Denver School of Nursing – ADN & BSN ProgramsNo Laboratory component for this class

BIO 206 & 308 – Ch 25 & 26 – Pulmonary Phys / Path

What are the three most important structures of the Respiratory System???

What are the three most important structures of the Respiratory System???

1. Lungs – WHY?

2. Muscles of Respiration – WHY?

3. Brain – WHY?

Secondary =

Tertiary=

Primary =

Muy Importante!=

The Respiratory System is divided into two general parts:

The Upper Respiratory Tract

The Lower Respiratory Tract

Where do you think the division starts?

What is the respiratory mucosa?

Proper Definition: From A&P Thibodeau: “Mucous membranes

are epithelial membranes that line body surfaces opening directly to the exterior (latin name, mucosa)... Their name is derived from the fact that they produce a film of mucus that coats and protects the underlying cells.”

In addition to protection, the mucus has other purposes, can you tell me what they are??

Function of Mucosa: Protection – for underlying tissue Immune Support!

Mechanically capture debris Presence of “mucins” (proteoglycans) Bacterial interface

Lubricant – to allow food to move in digestive tract, and if aspiration occurs in respiratory tract the mucosa will also allow for the pleasantry of “regurg” / emesis.

NosePharynxLarynxTracheaBronchiBronchiolesAlveoliLungsPleura

What is the purpose and function of each of these structures???

Remember what these are REALLY called?

Bronchioles

What are the serious membranes in the body?

Image from http://www.augustatech.edu/anatomy

Image from http://www.augustatech.edu/anatomy

Where are the 3 primary serous membranes found in the human body?

Serous membranes: Heart, lungs, GI

Image from http://www.augustatech.edu/anatomy

Illustration of the mechanism of respiration

Major and accessory muscles

Major muscles of inspiration▪ Diaphragm▪ External intercostals

Accessory muscles of inspiration▪ Sternocleidomastoid and scalene muscles

Accessory muscles of expiration▪ Abdominal and internal intercostal muscles

Alveolar surface tension and ventilation Function of surfactant

Elastic properties of the lung and chest wall Elastic recoil Compliance

Airway resistance

Work of breathing

Four steps Ventilation of the lungs Diffusion of oxygen from the alveoli into

the capillary blood Perfusion of systemic capillaries with

oxygenated blood Diffusion of oxygen from systemic

capillaries into the cells

Diffusion of CO2 occurs in reverse order

IN the PONS (of the Brain Stem)1) Apneustic CenterStimulates neurons to promote Inspiration via External intercostals and the diaphragm2) Pneumotaxic CenterStimulated neurons to promote Expiration via the Internal intercostals and rectus abdominis

Neurochemical controlRespiratory center

▪ Dorsal respiratory group▪ Ventral respiratory group▪ Pneumotaxic center▪ Apneustic center

Chemoreceptors1) Central Chemoreceptors ~ located in the medulla2) Peripheral Chemoreceptors ~ located in the Aorta &

the carotid bodies

Both detect increased levels in Carbon Dioxide, and then stimulate Increase in RR

Ventilate the alveoli

Diffuse gases into and out of the blood

Perfuse the lungs so the body receives oxygen

Ventilation Mechanical movement of gas or air

into and out of the lungs

Minute volume▪ Ventilatory rate multiplied by the volume of air per

breath

Alveolar ventilation

Lung Volume chart

Image Source: http://www.anaesthetist.com

Spirometry Diffusion capacity Residual volume Functional reserve capacity (FRC) Total lung capacity Arterial blood gas analysis Chest radiographs

Conducting airways Upper airways

▪ Nasopharynx▪ Oropharynx

Larynx▪ Connects upper and lower airways

Lower airways▪ Trachea▪ Bronchi▪ Terminal bronchioles

Gas-exchange airways Respiratory bronchioles Alveolar ducts Alveoli

▪ Epithelial cells▪ Type I alveolar cells

Alveolar structure Where diffusion of Respiratory gasses occurs

▪ Type II alveolar cells Surfactant production

Pulmonary circulation has a lower pressure than the systemic circulation

One third of pulmonary vessels are filled with blood at any given time

Pulmonary artery divides and enters the lung at the hilus

Each bronchus and bronchiole has an accompanying artery or arteriole

Alveolocapillary membrane Formed by the shared alveolar and capillary

walls

Gas exchange occurs across this membrane

Membrane formed by what cells?

