The respiratory system is the anatomical system of an organism that introduces respiratory gases to the interior and performs gas exchange. In humans the respiratory system include airways, lungs, and the respiratory muscles. Molecules of oxygen and carbon dioxide are passively exchanged, by diffusion, between the gaseous external environment and the blood. This exchange process occurs in the alveolar region of the lungs

1. The Department of Human anatomyThe Department of Human anatomy
Respiratory
System

2. The The respiratory systemrespiratory system is the anatomical is the anatomical
system of an organism that introducessystem of an organism that introduces
respiratory gases to the interior andrespiratory gases to the interior and
performs gas exchange. In humans theperforms gas exchange. In humans the
respiratory system include airways, lungs, andrespiratory system include airways, lungs, and
the respiratorythe respiratory
muscles. Molecules of oxygen and carbonmuscles. Molecules of oxygen and carbon
dioxide are passively exchanged, by diffusion,dioxide are passively exchanged, by diffusion,
between the gaseous external environment andbetween the gaseous external environment and
the blood. This exchange process occurs in thethe blood. This exchange process occurs in the
alveolar region of the lungsalveolar region of the lungs

3. General Functions of Respiratory
System:
 1. O2 (oxygen)oxygen) and CO2 (carbon dioxidecarbon dioxide)
exchange between blood and air
 2. speech and vocalization
 3. sense of smell
 4. helps control acid base balance of body
 5. breathing movements help promote
blood and lymph flow

4. Main Organs:
 nose
 pharynx
 larynx
 trachea
 primary bronchi
 lungs:
 bronchioles
 alveoli/respiratory membrane
these organs can also be subdivided
into:
 upper respiratory tract
Nose-pharynx-larynx
 lower respiratory tract
respiratory organs of the thorax

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6.  Functional classifications:Functional classifications:
 ConductingConducting portion: transports air.portion: transports air.
 RespiratoryRespiratory portion: carries out gas exchange.portion: carries out gas exchange.
 respiratory bronchiolesrespiratory bronchioles
 alveolar ductsalveolar ducts
 air sacs called alveoliair sacs called alveoli
 Upper respiratory tract is all conductingUpper respiratory tract is all conducting
 Lower respiratory tract has bothLower respiratory tract has both
conducting and respiratory portionsconducting and respiratory portions

7. Air passageways must be held open at all
times
 nasal passageways and throat follow
passages in skull bones and cartilage
 others held open by rings of cartilage

8. Nose
 separated from mouth by hard and
soft palate
 each nasal cavity is divided into 3
passageways by turbinates
(choncae)
turbulent passageways to insure that
all air makes contact with mucous
membranes
membranes are heavily vascualrized
 remove bacteria, debris and
particles
 warms and moisturizes air entering
lungs
 also contains receptors for smell
nasolacrimal ducts drain into nasal
cavity

9. Paranasal sinuses:Paranasal sinuses:
 In four skull bonesIn four skull bones
 paired air spacespaired air spaces
 decrease skull bone weightdecrease skull bone weight
 warm and moisten air
 sound resonance
 Named for the bonesNamed for the bones
in which they are housed.in which they are housed.
 frontalfrontal
 ethmoidalethmoidal
 sphenoidalsphenoidal
 maxillarymaxillary
 Communicate with the nasal cavity by ducts.Communicate with the nasal cavity by ducts.
 Covered with the same pseudostratified ciliatedCovered with the same pseudostratified ciliated
columnar epithelium as the nasal cavity.columnar epithelium as the nasal cavity.

