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221
CARDIOPULMONARY
ANATOMY AND PHYSIOLOGY
Chapter 1

Main function of lungs – bring atmospheric
gases into contact with the blood

Ventilation – The process of moving gas in and
out of the lungs

Respiration – moving oxygen and carbon
dioxide between air and blood
Upper Airways

Most important function
warms
 humidifies
 filters


Consists of
nose
 oral cavity (mouth)
 pharynx (throat)
 larynx (“voice box”)

inspired gas (air)
1. Nose

Air conditioning and filtering device

Nose is more resistant to airflow than mouth

Despite that resistance: Most adults breathe
through the nose at times of rest
***High nasal resistance from swollen mucous
and rapid breathing from exercise usually cause
people to switch to mouth breathing.

NASAL CAVITY
Septum

Cartilage – Divides nose
Right and Left Nostril
 Clinically = Right and Left NASAL FOSSAE


Some deflection occurs slightly to the left


Clinical Significance ___________________
Difficulty breathing through nose?

Deviated Septum? (Next Slide)
Nasal Cavity - Anatomical Structures
CONCHAE

Three Conchae bones
Superior, Middle, Inferior
 Create Turbulence
 AKA Turbinates



Conchae – covered with mucous membranes
Main purpose is to filter, humidification, heat
inhaled air
Nasal Fossae
Source: mayoclinic.com/health/medical/IM02743
3. Pharynx
Greek – “throat”
Comprised of 3 landmarks
Where the Nasal Cavity ends all the way down right
before the Larynx and Trachea- Fig 1-1 page 3
1. Nasopharynx -behind nasal cavity down to soft
palate
2. Oropharynx -behind oral cavity from soft palate to
base of tongue
3. Laryngopharynx aka Hypopharynx - below base
of tongue and above larynx
By the time air reaches the nasopharynx, inspired air
gains water vapor and heat from the nose and
humidification
Concept Question 1-1, pg. 5
 Answer:
 Nasal
Cannula: At what flow rate does the
nose lose its ability to humidify oxygen?
 Recommendation:
Ventilator
 Artificial
Nose – or HME
 Drawback
 If
–
thick secretions -
Back to the Pharynx
 NASOPHARYNX-
pg 5
 Connected to the middle ear by the
Eustachian Tubes aka _______________
AUDITORY TUBES
Eustachian Tube
Ear Drum
Outer
Inner
Middle
Middle Ear = Space behind ear drum
Pharynx (cont) pg 6

The laryngopharynx (hypopharynx) separates
the Esophagus and Trachea.
(digestive &respiratory tracts)

Sensory & motor nerves effect on pharyngeal
muscles prevents food and liquid aspiration in
the trachea
 PHARYNGEAL REFLEX
 Stimulation of this nerve = Gag & Swallow

Deeply unconscious patients may lose gag reflex


Aspiration risks increase
Intubation and mechanical ventilation is necessary
Pharyngeal Muscle Tone
pg 6
 Loss
in muscle tone

Base of tongue may fall back and occlude the
laryngopharynx
Snoring

Excessive occlusion/blockage = apnea

• Apnea = No air movement… No breathing
Intubation
 Often
done in patients who need support
in ventilation
 Endotrachael
Tube is inserted into the
trachea (Nasally, Orally, Tracheostomy)
Pharynx
C – Sniffing position. Pulls
the tongue forward out of the
way of the airway. Best for
intubation
Fig. 1-5
Pharynx
4. LARYNX
•Sometimes called the “VOICEBOX”
•Vocal cords control the size of the opening of the
trachea (glottis)
•Main Cartilage of the Larynx (the middle of neck)
is the Thyroid Cartilage, aka “ADAM’S APPLE”
• Function – Speech and __________________
Epiglottis – Flap
Larynx – aka Voice Box
Cartilage beneath it – Thyroid Cartilage “Adam’s Apple
At the opening of the Larynx
Epiglottis
The epiglottis does not “seal” the
airway, instead, the upward movement
of the larynx toward the base of the
tongue pushes the epiglottis down,
diverting food away from the glottis.
Left – No breathing or swallowing
Right – Swallow is initiated. Larynx moves up…. Forces the
epiglottis to bend down
Left – Epiglottis bends downward… Redirects from the the
larynx and trachea… Doesn’t seal it… just diverts food to the
esophagus
Right – Food passes to Esophagus
Left – After a complete swallow, the Epiglottis starts lifting
up again
Right – Epiglottis continues to lift up now as the patient
begins to exhales
Left – as exhalation continues to the oropharynx, epiglottis
is now nearly shut
Right – As the air flows out the mouth, epiglottis is
completely shut
Epiglottitis
 Life
Threatening
 Drooling/Difficulty Swallowing/Breathing
 Intubation
INTUBATION VISUAL
Thyroid and Cricoid
Thyroid is what we
refer to as the Adams
Apple… It encloses
the main cavity of the
Larynx
Fig. 1-6
Cricoid
 Narrowest
portion of the upper airway in
the infant
 Not
the narrowest in the adult, however
passing Endotracheal through may still be
difficult
Vocal Cords

