Respiratory System

Right lung: Three lobes Left lung: Two lobes

Help to clean air as it passes

Cartilage, which you can feel covering yourTrachea, protects it. Feel the rings in your neck?

• Affects of smoking on respiration? Look it up!

• What is Asthma? Look it up!

• What is bronchitis? Look it up!

Vocal Folds

•Functions–Maintain an open passageway for air movement (thyroid and cricoid)

–Epiglottis and vestibular folds prevent swallowed material from moving into larynx

–Vocal folds are primary source of sound production

You don’t have to know these terms!

Vocal Folds

• As air passes by the vocal cords and cause them to move, they vibrate the air and cause a sound.

• Males have larger vocal cords (hence the presence of the “Adams Apple”, the protruding Pharynx with cords inside.– Thus, they have deeper voices.

Alveolus (plural=alveoli)

• Very thin membranes

• Look like clumps of grapes

• Gas exchange occurs here, taking oxygen into the blood and moving carbon dioxide out into alveolar space.

• Major rout brings deoxygenated blood to the lungs via the pulmonary artery, to pulmonary capillaries, is oxygenated and returns to the heart through the pulmonary veins.

Blood flow

Movement of air into and out of lungs

• Air moves from area of higher pressure to area of lower pressure– Atmosphere has pressure (1 atm=760 torr) (at sea level, changes at

altitude)– When pressure inside thoracic cavity falls ________ 1 atm, air flows into

lungs, (and vice versa)• Pressure is inversely related to volume• When the intercostal muscles (muscles between ribs) and

________ increase volume of the thoracic cavity, pressure ____________.

• Diaphragm flexes down flat, making space bigger (inhalation). • Diaphragm relaxes bending up, descreasing space and increasing

pressure (now higher than 1 atm)– Remember things move form higher pressure to lower pressure– To inhale, pressure in lungs must be lower than 1atm– To exhale, pressure must be higher than 1atm

• How does breathing change on top of Mt. Everest? (look it up!)– Consider both available oxygen and variation in pressure

decreasesdiaphragm

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