10. Pharynx (throat)
- Is situated from base of skull to junction with
esophagus and trachea
- made of muscle and lined with mucous membrane
- junction between digestive and respiratory systems
divided into three regions:
a. Nasopharynx
 behind nose to level of soft palate
 includes uvula, tonsils (adenoids)
 auditory tube (eustachian tube)
b. Oropharynx
 behind mouth
 from soft palate to level of
hyoid bone
 palatine and lingual tonsils
c. Laryngopharynx
 from hyoid bone to
esophagus/larynx

11. Larynx (voice box)
 enlarged beginning portion of trachea
 composed of cartilage and muscles
 opening into larynx = glottis (prevent food
from entering lower respiratory system sound)
 9 cartilages:
 three individual piecesthree individual pieces
 Thyroid cartilageThyroid cartilage
 Cricoid cartilageCricoid cartilage
 EpiglottisEpiglottis
 three cartilage pairsthree cartilage pairs
 Arytenoids: on cricoidArytenoids: on cricoid
 Corniculates: attach toCorniculates: attach to
arytenoidsarytenoids
 Cuniforms:in aryepiglottic foldCuniforms:in aryepiglottic fold

12. Sound ProductionSound Production
 Two pairs of ligamentsTwo pairs of ligaments
 Inferior ligaments, calledInferior ligaments, called vocal ligamentsvocal ligaments
 covered by a mucous membranecovered by a mucous membrane
 are “true vocal cords”are “true vocal cords”
 they produce sound when air passesthey produce sound when air passes
between thembetween them
 Superior ligaments, calledSuperior ligaments, called vestibularvestibular
ligamentsligaments
 Covered by mucosaCovered by mucosa
 Are “false vocal cords”Are “false vocal cords”
 no function in soundno function in sound
productionproduction
 protect the vocal folds.protect the vocal folds.
 The vestibular folds attachThe vestibular folds attach
to the corniculate cartilagesto the corniculate cartilages ..

13.  The tension, length,The tension, length, and position of the vocaland position of the vocal
folds determine the quality of the sound.folds determine the quality of the sound.
 Longer vocal folds produce lower soundsLonger vocal folds produce lower sounds
 More taunt, higher pitchMore taunt, higher pitch
 Loudness based on force of airLoudness based on force of air
 Rima glottidisRima glottidis: opening between the vocal folds: opening between the vocal folds
 GlottisGlottis: rima glottidis and the vocal folds: rima glottidis and the vocal folds

16. Trachea
 extends from larynx to bronchi
(immediately anterior to the esophagus,immediately anterior to the esophagus,
inferior to the larynx, superior to theinferior to the larynx, superior to the
primary bronchi of the lungsprimary bronchi of the lungs)
 surrounded by 15 to 2015 to 20 “C” – shaped
bands of cartilage ends joined by bands
of muscle tissue (holds walls open,
prevents collapse)
 lined by pseudostratified ciliated
columnar epithelium

18.  At the level of theAt the level of the sternal anglesternal angle, the, the
trachea bifurcates into two smaller tubes,trachea bifurcates into two smaller tubes,
called thecalled the right and left primary bronchiright and left primary bronchi..
 Each primary bronchus projects laterallyEach primary bronchus projects laterally
toward each lung.toward each lung.
 The most inferior tracheal cartilageThe most inferior tracheal cartilage
separates the primary bronchi at theirseparates the primary bronchi at their
origin and forms an internal ridge calledorigin and forms an internal ridge called
thethe carina.carina.

19. Bronchi
 bronchi resemble trachea in structure (also
supported by C-shaped cartilages)
 also have lots of elastic connective tissue
 Right primary bronchusRight primary bronchus
 shorter, wider, and more verticallyshorter, wider, and more vertically
oriented than the left primaryoriented than the left primary
bronchus.bronchus.
 Foreign particles are more likely to lodgeForeign particles are more likely to lodge
in the right primary bronchus.in the right primary bronchus.
 each bronchus enters lung and continues to
divide into smaller and smaller branches =
bronchi, then into microscopic
bronchioles
 because of the extensive branching it
formes bronchial tree

