THE PULMONARY THE PULMONARY SYSTEMSYSTEM

EMRITA C. MENDOZA, R.N., EMRITA C. MENDOZA, R.N., M.D.M.D.

FUNCTIONS OF THE FUNCTIONS OF THE PULMONARY SYSTEMPULMONARY SYSTEM

Inhalation and Inhalation and exhalation of air exhalation of air through airways through airways to and from the to and from the lungslungs

(Ventilation)(Ventilation) To exchange To exchange

gases between gases between alveoli and alveoli and capillaries capillaries (Perfusion)(Perfusion)

FLOW OF AIR FLOW OF AIR THROUGH THE AIRWAYSTHROUGH THE AIRWAYS

Nostrils Nostrils Nasal passages and Nasal passages and

sinuses sinuses Pharynx Pharynx EpiglottisEpiglottis Larynx Larynx Trachea (windpipe)Trachea (windpipe) Main Bronchi (R & L)Main Bronchi (R & L) Secondary Lobar Secondary Lobar

BronchiBronchi Tertiary Lobular Tertiary Lobular

BronchiBronchi Terminal BronchiolesTerminal Bronchioles

ANATOMY OF ANATOMY OF THE AIRWAYSTHE AIRWAYS Larynx:Larynx:

muscular cords muscular cords protected by protected by circular circular cartilagescartilages

Trachea:Trachea: continues as continues as hyaline hyaline cartilages with cartilages with inner ciliated inner ciliated lininglining

ANATOMY OF THE ANATOMY OF THE AIRWAYSAIRWAYS Right main bronchus Right main bronchus

is shorter & wider is shorter & wider than the left.than the left.

Trachea divides into Trachea divides into the R & L primary the R & L primary bronchi at the bronchi at the carina.carina.

BRONCHUSBRONCHUS secondary bronchisecondary bronchi tertiary or segmental tertiary or segmental bronchibronchi respiratory respiratory bronchiolesbronchioles

LOCATION OF THE LOCATION OF THE LUNGSLUNGS

Two large, Two large, spongy organs spongy organs occupying the occupying the thoracic cavity thoracic cavity on either side of on either side of the heartthe heart

Composed of Composed of elastic elastic connective tissue connective tissue whose linings are whose linings are coated with coated with surfactantsurfactant

PLEURAL MEMBRANESPLEURAL MEMBRANES

Each lung is lined Each lung is lined with with visceral pleuravisceral pleura

Continuous with the Continuous with the parietal pleuraparietal pleura of of the thoracic cavitythe thoracic cavity

Space in between is Space in between is the the pleural cavitypleural cavity or or sac, which is sac, which is lubricated for easier lubricated for easier gliding of the lungsgliding of the lungs

RELATIONS OF THE LUNGSRELATIONS OF THE LUNGS

Lungs lie within the Lungs lie within the borders of the borders of the thoracic cagethoracic cage

Floor is the Floor is the diaphragm, which diaphragm, which is higher on the is higher on the rightright

Heart lies in Heart lies in between and between and anterior, occupying anterior, occupying the (L) cardiac the (L) cardiac notchnotch

Rib Levels of the LungsRib Levels of the Lungs

Apex or Apical Apex or Apical region = neck region = neck of the of the

first ribfirst rib Hilar region is Hilar region is

where a where a bronchus bronchus entersenters

Basilar region Basilar region lies along the lies along the basebase

Pleural CavitiesPleural Cavities

Costodiaphragmatic Costodiaphragmatic recessesrecesses

: Spaces in the : Spaces in the pleural cavities pleural cavities below each lung, below each lung, superior to the superior to the diaphragm.diaphragm.

Lobes of the LungsLobes of the Lungs

(R) lung(R) lung = 3 lobes = 3 lobes - upper, middle, - upper, middle,

lower lower fissures:fissures:

horizontal, horizontal, obliqueoblique

(L) lung(L) lung = 2 lobes = 2 lobes - upper with - upper with

lingula, lingula, lower lower fissure:fissure: oblique oblique

Bronchopulmonary Bronchopulmonary SegmentsSegments

The anatomical, The anatomical, functional, and functional, and surgical lung unit surgical lung unit

Composed of:Composed of:

A. tertiary bronchiA. tertiary bronchi

B. branch of B. branch of pulmonary pulmonary

arteryartery

C. lung parenchymaC. lung parenchyma

Histology of the AirwaysHistology of the Airways Conductive Conductive

portion of the portion of the respiratory tree:respiratory tree:

A. hyaline A. hyaline cartilage cartilage

B. smooth muscle B. smooth muscle C. inner elastic C. inner elastic layer: lined with layer: lined with ciliated epithelium ciliated epithelium with mucus-with mucus-secreting goblet secreting goblet cellscells

Conductive Conductive bronchioles:bronchioles: do not do not contain cartilage but contain cartilage but Clara cells which Clara cells which secrete cytochrome secrete cytochrome P-450 to attack P-450 to attack airborne toxinsairborne toxins

Histology of Respiratory Histology of Respiratory ParenchymaParenchyma

Respiratory Respiratory bronchioles are bronchioles are unciliated.unciliated.

