D1b: Respiration

Process by which air enters and exits body

All processes that supply O2 to cells for decomp. of glucose and co2 transport to lungs for exhalation

• Gas exchange between lungs and atmosphere • G.e between lungs and blood • Cell resp

Nasal cavity • hair and mucus are filter • mucus maintains moisture • opens into pharynx and branches into trachea and esophagus

Larynx • upper end of trachea • protected by cartilage • elastic ligaments=vocal chords which vibrate when air moves past

Trachea • Mucus=filter • ciliated cells sweep debris back to pharynx • supported by rings of cartilage

Bronchi • carry air to right and left lungs • has cartilage rings • branch into bronchioles

Alveoli • single layer of cells surrounded by capillaries • gas diffusion occurs do to concentration gradient (air to blood=passive) • high S:A • lipoproteins prevent sac from sticking to itself during exhalation

Mediate gas exchange with capillaries Flat and thin so low diffusion distance

Secretes pulmonary surfactant • wo surfactant=small radius and high pressure • w surfactant=alveoli can inflate and surface tension decreasing prevents sides of alveoli from adhering

• Air enters through nose and mouth • Air travels down larynx and trachea • Air goes into bronchi into bronchioles where gas exchange occurs

Pressure is inversely proportional to volume • when volume in thoracic cavity is high, pressure is low= gas in • inhaling:low pressure=air in • exhaling:high pressure= air out (Concentration gradient)

Separates thoracic cavity and abdominal cavity (dome shaped) • Inspiration: Diaphragm contracts= Down and flat and abdomen relaxes allowing pressure from diaphram to push it out • Expiration: diaphragm relaxes up a domed and abdomen contracts up

Inhalation- External contract= Ribs up and out, internal relax=elongate Exhalation- External relax=elongate and internal contract= ribs in and down

Protects lungs as fluid in pleural cavity prevents friction as lungs move against thoracic cavity walls

Tidal volume-normal air going in and out) • inspiratory reserve-additional air that can be inhaled • expiratory reserve- additional aur that can be exhaled • vital capacity-total volume of gas that can move in and out • residual volume- amount of air left in lungs after max exhalation

External- in lungs between aur and blood Internal-in body between blood and tissue

O2 high in alveolar and low in capillaries CO2 high in capillaries and low in alveoli

Equal volume of gases at same temp and pressure contain equal amount of molecules

Gases in mixture behave as if other isn’t there, exerting it’s own pressure P.P of o2 is high in atmosphere and low in veins(opposite w co2) When u inhale p.p of o2 id high in alveoli than capillaries so O2 moves to capillaries

• plasma doesn’t dissolve enough o2 but hemoglobin dissolves 70x more (has iron and bonds weaning to o2) • in lungs oxygenated blood leave alveoli and binds to o2 (association) • in tissues oxygen leaves blood and hemoglobin and enters cells (disassociation)

• O2 is used in cell resp and creates co2 • Co2 diffuses into blood vessel ( some bind to hemoglobin) • Majority of co2 combine w water+ carbonic acid • lows blood ph • maintains p.p of co2 so diffusion can continue • Carbonic acid is not stable so it separates into h* and hCO3- (bicarbonate) • H+ bind to hemoglobin= leftover o2 released (hemoglobin is ph buffer) • Once at alveoli’s capillary bed, o2 presence makes h+ leave hemoglobin 7.bicarbonate and h+ combine=H2O and co2 • Co2 diffuses into Alveoli and leaves body

• most co2 produced from cell resp enters blood plasma and combines w water to become carbonic acid • catalzyed by carbonic anhyrase • then disassociated into bicarbonate • decrease in co2 in plasma=decrease is p.p • h+ bibs to hemoglobin=ph buffer

Co2 attaches to gloom and o2 is Carried by heme