CARDIOPULMONARY ANATOMY AND PHYSIOLOGY RESPIRATORY 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 Consists of 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) Nostril Cavity is known as Nasal Fossae Clinical Significance – Suctioning with a nasal catheter may be easier through the right nostril

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

Source: mayoclinic.com/health/medical/IM02743 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 Have the students describe where the Pharynx is using page 3. Where the Nasal Cavity ends all the way down right before the Larynx and Trachea. (pg. 3) It’s broken up into three categories. NasoPharynx Oropharynx Largynopharynx aka Hypopharynx which means at the bottom (hypo) pharynx Have students write this down under Nasopharynx By the time air reaches the nasopharynx, inspired air gains water vapor and heat from the nose and humidification Nasopharynx behind nasal cavity down to soft palate behind oral cavity from soft palate to base of tongue Laryngopharynx below base of tongue and above larynx

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 - Tenacious excessive inspissated secretions Heated wire circuit

Back to the Pharynx NASOPHARYNX- pg 5 Connected to the middle ear by the Eustachian Tubes aka _______________ AUDITORY TUBES Eustachian Tube Ear Drum Inner Outer 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 Trachea aka Respiratory Tract

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 This maneuver pulls the tongue forward out of the way of the airway.

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 __________________ THE LARYYNX IS SOMETIMES CALLED THE “VOICEBOX” BECAUSE IT CONTAINS THE VOCAL CORDS, THAT CONTROL THE SIZE OF THE OPENING INTO THE TRACHEA (GLOTTIS) THE MAIN CARTILAGE OF THE LARYNX IN THE MIDDLE OF THE NECK IS THE THYROID CARTILAGE, SOMETIMES CALLED THE “ADAMS APPLE” BESIDES SPEECH, THE MAIN FUNCTION OF THE LARYNX IS SPEECH AND PREVENTION OF THE LOWER AIRWAY FROM ASPIRATING SOLIDS OR LIQUIDS THE EPIGLOTITIS 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. SEE PAGE 8 FIGURE 1-6

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 Epigottis starts lifting up again Right – Epiglottis continues to lift up now as the patient begins to exhales Left – After a complete swallow, the Epiglottis starts lifting up again Right – Epiglottis continues to lift up now as the patient begins to exhales

Right – As the air flows out the mouth, epiglottis is completely shut Left – as exhalation continues to the oropharynx, epiglottis is now nearly shut Right – As the air flows out the mouth, epiglottis is completely shut 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 Pg. 8 The 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 Can open and close 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 Conducting Airways No gas exchange takes place 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. 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 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) 44mg/L Fig. 1-10, pg. 11 Application…

Application During intubation, if the Tube is pushed too far, it most likely will enter the ____________________________ Chest Auscultation Chest Excursion Right mainstem. Always assess BS

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 Conduit or passage or pathway

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. ( ALL ALVEOLI ARE CONTAINED IN THE ACINUS) EACH TERMINAL BRONCHIOLE GIVES RISE TO AN ACINUS. Fig. 1-13

Alveoli and Capillaries (Alveoli-Capillary Membrane) 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 Show them how I draw it… SHOW LOW O2 AND HIGH CO2 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 Elastance Recoiling Properties 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 D. Heated, humidified inspired air

A. Better blood flow to the head 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 B. Air forced into the mouth easier passage to the lungs

A. A decrease in blood oxygen levels 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 A. A decrease in blood oxygen levels