The Respiratory System P. 1

Define pneumothorax.

"air in sac" and which means gas into the pleural cavity through an opening in the chest wall or a rupture of the lung.

Describe the pulmonary vascular system of the lungs and trace the flow of blood from the superior and inferior vena cava, through the right heart, lungs, left heart, and aorta.

(1) Deoxygenated blood arrives from the body through the superior and inferior vena cava into the right atrium (2) through the tricuspid valve into the right ventricle (3) through the pulmonary valve into the pulmonary artery (4) blood is oxygenated in the lungs (5) oxygenated blood re enters the heart through the pulmonary vein (6) enters left atrium (7) through the mitral valve into the left ventricle (8) through the aortic valve to the aorta to be pumped to the body

Normal amount of fluid in pleural space

0.26 ml/kg or about 18ml in a 70-kg adult.

Amount of pleural fluid produced per day

150 to 250 ml

Normal clearance mechanisms

visceral capillaries

State the average number of alveoli in the lung.

480 million

Pleural fluid pH:

7.60 to 7.65

Identify the components and structures found in the Mediastinum.

Contains organs and tissues in the center of the thoracic cage between the right and left lungs. Also contains the trachea, the heart, the major blood vessels that enter and exit the heart and various nerves, portions of the esophagus, the thymus gland, and lymph nodes.

Alveolar Type 11 cells

Cuboidal epithelia with apical microvilli. These cells do not function as gas exchange membranes. They (along with the Clara cells) manufacture surfactant, store it in vesicles called lamellated bodies, and secrete it onto the alveolar surface. They also recycle 50% of surfactant.

Define and describe the action and function of the "mucociliary escalator."

From the bronchioles up to the larynx, cilia moves material toward the pharynx. The stroking action of millions of cilia propels the surrounding mucus at a speed of approximately 2 cm/min. This mechanism allows inhaled particles to be removed within 24 hours.

Describe the following major components of the upper airway; Nose, Oral Cavity, Pharynx, and Larynx

Nose: is the structure that protrudes from the anterior part of the face and serves as a passageway for air to and from the lungs. It filters, humidifies, and conditions. Oral Cavity: space within the mouth containing the tongue and teeth. It is known as the accessory respiratory passage. Pharynx: is the throat, a tubule structure consisting of the nasopharynx, oropharynx, and laryngopharynx d.Larynx: voice box which is located between the base of the tongue and upper end of the trachea Larynx: voice box which is located between the base of the tongue and upper end of the trachea

Lymphatic vessels:

found superficially around the lungs just beneath the visceral pleura and in the dense connective tissue wrapping of the bronchioles, bronchi, pulmonary arteries, and pulmonary veins. Primary function is to remove excessive fluid and protein molecules that leak out of the pulmonary capillaries.

Lymphatic nodes:

organized collections of lymphatic tissue interspersed along the course of the lymphatic stream. Lymph nodes produce lymphocytes and monocytes. They act as filters, keeping particulate matter and bacteria from entering the bloodstream.

Alveolar Type 111 cells (alveolar macrophages)

play a major role in removing bacteria and other foreign particles that are deposited within the acini.

Identify the location and structure of the nasopharynx, oropharynx, and laryngopharynx.

1. .Nasopharynx is lined with pseudostratified ciliated columnar epithelium. Located between the posterior portion of the nasal cavity and the superior portion of the soft palate. 2. .Oropharynx is lined with nonciliated stratified squamous epithelium. Located between the soft palate and the base of the tongue. (includes palatine tonsils) 3. .Laryngopharynx is lined with nonciliated stratified squamous epithelium. Located between the base of the tongue and the entrance of the esophagus.

Describe the structure and function of the primary lobules, (acinus) of the lungs to include the Respiratory Bronchioles, Terminal bronchioles, alveolar ducts and sacs, alveoli.

1. A single terminal bronchiole supplies a cluster of respiratory bronchioles which makes acinus or primary lobule. 2. Is the functional units or gas exchange.

Describe the structure and function of the following components of the bronchial blood supply: Bronchial arteries, Azygos veins, and Hemiazygos veins and intercostals (Egan).

