The Respiratory systemThe Respiratory system

FunctionsFunctions

• Works closely with circulatory system, exchanging Works closely with circulatory system, exchanging gases between air and blood:gases between air and blood:

• Takes up oxygen from air and supplies it to blood (for Takes up oxygen from air and supplies it to blood (for cellular respiration).cellular respiration).

• Removal and disposal of carbon dioxide from blood Removal and disposal of carbon dioxide from blood (waste product from cellular respiration).(waste product from cellular respiration).

Homeostatic Role:Homeostatic Role:– Regulates blood pH.Regulates blood pH.– Regulates blood oxygen and carbon dioxide levels.Regulates blood oxygen and carbon dioxide levels.

External RespirationExternal Respiration

• VentilationVentilation– exchange of air between lungs and atmosphereexchange of air between lungs and atmosphere

• Gas Exchange in pulmonary capillariesGas Exchange in pulmonary capillaries• Breathing largely involuntary activityBreathing largely involuntary activity

Internal RespirationInternal Respiration

• All cells require oxygen for metabolismAll cells require oxygen for metabolism• All cells require means to remove carbon All cells require means to remove carbon

dioxidedioxide• Gas exchange at cellular levelGas exchange at cellular level

Structures of Respiratory SystemStructures of Respiratory System

• upper respiratory tractupper respiratory tract– nose, mouth, pharynx, epiglottis, larynx and nose, mouth, pharynx, epiglottis, larynx and

tracheatrachea

• lower respiratory tractlower respiratory tract– bronchial tree and lungsbronchial tree and lungs

NoseNose• nasal cavitynasal cavity• nasal septumnasal septum• mucous membranemucous membrane– mucusmucus– ciliacilia– olfactory receptorsolfactory receptors

PharynxPharynx

• NasopharynxNasopharynx– Posterior to the nosePosterior to the nose– Contains adenoids or pharyngeal tonsilsContains adenoids or pharyngeal tonsils

• OropharynxOropharynx– Posterior to the mouthPosterior to the mouth– Palatine tonsilsPalatine tonsils

• LaryngopharynxLaryngopharynx– Superior to the larynxSuperior to the larynx

EpiglottisEpiglottis

• Oropharynx and laryngopharynx serve as a Oropharynx and laryngopharynx serve as a common passageway for both food and aircommon passageway for both food and air

• Epiglottis acts as a lid or flap Epiglottis acts as a lid or flap that covers the larynx that covers the larynx and trachea (airway) and trachea (airway) so food does not enter so food does not enter the lungs. the lungs.

LarynxLarynx

• Also known as the voice boxAlso known as the voice box• Glottis (vocal apparatus)Glottis (vocal apparatus)– vocal bands or vocal cordsvocal bands or vocal cords

TracheaTrachea

• Windpipe or airwayWindpipe or airway• Mucous membrane lining with ciliaMucous membrane lining with cilia• Smooth muscle with Smooth muscle with

c-shaped cartilage ringsc-shaped cartilage rings• divides into two branches: divides into two branches: – Right bronchiRight bronchi– Left bronchiLeft bronchi

BronchiBronchi

• Bronchus, singularBronchus, singular• C-shaped cartilage rings with smooth muscleC-shaped cartilage rings with smooth muscle• Each bronchi divides into Each bronchi divides into

bronchioles bronchioles • Terminate in air sacs Terminate in air sacs

called alveoli called alveoli

AlveoliAlveoli

• Resembles a small balloon as it expands Resembles a small balloon as it expands and contracts with the flow of airand contracts with the flow of air

• CO2 diffuses from the blood in the CO2 diffuses from the blood in the capillaries, enters the alveoli, and is capillaries, enters the alveoli, and is exhaled exhaled

• On inspiration, O2 diffuses On inspiration, O2 diffuses from the alveoli to enter from the alveoli to enter the capillaries the capillaries

Thoracic CavityThoracic Cavity

• thoracicthoracic• thoraxthorax• mediastinummediastinum– heartheart– aortaaorta– esophagusesophagus– bronchibronchi– thymusthymus

Right-3 lobes Left-2 lobes

Lungs

trachea

PleuraPleura

• each lung enclosed in pleuraeach lung enclosed in pleura• parietal pleura (inner)parietal pleura (inner)• visceral pleura (outer)visceral pleura (outer)• pleural space or pleural cavitypleural space or pleural cavity• lubricating fluidlubricating fluid

