Human Biology- In The Blood Flashcards
Name seven uses of energy in the body of humans.
Muscle contraction, protein synthesis, cell division, active transport, growth, the passage of nerve impulses and the maintenance of a constant body temperature.
Define respiration
Restoration is the breakdown of nutrient molecules in living cells to release energy.
State and explain the difference in oxygen composition in exhaled and inhaled air.
In inhaled air oxygen takes up 21% (same at atmosphere) but it exhaled air, oxygen takes up 18%. This is because oxygen has diffused from the air in the alveoli into the blood.
State and explain the difference in carbon dioxide composition in exhaled and inhaled air.
In inhaled air, carbon dioxide takes up 0.04%, yet in exhaled air, carbon dioxide takes up 3%. This is because carbon dioxide has diffused from the blood into the air in the alveoli.
State and explain the difference in nitrogen composition in exhaled and inhaled air.
Nitrogen takes up 78% in both inhaled and exhaled air. This is because nitrogen gas has not been used by the body.
State and explain the difference in water vapour competition in exhaled and inhaled hair.
Water vapour percentage is very variable within inhaled air however it is saturated in exhaled air. This is because water evaporates from surfaces in the alveoli.
State and explain the difference in temperature for exhaled and inhaled air.
The temperature of inhaled air is very variable however it is 37°C in exhaled air. This is because heat is lost to the air from the lung services.
List the five features of gas exchange surfaces.
Moist, large surface area, thin, well ventilated, good blood supply.
Why must gas exchange surfaces be kept moist?
As cells die if they dry out.
Why must gas exchange surfaces have a large surface area?
To increase the number of molecules that can diffuse across at the same time.
Why must gas exchange surfaces be thin (ideally 1 cell thick)?
So that gases have a short distance over which to diffuse.
Why must gas exchange surfaces be well ventilated?
As a regular supply of fresh air keeps the concentration gradient for oxygen and carbon dioxide high.
Why must gas exchange surfaces have a good blood supply?
So that gases can be carried to and from the cells that need or produce them.
What is the larynx and what is its purpose?
(Voice box) There passes through here during breathing. When breeding out, the vocal chords can be made to vibrate. That sounds produced make up our speech.
What is the trachea and what is its purpose?
(Windpipe) tube that carries air towards the lungs. C-shaped rings of cartilage prevent the trachea collapsing during inhalation.