20.  Primary bronchiPrimary bronchi
 enter the hilum of each lungenter the hilum of each lung
 Also entering hilum:Also entering hilum:
 pulmonary vesselspulmonary vessels
 lymphatic vesselslymphatic vessels
 nerves.nerves.
 Secondary bronchi (or lobar bronchi)Secondary bronchi (or lobar bronchi)
 Branch of primary bronchusBranch of primary bronchus
 left lung:left lung:
 two lobestwo lobes
 two secondary bronchitwo secondary bronchi
 right lungright lung
 three lobesthree lobes
 three secondary bronchi.three secondary bronchi.
 Tertiary bronchi (or segmental bronchi)Tertiary bronchi (or segmental bronchi)
 Branch of secondary bronchiBranch of secondary bronchi
 left lung is supplied by 8 to 10 tertiary bronchi.left lung is supplied by 8 to 10 tertiary bronchi.
 right lung is supplied by 10 tertiary bronchiright lung is supplied by 10 tertiary bronchi
 supply a part of the lung called a bronchopulmonarysupply a part of the lung called a bronchopulmonary
segment.segment.

21. Bronchioles
 smallest branches of “respiratory tree”
 <1mm diameter
 no cartilage rings (but larger branches may have small
patches of cartilage)
 lined with ciliated cuboidal epithelium and layer of smooth
muscle
 asthma affects the smallest terminal bronchioles

23. Respiratory Bronchioles, AlveolarRespiratory Bronchioles, Alveolar
Ducts, and AlveoliDucts, and Alveoli
 Contain small saccular outpocketings calledContain small saccular outpocketings called
alveoli.alveoli.
 An alveolus is about 0.25 to 0.5 millimeter inAn alveolus is about 0.25 to 0.5 millimeter in
diameter.diameter.
 Its thin wall is specialized to promote diffusionIts thin wall is specialized to promote diffusion
of gases between the alveolus and the blood inof gases between the alveolus and the blood in
the pulmonary capillaries.the pulmonary capillaries.
 Gas exchange can take place in the respiratoryGas exchange can take place in the respiratory
bronchioles and alveolar ducts as well as in thebronchioles and alveolar ducts as well as in the
lungs, which contain approximately 300–400lungs, which contain approximately 300–400
million alveoli.million alveoli.
 The spongy natureThe spongy nature of the lung is due to theof the lung is due to the
packing of millions of alveoli together.packing of millions of alveoli together.

27. Gross Anatomy of the LungsGross Anatomy of the Lungs
 Each lung has a conical shape.Each lung has a conical shape.
 Its wide, concave base rests upon the muscular diaphragm.Its wide, concave base rests upon the muscular diaphragm.
 Its relatively blunt superior region, called the apex orIts relatively blunt superior region, called the apex or
(cupola), projects superiorly to a point that is slightly(cupola), projects superiorly to a point that is slightly
superior and posterior to the clavicle.superior and posterior to the clavicle.
 Both lungs are bordered by the thoracic wall anteriorly,Both lungs are bordered by the thoracic wall anteriorly,
laterally, and posteriorly, and supported by the rib cage.laterally, and posteriorly, and supported by the rib cage.
 Toward the midline, the lungs are separated from eachToward the midline, the lungs are separated from each
other by the mediastinum.other by the mediastinum.
 The relatively broad, rounded surface in contact with theThe relatively broad, rounded surface in contact with the
thoracic wall is called the costal surface of the lung.thoracic wall is called the costal surface of the lung.

33. Pleura and Pleural CavitiesPleura and Pleural Cavities
 The outer surface of each lung and the adjacentThe outer surface of each lung and the adjacent
internal thoracic wall are lined by a serousinternal thoracic wall are lined by a serous
membrane called pleura, which is formed frommembrane called pleura, which is formed from
simple squamous epithelium.simple squamous epithelium.
 The outer surface of each lung is tightlyThe outer surface of each lung is tightly
covered by the visceral pleura, while thecovered by the visceral pleura, while the
internal thoracic walls, the lateral surfaces ofinternal thoracic walls, the lateral surfaces of
the mediastinum, and the superior surface ofthe mediastinum, and the superior surface of
the diaphragm are lined by the parietal pleura.the diaphragm are lined by the parietal pleura.
 The parietal and visceral pleural layers areThe parietal and visceral pleural layers are
continuous at the hilum of each lung.continuous at the hilum of each lung.

