11Gas exchange Flashcards
Features of alveoli and their functions
- large surface area (to allow faster diffusion of gases cross the surface)
- thin walls (to ensure diffusion distances remain short, increasing the rate)
- good blood supply (to maintain a high conc gradient so diffusion occurs faster)
- good ventilation with air (so diffusion gradients can be maintained)
Difference in composition between inspired and expired air
Inspired air: 78% N2, 21% O2, 0.04% CO2 (less water vapour)
Expired air: 78% N2, 16% O2, 4% CO2 (more water vapour)
State effects of physical activity on the rate and depth of breathing
Increased rate of breathing.
Increased depth of breathing.
Function of cartilage in the trachea
Prevents trachea from collapsing in itself.
Lubricates your joints, reducing friction.
Role of the ribs, the intercostal muscles and the diaphragm in producing volume and pressure changes in the thorax during breathing in.
the intercostal muscles contract, pulling the ribcage upwards and outwards. the diaphragm contracts, pulling downwards. volume of the thorax increases and the pressure inside decreases. air is drawn into the lungs down a pressure gradient.
Role of the ribs, intercostal muscles and the diaphragm
in producing volume and pressure changes in the thorax during breathing out
the intercostal muscles relax pulling the ribcage downwards and inwards. the diaphragm relaxes, doming upwards. volume of the thorax decreases and the pressure inside increases. air is pushed out of the lungs
describe the effects of physical activity on the rate and depth of breathing
your heart and lungs work harder to supply the additional oxygen your muscles demand. Rate increases and depth.
goblet cell
lines the airways and secrete mucus in order to trap any microorganisms and dust particles which have been inhaled
ciliated cells
lining the airway’s cells, beat the mucus to get out of the respiratory tract, to prevent pathogens from entering.
Explain why your breathing rate and depth of breath changes during physical activity.
During physical activity, our muscles contract more and do more respiration which causes an increased carbon dioxide concentration to be in the blood, which is detected by the brain, leading to an increased rate and greater depth of breathing
function of cartilage in the gas exchange system
keeps trachea open
allows free flow of air into the lungs
allows flexibility/can breath even when swallowing
why do trained athletes have lower levels of lactic acid in their blood?
they do more aerobic respiration than anaerobic respiration. meaning less lactic acid is produced. More oxygen is supplied to muscles, meaning less oxygen debt. Less oxygen required to breakdown lactic acid to produce glucose/carbon dioxide and water. Quicker breakdown of lactic acid.
