The RESPIRATORY The RESPIRATORY SystemSystem

Functions of the Functions of the Respiratory SystemRespiratory System

• Provides structures and Provides structures and mechanisms for gas exchangemechanisms for gas exchange– Intake of OIntake of O22

– Elimination of COElimination of CO22

• Helps maintains body’s pHHelps maintains body’s pH

RespirationRespiration• The exchange of gases between the The exchange of gases between the

atmosphere, blood, and cellsatmosphere, blood, and cells• Pulmonary Ventilation - the exchange of Pulmonary Ventilation - the exchange of

air between the atmosphere and lungsair between the atmosphere and lungs• External (Pulmonary) Respiration - gas External (Pulmonary) Respiration - gas

exchange between the lungs and bloodexchange between the lungs and blood• Internal (Tissue) Respiration - gas Internal (Tissue) Respiration - gas

exchange between the blood and cells exchange between the blood and cells

Organs of the Organs of the Respiratory SystemRespiratory System

• NoseNose• PharynxPharynx• LarynxLarynx• TracheaTrachea• BronchiBronchi• LungsLungs

Respiratory System Respiratory System

Respiratory StructuresRespiratory Structures

NoseNose• External PortionExternal Portion

– Supporting bony frameworkSupporting bony framework– CartilageCartilage - Skin- Skin– Mucous membranesMucous membranes– Nostrils or external naresNostrils or external nares

• Internal Portion - large cavity within the Internal Portion - large cavity within the skullskull– Connects the external nose to the pharynx Connects the external nose to the pharynx

through two openings (Internal Nares)through two openings (Internal Nares)

External Nose External Nose StructuresStructures

NoseNose• Nasal Cavity - large cavity that Nasal Cavity - large cavity that

contains both the external and contains both the external and internal nose cavitiesinternal nose cavities

• divided into the right and left sides divided into the right and left sides by the NASAL SEPTUMby the NASAL SEPTUM

Internal Nose Internal Nose StructuresStructures

Functions of the NoseFunctions of the Nose• Warming, moisturizing and filtering Warming, moisturizing and filtering

incoming airincoming air• Smell (reception of olfactory Smell (reception of olfactory

stimulus)stimulus)• Resonating chamber for speechResonating chamber for speech

PharynxPharynx• Funnel-shaped tube about 13 cm longFunnel-shaped tube about 13 cm long• Extends from the internal nares down to Extends from the internal nares down to

the cricoid cartilage of the larynxthe cricoid cartilage of the larynx• Walls composed of skeletal muscle lined Walls composed of skeletal muscle lined

with a mucous membranewith a mucous membrane• Divided into three areasDivided into three areas

– Nasopharynx Nasopharynx – Oropharynx Oropharynx – LaryngopharynxLaryngopharynx

Regions of the Pharynx Regions of the Pharynx

Functions of the Functions of the PharynxPharynx

• Passageway for food and airPassageway for food and air• Resonating chamber for speech Resonating chamber for speech

Larynx Larynx (Voice Box) (Voice Box)

• A short passageway that connects A short passageway that connects the pharynx with the tracheathe pharynx with the trachea

• Walls of the larynx is composed of Walls of the larynx is composed of 9 pieces if cartilage9 pieces if cartilage– Three single pieces of cartilageThree single pieces of cartilage

• epiglottic cartilage (Epiglottis)epiglottic cartilage (Epiglottis)• thyroid cartilage (Adam’s Apple)thyroid cartilage (Adam’s Apple)• cricoid cartilage cricoid cartilage

(attaches the Larynx to the Trachea) (attaches the Larynx to the Trachea)– Three paired pieces of cartilageThree paired pieces of cartilage

• arytenoid - corniculate - cuneiform arytenoid - corniculate - cuneiform

Larynx StructuresLarynx Structures

EpiglottisEpiglottis• Large leaf-shaped piece of cartilage Large leaf-shaped piece of cartilage

lying on top of the larynxlying on top of the larynx– The stem of the epiglottic cartilage is The stem of the epiglottic cartilage is

attached to the thyroid cartilageattached to the thyroid cartilage• Leaf portion of the cartilage is Leaf portion of the cartilage is

unattached and acts like a trap door unattached and acts like a trap door covering the opening to the trachea covering the opening to the trachea which is called the glottis.which is called the glottis.– Dependent upon breathing or swallowing Dependent upon breathing or swallowing

