survival needs Flashcards
(7 cards)
survival needs
The goal of nearly all body systems is to maintain life. However, the human body is extremely delicate, so meeting certain survival needs—like nutrients, oxygen, water, and stable body temperature—is essential for helping the body function properly and live as long as possible.
nutrients
Nutrients from food contain the chemicals our bodies need for energy and building cells. Carbohydrates are the main source of energy for the body. Proteins and fats are important for building cell structures. Fats also help protect body organs and provide extra stored energy. Minerals and vitamins are needed for the chemical reactions that happen in cells and for carrying oxygen in the blood.
water
Water makes up about 60 to 80 percent of the body, depending on a person’s age. It is the most abundant chemical in the body and provides the fluid base for things like body secretions and excretions. We get water from food and drinks, and we lose it through evaporation from the lungs and skin, as well as through body secretions like sweat and urine.
tempature
The body temperature needs to stay around 37°C to keep chemical reactions working properly. If the body temperature drops too low, metabolic processes slow down, and eventually stop, which can lead to death. If the temperature gets too high, metabolism speeds up too much, and body proteins start to break down—which is also life-threatening.
Most of the body’s heat comes from skeletal muscle activity. We feel colder when blood vessels move closer to the skin’s surface or when sweat evaporates, which helps the body cool down.
oxygen
all nutrients in the world are useless without oxygen,because nutrients need oxygen to realous the energy.humans can only live for a few minutes without it.
atmospheric preasure
Atmospheric pressure is the force exerted on the surface of the body by the air around it. Proper breathing and the exchange of oxygen and carbon dioxide in the lungs depend on having the right level of atmospheric pressure. At high altitudes, like on a mountain, where the air is thinner and atmospheric pressure is lower, gas exchange becomes too slow to effectively support cellular metabolism.
the mere preasence of these survials needs are not going to just keep us alive
We need to have all of the survival needs in the right balance. For example, we can’t have too much water, but we also can’t go without water—either extreme can be dangerous and even lead to death.
