1. Lower Airway Larynx Tracheobronchial Tree (TB Tree) Trachea Bronchi
Bronchioles
Respiratory
Terminal

2. Hyoid Bone Not part of the larynx.
The Hyoid bone is an anchor for the anterior muscles of the neck and is highly mobile. It also attaches to the muscles of the tongue to provide a stable or mobile base as the mobility of the tongue requires.

3. Larynx Voice Box Function Prevents aspiration
Generates sound for speech
Conducts air between the pharynx and trachea
Creates pressure changes

4. Aspiration Increased Risk of Aspiration Extremes of Age Recent Meal
Table 1
Aspiration
Aspiration is the movement of food, liquid, vomit or a foreign substance into the trachea.
Aspiration usually involves coughing or choking until the substance is removed if the patient has intact reflexes
If large amounts of material or acidic, caustic materials (vomit) are aspirated, lung damage will result
Increased Risk of Aspiration
Extremes of Age
Recent Meal
Delayed gastric emptying
Trauma
Depressed level of consciousness
Poor motor control

5. Cartilages of the Larynx
Composed of nine cartilages
Three unpaired cartilage
Thyroid (Greek for Oblong Shield)
Cricoid (Greek for ring)
Epiglottitis (Greek for “above glottis”)
Three paired cartilages (six total)
Arytenoids (Greek for ladle)
Corniculates (Latin for horns – cornucopia)
Cuneiforms (Latin for wedge)

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9. 2. Arytenoid cartilage
3. Cervical trachea
6. Epiglottic larynx
7. Epiglottis
8. False Vocal Cords
9. Hyoid Bone
12. Subglottic larynx
15. True Vocal Cords

10. Paired Cartilages
The Arytenoids, Cuneiforms, and Corniculates are all associated with movement of the vocal cords and are used in phonation.

11. Thyroid Cartilage
The largest laryngeal cartilage is the thyroid cartilage
“Adam’s Apple”
Superior border has a V-shaped notch.
Suspended from hyoid bone.
Posterior wall is open.
The true and false vocal cords are found on the interior of the larynx.

12. Vocal Cords Two pairs of folds that protrude inward:
Upper pair – False cords
Lower pair – True cords
The space between the vocal cords is called the rima glottidis or glottis
Narrowest portion of the adult airway

13. Vocal Cords

14. Vocal Cords Vocal Cord Abduction Vocal Cord Adduction
Cords are opening or moving away from the midline
This occurs during inspiration
Vocal Cord Adduction
Cords are moving toward the midline or coming together
This occurs during expiration

16. Epiglottis
Spoon-shaped cartilage which prevents aspiration by covering the opening of the larynx during swallowing.
The tongue and the epiglottis are connected by folds of mucous membranes which form a small space called the vallecula.

17. Intubation
A device called a laryngoscope is used to visualize the laryngeal structures.
It is composed of a handle and one of two types of blades:
A curved blade (McIntosh)
A straight blade (Miller or Wisconsin)

18. A curved laryngoscope blade is inserted into the vallecula during intubation to lift the epiglottis indirectly.
A straight laryngoscope blade is used to directly lift the epiglottis during intubation

19. Cricoid Cartilage Resembles signet (class) ring. Inferior to Thyroid.
Only complete ring of laryngeal structures.
Inferior border is attached to the first C-shaped tracheal ring.
The narrowest portion of the airway in an infant.
We use this fact when ventilating infants as infant ET tubes do not have cuffs to seal the trachea.

21. Cricothyroid membrane
Connects the cricoid and thyroid cartilages
Is the site for an emergency airway
Cricothyrotomy

23. Laryngeal Swelling http://www.rale.ca/Stridor.htm
Swelling (edema) at the glottis, subglottic or supraglottic region can cause stridor
Stridor is a high pitched crowing sound usually heard on inspiration from air traveling through a narrowed opening
Croup, Epiglottis, Foreign Body

24. Laryngospasm
A laryngeal reflex which will close the vocal cords inside the larynx
Laryngospasm results from
Extubations
Near drowning
Inhalation of noxious substances
Smoke inhalation

25. Valsalva Maneuver
Forced expiratory effort against a closed glottis to increase intrathoracic pressure (defecation) or to inflate the eustachian tubes and middle ears (“clearing” of the ears on airplanes).
The larynx will tightly seal preventing air from escaping during physical work
Lifting, pushing, throat-clearing, vomiting, urination, defecation and parturition.

26. Head Position Flexed Extended

28. Histology of the Larynx
Above the vocal cords
stratified squamous epithelium
Below the vocal cords
pseudostratified columnar epithelium
Trachea to respiratory bronchioles

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30. Tracheobronchial Tree
Two Divisions
Cartilaginous Airways
Primarily conducting airways; no gas exchange.
Noncartilaginous Airways
Both conducting airways and sites of gas exchange.
Dichotomous Branching
Each airway divides into two “daughter” branches
Each division (bifurcation) gives rise to a new generation of airways
As airways divide, they become
Shorter
Narrower
More numerous

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33. Cartilaginous Airways
Trachea
Main Stem Bronchi
Lobar Bronchi
Segmental Bronchi
Subsegmental Bronchi

34. Lobar Bronchi

35. Trachea Generation 0 11 – 13 cm long and 1.5 – 2.5 cm wide.
Extends from Cricoid cartilage (6th cervical vertebrae) to the 2nd costal cartilage or 5th thoracic vertebrae.
C6 – T5
C-shaped cartilages supports the trachea.
Posterior wall is contiguous with esophagus.