EpiglottisEpiglottis

GlottisGlottis• The opening from the pharynx to the The opening from the pharynx to the

larynx that contains the vocal cordslarynx that contains the vocal cords– Vocal Cords - mucous membrane folds Vocal Cords - mucous membrane folds

that extend across the glottis in two that extend across the glottis in two layerslayers

• upper layer or folds - false vocal foldsupper layer or folds - false vocal folds• lower layer or folds - true vocal folds lower layer or folds - true vocal folds

• Sounds originate from vibration of Sounds originate from vibration of these true vocal cordsthese true vocal cords

Glottis and Vocal CordsGlottis and Vocal Cords

TracheaTrachea• Tubular passageway about 12 cm long Tubular passageway about 12 cm long

and 2.54 cm in diameterand 2.54 cm in diameter• Anterior to the esophagusAnterior to the esophagus• Extends from the larynx to about the Extends from the larynx to about the

5th thoracic vertebrae5th thoracic vertebrae• Composed of 16 - 20 C-shaped cartilage Composed of 16 - 20 C-shaped cartilage

rings stacked upon one anotherrings stacked upon one another– Hyaline cartilage ringsHyaline cartilage rings– Covers the anterior and lateral wallsCovers the anterior and lateral walls

Trachea and EsophagusTrachea and Esophagus

TracheaTrachea• Non-cartilaginous posterior softer Non-cartilaginous posterior softer

portion of the trachea allows for portion of the trachea allows for expansion of the esophagus during expansion of the esophagus during swallowingswallowing

• Lined with ciliated epitheliumLined with ciliated epithelium• The point where the trachea The point where the trachea

bifurcates is called the carinabifurcates is called the carina– About the 5th thoracic vertebraeAbout the 5th thoracic vertebrae

BronchiBronchi• Tubes that branch off of the trachea at the Tubes that branch off of the trachea at the

carina and extend into the lungscarina and extend into the lungs• Left Primary Bronchus Left Primary Bronchus

(Left Mainstem Bronchus) (Left Mainstem Bronchus) • Right Primary Bronchus Right Primary Bronchus

(Right Mainstem Bronchus)(Right Mainstem Bronchus)– Shorter and more verticalShorter and more vertical– Swallowed objects more likely to lodge in the Swallowed objects more likely to lodge in the

right primary bronchus than the left right primary bronchus than the left

BronchiBronchi• Also composed of cartilaginous ringsAlso composed of cartilaginous rings• Continue branching as they enter the Continue branching as they enter the

lungs into a structure called the lungs into a structure called the bronchial treebronchial tree– Trachea Trachea

-Mainstem (Primary) Bronchi -Mainstem (Primary) Bronchi - - Secondary (Lobar) Bronchi Secondary (Lobar) Bronchi - Segmental (Tertiary) Bronchi - Segmental (Tertiary) Bronchi - Terminal Bronchioles - Terminal Bronchioles - Respiratory - Respiratory Bronchioles Bronchioles - Alveolar - Alveolar DuctsDucts

Bronchial TreeBronchial Tree

LungsLungs• Paired - cone shaped organs that Paired - cone shaped organs that

occupy most of the thoracic cavityoccupy most of the thoracic cavity• Separated from each other by the Separated from each other by the

heart and other structures of the heart and other structures of the mediastinummediastinum

• Surrounded by a double layered Surrounded by a double layered serous membrane called the pleural serous membrane called the pleural membranemembrane

Left LungLeft Lung

Pleural Membrane Pleural Membrane • Parietal Pleura - outer layer of the pleural Parietal Pleura - outer layer of the pleural

membranemembrane– Attached to the thoracic wallAttached to the thoracic wall

• Visceral Pleura - inner layer of the pleural Visceral Pleura - inner layer of the pleural membranemembrane– Attached to the lungs themselvesAttached to the lungs themselves

