Pulmonary Pt1 Flashcards
What are the 3 processes required for respiration
1) Ventilation (breathing)
2) External (pulmonary) respiration - gas exchange in the lungs
3) Internal (tissue) respiration - gas exchange in the tissues
2 Structural categories of the Resp. Sys. vs 2 Functional categories of the Resp Sys.
- Structural
1) Upper respiratory system - nose, pharynx, paranasal sinuses and assoc. structures
2) Lower respiratory system - larynx, trachea, bronchi and lungs - Functional
1) Conducting zone - dead space up to terminal bronchioles
2) Respiratory zone - gas exchange in alveoli
Mallampati Score
-Used to predict ease of intubation or if the pt has OSA.
Class I - Full visibility of tonsils, uvula, and soft palate
Class II - Visibility of hard and soft palate, upper portion of tonsils and uvula
Class III - Soft and hard palate and base of the uvula are visible
Class IV - Only hard palate visible
How are the 12 pairs of ribs categorized?
1) True Ribs (1-7) - Directly attached to sternum via costal cartilage
2) False Ribs (8-10) - Indirectly attached
3) Floating ribs (11-12) - Not attached to sternum
Supernumerary Ribs
- Extra ribs
1) Cervical - Elongation of transverse process of 7th cervical vertebra (0.5% incidence)
2) Lumbar - Elongation of transverse process of lumbar vertebrae (less common)
How do the ribs accommodate physiological function
1) Allows flexibility for movement that is needed for ventilation
2) Oblique orientation allows for elevation of rib cage with lung expansion
3 parts of the Sternum
1) Manubrium - uppermost part
2) Body - middle part
3) Xyphoid process - lower most part
Suprasternal notch
- aka Jugular notch
- trachea lies posterior to and in line with the jugular notch
- same horizontal plane as 2nd thoracic vertebra
- signifies midpoint of trachea and ideal location for the distal tip of the ET tube
Sternal Angle
- aka angle of Louis
- where the manubrium joins the body of the sternum
- bifurcation of the trachea (carina) occurs at this level (t4-t5)
Manubriosternal Joint
- hinge-like joint btw manubrium and body of sternum
- allows hinge-like forward movements of sternum during inspiration and backward movement during expiration
Functions of the Nose 👃
1) Warms, cleanses, and humidifies inhaled air
2) Detects odors
3) Resonating chamber amplifies the voice
Bony and cartilaginous supports of the nose
1) Superior Half - nasal bones medially and maxillary laterally
2) Inferior Half - Lateral and alar cartilages
3) Ala Nasi - Flared portion shaped by dense CT, forms lateral wall of each nostril
Nasal Cavity
1) Extends from nostrils to posterior nares
2) Includes Vestibule and nasal septum
3) Vestibule - dilated chamber inside ala nasi (stratified squamous epithelium, vibrissae: guard hairs)
4) Nasal septum - divides cavity into r and l chambers called nasal fossae.
Which part of the nasal anatomy specifically warms, cleans and moistens the air for the lungs?
Turbinates and sinuses
Nasal Conchae
- 3 folds of tissue on lateral wall of nasal fossa
- mucous membranes supported by thin scroll-like turbinate bones
*Nasal Meatuses
- narrow air passage beneath each conchae
* - narrowness and turbulence ensures air contacts mucous membranes
*Olfactory mucosa vs. Respiratory mucosa
1) Olfactory mucosa - Lines roof of nasal fossa
* 2) Respiratory mucosa - Lines rest of nasal cavity with ciliated pseudo-stratified epithelium.
*Defensive role of mucosa?
*Mucus (from goblet cells) traps inhaled particles (i.e. bacteria) which is then destroyed by lysozyme and IgA
Function of cilia of respiratory epithelium
sweep debris-laden mucus into pharynx to be swallowed
Erectile tissue of inferior concha
venous plexus that rhythmically engorges with blood and shifts flow of air from one side of fossa to the other once or twice an hour to prevent drying
3 Divisions of the pharynx
1) Nasopharynx - psuedostratified epithelium
2) Oropharynx - stratified squamous epithelium
3) Laryngopharynx - stratified squamous
*Nasopharynx
- posterior to choanae
- dorsal to soft palate
- receives auditory tubes and *contains pharyngeal tonsil
- 90 degree downward turn traps large particles ( >10μm)
Oropharynx
- space between soft palate and root of tongue
- inferiorly down to hyoid bone
- contains palatine and lingual tonsils
Laryngopharynx
- hyoid bone to level of cricoid cartilage
Glottis
Vocal cords and opening between
Epiglottis
Flap of tissue that guards glottis, directs food and drink to esophagus
Differences in infants’ larynx
- higher in throat, forms a continuous airway from nasal cavity that allows breathing while swallowing
- by age 2, more muscular tongue forces larynx down
Attachments of true vocal chords
True vocal cords are attached anteriorly to the thyroid cartilage and posteriorly to the arytenoid cartilage
Larynx
- Located between c3-c6 (in adults) and c3-c5 superiorly (in children)
- framework formed by 9 total pieces of cartilage (3 paired and 3 unpaired)
3 paired vs unpaired cartilage of the larynx
- Paired (arytenoid, corniculate, and cuneiform)
- Unpaired (Epiglottis, thyroid, cricoid)
Vertebral levels in the Larynx
1) Hyoid - c2/c3
2) Thyrohyoid membrane - c4
3) Laryngeal prominence - c5
4) Cricoid cartilage and start of trachea - c6
The 9 cartilages of the Larynx
1) Epiglottic - most superior
2) Thyroid - largest; forms laryngeal prominence
3) Cricoid - connects larynx to trachea
4/5) Arytenoid x2 - posterior to thyroid cartilage
6/7) Corniculate - attached to arytenoid cartilages like a pair of little horns
8/9) Cuneiform - support soft tissue between arytenoids and epiglottis
Narrowest portion of the airway on a pediatric patient?
