respiratory 221 cardiopulmonary anatomy and physiology

RESPIRATORY RESPIRATORY 221 221

CARDIOPULMONARY CARDIOPULMONARY ANATOMY AND ANATOMY AND PHYSIOLOGYPHYSIOLOGY

Chapter 1Chapter 1

Main function of lungs – bring Main function of lungs – bring atmospheric gases into contact with the atmospheric gases into contact with the bloodblood

Ventilation – The process of moving gas Ventilation – The process of moving gas in and out of the lungsin and out of the lungs

Respiration – moving oxygen and Respiration – moving oxygen and carbon dioxide between air and bloodcarbon dioxide between air and blood

Upper AirwaysUpper Airways

Most important functionMost important function warmswarms humidifieshumidifies filtersfilters

Consists of Consists of nosenose oral cavity (mouth)oral cavity (mouth) pharynx (throat)pharynx (throat) larynx (“voice box”)larynx (“voice box”)

inspired gas (air)

1. Nose1. Nose Air conditioningAir conditioning and filtering device and filtering device

Nose is more resistant to airflow than Nose is more resistant to airflow than mouthmouth

Despite that resistance: Most adults Despite that resistance: Most adults breathe through the nose at times of restbreathe through the nose at times of rest

***High nasal resistance from swollen ***High nasal resistance from swollen mucous and rapid breathing from mucous and rapid breathing from exercise usually cause people to switch exercise usually cause people to switch to mouth breathing. to mouth breathing.

NASAL CAVITYNASAL CAVITYSeptumSeptum

Cartilage – Divides nose Cartilage – Divides nose Right and Left NostrilRight and Left Nostril Clinically = Right and Left Clinically = Right and Left NASAL FOSSAENASAL FOSSAE

Some deflection occurs slightly to the Some deflection occurs slightly to the leftleft Clinical Significance ___________________Clinical Significance ___________________

Difficulty breathing through nose?Difficulty breathing through nose? Deviated Septum? (Next Slide)Deviated Septum? (Next Slide)

Nasal Cavity - Anatomical Nasal Cavity - Anatomical StructuresStructuresCONCHAECONCHAE

Three Conchae bonesThree Conchae bones Superior, Middle, InferiorSuperior, Middle, Inferior Create TurbulenceCreate Turbulence AKA TurbinatesAKA Turbinates

Conchae – covered with mucous Conchae – covered with mucous membranesmembranes

Main purpose is to filter, Main purpose is to filter, humidification, heat inhaled airhumidification, heat inhaled air

Source: mayoclinic.com/health/medical/IM02743

Nasal FossaeNasal Fossae

3. Pharynx

Greek – “throat” Comprised of 3 landmarksComprised of 3 landmarks

Where the Nasal Cavity ends all the way down right Where the Nasal Cavity ends all the way down right before the Larynx and Trachea- Fig 1-1 page 3before the Larynx and Trachea- Fig 1-1 page 3

1. Nasopharynx 1. Nasopharynx -behind nasal cavity down to soft -behind nasal cavity down to soft palatepalate

2. Oropharynx 2. Oropharynx --behind oral cavity from soft palate to behind oral cavity from soft palate to base of tonguebase of tongue

3. Laryngopharynx aka Hypopharynx - 3. Laryngopharynx aka Hypopharynx - below base below base of tongue and above larynxof tongue and above larynx

By the time air reaches the nasopharynx, inspired air By the time air reaches the nasopharynx, inspired air gains water vapor and heat from the nose and gains water vapor and heat from the nose and humidificationhumidification

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 TUBESAUDITORY TUBES

OuterMiddle

Inner

Eustachian Tube

Ear Drum

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 Tonepg 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

Fig. 1-5

C – Sniffing position. Pulls the tongue forward out of the way of the airway. Best for intubation

Pharynx

4. LARYNX4. 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 – FlapLarynx – aka Voice BoxCartilage 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 againRight – 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 INTUBATION VISUAL

Thyroid and Cricoid

Fig. 1-6

Thyroid is what we refer to as the Adams Apple… It encloses the main cavity of the Larynx

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 Airwayspg 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

Fig. 1-8

Also referred to as:

Conducting AirwaysNo gas exchange takes placeThis 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.

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 AirwaysNo gas exchange takes placeThis 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 pathwayonduit 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

Fig. 1-12

position patients during PD&P.

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 placeGas Exchange takes place

Elastic fibers can be destroyed by disease Emphysema Prevents air from escaping the lung during

exhalation• “Air Trapping”

The AcinusThe Acinus

Fig. 1-13

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.

Alveoli and CapillariesAlveoli and Capillaries((Alveoli-Capillary Membrane)Alveoli-Capillary Membrane)

AlveoliAlveoli 300 million (300 x 10300 million (300 x 1066) alveoli in adult lungs) alveoli in adult lungs

100 to 300 microns (100 to 300 microns (m) in diameterm) in diameter

Pulmonary capillaries Pulmonary capillaries in contact with alveolar membranein contact with alveolar membrane just large enough to allow passage of red blood just large enough to allow passage of red blood

cellscells facilitate gas exchangefacilitate 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

Airflow ObstructionAirflow Obstruction

Compliance

Distending Distending PropertiesProperties

Elastance

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 headB. Air forced into the mouth easier passage

to the lungsC. Easier mouth alignmentD. 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