1. BY Dr Pradeep Kumar Karem
MODERATOR-Dr VENUGOPAL MD
PROFESSOR OF ANAESTHESIOLOGY
REGIONAL ENT HOSPITAL

2.  Respiratory organs
 Upper respiratory tract
 Nose, nasal cavity, and paranasal sinuses
 Pharynx and larynx
 Lower respiratory tract
 Trachea
 Bronchi and smaller bronchioles
 Lungs and alveoli

4.  Provides an airway for respiration
 Moistens and warms air
 Filters inhaled air
 Resonating chamber for speech
 Houses olfactory receptors

5.  External nares – nostrils
 Nasal cavity divided by – nasal septum
 Posterior nasal apertures-choanae
continous with nasopharynx–

6.  Superior and middle nasal conchae
 Part of the ethmoid bone
 Inferior nasal conchae
 Separate bone
 Project medially from the lateral wall of the nasal
cavity
 Create streamline flow of air and provide larger
surface area for humidification of air

7.  Two types of mucous membrane
 Olfactory mucosa
 Near roof of nasal cavity
 Houses olfactory (smell) receptors
 Respiratory mucosa
 Lines nasal cavity
 Epithelium is pseudostratified ciliated columnar

8.  May provide air
condition to inspired air
by supplying warm and
humid air.
 May reduce weight of the
skull or simply act as
protector to to eyes in
trauma.
 May thermally insulate
skull base and orbit.

9.  Through out respiratory tract cilia are present which
prevent the accumulation of secretions.
 In nose the flow f cilia is swept towards the pharynx,..
 In the bronchial tree the flow is swept towards the
entrance of larynx.
o Factors affecting ciliary activity
• All volatile general anaesthetics depress the propelling
action of cilia.
• They also decrease the secretions and there by reduces
ciliary activity.
• Opiates has direct depressant action over the cilia while
atropine weakens the ciliary activity by altering the
viscosity of the mucous.

10.  Funnel-shaped passageway
 Connects nasal cavity and mouth
 Divided into three sections by location
 Nasopharynx
 Oropharynx
 Laryngopharynx

11.  Only an air passageway
 Closed off during swallowing
 Pharyngeal tonsil (adenoids)
 Located on posterior wall
 Destroys entering pathogens
 Contains the opening to the pharyngotympanic tube
(auditory tube)
• Tubal tonsil
 Provides some protection from infection

12.  Arch-like entranceway – fauces
 Extends from soft palate to the epiglottis
 Epithelium
 Stratified squamous epithelium
 Two types of tonsils in the oropharynx
 Palatine tonsils – in the lateral walls of the fauces
 Lingual tonsils – covers the posterior surface of the
tongue

13.  Passageway for both food and air.
 Epithelium
 Stratified squamous epithelium
 Continuous anteriorly with the larynx and
posteriorly with esophagus.

14.  Three functions
 Voice production
 Provides an open airway
 Routes air and food into the proper channels
 Superior opening is
 Closed during swallowing
 Open during breathing

15.  Larynx is formed by Nine Cartilages
 Thyroid cartilage
 Shield-shaped, forms laryngeal prominence (Adam’s apple)
 Three pairs of small cartilages
 Arytenoid cartilages
 Corniculate cartilages
 Cuneiform cartilages
 Epiglottis
 Cricoid cartilage

16.  Vocal ligaments of the larynx
 Vocal folds (true vocal cords)
 Act in sound production
 Vestibular folds (false vocal cords)
 No role in sound production
 Epithelium of the larynx
 Stratified squamous – superior portion
 Pseudostratified ciliated columnar – inferior portion

19.  Superior laryngeal nerve
• Supplies cricothyroid muscle .
• Sensory supply to larynx above vocal cords
 Recurrent laryngeal nerve
• Supplies all intrinsic muscles except cricothyroid.
• Sensory supply to larynx below vocal cords.

20.  Unilateral superior laryngeal nerve palsy.
 Unilateral recurrent laryngeal nerve palsy.
 Bilateral recurrent laryngeal nerve palsy.
 Unilateral recurrent and superior laryngeal nerve
palsy.
 Bilateral recurrent and superior laryngeal nerve palsy.

