Anatomy and Physiology Lecture Quiz 2/27

About _____________________________________ years ago, a fishy looking thing became the first organism to breathe air. They did it through diffusion: when a material automatically flows from where its concentration is _____________________ to where it is _______________________.

380 million; high to low

Both lungs contain 700 million alveoli, making for ________________________ of moist membrane surface area.

75 sq meters

_______________________________ were an efficient new way to bring in oxygen.

Lungs

Simple diffusion does not bring in enough oxygen to support larger life forms. In order to get bigger, organisms needed a _______________________________________system to move bulk amounts of oxygen around inside their bodies faster and a ________________________________________ system to bring more oxygen in contact with their wet membranes.

circulatory; respiratory

One of the keys to efficient diffusion of any material is distance. You want a molecule to be as ______________ to its destination as possible.

close

When you breathe in, your diaphragm RELAXES/CONTRACTS and flattens and the intercostals muscles between your ribs contract, causing the chest cavity to expand and making the air pressure inside your lungs LOWER/HIGHER than the air outside your body, and the air rushes into your lungs. The opposite happens when you breathe out.

contracts; lower

The _________________________________ keeps food particles from entering your lungs.

epiglottis

Bulk flow moves LARGE/SMALL numbers of molecules quickly.

large

The alveoli is the site where ________________________________ diffuses out of the lungs and into the blood while _____________________________________ diffuses out of the blood, into the lungs, and then back up the same route that the air came in.

oxygen; carbon dioxide

Your ______________________________ system is set up to take advantage of bulk flow and simple diffusion.

respiratory

Your nose has a very important function: it __________________________ and moistens incoming air so it doesn't dry out the sensitive lung cells that must remain _______________________.

warms; wet