Phys: airways and pulm blood flow

Explain external respiration versus internal respiration

external: oxygenating the blood from the air (happens in the lungs)

internal: oxygen going into the tissues from the oxygenated blood

At what generation does cartilage stop?

10

What parts of the repsiratory tree have cilia?

from the trachea → bronchi → bronchioles → repiratory bronchioles

(not the alveolar ducts or sacs)

On the respiratory tree, where does the conducting zone stop and the respiratory zone start?

conducting zone ends at the bronchioles

respiratory zone starts at the repsiratory bronchioles

What are the four major functions of the conducting zone?

functions: humidify, warm, and filter air

other: also has the mucociliary elevator

Which receptors and division go with bronchodilation vs broncoconstriction?

dilation: sympathetic; beta-2 adrenergic receptors

constriction: parasympathetic; muscarinic Ach receptors

What are 3 substances that can dilate the bronchi?

epinephrone, isoproterenol, and albuterol

At what generation does the split between the conducting zone and respiratory zone happen?

16

how many alveoli are there per lung?

300 million

explain type I and type II pneumocytes

type I: the thin flat area that allows or gas exchange

type II: stem cells; also have lamellar bodies that produce surfactant (breaks surface tension)

pulmonary circulation is a ____ pressure system

bronchial circulation is a ____ pressure system

pulm: low

bronch: high

Explain why the pulmonary artery is one of the only arteries that carries low oxygenated blood

the pulm artery brings blood from RV to lungs then the pulm vein brings the oxygenated blood back to the LA

Explain pulmonary circulation versus bronchial circulation

pulm: functions to oxygenate the blood so it can go to the rest of the body

bronch: brings oxygenated blood to the lungs so the tissues can get O2

explain the significance of the bronchopulmonary anastomosis

this is the site where the brnonchial and pulmonary circulation meet

blood O2 content slightly drops here (bc mixing)

explain Laplace law with respect to the alveoli

pressure and radius are inversly proportional; so a small alveoli has more pressure

What keeps the smaller alveoli that have so much pressure (Laplace law) from collapsing?

sulfactant (dipalmitoyl phosphatidycholine; DPPC)