Ch. 39 Flashcards
What is the upper airway composed of and what is its function?
It’s composed of the nose, pharynx, larynx, and epiglottis
It’s main function is to warm, filter, and humidify inspired air
The respiratory system performs it’s functions through pulmonary ventilation, respiration, and perfusion. Normal functioning depends on what 3 factors?
- The integrity of the airway system to transport air to and from the lungs
- A properly functioning alveolar system in the lungs to oxygenate venous blood and to remove carbon dioxide from the blood
- A properly functioning cardiovascular and hematologic system to carry nutrients and wastes to and from body cells
What is the lower airway composed of and what is its function?
The lower airway…also known as the tracheobronchial tree, is composed of the trachea, right and left main stem bronchi, segmental bronchi, and terminal brochioles.
It’s main function is the conduction of air, mucocilary clearance, and production of pulmonary surfactant
What are cilia?
Cilia, are microscopic hair like projections, that propel trapped material and accompanying mucus toward the upper airway so they can be removed by coughing.nremoval is facilitated when mucus is watery in consistency
Describe the lungs
Each lung is divided into lobes. The right lung has 3 lobes, the left has 2. Each lobe is subdivided into segments/lobules. The right lung has 10 segments the left has 8.
What are alveoli?
At the end of the terminal bronchioles there are clusters of alveoli, small sacs. The alveoli are the site of gas exchange. The average adult has more than 300 million alveoli.
What is surfactant?
Surfactant, a detergent like phospholipid, reduces the surface tension between the moist membranes of the alveoli, preventing their collapse. When surfactant production is reduced, the lungs become stiff and alveoli collapse.
The lungs and thoracic cavity are lined with a serous membrane called pleura. What type lines each?
Lungs : visceral pleura
Thoracic cavity: parietal pleura
True or false pressure within the plural space is always subatmospheric/negative. This constant negative intrapleural pressure, along with the plural fluid, holds the lungs in an expanded position
True
What is pulmonary ventilation?
Pulmonary ventilation refers to the movement of air into and out of the lungs
What is respiration?
Respiration involves gas exchange between the atmospheric air in the alveoli and blood in the capillaries
What is perfusion?
Perfusion is the process by which oxygenated capillary blood passes through body tissues
The process of ventilation has two phases, inspiration and expiration. Describe them
Inspiration, the active phase, involve movement of muscles and a thorax to bring air into the lungs
Expiration, the passive phase, is the movement of air out of the line
Boggles law
According to Boyles law, the volume of a gas at a constant temperature varies inversely with the pressure. This means that less pressure in the lungs facilitate the movement of more air into the lungs. The pressure within the lines decreases as the volume of the lungs increase
Describe inhalation
During inspiration, the following events occur, the diaphragm contracts and descends, lengthening the thoracic cavity, that external intercostal muscles contract, lifting the ribs upward and outward, and the sternum push forward, enlarging the chest from front to back. This combination of an increase lung volume and decreased intro pulmonary pressure allowed atmospheric air to move from an area of greater pressure into an area of lesser pressure
Describe expiration
The relaxation of these structures then results in expiration. The diaphragm relaxes and moves up, the ribs move down, and the sternum drops back into position. This causes a decreased volume in the lungs and an increase in intrapulmonic pressure. As a result air in the lungs moves from an area greater pressure to one of lesser pressure and is expired
What helps maintain respiratory movements at times when breathing is difficult?
The accessory muscle of the abdomen, neck and back are used to maintain respiratory movements at times when breathing is difficult. These muscles are used to facilitate breathing, the movement is called retractions. The most common retractions involved intercostal, scalene, sternocleidomastoid, trapezius, and pectoralis muscles.
Where does respiration occur?
Respiration occurs at the terminal alveolar capillary system. Gases are exchanged between the air and blood via the dense network of capillaries in the respiratory portion of the lungs and he thin alveolar walls
Gas exchange occurs via diffusion. What is diffusion?
Diffusion is the movement of gas the particles from areas of higher pressure or concentration to areas of lower pressure concentration. In respiration diffusion refers to the movement of oxygen and carbon dioxide between the air in the alveoli and the blood in the capillaries.
What is atelectasis?
Atelectasis is incomplete lung expansion or the collapse of alveoli, it prevents pressure changes and exchange of gas by diffusion in the lungs
True or false
Atelectasis areas of the lung cannot fulfill the function of respiration
True
What are some examples that can predispose a patient to have atelectasis?
Obstruction of the airway by foreign bodies, mucus, airway constriction, tumors, and large blood vessels, and immobility.
If a problem exists in ventilation, respiration, or perfusion, hypoxia may occur. What is hypoxia?
Hypoxia is a condition in which an in adequate amount of oxygen is available to cells.
What are common symptoms of hypoxia?
The most common symptoms of hypoxia are dyspnea,(difficulty breathing) and elevated blood pressure with the small pulse pressure, increased respiratory and pulse rate, pallor, and cyanosis.
Anxiety, restlessness, confusion, and drowsiness also are common signs of hypoxia