1. Bronchial arteries - Arteries arise from aorta and follow TB tree as far as terminal bronchioles; Nourishes the TB tree. 2. Azygos veins and Hemiazygos veins - This is where bronchial venous blood is drained to the right atrium. Some drain through the pulmonary capillaries to the pulmonary veins to left atrium.

State the two major types of airways.

1. Cartilaginous Airways: serve to conduct air between the external environment and the sites of gas exchange. 2. Noncartilaginous Airways: serve as both conductors of air and as sites of gas exchange.

List the four primary functions of the upper airway.

1. Conduct air 2. Humidify and warm or cool inspired air 3. Filter foreign materials 4. Speech and smell

Identify the structure and function of the following components of the larynx; False cords, true cords, Glottis

1. False cords: upper pair of folds made up of mucous membrane in the interior portion of the larynx. It plays no role in vocalization. 2. True cords: lower pair of mucous membrane folds which are the vocal cords. 3. Glottis: the space between the vocal chords. It is the narrowest point in the larynx in an adult, in which inhaled air leaves the pharynx and enters the larynx.

State the three major functions of the larynx.

1. Passageway of air between the pharynx and trachea 2. Protective mechanism against aspiration of solids and liquids 3. Generates sound and speech

State what size particles will be impacted on the nasal mucosa.

10 micrometers

Describe the components and function of the epithelial lining of the TB tree.

A mucous layer, commonly referred to as the mucous blanket, covers the epithelial lining of the tracheobronchial tree. It is made up of 95%. The mucous is produced by (1) the goblet cells, and (2) the submucosal, or bronchial glands. Goblet cells empty when stimulated by infection or inhaled smoke or dust. The submucosal glands produces most of the mucous blanket and up to 100 mL of bronchial secretions a day.

State the % of the total cardiac output that flows through the bronchial circulation

Approximately 1% to 2%

Pores of Kohn

Bands of fibers that support the alveolar cells and the shape of the alveolus. Small openings are located in the alveolar septa and some allow gas to move from one alveolus to another. They facilitate the collateral movement of gas and help maintain alveolar volume.

Discuss the pressure in the pleural space.

Because the lungs have a natural tendency to collapse and the chest wall has a natural tendency to expand, a negative or subatmospheric pressure (negative intrapleural pressure) normally exists between the parietal and visceral pleurae. Pleural membranes hold the lung tissue to the inner surface of the thorax and diaphragm, causing the lungs to expand.

Identify the location and structure of the following non-cartilaginous airways:

Bronchioles: Less than 1mm in diameter and no longer surrounded by connective tissue sheaths. Found between 10th and 15th generation. No cartilage and surrounded by spiral muscle fibers and the epithelial cells are more cuboidal in shape. Terminal bronchioles: The conducting tubes of the tracheobronchial tree at the end between 16 and 19 generation. Average diameter is 0.5 mm and the epithelium usually flattens and becomes cuboidal in shape Canals of Lambert: As the walls of the terminal bronchioles progressively becomes thinner, small channels. Tiniest pathway which becomes important for secondary avenues for collateral ventilation in pts. Clara cells: Thick protoplasmic extensions that bulge into the lumen of the terminal bronchioles.

Define carina and discuss the angles of the R and L mainstem bronchus to include the clinical significance.

Carina: bifurcation of the trachea into the right and left main stem bronchi. It is also the important landmark used to identify the level where the two main stem bronchi branch off from trachea. Trachea: 12 cm long and diameter of 2 cm. The cartilaginous rings around the trachea help support it so it does not collapse during exhalation. The right bronchus branches off at an angle of approx. 20 to 30 degrees and the left bronchus branches off to an angle of approx. 45 to 55 degrees. The lower angle branching of the right bronchus results in a greater frequency of foreign body passage into the right lung because of the more direct pathway.

Compare and contrast the differences between the sizes of the R and L lung.

Compare: They both have an apex and base and are subdivided by fissures into lobes which are subdivided further into bronchopulmonary segments. Contrast: The right lung is larger and heavier and has 3 lobes. The left side has 2 lobes.