34. Pleura and Pleural CavitiesPleura and Pleural Cavities
 The potential space between theseThe potential space between these
serous membrane layers is a pleuralserous membrane layers is a pleural
cavity.cavity.
 The pleural membranes produce a thin,The pleural membranes produce a thin,
serous fluid that circulates in the pleuralserous fluid that circulates in the pleural
cavity and acts as a lubricant, ensuringcavity and acts as a lubricant, ensuring
minimal friction during breathing.minimal friction during breathing.

40. Aging and the RespiratoryAging and the Respiratory
SystemSystem
 BecomesBecomes less efficientless efficient with age due to severalwith age due to several structuralstructural changes.changes.
 Decrease in elastic connective tissueDecrease in elastic connective tissue in the lungs and the thoracicin the lungs and the thoracic
cavity wall.cavity wall.
 Loss of elasticityLoss of elasticity reducesreduces the amount of gas that can be exchangedthe amount of gas that can be exchanged
with each breath and results in awith each breath and results in a decreasedecrease in the ventilation rate.in the ventilation rate.
 EmphysemaEmphysema may cause a loss of alveoli or their functionalitymay cause a loss of alveoli or their functionality
 Reduced capacity for gas exchange can cause an older person toReduced capacity for gas exchange can cause an older person to
become “short of breath” upon exertion.become “short of breath” upon exertion.
 Carbon, dust, and pollution material graduallyCarbon, dust, and pollution material gradually accumulateaccumulate in ourin our
lymph nodes and lungs.lymph nodes and lungs.

42. Respiratory diseases can be classified in many different ways,Respiratory diseases can be classified in many different ways,
including by the organ or tissue involved, by the type andincluding by the organ or tissue involved, by the type and
pattern of associated signs and symptoms, or by the causepattern of associated signs and symptoms, or by the cause
(etiology) of the disease.(etiology) of the disease.
Inflammatory lung diseaseInflammatory lung disease
Characterised by a high neutrophil count, e.g. asthma, cysticCharacterised by a high neutrophil count, e.g. asthma, cystic
fibrosis, emphysema, chronic obstructive pulmonaryfibrosis, emphysema, chronic obstructive pulmonary
disorder or acute respiratory distress syndrome.disorder or acute respiratory distress syndrome.
Allergic reactions due to exposure to certain agents (i.e. foods)Allergic reactions due to exposure to certain agents (i.e. foods)
are a relatively common cause of acute respiratory disease.are a relatively common cause of acute respiratory disease.
Some common examples include sea foods prawns, someSome common examples include sea foods prawns, some
fatty fish, radish, arrow root, lady's finger, lemon, moongfatty fish, radish, arrow root, lady's finger, lemon, moong
dhal, peanuts, water content spinach, curd, bananas,dhal, peanuts, water content spinach, curd, bananas,
grapes, pomegranates, berries, custard apple, ice creams,grapes, pomegranates, berries, custard apple, ice creams,
etc. In summer, bad weather condition mean sandy andetc. In summer, bad weather condition mean sandy and
dusty weather or some may affect in winter also.dusty weather or some may affect in winter also.

43. Obstructive lung diseasesObstructive lung diseases
 Obstructive lung diseases are diseases of the lungObstructive lung diseases are diseases of the lung
where the airways (i.e. bronchi, bronchioles, alveoli)where the airways (i.e. bronchi, bronchioles, alveoli)
become reduced in volume or have free flow of gasbecome reduced in volume or have free flow of gas
impeded, making it more difficult to move air in and outimpeded, making it more difficult to move air in and out
of the lung.of the lung.
Chronic Obstructive Pulmonary Disease (COPD)Chronic Obstructive Pulmonary Disease (COPD)
 Chronic Obstructive Pulmonary Disease (COPD),Chronic Obstructive Pulmonary Disease (COPD),
which includes asthma an example of an obstructivewhich includes asthma an example of an obstructive
lung disease, is where the airways become damaged,lung disease, is where the airways become damaged,
causing them to narrow.causing them to narrow.