Form triangular opening into trachea


narrowest part of adult larynx
Can open and close

when closed allows pressure generation needed to cough
• Cough = important defense mechanism for lung

artificial airway removes vocal cords’ ability to seal airway
and cough effectively

Vocal cord edema (croup - Pediatrics; stridor - ETT)

Laryngospasm during extubation - hoarseness
Upper Airway Summary
The nose alters inspired air by:
A. Humidifying, cooling, and reducing flow
velocity
B. Cooling, filtering, and humidifying
C. Humidifying, filtering, and warming
D. Warming, reducing flow velocity, and
filtering
Upper Airway Summary
The ________ is referred to as the voicebox
A. Pharynx
B. Larynx
C. Trachea
D. Cricoid
Upper Airway Summary
The Adam’s Apple is the name given to the:
A. Thyroid
B. Larynx
C. Trachea
D. Cricoid
Airways Vs. Alveoli
Lower Airways
pg 10

Dichotomous branching pattern from trachea
 Each airway divides into two smaller airways


(See next slide)
Each bifurcation creates new generation of
airways
 Tracheobronchial “tree” Figure 1-8
Lower Airways
Also referred to as:
Conducting Airways
No gas exchange takes place
This are can be obstructed
with secretions and mucus
This is part one of the lung…
the other part is the
parenchyma where the alveoli
and tissues exist.
Fig. 1-8
Trachea and Main Bronchi

Trachea





8-20 C-shaped cartilages
Begins at 6th cervical vertbra
11 cm long in adults
1.5-2.5 cm in diameter
Carina – point of division fig-1-8



bifurcation of trachea into right and left bronchi
right bronchus at 20-30 degrees from midline
left bronchus at 45-55 degrees from midline
• smaller in diameter, but twice as long

air is 100% saturated and at 37o C at this point
• ISB (Isothermic Saturation Boundary… See Fig. 1-10)
Application
 During
intubation, if the Tube is pushed
too far, it most likely will enter the
____________________________
Chest Auscultation
Chest Excursion
Carina
Conducting Airways
No gas exchange takes place
This area can be obstructed with
secretions and mucus
Lung parenchyma where the alveoli and
tissues exist is where gas exchange starts
Conducting Airway Anatomy
Conduit or passage or pathway
 Airways:
trachea to just before alveolar
level:



no gas exchange
conduit for air to reach alveoli
23-27 subdivisions beginning at trachea
 Right
and left mainstem bronchi
position patients
during PD&P.
Fig. 1-12
Problem with airway disease
 Obstruction
 Airflow
resistance
Lung Parenchyma
 ACINUS
(pg 14)
 Functional tissue of the lung
 Contains elastic fibers


surrounds airways
Gas Exchange takes place
 Elastic


fibers can be destroyed by disease
Emphysema
Prevents air from escaping the lung during
exhalation
• “Air Trapping”
The Acinus
THE ACINUS IS THE FUNCTIONAL RESPIRATORY UNIT OF THE LUNGS.
Fig. 1-13
( ALL ALVEOLI ARE CONTAINED IN THE ACINUS)
EACH TERMINAL BRONCHIOLE GIVES RISE TO AN ACINUS.
Alveoli and Capillaries
(Alveoli-Capillary Membrane)
 Alveoli
 300 million (300 x 106) alveoli in adult lungs

100 to 300 microns (m) in diameter
 Pulmonary



capillaries
in contact with alveolar membrane
just large enough to allow passage of red blood
cells
facilitate gas exchange
Alveoli and Capillaries
Fig. 1-17
Problem with Alveolar Disease



Compliance
Elastance
Restriction- where volume is restricted
Alveolar Disease
 Alveolar
Collapse

Atelectasis ??

Clinical focus 1-5
Resistance
Compliance
Elastance
Airflow Obstruction
Distending
Properties
Recoiling
Properties
Summary
Patients requiring a tracheostomy would
benefit most from:
A. High airflows provided to the trachea
B. Dehumidified air provided to the airway
C. Cool mist for adequate hydration
D. Heated, humidified inspired air
CPR is often done outside the hospital
setting. An important technique in
ventilating the patient involves tilting the
victim’s head back and thrusting the jaw
forward. This is done to allow:
A. Better blood flow to the head
B. Air forced into the mouth easier passage
to the lungs
C. Easier mouth alignment
D. Reducing the chance of damage to the
upper airways
Certain lung diseases impair the A-C
membrane’s gas-diffusing capabilities. An
important consequence of this would be:
A. A decrease in blood oxygen levels
B. A decrease in blood carbon dioxide levels
C. An increase in blood oxygen levels
D. An increase in blood oxygen levels and
carbon dioxide levels