Pulmonary surfactant

Composed of phospholipids and proteins (surfactant proteins A -D). Surfactant reduces surface tension of the alveolus, sheds water from the alveolar surface, helps prevent alveolar surface tension-driven collapse, improves lung compliance, reduces the work of breathing, and protects the alveolar surface.

List the major structures and corresponding generations of the TB tree.

Conduction zone Cartilaginous airways a. Trachea: 0 b. Main stem bronchi: 1 c. Lobar bronchi: 2 d. Segmental bronchi: 3 c. Subsegmental bronchi: 4-9 Noncartilaginous airways a. Bronchioles: 10-15 b. Terminal bronchioles: 16-19 Respiratory zone Sites of gas exchange a. Respiratory bronchioles: 20-23 b. Alveolar ducts: 24-27 c. Alveolar sacs: 28

Describe "effort closure" of the larynx.

Effort closure refers to a tight closure of the larynx and the build up of the intrapulmonary pressure through muscular effort. It is generated by the false and true vocal chords. It is necessary to generate loud sounds and for effective coughing and sneezing.

List the Three layers of the Tracheobronchial (TB) Tree.

Epithelial Lining Lamina Propria Cartilaginous Layer

Describe the clinical connection associated with the excessive airway secretions.

Excessive airway secretions can lead to excessive accumulation, partial airway obstruction and air trapping, alveolar hyperinflation, or complete airway obstruction and airway collapse. It can adversely affect or block alveolar gas exchange. Also it can increase the pt's airway resistance to gas flow and, therefore, diminish the cough. Bacterial infections of airways usually excessive when bronchial secretions are chronically present. Secretions are usually green and yellow. Pt's cough sounds noisy, moist-sounding. When listening to chest, usually will hear rhonchi during exhale and crackles during inhale. Therapies include postural drainage therapy, cough and deep breathing techniques, and positive airway pressure (PAP).

List the three primary functions of the nose.

Filter, humidify, and condition warm or cool inspired air

State the variances in alveoli number and size.

In adults can range from 270 to 790 million depending on their height. Alveoli found in the apical regions of the vertical lung have greater diameters than alveoli in the basal regions as a results of gravitational effects.

Describe the difference between the right and left hemi-diaphragm.

In an upright position and with the diaphragm relaxed, the liver forces the dome of the right hemidiaphragm upward approx. 1 cm higher than then the left hemidiaphragm at the end of a quiet exhalation. The highest portion of the R dome sits at the 8th or 9th thoracic vertebra posteriorly and at the 5th rib anteriorly. The L dome sits 9th or 10th thoracic vertebra posteriorly and the 6th rib anteriorly.

Identify and describe the parietal pleura, visceral pleura, and pleural cavity.

Parietal pleura: Lines the inside of the thoracic walls, the thoracic surface of the diaphragm, and the lateral portion of the mediastinum. Visceral pleura: is firmly attached to the outer surface of each lung and extends into each of the interlobar fissures. Pleural cavity: The potential space between the visceral pleura and parietal pleura

Describe what is meant by patency of the airway and the effort of positioning on airway patency.

Patency of the airway means that the pharynx, the larynx, and oral cavity must be in the right position in order for the upper airway to open freely, especially for an unconscious pt. To alleviate the problem in an unconscious pt, the neck is extended which helps open the airway and prevents the tongue from blocking the rear of the pharynx.

Describe the clinical connection associated with postural drainage therapy.

Postural drainage is applied by RTs to pts with excessive airway secretions which involves positioning the pt (with pillows and bed positions) to use gravity to help mobilize excessive bronchial secretions from the bronchial lung segments. Indications of postural drainage may include (1) excessive bronchial secretions; (2) a weak or absent cough; (3) breath sounds rhonchi (gurgling wet sounds); and/or (4) abnormal chest radiograph that indicates mucus plugging with alveolar collapse (atelectasis).

Describe the use of accessory muscles in patients with COPD.

