice, and regulation.

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Description

Explore the critical insights from Chapter 3 of Logue regarding water scarcity and thirst. The quiz covers the importance of fresh water access and the severe implications of dehydration on human health. Understand the need for sustainable water use in a rapidly changing world.