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1. Anatomy of Upper& lower
airway and Diaphragm
PRESENTED BY: DR AKSHAY R NAIR
MODERATOR: DR R PAURANIK
DR R S GILL

2. Airway
From nasal openings to alveoli
divided into
> upper airway –
• Common passage for respiratory, digestive and
phonatory functions
• from nose/oral cavity to Larynx
> lower airway – from trachea to alveoli
◦ Passage for respiratory function

3. Upper airway

4. nose
EXTERNAL NOSE :
Partly bony:- Nasal bones and fontal process of maxillary bon
Party cartilaginous- sup & inf nasal cartilages, septal cartilage and alar cartilages
NASAL CAVITY
Divided into 2 halves by nasal septum in midline
Has 3 segments
◦ Vestibule- anterior most part- skin covered- has hair follicles & sebaceous glands
◦ Respiratory segment- lined by pseudo stratified epithelium
Has openings of nasal sinuses
◦ Olfactory segment- Bipolar neuro sensory cells and supporting cells

5. PARANASAL SINUSES

6. pharynx
Musculo- membraneous tube
extending from base of skull upto pharyngo- esophageal junction inferiorly ( corresponds to C6 vertebra)
3 parts-
• Naso pharynx- behind nasal cavity
◦ Extends from base of skull to soft palate
• Oro pharynx- behind oral cavity
◦ Extends- from soft palate to upper border of epiglottis
• Laryngopharynx- upper border of epiglottis to cricoid cartilage
Nerve supply -IX th and Xth cranial nerves

7. Larynx
Organ of phonation
Sphincter at the inlet of the lower respiratory passages
EXTENT :
•Lies in the anterior midline of the neck and extends from root of tongue to trachea
•Adult male – C3-C6 vertebra
•Adult female and children – C1-C4
SIZE :
•Males – 44mm in length, 23mm AP diameter
•Females – 36mm in length, 17mm AP diameter
•Internal diameter – 3mm upto 3 years, 12mm in adults

8. Larynx is made up of :
◦ Cartilages: connected by joints, ligaments and membranes
◦ Muscles
◦ Cavity lined by mucous membrane
CARTILAGES :
UNPAIRED
Thyroid
Cricoid
Epiglottis
PAIRED
Arytenoid
Corniculate
Cuneiform

9. A - Epiglottis
B - Thyroid
C - Cricoid
D – Areytenoid
E - Corniculate
F – Hyoid bone

10. LARYNGEAL JOINTS:
CRICOTHYROID JOINT :
Synovial joint between the inferior cornua of thyroid and the side of the cricoid cartilage.
Tension and relaxation of vocal cords.
CRICOARYTENOID JOINT :
Synovial joint between the base of the arytenoid cartilage and the upper of the cricoid
cartilage.
Adduction and abduction of the vocal cords

11. Laryngeal ligaments
Extrinsic
THYROHYOID MEMBRANE:
HYOEPIGLOTTIC LIGAMENT:
CRICOTRACHEAL LIGAMENT
intrinsic
quadrate membrane- extends from the arytenoid cartilage
to the epiglottis.
conus elasticus- or cricovocal membrane extends upwards and medially from the arch of the cricoid
cartilage
. The upper free border of the conus elasticus forms the vocal fold

12. Muscles of larynx
EXTRINSIC

13. Intrinsic Muscles
CONTROL TENSION ON THE CORDS
•Vocalis – relaxes vocal cord
•Thyro areytenoid – relaxes vocal cord
•Cricothyroid – tense the vocal cord
CONTROL RIMA GLOTTIDES
• Posterior cricoarytenoid
• Lateral cricoareytenoid
• Inter areytenoids
CONTROL INLET
• Thyro-epiglotticus
• Ary-epiglotticus
• Oblique arytenoid
• Transverse arytenoid

15. NERVE SUPPLY OF LARYNX
MOTOR NERVES
•Recurrent laryngeal nerve supplies all intrinsic muscles
except cricothyroid.
•External laryngeal nerve supplies cricothyroid muscle.
SENSORY NERVES
•The internal laryngeal nerve supplies the mucous
membrane up to the level of the vocal folds.
•The recurrent laryngeal nerve supplies below the level of
the vocal folds.

16. Lower airway

17. TRACHEA
•The trachea is a midline structure that extends from lower
end of cricoid cartilage to bronchial bifurcation (carina) at
the lower border of the fourth thoracic vertebra. (T4)
•Comprised of 16-20 C shaped cartilage rings joined
vertically by fibro-elastic tissue and covered posteriorly by
smooth muscle(trachealis) and fibrous tissue.
•In adults, length – 10-12cm, diameter – 15-20mm

18. ANATOMICAL RELATIONS
•Anterior – thyroid gland covering 2nd and 3rd tracheal
rings, inferior thyroid veins, strap muscles of neck
• Posterior -
• esophagus on the left
• vertebral bodies on the right
• recurrent laryngeal nerve
• vagus nerve
•Lateral – lobes of thyroid, common carotid artery,
inferior thyroid artery

19. BLOOD SUPPLY AND LYMPHATIC DRAINAGE
•proximal trachea- inferior thyroid vessels and their tracheoesophageal branches
•distal trachea, carina, and main bronchi- bronchial arteries
•Venous drainage - azygous and hemi azygous systems.
•Lymphatic drainage – from paratracheal nodes deep cervical nodes.
NERVE SUPPLY
•By tracheal branches originating from - thoracic sympathetic chain and
inferior ganglion of the vagus nerve.
Responsible for
• tracheobronchial muscle tone (bronchoconstriction or bronchodilation),
• mucous production
• vascular permeability.
• Afferent vagal fibers are also responsible for sneezing and cough reflex.