21.  Loss of sensation of supraglottic larynx
 Frequent throat clearing, paroxysmal cough
 Vocal fatigue and vague foreign body sensation
Loss of motor function of cricothyroid muscle
 Slight voice change and diplophonia
 Signs
 Normal vocal cord position during quiet respiration
 Deviation of posterior commissure to paralysed side
 Shortened vocal cord on paralysed side.

22.  Loss of sensory supply below vocal cords
 Loss of abduction with intact adduction by
cricothyroid
 Voice is breathy but compensation occurs
 Signs
 Vocal cord assumes paramedian position
 Airway is adequate but may be compromised with
exertion

23.  Loss of abductors of both sides except for cricothyroid
muscle.
 Vocal cords are in paramedian position
 Voice is fair
 No aspiration
 Degree of airway compromise may range from mild to
severe stridor and dysnoea.
 May develop gradually or suddenly leading to
emergency.

24.  Both vocal cords remain in intermediate
position(because of absence of cricothyroid
adduction)
 Very breathy voice
 Possible risk of aspiration

25.  Both vocal cords are in intermediate position, flaccid
and motionless.
 Apnoea and high risk of aspiration.

26.  Is a tube which descends into the mediastinum.
 It is kept open by C-shaped cartilage rings which are
incomplete posteriorly.

27.  It is 10-11cm in length extending from lower part of
larynx.
 It starts at the level of 6th cervical vertebra and ends
near carina where it divides into left and right main
bronchus.
 Carina correspondes to the level of 5th thoracic
vertebra
 The trachea moves up with respiration and with
alterations with the position of the head.
 In deep inspiration the carina can descend as much as
2.5cm.

28.  Extension of the head and neck for maintaining an
airway in anaesthetised patients increases the length
of the trachea by 23 to 30 %.
 If the patient is intubated with flexion at the atlanto-
occipital joint, the ET tube reaching just beyond the
vocal cords, with subsequent hyperextension of the
head the tube may be withdrawn into pharynx.

29.  The trachea divides at the carina into right and left
main bronchus.
 The bronchi divide dichotomously into several million
terminal bronchioles to terminate in one or more
respiratory bronchioles.
 Bronchioles are less than 1mm in diameter, they do
not have cartilage in their walls.
 Smooth muscles are found in the walls of the airways
upto the level of alveolar ducts.

30. RIGHT MAIN BRONCHUS
• It is 2.5cm long and is wider and shorter than the
left bronchus.
• In children under the age of 3yrs the angulation of
two main bronchus at carina are equal on both
sides.
• In adults the right main bronchus is angulated at
25˚and the left main bronchus is angulated at
45˚from midline.
• As the right bronchus is nearly vertical there is
much tendency for the ETtubes and suction
catheters to enter the lumen.

31.  Right main bronchus is also the commonest site for
aspiration .
 The right main bronchus divides into three lobar
bronchus to supply respective lobes.
 If a patient in right lateral position aspirates, the
material gravitates into lateral portion of posterior
segment of upper lobe.
 If pt is in supine and aspirates the material gravitates
to apical segment of lower lobe.

32. LEFT MAIN BRONCHUS
• It is narrower than the right bronchus and is nearly
5cm long.
• The left main bronchus divides into two lobar bronchi
for upper and middle lobes.
• As the left bronchus is 5cm long without any
branching it is particularly suitable for intubation and
blocking during thoracic surgery.

33.  The cartilagenous rings that are seen in bronchioles
are replaced by cartilagenous plates as the size of
bronchioles decrease.
 The cartilage completely disappear when their size
reaches to 0.6mm
 The small terminal bronchioles as supported by
smooth muscle cells.
 Distal to each terminal bronchiole is an acinus, which
consists of three to four orders of respiratory
bronchioles.
 Respiratory bronchioles lead to alveolar ducts. The
walls of these ducts consist of alveolar sacs or the
mouths of alveoli..

36.  ALVEOLI
 Respiratory zone starts at respiratory bronciole
which consists mainly millions of alveoli.
 Alveoli consist of
 Type I cells and basal laminae
 Scattered among type I cells
 Cuboidal epithelial cells – type II cells
 Secrete surfactant
 Surfactant is a mixture of phospholipids(dipalmitoyl-
phosphatidyl-choline)
 Surfactant is secreted by type 2 pnuemocytes and it
protects alveoli from collapse during expiration.

