Buscar
Estás en modo de exploración. debe iniciar sesión para usar MEMORY

   Inicia sesión para empezar

level: Single cells and animals

Questions and Answers List

level questions: Single cells and animals

QuestionAnswer
How do you workout surface: volume ratio ?Workout out the surface area and then for volume and work out the simplest form
Factors that increase diffusionLarge surface Short diffusion pathway Maintaining a different concentration gradient
InspirationThe diaphragm muscle contracts and flatten downwards . The external intercostal muscles contract, pulling the ribs up and out. The internal intercostal muscles remain relaxed . This increases the volume of thorax and the lungs , and stretches the elastic walled alveoli. This decreases the pressure of air in the alveoli below atmospheric. Air flows in from high pressure to low pressure .
Normal expirationThe diaphragm muscle relaxes and curve upwards . The external intercostal muscles relax , allowing the ribs to fall . This decreases the volume of the thorax and the lungs , and allows the alveoli to shrink by elastic recoil . This increases the pressure of air in the alveoli above atmosphere. Air flows out from high to low pressure .
Structural adaptions of the alveoli- small to increase surface area -single layer of flattened epithelial cells for a short diffusion pathway -maintain conc gradient