20. TRACHEO-BRONCHIAL TREE
•The trachea divides at the level of T4 into two primary principal bronchi, one for each lung.
•The right principal bronchus is 2.5 cm long and left principal bronchus is 5 cm long.
•Right one is shorter, wider and more in line with the trachea. Left one is longer, narrower and more
oblique.
•Right bronchus makes an angle of 25° with tracheal bifurcation, while left bronchus makes an angle
of 45° with the trachea.
•In children younger than 3 years of age, the angles created are approximately equal, about 55
degrees.
•Each Primary bronchus enters the lung through the hilum, and divides into secondary lobar bronchi,
one for each lobe of the lungs. Thus there are 3 on the right side, and 2 on the left side.

21. •Each lobar bronchus divides into tertiary or
segmental bronchi, one for each
bronchopulmonary segment; which are 10
on the right side and 10 on the left side.
•The segmental bronchi divide repeatedly to
form terminal bronchioles which further
divide to form smaller branches called
respiratory bronchioles
•Each respiratory bronchiole aerates a small
part of the lung known as a pulmonary unit

22. PULMONARY UNIT
It forms the functional unit of lung
Aerated by a respiratory bronchiole
Consists of:
•Alveolar ducts
•Atria
•Air saccules
•Pulmonary alveoli (gas exchange)

23. CONDUCTING PART
• 1-14th generation
• From trachea up to
terminal bronchiole
RESPIRATORY PART
• 16th to 23rd generation
• From respiratory
bronchiole till alveoli
FUNCTIONAL AIRWAY DIVISION
TRANSITIONAL PART
• 15th generation
• Respiratory bronchiole

24. BRONCHOPULMONARY SEGMENTS
•They are well-defined pyramid shaped anatomical segments aerated by
tertiary/segmental bronchus, with apex directed towards hilum and base directed
towards periphery.
•Each segment has a segmental bronchus, segmental artery, autonomic nerves and
lymph vessels.
•The segmental venules lies in the connective tissue between adjacent pulmonary
units of bronchopulmonary segments.

27. Anatomy of Diaphragm

28. OVERVIEW
⦁ The diaphragm is a:
⦁ sheet-like
⦁ dome-shaped (when relaxed)
⦁ skeletal muscle,
⦁ separating the thoracic cavity above from
the abdominal cavity below.
⦁ It is the most important muscle of
respiration

29. ⦁ It has:
⦁ Right dome:
⦁ It reaches the upper border of the 5th rib
⦁ Left dome:
⦁ It reaches the lower border of the 5th rib
⦁ Central tendon:
⦁ It lies at the level of the
xiphisternal joint.
• The right dome is higher than the left dome
because of the liver.
• The central tendon lies between the domes
and at a lower level.
• The central tendon is fused above with the
pericardium.

30. ORGIN
It has three parts:
⦁ Sternal part: arises from the deep
surface of the xiphoid process.
⦁ Costal part: arises from the deep surfaces
of the lower 6 ribs and costal cartilages.
⦁ Vertebral part: arises as crura
⦁ Right crus: from L1, L2 & L3
⦁ Left crus: from L1 & L2
Insertion: the central tendon

31. MOTOR :
PHRENIC NERVE – C3-C4-C5
SENSORY
CENTRAL PART-Phrenic nerve
PERIPHERAL PART – lower six intercoastal nerves
NERVE SUPPLY

32. Blood supply
⦁ Arterial Supply:
⦁ Branches from the internal thoracicartery
⦁ Inferior phrenic arteries (fromthe abdominal
aorta)
⦁ Lower intercostalarteries.
⦁ Veins:
⦁ Accompanythe arteries

33. OPENINGS IN THE DIAPHRAGM

34. RELATIONS
⦁ Superiorly:
⦁ Pleura and lungs:reston thecorresponding
dome
⦁ Heart and pericardium:
rests on the centraltendon
⦁ Inferiorly:
⦁ Liver:under the right domeand central
tendon
⦁ Stomach and spleen:
under the leftdome
⦁ Right and left Kidneys: under the
corresponding dome

35. Contraction ofthediaphragm leads to:
 Decrease in the intrathoracicpressure whichleads to:
⦁ Inspiration
⦁ Increasedvenousreturn
 Increasein the intra-abdominalpressure:which is helpfulin
⦁ Defection
⦁ Micturation
⦁ Child birth
⦁ Constant contraction of the diaphragm andabdominalmuscleshelpssupport of
the vertebral column during weight lifting