Barometric pressurePartial pressure

Partial pressure of water vapor

Barometric pressure Partial

pressure Speaking of partial

pressure…

Have you ever wondered what the partial pressure of O2 is at sea level is?

Distribution of ventilation and perfusion

Gravity and alveolar pressure

Ventilation-perfusion ratio(0.8)

Oxygen transport Diffusion across the alveolocapillary

membrane Determinants of arterial oxygenation

▪ Hemoglobin binding, oxygen saturation Oxyhemoglobin association and

dissociation▪ Oxyhemoglobin dissociation curve▪ Bohr effect

Carbon dioxide transport Dissolved in plasma

Bicarbonate(HCO3) Carbamino compounds (hemaglobin)

Haldane effect

Dissolved in plasma-Pco2 Arterial -5% Venous-10%

Bicarbonate-HCO3 Arterial-90% Venous-60%

Carbamino compounds-Hb Arterial-5% Venous-30%

Hypoxic pulmonary vasoconstriction

Caused by low alveolar PO2

Blood is shunted to other, well-ventilated portions of the lungs▪ Provides better ventilation and perfusion

matching▪ If hypoxia affects all segments of the lungs,

the vasoconstriction can result in pulmonary hypertension

Acidemia also causes pulmonary artery constriction

Image Source: http://www.gilmerfreepress.net

Dyspnea Subjective sensation of uncomfortable

breathing Orthopnea

▪ Dyspnea when a person is lying down

Paroxysmal nocturnal dyspnea (PND)

Dyspnea Subjective sensation of uncomfortable

breathing Orthopnea

▪ Dyspnea when a person is lying down

Paroxysmal nocturnal dyspnea (PND) Generally w LV Failure

Abnormal breathing patterns Kussmaul respirations (hyperpnea)

Cheyne-Stokes respirations

Hypoventilation Hypercapnia

Hyperventilation Hypocapnia

Cough Acute cough Chronic cough

Hemoptysis

Cyanosis PainClubbing Abnormal sputum

HypercapniaHypoxemia

Hypoxemia versus hypoxia Ventilation-perfusion abnormalities

▪ Shunting

Acute respiratory failurePulmonary edema

Excess water in the lungs

What is missing from this cartoon?

Aspiration Passage of fluid and solid particles into the lungs

Atelectasis Compression atelectasis Absorption atelectasis

Bronchiectasis Persistent abnormal dilation of the bronchi

Squeeze

Bronchiolitis Inflammatory obstruction of the small

airways Most common in children Occurs in adults with chronic bronchitis,

in association with a viral infection, or with inhalation of toxic gases

(50% of the time due to what virus??)

Bronchiolitis obliterans Late-stage fibrotic disease of the airways Can occur with all causes of bronchiolitis

Pneumothorax Open pneumothorax

Tension pneumothorax

Spontaneous pneumothorax

Secondary pneumothorax

One way valve

Pleural effusion Transudative effusion

Exudative effusion

Hemothorax

Empyema▪ Infected pleural effusion

Chylothorax

Pleural space

Blood

Abscess formation and cavitation Abscess Consolidation Cavitation

Pulmonary fibrosis Excessive amount of fibrous or

connective tissue in the lung

Chest wall restriction Compromised chest wall

▪ Deformation, immobilization, and/or obesity

Flail chest Instability of a portion of the chest wall

Inhalation disorders Exposure to toxic gases Pneumoconiosis

▪ Silica▪ Asbestos▪ Coal

Allergic alveolitis▪ Extrinsic allergic alveolitis ▪ (hypersensitivity pneumonitis)