• Between the parietal pleura and the Between the parietal pleura and the visceral pleura is a potential space called visceral pleura is a potential space called the pleural cavitythe pleural cavity– Contains pleural (serous) fluid (reduces friction)Contains pleural (serous) fluid (reduces friction)

Gross Anatomy of the Gross Anatomy of the LungsLungs

• Extend from the diaphragm to an area Extend from the diaphragm to an area about 2.54 cm above the clavicles on about 2.54 cm above the clavicles on both sides of the thoracic cavityboth sides of the thoracic cavity

• BaseBase• ApexApex• Hilus Hilus • Costal Surface Costal Surface • Mediastinal SurfaceMediastinal Surface• Cardiac NotchCardiac Notch

Lobes and FissuresLobes and Fissures• each Lung is divided into lobes by each Lung is divided into lobes by

one or more fissuresone or more fissures• Oblique Fissure (both Lungs)Oblique Fissure (both Lungs)• Horizontal Fissure (Right Lung only)Horizontal Fissure (Right Lung only)• Superior LobeSuperior Lobe• Inferior LobeInferior Lobe• Middle Lobe (Right Lung only)Middle Lobe (Right Lung only)

LungsLungs

AlveoliAlveoli• A cup shaped out pouching of A cup shaped out pouching of

epithelial tissue epithelial tissue • Place where external respiration Place where external respiration

occurs (gas exchange between the occurs (gas exchange between the lungs and the blood)lungs and the blood)

• Lungs contain 300 - 500 million Lungs contain 300 - 500 million alveolialveoli– Surface area of about 750 sq. ft.Surface area of about 750 sq. ft.– The size of a Tennis CourtThe size of a Tennis Court

AlveoliAlveoli

Physiology of Physiology of VentilationVentilation

• Ventilation - the process of inhaling and Ventilation - the process of inhaling and exhaling air in and out of the lungsexhaling air in and out of the lungs

• Pulmonary Ventilation - the process by Pulmonary Ventilation - the process by which air flows between the lungs and which air flows between the lungs and the external environment the external environment

• Due to a change in pressure between Due to a change in pressure between the atmosphere and the air in the lungsthe atmosphere and the air in the lungs

Physiology of Physiology of VentilationVentilation

Inspiration (Inhalation)Inspiration (Inhalation)• Bringing air into the lungs from the Bringing air into the lungs from the

external environmentexternal environment• The lungs themselves contain no The lungs themselves contain no

muscles and thus depend upon the muscles and thus depend upon the relationship with the muscles of relationship with the muscles of the walls of the thoracic cavity to the walls of the thoracic cavity to alter lung volumesalter lung volumes

VentilationVentilation

Muscles of VentilationMuscles of Ventilation

Expiration (Exhalation)Expiration (Exhalation)• Movement of air from the lungs to the Movement of air from the lungs to the

external environmentexternal environment• Normally a passive process (no Normally a passive process (no

energy or muscular contractions energy or muscular contractions required)required)

• Dependent upon muscle and lung Dependent upon muscle and lung elasticityelasticity

• May become active during high levels May become active during high levels of physical activityof physical activity– Most people require ventilation rates Most people require ventilation rates

above 55% - 65% of their vital above 55% - 65% of their vital capacity for expiration to become activecapacity for expiration to become active

SpirometrySpirometry• The process of measuring lung The process of measuring lung

volumes and rates of air exchange volumes and rates of air exchange between the lungs and the between the lungs and the external environmentexternal environment

• Values will vary depending upon:Values will vary depending upon:– ageage - gender- gender - size (height)- size (height)

Lung ParametersLung Parameters• Tidal Volume (TV) - 500 ml - Tidal Volume (TV) - 500 ml -

volume of air moved in and out of volume of air moved in and out of the lungs during breathingthe lungs during breathing

• Vital Capacity (VC) - 4500 ml - Vital Capacity (VC) - 4500 ml - maximum volume of air that can maximum volume of air that can be exhaled after taking the be exhaled after taking the deepest possible inhalation deepest possible inhalation VC - TV + IRV VC - TV + IRV + ERV+ ERV

SpirometrySpirometry

Physiology of Physiology of RespirationRespiration

Respiratory CenterRespiratory Center

Chemical StimuliChemical Stimuli• Determines how fast and how Determines how fast and how

deeply an individual breathesdeeply an individual breathes• Very sensitive to the levels of COVery sensitive to the levels of CO22

and Hand H++ ion concentration in the ion concentration in the bloodblood

• Monitored by chemoreceptors at:Monitored by chemoreceptors at:– carotid arteries, aorta, and the carotid arteries, aorta, and the

medulla oblongata.medulla oblongata.