36. Trachea The end of the trachea is called the carina.
This is the division of the trachea into the right and left mainstem bronchi.
Air is 100% saturated with water vapor and is warmed to 37 °C (body temperature).
The carina is located at approximately T5 or the Angle of Louis.
The surgical opening into the trachea is called a tracheostomy.
2nd or 3rd tracheal ring.

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38. Main Stem Bronchi Generation 1
Trachea divides into the right and left mainstem bronchi – one for each lung
Right Mainstem is wider, shorter and more vertical
Branches at a 25 degree angle
Left Mainstem
Branches at a 40 – 60 angle
Infants
Both mainstem bronchi form a 55 angle with the trachea

39. Newborn

40. Complications of Intubation
During intubations, if the tube is advanced to far, the tube will usually go into the right mainstem bronchi.
Lung inflation will be absent on the left but present on the right.
Withdraw tube until bilateral sounds are heard.
Failure to hear lung sounds or visualize chest inflation on either side means the tube is probably in the stomach.
Extubate the patient and re-attempt the intubation.

41. Aspiration Children who aspirate objects
Foreign body usually lodged in right main stem bronchi secondary to the angle being less acute.
Wheezing on right or absent lung sounds (breath sounds).

42. Lobar Bronchi Generation 2
Lobar Bronchi correlate to the number of lobes of the lung.
The right mainstem bronchi will divide into the right upper, right middle and right lower lobe bronchi.
The left mainstem bronchi will divide into the left upper and left lower lobe bronchi.

43. Segmental Bronchi Generation 3
Correlate with the segments of the lung.
There are 10 segmental bronchi on the right.
There are 8 segmental bronchi on the left.

44. Subsegmental Bronchi 4th to 9th Generations 1 to 4 mm in diameter
Connective tissue containing:
Nerves
Lymphatics
Bronchial Arteries

46. Non-Cartilaginous Airways
Bronchioles
10th to 15th Generation.
1 mm in diameter.
Simple cuboidal epithelium.
No cartilage.
Terminal Bronchioles
Less than 0.5 mm in diameter.
No cartilage (lack of support).
Cilia and mucous glands disappear.
Clara Cells appear
Inter-bronchiole connections called Canals of Lambert begin to appear.

48. Blood Supply to the Tracheobronchial Tree
Bronchial Blood Supply
Bronchial arteries nourish the tracheobronchial tree
The arteries arise from the aorta and follow the tracheobronchial tree as far as the terminal bronchioles.
Beyond the terminal bronchioles pulmonary arteries & capillaries feed the airways & alveoli.
Normal bronchial blood flow is approximately 1% of the cardiac output.
Also feed the mediastinal lymph nodes, pulmonary nerves, part of the esophagus and the visceral pleura.

49. Review of TB Tree Trachea Mainstm Bronchi Lobar Bronchi
Segmental Bronchi
Subsegmental Bronchi
Bronchioles – cartilage disappears
Terminal Bronchioles

50. Site of Gas Exchange “The Respiratory Zone”
Consists of the respiratory bronchioles, alveolar ducts, and alveolar sacs, and alveoli.
Parenchyma, Acinus or Primary Lobule.

52. Creative Commons Attribution

53. Alveolar Epithelium Two principal cell types: Alveolar Type I Cells
Squamous pneumocyte
Broad thin cells.
95% of alveolar surface
0.1 m to 0.5 m thick
Alveolar Type II Cells
5% of alveolar surface
Cuboidal in shape
Responsible for secretion of pulmonary surfactant that reduce surface tension and keep the alveoli stable.

54. Facts about the Lungs There are 300 million alveoli in the lungs.
The surface area of the lungs is square meters (Tennis Court).
The lung has 35 times more surface area then the skin.

55. Additional Components of Alveolar Epithelium
Pores of Kohn
Small holes in the walls of interalveolar septa.
3 m to 13 m in diameter
Alveolar Macrophages or Type III alveolar cells.
Major role in removing bacteria and other foreign particles.
Interstitium
Gel-like substance between alveoli-capillary clusters that add support

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59. Lung
Extends from the diaphragm to 1-2 cm above the clavicles (about the 1st rib).
The lung apex is at the top of the lung and is somewhat pointed.
The base is broad and concave and lies at about the 6th rib or xiphoid process anteriorly, the 8th rib laterally, and the 11th rib posteriorly.
The right lung is larger and heavier than the left.

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61. Lung Lobes and Segments
Right lung
Three Lobes
Upper, Middle, Lower
Divided by the Horizontal and Oblique fissures.
10 Segments
Left lung
Two Lobes
Upper and Lower
Divided by the Oblique fissures.
8 Segments

63. LOBES AND SEGMENTS OF THE LUNGS
RIGHT LUNG
LEFT LUNG
UPPER LOBE
UPPER LOBE (UPPER DIVISION)
APICAL SEGMENT ANTERIOR SEGMENT
POSTERIOR SEGMENT
APICAL/POSTERIOR
ANTERIOR
MIDDLE LOBE
UPPER LOBE (LINGULA)
LATERAL
MEDIAL
SUPERIOR
INFERIOR
LOWER LOBE
ANTERIOR BASAL
MEDIAL BASAL
LATERAL BASAL
POSTERIOR BASAL
ANTERIOR/MEDIAL BASAL

64. Lung Fissures Oblique Fissure Horizontal or minor Fissure
Found in the left and right lung
Separates the upper and lower lobes of both lungs
Horizontal or minor Fissure
Found only in the right lung
Separates the upper and middle lobes

65. Horizontal fissure Oblique fissure

67. Hilum
The hilum is where arteries, veins, bronchi, nerves and lymph vessels enter and leave the lung.
It is located on the medial border of the lung.

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