Pressure and Stress in Physics
12 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the unit of pressure used in medicine to measure blood pressure?

  • Ib/in^2
  • atm
  • mmHg (correct)
  • N/m^2
  • How is stress defined?

  • As the force per unit area in a solid (correct)
  • As the mass per unit volume in a solid
  • As the weight per unit area in a solid
  • As the volume per unit area in a solid
  • How is pressure defined in a gas or liquid?

  • As the force acting on the object
  • As the force per unit volume
  • As the weight of the object
  • As the force per unit area (correct)
  • What is absolute pressure equal to?

    <p>Gauge pressure + atmospheric pressure</p> Signup and view all the answers

    What is gauge pressure?

    <p>The measured pressure for a gas inside a closed system</p> Signup and view all the answers

    In which situation do we experience negative pressure?

    <p>When breathing in (inspiring)</p> Signup and view all the answers

    What is the purpose of valves in the digestive tract?

    <p>To permit unidirectional flow of food</p> Signup and view all the answers

    Why is intrathoracic pressure sometimes measured by the pressure in the esophagus?

    <p>To assess pressure in the GI system</p> Signup and view all the answers

    What happens to the pressure in the stomach during eating?

    <p>It increases due to stretching</p> Signup and view all the answers

    What factor causes a significant increase in pressure in the stomach during eating?

    <p>Air swallowed during eating</p> Signup and view all the answers

    What is a common outcome of air trapped in the stomach during eating?

    <p>Visible air on a chest x-ray</p> Signup and view all the answers

    In which part of the body is the pressure usually greater than atmospheric in the gastrointestinal system?

    <p>Stomach</p> Signup and view all the answers

    Study Notes

    Pressure and Stress

    • Pressure is defined as the force per unit area in a gas or a liquid.
    • Units of pressure: atm, N/m², dyne/cm², cm H₂O, mmHg, Ib/in².

    Stress

    • Stress is defined as the force per unit area in a solid.

    Pressure in Medicine

    • Pressure in medicine is measured as the height of a column of mercury (Hg).
    • A peak blood pressure of 120 mmHg is equal to a column of mercury of this height.

    Pressure Formula

    • P = ρgh
    • Where P is pressure, ρ is density of the liquid, g is acceleration due to gravity, and h is the height of the column.

    Types of Pressure

    • Gauge pressure: the measured pressure for a gas inside a closed system (e.g., pressure in a bicycle tire).
    • Atmospheric pressure: the pressure due to the weight of the air above us.
    • Absolute pressure: gauge pressure + atmospheric pressure.
    • Negative pressure: the pressure in certain places in the body where the pressure is lower than atmospheric pressure (e.g., when we breathe in).

    Pressure in the Body

    • The body has an opening through the digestive tract, with valves designed to permit unidirectional flow of food.
    • The pressure in the esophagus is coupled to the intrathoracic pressure and is usually less than atmospheric.
    • In the stomach, pressure increases during eating due to the walls being stretched, but the increase is very slow.
    • A more significant increase in pressure is due to air swallowed during eating, which can cause burping or belching.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Learn about pressure and stress in physics, including their definitions, units of measurement, and applications in medicine. Understand the relationship between pressure and the height of a column of mercury in medical contexts.

    More Like This

    Use Quizgecko on...
    Browser
    Browser