VentilatoryVentilatoryHomeostasisHomeostasis

RESPIRATORY RESPIRATORY DISORDERS AND DISORDERS AND HOMEOSTATIC HOMEOSTATIC IMBALANCESIMBALANCES

Bronchiogenic Bronchiogenic CarcinomaCarcinoma

(Lung Cancer)(Lung Cancer)• Most fatal cancer in the U.S.Most fatal cancer in the U.S.• Highly metastatic Highly metastatic • Usually linked with cigarette smokingUsually linked with cigarette smoking• Starts in the walls of the bronchi due Starts in the walls of the bronchi due

to irritation of the bronchiole to irritation of the bronchiole epitheliumepithelium

• Common irritants include smoking, Common irritants include smoking, pollution, dust particlespollution, dust particles

• 20 times more prevalent in smokers 20 times more prevalent in smokers than non- smokersthan non- smokers

EmphysemaEmphysema• ““Blown up or full of air”Blown up or full of air”• A condition where the alveolar walls lose A condition where the alveolar walls lose

their elasticity and remain filled with air their elasticity and remain filled with air during expirationduring expiration

• Alveoli become damaged and eventually Alveoli become damaged and eventually merge together to form large air sacs with merge together to form large air sacs with reduced overall volumereduced overall volume

• Patients often develop a barrel chestPatients often develop a barrel chest• Generally caused by cigarettes, pollution, Generally caused by cigarettes, pollution,

industrial dust particlesindustrial dust particles

Coryza and InfluenzaCoryza and Influenza• Common cold and fluCommon cold and flu• Caused by one of many virusesCaused by one of many viruses• Antibiotics cannot helpAntibiotics cannot help• Medications used to treat the Medications used to treat the

symptomssymptoms– sneezingsneezing - coughing- coughing– congestioncongestion - rhinorrhea- rhinorrhea

• May result in rhinitis: inflammation of May result in rhinitis: inflammation of the nasal mucosathe nasal mucosa

PneumoniaPneumonia• Acute infection or inflammation of the Acute infection or inflammation of the

alveoli of the lungsalveoli of the lungs• Most common infectious cause of death Most common infectious cause of death

in the U.S.in the U.S.• Alveolar sacs fill with fluid and dead Alveolar sacs fill with fluid and dead

white blood cells reducing the amount white blood cells reducing the amount of functional surface area of the lungsof functional surface area of the lungs

• Most commonly caused by bacteriumMost commonly caused by bacterium– Streptococcus pneumoniaeStreptococcus pneumoniae

• Affects those in poor health or Affects those in poor health or compromised immune systemcompromised immune system

Sudden Infant Death Sudden Infant Death Syndrome (SIDS)Syndrome (SIDS)

• 10,000 infant deaths per year in the 10,000 infant deaths per year in the U.S.U.S.

• Cause is not known but thought to be Cause is not known but thought to be caused by an infectious agent or caused by an infectious agent or compressed carotid arterycompressed carotid artery

• Most deaths occur in the fall or winterMost deaths occur in the fall or winter• Over 50% of SIDS death children had Over 50% of SIDS death children had

an upper respiratory infection within an upper respiratory infection within the past two weeksthe past two weeks

• May also be caused by improper May also be caused by improper positioning for sleeping in the cribpositioning for sleeping in the crib

Tuberculosis (Tb)Tuberculosis (Tb)• Caused by a bacteriumCaused by a bacterium

– Mycobacterium tuberculosisMycobacterium tuberculosis• An infectious communicable disease An infectious communicable disease

that destroys the lung tissue and that destroys the lung tissue and pleurapleura

• Replaced by fibrous connective tissue Replaced by fibrous connective tissue called tuberclescalled tubercles

• Disease is spread by inhalation of the Disease is spread by inhalation of the bacteriumbacterium