Used to be considered the cricoid. but newer studies suggest it is the glottic opening
Laryngeal Cavity
- Includes the rima glottidis and the glottis, and is narrowest portion of the upper airway in the adult
Rima Glottidis
Opening between true vocal cords and the arytenoid cartilages
Glottis
True vocal cords and the rima glottidis
Etrinsic Muscles
- Connects larynx to hyoid bone
- Elevates larynx up and forward during swallowing
- Includes supra hyoid and infra hyoid muscles
Suprahyoid muscles
stylhyoid, mylohyoid and diagstric
Infrahyoid muscles
omohyoid, sternothyroid, thyohyoid, and sternohyoid
Aryepiglottic
- narrows inlet
- closes glottis
Oblique Aretynoid
- narrows inlet
- closes glottis
Result of Aryepiglottic and Oblique Aretynoid acting together
Together, they act as a purse-string sphincter during swallowing
Thyroepiglottic
Widens inlet
Intrinsic muscles
- rotates cornicate and arytenoid cartilages
- adducts vocal cords (tightens for high pitch sounds)
- Abducts vocal cords (loosens for low pitch sounds)
Muscles involved with movement of vocal cords?
1) Cricothyroids
2) Thyroarytenoids
3) Lateral Cricoarytenoids
4) Transverse arytenoids
5) Oblique Arytenoids
6) Posterior Cricoarytenoids
Cricothyroids
Tense vocal cords
Thyroarytenoids
relax vocal cords, also includes the vocals muscle which adjusts the tension of the cords
Lateral Cricoarytenoids
adducts and classes cords
Transverse arytenoids
adducts and closes cords
Oblique Arytenoids
adducts and classes cords
Posterior Cricoarytenoids
abducts, folds and open vocal cords
Blood Supply to the Larynx
Blood supply to the larynx is supplied via the external carotids & subclavian arteries and internal jugular vein
Sensory innervation of the larynx
- Via CN X/vagus
- Interior branch of superior laryngeal provides sensation for upper portion of the larynx own to and including upper half of the vocal cords
- recurrent laryngeal nerve - transmits sensation below the true cords and half of the lower cords
Motor innervation of the larynx
- all intrinsic muscles except the cricothyroid are innervated by the RECURRENT LARYNGEAL nerve
- crycothyroid muscle is innervated by superior laryngeal nerve
Trachea characteristics
1) Fibrocartilaginous tube, approximately 10-20cm long and 12mm in diameter
2) Begins at the end of the larynx (C6) and extends to T5-6
3) Supported by 16-20 C-shaped rings of cartilage with smooth muscle posteriorly
4) The carina is the lower most portion of the trachea where it divides into primary bronchi
5) Lined with ciliated pseudostratified epithelium which functions as mucociliary escalator
Removing Inhaled Particles
1) The lungs produce 100mL of mucous per day
2) Turbulent flow helps trap precipitate
3) Cough Reflex
4) Mucociliary escalator mechanism - Ciliated epithelial cells beat particles up the airway to be swallowed in the oropharynx which is Impaired by endotracheal intubation and volatile anesthetics
Flow of inspired air from trachea to alveoli
Trachea»_space;> L/R main bronchi»_space;> Lobar bronchi»_space;> Segmental Bronchi»_space;> Bronchioles»_space;> Terminal Bronchioles»_space;> Respiratory Bronchioles»_space;> Alveolar Ducts»_space;> Alveolar Sacs»_space;> Alveoli
Conducting/Dead space includes ______ ?
Trachea»_space;> L/R main bronchi»_space;> Lobar bronchi»_space;> Segmental Bronchi»_space;> Bronchioles»_space;> Terminal Bronchioles
Respiratory/Gas Exchange includes _____ ?
Respiratory Bronchioles»_space;> Alveolar Ducts»_space;> Alveolar Sacs»_space;> Alveoli
Secondary (Lobar) Bronchi
- Bronchospasm occurs here
- Three on the right, two on the left (related to lobes)
SEGMENTAL BRONCHI
- Bronchospasm occurs here, can be treated by increasing positive pressure, deepening the anesthetic, increasing the inspiratory time of ventilation, and directly spraying lidocaine into the trachea
- Ten on right, eight on left
TERMINAL BRONCHIOLES
- Diameter of 1 mm and contain NO cartilage
- Relatively thick smooth muscle wall compared to lumen
- Can contract during asthma attack
- No goblet cells
Bronchial Circulation
- Supplied by systemic circulation
- Some mixes with alveolar venous return, causing an anatomic shunt – area of the lung where there is perfusion but no ventilation.
