Nose & Mouth: Entry & Exit Point. Nasal cavity filters air.
Pharynx: Throat
Larynx: Voice box, Adams apple. Top of trachea.
Vocal Cords: In larynx. 2 elastic folds of tissue which vibrate as air passes
to create noise.
Trachea: Windpipe. Has cartilage rings to prevent collapse. Cilia sweep out
contaminants.
Bronchus (1)/ Bronchi (2): Small main branches connect trachea to lungs.
Lungs: Main organs of respiratory system. The site of air/ blood interface.
Bronchiole: Smaller branched air passages within lungs.
Alveoli: (Fig 32-15 & 32-17) Tiny hollow air sacs of thin, flexible membranes
w/ numerous capillaries. Diffusion. Actual site of respiration.
Red Blood Cell/ Hemoglobin: (Fig. 32-17) Carries O2 and C02 through circulatory
system. Hemoglobin is red protein that carries much O2.
Diaphragm: (Fig. 32-16) Large flat muscle below lungs, above abdominal cavity
that moves to cause breathing.
Inhalation/ Inspiration: Diaphragm lowers. Air pulled into lungs. Air pressure
drops in lungs (less air), so air diffuses in.
Exhalation/ Expiration: Diaphragm raises. Air leaves lungs. Air pressure
raises in lungs (more air in smaller space), so air diffuses to outside.
Breathing rate controlled by amount of CO2 in blood. Receptor in aorta sends
message to lower brain, which sends message to diaphragm to move up or down.
This is all involuntary (no thinking involved!).