Pts with advanced COPD often use accessory muscles to assist the flattened diaphragm, helping relieve their work of breathing. The muscle groups used include the shoulder and neck muscles. To use these muscles, the shoulder girdle must be stabilized. Pts. with COPD often do this by supporting their arms on a stationary object in front of them, forming a "tripod" position. This immobilizes the shoulders and allows the accessory muscles to raise the anterior chest wall.

Define the "pump handle" effect of rib movement.

Pump handle: The sternum moves upward, causing the anterior-posterior portion of the thorax to increase

Describes how the ANS relates to neural control of the lungs.

The ANS is the part of the nervous system that regulates involuntary vital functions, including the activity of cardiac muscle, smooth muscle, and glands.

Alveolar Type 1 cells:

The alveolar septa (wall) are covered with extremely flat squamous epithelia. They form a "patchwork"-like surface that covers the alveolar capillaries and forms the gas exchange surface of the alveolus. At the edges where they meet, they form tight junction which helps to limit the movement of material into the alveolar airspace from the interstitial space.

Define costophrenic angle.

The angle where the costal parietal pleura join the diaphragmatic parietal pleura. It is located in the right and left lateral and inferior regions of the thoracic cavities.

Identify the cricothyroid ligament and state the emergency airway procedure associated with this ligament.

The cricothyroid ligament spans the space between the thyroid and the cricoid cartilage. This membrane is used for placement of an emergency of a prosthetic airway in pts. who have a life threatening blockage of airway.

Define and describe the muscles used for normal breathing.

The diaphragm is the major muscle for ventilation. It is a dome-shaped musculofibrous partition located between the thoracic cavity and abdominal cavity. Diaphragm is composed of two separate muscles known as the R and L hemidiaphragm. Other muscles used are the external intercostal muscles.

Describe the Valsalva maneuver.

The effort closure during exhalation. The lumen of the larynx is tightly sealed, preventing air from escaping during lifting, pushing, coughing, and/or vomiting

List the dimensions and state the functions of the epiglottis.

The epiglottis prevents aspiration of foods and liquids by covering the opening of the larynx. Its dimensions are 2 to 4 cm long, 2 to 3 cm wide, and 2 to 5 mm deep

Define the "bucket handle" effect of rib movement.

The external intercostal muscles also work during inspiration to elevate the lateral portion of the thoracic cavity

Define the sternal angle or Angle of Louis.

The joint between the manubrium and the body of the sternum

List the two nerves that innervate the larynx and the possible results of injury to these nerves.

The left and right inferior laryngeal nerve or recurrent laryngeal nerve. Injuries to these nerves can cause partial or complete paralysis to the vocal chords and the ability to swallow correctly.

Describe how the lungs are organized into lobes and segments and the airways that supply them.

The lobes are subdivided further into bronchopulmonary segments. Each segment is supplied with gas from single segmental bronchus. Lung has 10 segments.Bronchi divide and divide into smaller bronchi. Terminal bronchioles are the smallest conducting airway and function to supply gas to the resp. zone of lung. Increased cross-sectional area reduces the velocity of gas flow during inspiration. First, laminar flow develops minimizing resistance in the small airways and decreases the work associated with inspiration. Second, low gas velocity rapid mixing of alveolar gases which stable pressure of O2 and CO2.

Describe how particles trapped in the nose are normally cleared.

The particles trapped in the nose are normally cleared by ciliary action or nose blowing.

Identify the effects of the sympathetic and parasympathetic nervous systems on bronchial smooth muscle.

The sympathetic nervous system, which accelerates the heart rate, constricts blood vessels, relaxes bronchial smooth muscles, and raises blood pressure. The parasympathetic nervous system, which slows the heart rate, constricts bronchial smooth muscles, and increases intestinal peristalsis and gland activity.

Describe the vallecula and state the procedure for which this is a key landmark.

The vallecula is the space between the tongue and the epiglottis. It serves as a key landmark in oral intubation.

State the % of alveolar surface area covered with Type 1 and 11 cells.

Type 1: 95% Type 11: 5%

Define pleural effusion

accumulation of excess fluid in the pleural cavity