44. AsthmaAsthma
 Asthma is another example of an obstructive lung disease, (and of anAsthma is another example of an obstructive lung disease, (and of an
inflammatory lung disease).inflammatory lung disease).
 Asthma attacks can be brought on by triggers, such as air pollution,Asthma attacks can be brought on by triggers, such as air pollution,
tobacco smoke, factory fumes, cleaning solvents, infections, pollens,tobacco smoke, factory fumes, cleaning solvents, infections, pollens,
foods, cold air, exercise, chemicals and medications. Triggers are highlyfoods, cold air, exercise, chemicals and medications. Triggers are highly
individual and may not be related to allergens. Many asthmatics are notindividual and may not be related to allergens. Many asthmatics are not
allergic to common allergens such as mold, ragweed, dust or pollens.allergic to common allergens such as mold, ragweed, dust or pollens.
Restrictive lung diseasesRestrictive lung diseases
 Restrictive lung diseases (also known as interstitial lung diseases) are aRestrictive lung diseases (also known as interstitial lung diseases) are a
category of respiratory disease characterized by a loss of lungcategory of respiratory disease characterized by a loss of lung
compliance, causing incomplete lung expansion and increased lungcompliance, causing incomplete lung expansion and increased lung
stiffness. E.g. in infant respiratory distress syndrome (IRDS).stiffness. E.g. in infant respiratory distress syndrome (IRDS).
Respiratory tract infectionsRespiratory tract infections
 Infections can affect any part of the respiratory system. They areInfections can affect any part of the respiratory system. They are
traditionally divided into upper respiratory tract infections and lowertraditionally divided into upper respiratory tract infections and lower
respiratory tract infections.respiratory tract infections.

45. Upper respiratory tract infectionUpper respiratory tract infection
 The most common upper respiratory tract infection isThe most common upper respiratory tract infection is
the common cold however, infections of specific organs of thethe common cold however, infections of specific organs of the
upper respiratory tract such as sinusitis, tonsillitis, otitisupper respiratory tract such as sinusitis, tonsillitis, otitis
media, pharyngitis and laryngitis are also considered uppermedia, pharyngitis and laryngitis are also considered upper
respiratory tract infections.respiratory tract infections.
Lower respiratory tract infectionLower respiratory tract infection
 The most common lower respiratory tract infection inThe most common lower respiratory tract infection in
is pneumonia, a lung infection. Pneumonia is usually causedis pneumonia, a lung infection. Pneumonia is usually caused
by bacteria, particularlyStreptococcus pneumoniae in Westernby bacteria, particularlyStreptococcus pneumoniae in Western
countries. Worldwide, tuberculosis is an important cause ofcountries. Worldwide, tuberculosis is an important cause of
pneumonia. Other pathogens such as viruses and fungi canpneumonia. Other pathogens such as viruses and fungi can
cause pneumonia for example severe acute respiratorycause pneumonia for example severe acute respiratory
syndrome and pneumocystis pneumonia. A pneumonia maysyndrome and pneumocystis pneumonia. A pneumonia may
develop complications such as a lung abscess, a round cavitydevelop complications such as a lung abscess, a round cavity
in the lung caused by the infection, or may spread toin the lung caused by the infection, or may spread to
the pleural cavity.the pleural cavity.

46.  Respiratory tumorsRespiratory tumors
 Tumours of the respiratory system are eitherTumours of the respiratory system are either
malignant or benign.malignant or benign.
 Malignant tumorsMalignant tumors
 Malignant tumors, or cancers of the respiratoryMalignant tumors, or cancers of the respiratory
system, particularly lung cancers, are a majorsystem, particularly lung cancers, are a major
health problem responsible for 15% of all cancerhealth problem responsible for 15% of all cancer
diagnoses and 29% of all cancer deaths.diagnoses and 29% of all cancer deaths.[3][3] The The
majority of respiratory system cancers aremajority of respiratory system cancers are
attributable to smoking attributable to smoking tobaccotobacco..