DiaphragmDiaphragm• muscle separating chest and abdomenmuscle separating chest and abdomen• inspirationinspiration,, diaphragm contracts and diaphragm contracts and

increases thoracic spaceincreases thoracic space– air flows inair flows in

• expirationexpiration, diaphragm relaxes and , diaphragm relaxes and decreases thoracic spacedecreases thoracic space– air flows outair flows out

• phrenic nervephrenic nerve

RespirationRespiration

• external respirationexternal respiration - exchange of gases in - exchange of gases in lungslungs

• internal respirationinternal respiration - exchange of gases within - exchange of gases within cells of the body organs and tissuescells of the body organs and tissues

• ventilationventilation - movement of air - movement of air

PathologyPathologyBreathing DisordersBreathing Disorders

• Chronic Obstructive Pulmonary DiseaseChronic Obstructive Pulmonary DiseaseCOPD (COLD)COPD (COLD)

• DyspneaDyspnea• BradypneaBradypnea• TachypneaTachypnea

COPDCOPD

• AsthmaAsthma– bronchospasms, parosysmal, productive cough, bronchospasms, parosysmal, productive cough, – mucolytics, bronchodilatorsmucolytics, bronchodilators

• Chronic BronchitisChronic Bronchitis– mucosal swelling, productive cough, chest painmucosal swelling, productive cough, chest pain– expectorants, bronchodilators, steroidsexpectorants, bronchodilators, steroids

• EmphysemaEmphysema– barrel-chest, dyspnea, orthopneabarrel-chest, dyspnea, orthopnea

InfluenzaInfluenza

• Acute infectious Acute infectious respiratory diseaserespiratory disease

• ViralViral• Fever, chills, headache, Fever, chills, headache,

myalgia, anorexiamyalgia, anorexia• Avoid aspirin in Avoid aspirin in

childrenchildren

Pleural EffusionsPleural Effusions

• Excess fluid in pleural cavityExcess fluid in pleural cavity• associated with congestive heart failure, associated with congestive heart failure,

ascites, infectious lung diseases, traumaascites, infectious lung diseases, trauma• diagnosisdiagnosis– auscultation, percussionauscultation, percussion

• Empyema, hydrothorax, hemothorax, Empyema, hydrothorax, hemothorax, pnrumothorax, pyopneumothoraxpnrumothorax, pyopneumothorax

• thoracentesisthoracentesis

TuberculosisTuberculosis

• Infectious, highly communicable Infectious, highly communicable diseasedisease

• aerosol transmissionaerosol transmission• primary tuberculosis, tuberclesprimary tuberculosis, tubercles• immunocompromisedimmunocompromised• effects other organ systemseffects other organ systems• drug resistant strainsdrug resistant strains

BronchopneumoniaBronchopneumonia

• Inflammatory disease of lungsInflammatory disease of lungs• lobar, bilaterallobar, bilateral• hemoptyisishemoptyisis• consolidationconsolidation• Pneumocystis carinii Pneumocystis carinii • lavagelavage

Cystic FibrosisCystic Fibrosis

• Hereditary disorder, affects exocrine glandsHereditary disorder, affects exocrine glands• systemic involvementsystemic involvement– lungs, pancreas, digestive tractlungs, pancreas, digestive tract

• Viscous mucus blocks bronchiolesViscous mucus blocks bronchioles• Gas exchange impairedGas exchange impaired

Respiratory Distress SyndromeRespiratory Distress Syndrome

• SurfactantSurfactant– decreases the surface tension of decreases the surface tension of

the alveolithe alveoli– needed for alveoli to fill with air needed for alveoli to fill with air

and expand (compliance)and expand (compliance)• Infant respiratory distress syndrome Infant respiratory distress syndrome

(hyaline membrane disease)(hyaline membrane disease)• Adult respiratory distress syndromeAdult respiratory distress syndrome

OncologyOncology

• Primary Pulmonary CancerPrimary Pulmonary Cancer• Smoking is leading cause of ALL Smoking is leading cause of ALL

TYPES OF LUNG CANCERSTYPES OF LUNG CANCERS• common site: epithelium of bronchicommon site: epithelium of bronchi– bronchogenic carcinomabronchogenic carcinoma– masses form and block air passagesmasses form and block air passages– metastasizes frequently to lymph noes, metastasizes frequently to lymph noes,

liver, bones, brain, or kidneyliver, bones, brain, or kidney