Chapter 2-Respiratory System-Physiology and Physics of Respiration Flashcards
Boyle’s law (1)
Given a gas of constant temperature, increasing the volume of the chamber in which the gas is contained will cause a corresponding decrease in pressure. Decreasing the volume of the chamber will cause an increase in pressure.
Boyle’s Law (2)
If you increase the volume, pressure will decrease (negative pressure)
If you decrease the volume, the pressure will increase (positive pressure)
Boyle’s Law, Inhalation
expansion of thoracic cavity increases the volume, which decreases the air pressure - air flows into the lungs
Quiet (passive) inspiration
Mostly accomplished through diaphragm
Active (forced) inspiration
Uses muscles of inspiration
Boyle’s Law, Exhalation
compression of the thoracic cavity decreases the volume of the lungs which increases air pressure - air flows out of the lungs
Quiet (passive) expiration
System is restored to a resting position after inspiration.
Driven by forces of torque, elasticity and gravity.
Active (forced) expiration
Muscular effort enhances act of expiration.
Abdomen is compressed.
Muscles reduce size of thorax.
Rate of Breathing
Measured in breaths per minute.
Variables affecting rate: age, activity level, muscle weakness/strength, illness.
Rate of Breathing
Spastic
excessive tone
Rate of Breathing
Flaccid
too little tone
Lung Volumes and Capacities
Spirometer
device used to measure lung volume and capacities
Lung Volumes and Capacities
Volumes
amount of air inhaled or exhaled
Lung Volumes and Capacities
Tidal volume
Volume of air exchanged during one cycle of respiration
Lung Volumes and Capacities
Inspiratory reserve volume
Volume of air that can be inhaled after a tidal inspiration
Lung Volumes and Capacities
Expiratory reserve volume
Volume of air that can be expired following passive tidal expiration
Lung Volumes and Capacities
Residual Volume
The volume of air in the lungs after a maximum exhalation
Lung Volumes and Capacities
Capacities
combined volumes that express physiological limits
Lung Volumes and Capacities
Vital capacity
The combination of inspiratory reserve volume, expiratory reserve volume, and tidal volume, representing the capacity of air available for speech
Lung Volumes and Capacities
Total lung capacity
Sum of all the lung volumes
Lung Volumes and Capacities
Functional residual capacity
Air that remains in the body after passive exhalation
Lung Volumes and Capacities
Inspiratory capacity
The maximum inspiratory volume possible after tidal expiration
Breathing for Life (also called quiet breathing)
Location of air intake: nose,
Ratio of time for inhalation vs. exhalation: Inhale 40%, Exhale 60%,
Muscle activity for exhalation: passive (muscles of thorax and diaphragm relax),
Chest wall position: abdomen is positioned outward relative to rib cage
Breathing for speech
Location of air intake: mouth,
Ratio of time for inhalation vs.exhalation: Inhale 10%, Exhale 90%,
Muscle activity for exhalation: active (thoracic and abdominal muscles contract to control recoil of rib cage and diaphragm),
Chest wall position: Abdomen is positioned inward relative to rib cage
Respiratory Problems, Symptoms
Dyspnea
Subjectively perceived discomfort in breathing that can vary from mild to extreme.
Shortness of breath,
The need to work harder to breathe,
Chest tightness
Respiratory Problems, Symptoms
Stridor
Audible sound that occurs during inspiration and/or expiration
Respiratory Problems
Asthma
Obstructive
Swelling in bronchioles that decreases the diameter of the bronchial branches, Increased resistance to airflow
Respiratory Problems
Emphysema
Obstructive
Breakdown of lung in which the alveoli (small sacs) are destroyed,
Decreased oxygen exchange between the air and blood stream,
Causes decreased vital capacity,
Common cause is smoking
Respiratory Problems
Diseases of the pleura, Pleurisy
Restrictive
Condition in which there is inflammation of the plural linings, Causes extreme pain during breathing due to the loss of lubrication
(Respiratory Problems
Pneumonia
Restrictive
Inflammation of the lungs caused by a bacterial or viral infection,
Causes the alveoli to fill with fluid,
Can be caused by aspiration of fluids or food into the lungs due to poor swallow function
Respiratory Problems
Stroke
Central
Sudden interruption in the blood supply of the brain, Depending on location of the brain damage can cause decrease in muscular strength or coordination (May affect the control of the muscles of respiration)
(Clinical Application, Posture Support): Sitting posture
May cause some restraint of diaphragm movements,
Gravity pulls the abdominal viscera down,
Supports inspiration and expiration
(Clinical Application, Posture Support): Supine position
Gravity pulls the abdominal viscera toward the spine,
Muscles of inspiration must elevate both abdomen and rib cage against gravity,
Increase effort required for inspiration and expiration
(Clinical Application, Use of air supply):
How a person uses and controls air flow is typically more important than lung capacity.
Improve coordination of respiration and phonation,
Important to measure the patient’s respiratory function both non-speech and speech tasks,
Treatment exercises should be practiced in speech contexts rather than in non-speech contexts
