Breathing + Respiration Flashcards
What is the importance of a surface area to volume ratio?
As living organisms get bigger their surface area to volume ratio decreases which makes it difficult to exchange materials with the environment
What are the effects of a small surface area to volume ratio?
Gases and food molecules can no longer reach every cell inside the organism by simple diffusion, metabolic waste can’t be removed fast enough to avoid poisoning in the cells.
What is the function of the respiratory system?
To ventilate the lungs to allow breathing
Where are your lungs found?
Upper part of your body, in the thorax
What protects your lungs?
Ribcage
What separates your lungs from digestive organs?
Diaphragm
Why is the respiratory system important?
It takes air into and out of the body so that oxygen from air can diffuse into the bloodstream and carbon dioxide can diffuse out of the bloodstream into the air
What happens during inhalation?
Intercostal muscles contract
Ribs move upwards and out
Diaphragm contracts/flattens
Volume of thorax increases
Pressure decreases
Air moves in
What happens during the process of exhalation?
Intercostal muscles relax
Ribs move in and downwards
Diaphragm relaxes (domes up)
Volume of thorax decreases
Pressure increases
Air moves out
How are alveoli in the lungs adapted for gas exchange?
Alveoli have a large surface area, they have a rich blood supply due to blood capillaries, thin walls made of flattened cells.
When must artificial breathing aids be used?
When spontaneous breathing of patient is stopped due to disease or injury
What are the two main types of mechanical ventilators?
Negative pressure ventilators, positive pressure ventilators
What is the function of negative pressure ventilators?
Allow air to be drawn into the lungs which is exhaled passively as chest collapses down
How do negative pressure ventilators work?
Patient lays in a metal cylinder with head sticking out
There is tight seal around the neck
Air is pumped out of the chamber which lowers pressure inside to form a vacuum
What is the function of positive pressure ventilators?
They force a carefully measured breath into lungs to inflate them, air pressure stops and lungs deflate to force air out