The four important characteristics of respiratory surface are:
1. Thin walls
2. Moisture
3. Large surface area
4. Blood supply
Respiratory system or respiratory tract is divided into upper and lower tract. Upper respiratory tract includes nose and its cavities, sinuses, pharynx and the part of the larynx. Lower respiratory tract consists of the trachea, bronchi, bronchioles and the alveoli.
Alveoli are the ends of the respiratory tract the smallest units in it. Alveoli are small folded air sacs that are branching off from alveolar ducts and providing an extremely large surface area for the gas exchange. Gas exchange occurs thanks to small blood vessels – capillaries that surround alveoli and it occurs via the process of diffusion.
So, respiratory surface is thin membrane also known as the blood–air barrier that consists of the alveolar epithelial cells, their basement membranes and the endothelial cells of the alveolar capillaries.
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Question:What is one difference between the theory of continental drift and the one theory of plate tectonics
Answer/Explanation: Continental drift is the hypothesis that states that the continents once formed a single landmass(Pangaea) broke up and drifted to their present locations.Sea-floor spreading the process by which new oceanic lithosphere(sea floor) forms as magma rises to Earth's surface and solidifies at a mid-ocean ridge.
