Anatomy B/C

[kappakun]

What is the first structure of the respiratory tree to lack smooth muscle?
I know the upper bronchioles have smooth muscle, but what about the terminary bronchioles? Or respiratory bronchioles?

[foreverphysics]

It's cartilage from the trachea down to the bronchi. Anything down from that is smooth muscle.
(Verification, SciBomb?)

[kappakun]

Hmm.. the terminal bronchioles signify the end of the conducting zone, while the respiratory zone start with respiratory bronchioles. Somewhere during the transition between bronchioles and the alveoli, there is no more smooth muscle. Since the respiratory zone is the start of gas exchange, I think it would make sense for the respiratory bronchiole to not have smooth muscle anymore, although I am not sure about this. What do you guys think?

[SciBomb97]

Actually, all portions of the bronchial tree have smooth muscle. The larger bronchi have incomplete rings of cartilage outside the smooth muscle ring, and and smallest bronchi have irregularly spaced plates of cartilage on the outside of the muscle. After that (that is, from the bronchioles down) the airways are made up entirely of a thicker ring of smooth muscle because the muscle along can hold open the airways due to the small diameter of the airways. The smooth muscle disappears in the alveoli, where the walls become completely epithelial cells.

[liutony66]

Lastly, the parts of the brain which control different processes may be on the test, but that's also something you may want to put on the cheat sheet.

Just a clarification, which part of the brain controls different processes? I know that because respiration and digestion are largely automatic functions they are controled by the medulla oblongota, but is there any other things that we should know about that?

[Flavorflav]

There are also important respiratory centers in the pons, and the hypothalamus regulates hunger. I wouldn't expect to see too much on the brain, though.

[SciBomb97]

They might put some questions that point to the general areas of the brain, but probably nothing specific.

[Not Ur Average Bear]

For anatomy, do we need to know about the teeth and do we need to know about respiratory hormones?

[SciBomb97]

You need to know about the teeth.
Not sure what you mean by respiratory hormones.

[liutony66]

What is the significance of the peritoneum? (in terms of significance in the test)