Acute respiratory distress syndrome (ARDS) Fulminant form of respiratory failure

characterized by acute lung inflammation and diffuse alveolocapillary injury

Injury to the pulmonary capillary endothelium

Inflammation and platelet activation Surfactant inactivation Atelectasis

Acute respiratory distress syndrome (ARDS) Manifestations

▪ Hyperventilation▪ Respiratory alkalosis▪ Dyspnea and hypoxemia▪ Metabolic acidosis▪ Hypoventilation▪ Respiratory acidosis▪ Further hypoxemia▪ Hypotension, decreased cardiac output, death

Acute respiratory distress syndrome (ARDS) Evaluation and treatment

▪ Physical examination, blood gases, and radiologic examination

▪ Supportive therapy with oxygenation and ventilation and prevention of infection

▪ Surfactant to improve compliance

Postoperative respiratory failure Atelectasis Pneumonia Pulmonary edema Pulmonary emboli Prevention

▪ Frequent turning, deep breathing, early ambulation, air humidification, and incentive spirometry

Airway obstruction that is worse with expiration

Common signs and symptoms Dyspnea and wheezing

Common obstructive disorders Asthma Emphysema Chronic bronchitis

“Chronic inflammatory disorder of the airways”

Inflammation results from hyperresponsiveness of the airways

Can lead to obstruction and status asthmaticus

Symptoms include expiratory wheezing, dyspnea, and tachypnea

Peak flow meters, oral corticosteroids, inhaled beta-agonists, and anti-inflammatories used to treat

Chronic bronchitis Hypersecretion of mucus and chronic

productive cough that lasts for at least 3 months of the year and for at least 2 consecutive years

Inspired irritants increase mucus

production and the size and number of mucous glands

Chronic bronchitis The mucus is thicker than normal

Bronchodilators, expectorants, and chest physical therapy used to treat

Emphysema Abnormal permanent enlargement of the

gas-exchange airways accompanied by destruction of alveolar walls without obvious fibrosis

Loss of elastic recoil Centriacinar emphysema Panacinar emphysema

ULL

Pneumonia Community-acquired pneumonia

▪ Streptococcus pneumoniae

Hospital-acquired (nosocomial) pneumonia Pneumococcal pneumonia Viral pneumonia

Lobar

Tuberculosis Mycobacterium tuberculosis Acid-fast bacillus Airborne transmission Tubercle formation Caseous necrosis Positive tuberculin skin test (PPD)

Cavitary

Acute bronchitis Acute infection or inflammation of the

airways or bronchi Commonly follows a viral illness Acute bronchitis causes similar

symptoms to pneumonia but does not demonstrate pulmonary consolidation and chest infiltrates

Pulmonary embolism Occlusion of a portion of the pulmonary

vascular bed by a thrombus, embolus, tissue fragment, lipids, or an air bubble

Pulmonary emboli commonly arise from the deep veins in the thigh

Virchow triad▪ Venous stasis, hypercoagulability, and

injuries to the endothelial cells that line the vessels

Pulmonary hypertension Mean pulmonary artery pressure 5 to 10

mm Hg above normal or above 20 mm Hg

Pulmonary hypertension Classifications

▪ Pulmonary arterial hypertension

▪ Pulmonary venous hypertension-CHF

▪ Pulmonary hypertension due to a respiratory disease or hypoxemia-COPD

▪ Pulmonary hypertension due to thrombotic or embolic disease-PE

▪ Pulmonary hypertension due to diseases of the pulmonary vasculature

Primary pulmonary hypertension Idiopathic

Diseases of the respiratory system and hypoxemia are more common causes of pulmonary hypertension

Pulmonary heart disease Right ventricular enlargement Secondary to pulmonary hypertension Pulmonary hypertension creates chronic

pressure overload in the right ventricle

Lip cancer Most common form

Exophytic Stages

Laryngeal cancer Forms

▪ Carcinoma of the true vocal cords (most common)

▪ Supraglottic▪ Subglottic

Bronchogenic carcinomas

Most common cause is cigarette smoking Heavy smokers have a 20 times’ greater

chance of developing lung cancer than nonsmokers

Smoking is related to cancers of the larynx, oral cavity, esophagus, and urinary bladder

Environmental or occupational risk factors are also associated with lung cancer

of Pathopysiology!!

Remember to…

KEEP UP WITH YOUR:

1) Text READING2) Powerpoint Review3) Study Guide Prep