37.  Features of alveoli
 Surrounded by elastic fibers.
 Interconnect by way of alveolar pores
 Internal surfaces
 A site for free movement of alveolar macrophages.
 Absence of surfactant at birth causes respiratory
distress syndrome.
 Oxygen therapy also lead to reduction of the
surfactant and hence it should be used in lower most
possible concentration.

40.  A double-layered sac surrounding each lung
 Parietal pleura
 Visceral pleura
 Pleural cavity
 Potential space between the visceral and parietal pleurae
 Pleurae help divide the thoracic cavity
 Central mediastinum
 Two lateral pleural compartments

42.  Major landmarks of the lungs
 Apex, base, hilum, and root
 Left lung
 Oblique fissure divides it to
• Superior and inferior lobes
 Right lung
 Oblque and horizontal fissure divides it to
• Superior, middle, and inferior lobes

43.  Each is cone-shaped
with anterior,
lateral and posterior
surfaces contacting
ribs
 Superior tip is apex,
just deep to clavicle
 Concave inferior
surface resting on
diaphragm is the
base

45.  Each lobe is made up of bronchopulmonary
segments separated by dense connective tissue
 Each segment receives air from an individual segmental
(tertiary) bronchus
 Approximately 10 bronchopulmonary segments in each
lung
 Limit spread of infection
 Can be removed more easily because only small vessels
span segments
 Smallest subdivision seen with the naked eye is the
lobule
 Hexagonal on surface, size of pencil eraser
 Served by large bronchiole and its branches
 Black carbon is visible on connective tissue separating
individual lobules in smokers and city dwellers

47.  Bronchopulmonary segments consists of segmental
bronchus, its branches and associated arteries,.
 They occupy a central position in each segment.
 Many tributaries of the pulmonary veins run between
segments, serving adjacent segments which drain into
more than one vein.
 Thus a bronchopulmonary segment is not a complete
vascular unit with an individual bronchus, artery and
vein.
 During resection of segments it is obvious that the
planes between them are not avascular but are crossed
by pulmonary veins and sometimes by branches of
arteries.

48.  The lungs have two functionally distinct circulatory
pathways.
 These are the pulmonary vessels, which convey
deoxygenated blood to the alveolar walls and drain
oxygenated blood back to the left side of the heart.
 The much smaller bronchial vessels, which are derived
from the systemic circulation and provide oxygenated
blood to lung tissues which do not have close access to
atmospheric oxygen.

49.  The lungs are innervated by vagal and sympathetic
fibres.
 The vagal fibres supply the bronchial muscles and
glands and are bronchoconstrictor and secretomotor.
 The efferent sympathetic fibres are inhibitory. They
relax the bronchial smooth muscle and also have
vasoconstrictor effects.

50.  Spasm occures mainly on the bronchioles.
 It is most commonly encountered in patients with irritable
bronchial tree i.e, in chronic bronchitis patients and
asthmatics.
 Stimulation can be due to chemical, mechanical and
neurogenic factors.
 Constriction of the bronchiole occurs mostly in expiration
than in inspiration.
 Diagnosis of bronchospasm should be made only when all
other ventilatory causes has been excluded.
 Should be treated in the same way of acute asthmatic
attack.

51.  Asthma is characterised by bronchospasm with
precipitating factors such as allergy.
 Anxiety for surgery may also precipitate
bronchospasm.
 It is important to reassure the patient for relief of
anxiety.
 Appropriate premedication has to be used by using
anxiolytics and anti histaminics.
 Sever e asthmatics with steroid therapy has to be given
hydrocortisone as apremedication.

52.  During anaesthesia it is important to reduce irritation
of broncial tree and intubation is avoided as far as
possible.
 Halothane is useful with its bronchodilating property.
 In the event of bronchospasm during anaesthesia, 250-
500mg of aminophylline is given intravenously over
5min which will improve ventilation.

53. Metabolic functions of the lungs
 Lungs are major site of inactivation of 5-
hydroxytryptamine,bradykinin and noradrenaline
 Converting enzyme present on the luminal surface of
endothelial cells catalyses the hydrolysis of angiotensin I to
angiotensin II.
 PGE1 , PGE2 or PGF2 are removed in one passage through lungs
whereas PGA1 , PGA2 and prostacyclins pass through
unchanged.
 Prostacyclin, which is a vasodilator and potent inhibitor of
platelet aggregation is produced partly in lungs.
 Certain anaphylactic mediators like histamine and SRS-A (slow
reacting substances of anaphylaxis)are also released by lungs.