Bronchial Innervation
1) Sensory & Motor via Vagus
2) Parasympathetic: Ach bronchoconstriction
3) Sympathetic: Epi/Norepi bronchodilation
Respiratory Zone
-Composed of Acinus (terminal respiratory unit)
(Respiratory bronchioles Alveolar ducts, Alveoli
(Alveoli are formed from birth to age 4, they continue to maximally expand until age 8)
Respiratory bronchioles
first segment of airway where gas exchange occurs (transitional zone)
Alveolar ducts
walls completely lined with alveoli
Alveolar sac
located at end of each 3rd generation of alveolar ducts
What is the main mechanism for gas transfer from the alveoli into the blood?
Diffusion - More lipid soluble anesthetics will diffuse easier, resulting in build up in the blood stream
Diffusion calculation
Diffusion = Area/Thickness
In a normal lung, how large is the the area of the blood gas interface?
About the size of a tennis court
Alveoli characteristics
- 300 million in the adult
- Polygon shape maximizes surface area
- Surrounded by 1,000 pulmonary capillaries each
- Two types
Type I alveolar cells
- Squaous
- Form walls of alveoli
- Involved in gas exchange
Type II alveolar cells
- Cuboidal
- Produce surfactant
- Differentiate into type I cells when needed
- not significant component of the respiratory membrane
Why is gas exchange limited in a chronically injured lung i.e. pulmonary fibrosis
because alveolar epithelium is lined entirely by type II cells
Role of alveolar macrophages
eliminates foreign debris
What are alveolar pores
aka pores of Kohn are opening in the walls btw adjacent alveoli that allow for collateral ventilation
What is alveolar interdependence
If an alveolus start to collapse, the surrounding alveoli are stretched and then recoil, exerting expanding forces in the collapsing alveolus to open it.
3 things that prevent alveoli collapse
1) Surfactant
2) Alveolar pores
3) Interpdependence
Right vs Left Lung
- Right lung (3 lobes, receives 60% of CO)
- Left lung (2 lobes and narrower; receives 40% of CO)
Innervation of lungs
- The lungs are innervated by the pulmonary plexus
- Sympathetic fibers T2-T6 and parasympathetic fibers from the vagus
Pain receptors in lungs?
There are few to no pain receptors in lungs
Parasympathetic vs Sympathetic innervation of the lungs
1) Parasympathetic fibers produce constriction of the airways and increase mucus secretion by the mucus glands
2) Sympathetic hormones produce dilation of the airways (beta-2 response)
Pleural Fluid
10cc produced per lung to prevent friction in pleural cavity and create a pressure gradient
Visceral vs. parietal pleura
1) Visceral pleura - attached to outer surface of the lungs
2) Parietal pleura - line the wall of the thoracic cavity
Diaphragm
- Accounts for most tidal volume (60-75%)
- Dome shaped muscle that forms the floor of the thorax and separates the thoracic cavity and the abdominal cavity
- rvation is supplied by paired phrenic nerves (c3-c5; c4 = 70% contribution)
- Allows for half of the diaphragm to continue working if one side is damaged
- Motor AND sensory nerves
2 halves of the diaphragm
1) Hemidiaphragms - Right side, which is higher (raised up by liver), pushes left side down.
2) Major diaphragmatic foramina - Includes vena cava foramen, esophageal hiatus and aortic hiatus
Referral areal for diaphragmatic pain
shoulders
Major factors affecting the position of the diaphragm
1) Recoil of lungs
2) Thoracic viscera pressure (i.e. CHF)
3) Abdominal viscera pressure (i.e. pregnancy)
4) Abdominal muscle activity (contraction pushes diaphragm upward)
Movement of diaphragm during normal breathing
1) 1-2cm normal tidal breathing
2) 7-13cm with deep breathing
Intercostal Muscles
1) External Intercostals - Oriented obliquely forward and downward, responsible for 25% of TV, lifts up ribs during inspiration
2) Internal Intercostals - Oriented backwards and downwards, assist in expiration by pulling ribcage down and aids in forced expiration.
3 factors affecting ventilation
1) Surface Tension - Inwardly directed force in the alveoli which must be overcome to expand the lungs during each inspiration
2) Elastic Recoil - Decreases the size of the alveoli during expiration
3) Compliance - Ease with which the lungs and thoracic wall can be expanded
Whta is Spontaneous Epistaxis? Where is it most common?
Spontaneous nosebleed - most common site is the inferior Concha
8 Differences in Infant/pediatric airway vs. Adult airway
Infant/Pediatric airway:
1) Narrow nostrils
2) Round occiput
3) Tongue relatively large for mouth
4) Epiglottis omega shaped and floppy
5) Larynx higher in neck
6) Vocal cords slant anteriorly
7) Short Neck
8) Cricoid ring narrowest in diameter
