Chapter 22:Chapter 22:Respiratory SystemRespiratory System

Respiratory VolumesRespiratory Volumes

Respiratory Volumes and Respiratory Volumes and CapacitiesCapacities• Respiratory volumes Respiratory volumes The amount of The amount of

air that is flushed in and out of the lungsair that is flushed in and out of the lungs

• Respiratory capacities Respiratory capacities Specific Specific sums of the respiratory volumes sums of the respiratory volumes

• SpirometerSpirometer measures respiratory measures respiratory volumesvolumes

Respiratory VolumesRespiratory Volumes• Tidal volume (TV)– Tidal volume (TV)– during normal quiet breathing during normal quiet breathing

the amount of air that moves into and out of lungsthe amount of air that moves into and out of lungs– 20 yrs 155 lbs 20 yrs 155 lbs 500 ml 500 ml

• Inspiratory reserve(IRV) Inspiratory reserve(IRV) – the amount of – the amount of air that can be inspired forcibly beyond the air that can be inspired forcibly beyond the normal inhalation (2100 – 3200 ml)normal inhalation (2100 – 3200 ml)

Respiratory VolumesRespiratory Volumes

• Expiratory reserve (ERV)– Expiratory reserve (ERV)– the amount of the amount of air that can be evacuated from the lungs air that can be evacuated from the lungs after normal exhalation (1000 – 1200 ml)after normal exhalation (1000 – 1200 ml)

Respiratory VolumesRespiratory Volumes

• Residual volume (RV) – Residual volume (RV) – the amount of air left in the the amount of air left in the lungs after the most strenuous expiration (1200 ml)lungs after the most strenuous expiration (1200 ml)– Helps to keep the alveoli open and prevent lung collapseHelps to keep the alveoli open and prevent lung collapse

Respiratory VolumesRespiratory Volumes

• Inspiratory Capacity (IC) Inspiratory Capacity (IC) – Total amount of air that can be inspired after a Total amount of air that can be inspired after a

tidal expirationtidal expiration– IC = TV + IRVIC = TV + IRV

Respiratory CapacitiesRespiratory Capacities

• Functional residual capacity (FRC)Functional residual capacity (FRC)– Volume of air remaining in the lungs after a Volume of air remaining in the lungs after a

normal tidal expirationnormal tidal expiration– FRC = ERV + RVFRC = ERV + RV

Respiratory CapacitiesRespiratory Capacities

• Vital capacity (VC)Vital capacity (VC)– Maximum amount of air that can be expired after a Maximum amount of air that can be expired after a

maximum inspiratory effortmaximum inspiratory effort– VC = TV + IRV + ERVVC = TV + IRV + ERV– Should be 80% of TLCShould be 80% of TLC

Respiratory CapacitiesRespiratory Capacities

• Total lung capacity (TLC)Total lung capacity (TLC)– Maximum amount of air contained in lungs after Maximum amount of air contained in lungs after

maximum inspiratory effort (sum of all volumes)maximum inspiratory effort (sum of all volumes)– TLC = TV + IRV + ERV + RVTLC = TV + IRV + ERV + RV

Respiratory CapacitiesRespiratory Capacities

Anatomic Dead SpaceAnatomic Dead Space• Inspired air that Inspired air that

fills the conducting fills the conducting passageways, but passageways, but doesn’t contribute doesn’t contribute to gas exchangeto gas exchange

• About 150 mLAbout 150 mL• Easy way to Easy way to

determine determine your your ideal weight in ideal weight in pounds is dead pounds is dead space in mLspace in mL

CoughingCoughing

• A long-drawn and deep inhalation followed A long-drawn and deep inhalation followed by complete closure of glottis, which results by complete closure of glottis, which results in a strong exhalation that suddenly pushes in a strong exhalation that suddenly pushes the glottis open and sends a blast of air the glottis open and sends a blast of air through the upper respiratory passages. through the upper respiratory passages. Stimulus may be a foreign body lodged in Stimulus may be a foreign body lodged in larynx, trachea, or epiglottislarynx, trachea, or epiglottis

SneezingSneezing

• Spasmodic contraction of muscles of Spasmodic contraction of muscles of exhalation that forcefully expels air through exhalation that forcefully expels air through the nose and mouth. Stimulus may be an the nose and mouth. Stimulus may be an irriatation of the nasal mucosairriatation of the nasal mucosa

YawningYawning

• A deep inhalation through the widely A deep inhalation through the widely opened mouth producing an exaggerated opened mouth producing an exaggerated depression of the mandible. It may be depression of the mandible. It may be stimulated by drowsiness, fatigue, or stimulated by drowsiness, fatigue, or someone else’s yawning. Precise cause is someone else’s yawning. Precise cause is unknownunknown

HiccuppingHiccupping• Spasmodic contraction of the diaphragm Spasmodic contraction of the diaphragm

followed by a spasmodic closure of the followed by a spasmodic closure of the glottis, which produces a sharp sound on glottis, which produces a sharp sound on inhalation. Stimulation is usually irritation inhalation. Stimulation is usually irritation of the sensory nerve endings of the GI tractof the sensory nerve endings of the GI tract

Chapter 22:Chapter 22:Respiratory SystemRespiratory System

Transport of Respiratory Transport of Respiratory GasesGases

Transport of Respiratory Transport of Respiratory GasesGases

• Oxygen TransportOxygen Transport– Dissolved in the plasma – 1.5 %Dissolved in the plasma – 1.5 %

•OO2 2 is poorly soluble in wateris poorly soluble in water

• Oxygen TransportOxygen Transport– Bound to hemoglobin – 98.5% Bound to hemoglobin – 98.5%

•Hemoglobin (Hb) is composed of 4 Hemoglobin (Hb) is composed of 4 polypeptide chains, each bound to an iron-polypeptide chains, each bound to an iron-containing heme group.containing heme group.

•The The iron binds the oxygeniron binds the oxygen. Each . Each hemoglobin can take 4 oxygen molecules.hemoglobin can take 4 oxygen molecules.

•After first oxygen binds, the Hb molecules After first oxygen binds, the Hb molecules changes shape changes shape each oxygen afterwards each oxygen afterwards binds quicker than the lastbinds quicker than the last

Transport of Respiratory Transport of Respiratory GasesGases

• Carbon dioxide TransportCarbon dioxide Transport– Dissolved in plasma – 7 - 10%Dissolved in plasma – 7 - 10%– Bound to hemoglobin – ~20% Bound to hemoglobin – ~20%

•Binds directly to the Binds directly to the globinglobin•Doesn’t compete with oxygen transportDoesn’t compete with oxygen transport

– Bicarbonate ion (HCOBicarbonate ion (HCO33--) in plasma – ~70%) in plasma – ~70%

•COCO22 + H + H22O HO H22COCO33 H H++ + HCO + HCO33--

•COCO2 2 enters RBC and reaction takes place very enters RBC and reaction takes place very quickly quickly HCO HCO33

-- moves from RBC into the plasma. moves from RBC into the plasma.•Reaction also takes place but at a much slower Reaction also takes place but at a much slower

rate!rate!

Transport of Respiratory Transport of Respiratory GasesGases

RespirationRespiration• External respiration External respiration Pulmonary gas Pulmonary gas

exchange exchange gas exchange between lungs and gas exchange between lungs and the bloodthe blood

• Internal respiration Internal respiration systemic gas exchange systemic gas exchange gas exchange between blood and the tissue gas exchange between blood and the tissue

• Cellular respiration Cellular respiration blood to cells, cells use blood to cells, cells use OO22 to break down food for useable energy to break down food for useable energy (ATP)(ATP)