Interstitial connective Interstitial connective tissue supports the tissue supports the ductsducts

Alveoli contain Alveoli contain macrophages and macrophages and pneumocytes:pneumocytes:

Type I Type I – simple – simple squamous epithelium squamous epithelium sensitive to sensitive to neutrophilic neutrophilic lysozymeslysozymes

Type II – secretes Type II – secretes surfactantsurfactant

Mechanics of Mechanics of VentilationVentilation

INSPIRATIONINSPIRATIONrespiratory muscles contract respiratory muscles contract

(diaphragm,intercostal (diaphragm,intercostal m.)m.)

increased thoracic increased thoracic diameter diameter

Decreased pressureDecreased pressure

Air goes inAir goes in

EXPIRATIONEXPIRATION

Respiratory muscles relaxRespiratory muscles relax

Decreased thoracic Decreased thoracic diameterdiameter

Increased pressureIncreased pressure

Air goes outAir goes out

Respiratory Rate (RR)Respiratory Rate (RR)

Inspiration-Inspiration-expiration cycle is expiration cycle is measured in cpm measured in cpm (cycles per (cycles per minute)minute)

Normal adult RR: Normal adult RR: 14-20cpm 14-20cpm

Children 20-30 Children 20-30 cpmcpm

Infants 40-60 cpmInfants 40-60 cpm

Regulation of RespirationRegulation of Respiration RESPIRATORY RESPIRATORY

CENTER in the CENTER in the BRAINSTEM.BRAINSTEM.

- activated by acidic - activated by acidic blood pH due to blood pH due to excess CO2 which excess CO2 which forms carbonic acid:forms carbonic acid:

CO2 + H20 CO2 + H20 H2CO3H2CO3

CAROTID AND AORTIC CAROTID AND AORTIC CHEMORECEPTORS CHEMORECEPTORS

- help regulate breathing- help regulate breathing

- High [CO2] or low [O2] - High [CO2] or low [O2] in the blood will make in the blood will make chemoreceptors send chemoreceptors send nervous impulses to the nervous impulses to the medulla and pons to medulla and pons to inform the phrenic nerveinform the phrenic nerve

Phrenic nerve stimulates Phrenic nerve stimulates the diaphragm tothe diaphragm to contractcontract

Breathing PatternsBreathing Patterns BIOTS: BIOTS:

breathing with breathing with irregularly irregularly alternating alternating periods of apnea periods of apnea and hyperpneaand hyperpnea

e.g.meningitis and e.g.meningitis and brain disorders brain disorders that cause that cause ICP ICP

CHEYNE-STOKESCHEYNE-STOKES:: common but common but usually abnormal usually abnormal periods of apnea periods of apnea lasting 10-60 lasting 10-60 seconds followed by seconds followed by gradual increase gradual increase then decreasethen decrease

e.g. frontal lobe e.g. frontal lobe and diencephalic and diencephalic dysfunctiondysfunction

Breathing PatternsBreathing Patterns COGWHEELCOGWHEEL

– – respiratory respiratory murmur, not murmur, not continuous but continuous but broken into broken into waves waves

e.g. bronchitis e.g. bronchitis and possible TBand possible TB

KUSSMAUL KUSSMAUL – deep, – deep, gasping gasping breathingbreathing

e.g. diabetic e.g. diabetic ketoacidosis and ketoacidosis and comacoma

Alveolar Ventilation/ Alveolar Ventilation/ PerfusionPerfusion

VENTILATION (V) VENTILATION (V) -refers to air -refers to air flowflow

PERFUSION (Q) PERFUSION (Q) - -refers to blood flowrefers to blood flow

V/Q measured V/Q measured in ml/min in ml/min

Normal V/Q: Normal V/Q: 0.8 ml/min 0.8 ml/min

V/Q mismatch V/Q mismatch occurs when occurs when diseases affect diseases affect either floweither flow

ARTERIAL BLOOD GASES ARTERIAL BLOOD GASES (ABG)(ABG)

Measurements of the amounts of gases in the Measurements of the amounts of gases in the bloodstream useful to help diagnose bloodstream useful to help diagnose conditions like acute respiratory distress conditions like acute respiratory distress syndrome (ARDS)syndrome (ARDS)

PULMONARY FUNCTION PULMONARY FUNCTION TESTS (PFT)TESTS (PFT)

•A spirometer can also be used to measure air flow.A spirometer can also be used to measure air flow.• Patient is guided to exhale forcefully into a tube Patient is guided to exhale forcefully into a tube which can measure RR and various lung volumeswhich can measure RR and various lung volumes