Lungs Flashcards
In large organisms their surface are allows what?
Their surface area is small so often have a high rate of metabolism and a specialised gas exchange mechanism.
In small unicellular organisms their surface area allows what to be sufficient?
Their surface are to volume ratio Is so large that diffusion through body surface is sufficient,
Human lungs internally minimise what?
Heat and water loss.
What does the human respiratory system consist of?
Epiglottis, trachea, bronchi, bronchioles, alveoli, pleural membranes, ribs, intercostal muscles, diaphragm, all involved ventilation and gas exchange.
Nasal cavity.
Filters air and warms air increasing gas molecular kinetic energy and gas exchange efficiency.
Trachea.
C shaped cartilage, stops trachea collapsing, and allows oesophagus to expand for food bolus moving down.
Bronchi.
Narrow into bronchioles.
Tina of cartilage to stop collapsing
Alveoli.
Site of gas exchange.
Massive surface area
On cell thick increasing efficiency of gas exhange
Diaphragm.
Separates chest cavity from abdominal cavity.
Rib age.
Intercostal muscle between ribs repairable for elevation of ribs.
External - further outward.
Internal - further inward
Pleural membrane.
Surrounds lungs and protects from rubbing with ribs.
Epiglottis.
Small flap of skin PREVEBTING food from entering windpipe.
Lungs left
Two lobes.
Smaller than right makes room for heart.
Lungs right.
3 lobes.
Lungs have what for rapid diffusion and for transport to maintain diffusion gradient?
Extensive capillary network.
Inspiration.
Diaphragm muscle contracts and lowers.
External intercostal muscles contract, moving ribs up.
Volume of thorax increases.
Pressure decreases. Air drawn into alveoli down pressure gradient.
Expiration.
Diaphragm muscle relaxes and raises.
External intercostal muscles relax
Volume of thorax decreases.
Pressure increases, and air forced out of alveoli down pressure gradient.
Surfactant and water found where? What is surfactant?
As the doll of moisture on alveolus.
Surfactant- anti sticking, overcomes surface tension keeping alveoli open, given to premature babies.
Respiratory exchange can be studied with spirometer. For asthma and emphysema. What do they involve?
Asthma causes reduced airflow due to muscular spasm and bronchioles constriction together with inflammation.
Emphysema involves breakdown of alveoli walls reducing surface area
