Human survival depends on more than simply having food and water. Cells need oxygen to support energy production, and the body needs nutrients to provide water, energy, building materials, and substances that enable essential processes.
Air contains about 20 percent oxygen. The body uses oxygen in chemical reactions that help produce adenosine triphosphate (ATP), the molecule that supplies usable energy for cellular activities.
All flashcards
Why does the body need oxygen?
Oxygen supports chemical reactions that help produce ATP, the usable energy source for cellular activities.
What are the primary energy-yielding nutrients?
Carbohydrates and lipids. Their breakdown products can be used in metabolic processes that produce ATP.
What makes water essential to human survival?
Water provides the medium for many chemical reactions, dissolves and transports substances, forms much of cells and body fluids, helps regulate temperature, and cushions and lubricates structures.
How do macronutrients differ from micronutrients?
Macronutrients, such as water and energy-yielding nutrients, are needed in large amounts. Micronutrients are vitamins and minerals needed in smaller amounts for essential processes and structures.
What causes decompression sickness?
A drop in pressure can cause dissolved gases, mainly nitrogen, to form bubbles in blood and tissues.
Quiz questions
Why is sweating less effective in humid conditions?Answer: Sweat evaporates less readily, so it removes less heat.
Why does the body reduce blood flow to the hands and feet during cold exposure?Answer: It limits heat loss from the extremities and helps keep the core warm.
Why might clinicians cool a patient during some open-heart surgeries?Answer: Cooling lowers the metabolic needs of the brain, heart, and other organs.
How can a rapid pressure decrease cause decompression sickness?Answer: Dissolved gases, mainly nitrogen, can form bubbles in blood and tissues.
What is the functional requirement for blood pressure?Answer: It must perfuse tissues without placing excessive force on blood vessels.
Based on Anatomy and Physiology 2e by J. Gordon Betts, Kelly A. Young, James A. Wise, Eddie Johnson, Brandon Poe, Dean H. Kruse, Oksana Korol, Jody E. Johnson, Mark Womble, Peter DeSaix (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.