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 Trachea
 Bronchi
 Bronchioles
 Respiratory
 Terminal

 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.

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

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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

 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)

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

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

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

 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

 Vocal Cord Abduction
 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
 http://www.entusa.com/normal_larynx.htm

 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 .

 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)

 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

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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.

 Connects the cricoid and thyroid cartilages
 Is the site for an emergency airway
 Cricothyrotomy

 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


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

 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.

 Above the vocal cords
 stratified squamous epithelium
 Below the vocal cords
 pseudostratified columnar epithelium
 Trachea to respiratory bronchioles

 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

 Trachea
 Main Stem Bronchi
 Lobar Bronchi
 Segmental Bronchi
 Subsegmental Bronchi

Lobar Bronchi

 Generation 0
 11 – 13 cm long and 1.5 – 2.5 cm wide.
 Extends from Cricoid cartilage (6 th cervical vertebrae) to the 2 nd costal cartilage or 5 th thoracic vertebrae.
 C6 – T5
 15 - 20 C-shaped cartilages supports the trachea.
 Posterior wall is contiguous with esophagus.

 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 .
 2 nd or 3 rd tracheal ring.

 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

Newborn

 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.

 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).

 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.

 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.

 4 th to 9 th Generations
 1 to 4 mm in diameter
 Connective tissue containing:
 Nerves
 Lymphatics
 Bronchial Arteries

 Bronchioles
 10 th to 15 th 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.

 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.

 Trachea
 Mainstm Bronchi
 Lobar Bronchi
 Segmental Bronchi
 Subsegmental Bronchi
 Bronchioles – cartilage disappears
 Terminal Bronchioles

 Consists of the respiratory bronchioles, alveolar ducts, and alveolar sacs, and alveoli.
 Parenchyma, Acinus or Primary Lobule.

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Attribution

 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.

 There are 300 million alveoli in the lungs.
 The surface area of the lungs is 75-85 square meters (Tennis Court).
 The lung has 35 times more surface area then the skin.

 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

 Extends from the diaphragm to 1-2 cm above the clavicles (about the 1 st 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 6 th rib or xiphoid process anteriorly, the 8 th rib laterally, and the 11 th rib posteriorly.
 The right lung is larger and heavier than the left.

 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

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

 Oblique 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

 Horizontal fissure
 Oblique fissure

 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.