Exam 3- Chapter 16 Flashcards
What 3 things does respiration include?
- Ventilation (breathing)
- Gas exchange between blood and lungs and between blood and tissues
- Oxygen utilization by tissues to make ATP
What is external respiration?
Ventilation and gas exchange in lungs
What is internal respiration?
Oxygen utilization and gas exchange in tissues
What are the two divisions of the respiratory system?
- Respiratory Zone
2. Conduction Zone
What is the GENERAL function of the respiratory zone division of the respiratory system?
site of gas exchange
What is the GENERAL function of the conduction zone division of the respiratory system?
gets air to the respiratory zone
Describe the conduction route of the conduction zone (10 steps).
- Air travels down the nasal cavity
- Pharynx
- Larynx
- Trachea
- Right and left primary bronchi
- Secondary bronchi
- Tertiary bronchi —> (more branching)
- Terminal bronchioles
- Respiratory zone (respiratory bronchioles)
- Terminal alveolar sacs
What are the 3 specific functions of the conduction zone division of the respiratory system?
- Transports air to the lungs
- Warms, humidifies, filters, and cleans the air
(Mucus traps small particles, and cilia move it away from the lungs) - Voice production in the larynx as air passes over the vocal folds
In the conduction zone, how are small particles moved away from the lungs?
Mucus traps small particles, and cilia move it away from the lungs
What are alveoli? Function?
Air sacs in the lungs where gas exchange occurs
How many alveoli are there?
300 million of them
How are alveoli and surface area related?
Provide large surface area (760 square feet) to increase diffusion rate
What is within the central mediastinum of the thoracic cavity? What fills the rest of the thoracic cavity?
- Heart
- Trachea
- Esophagus
- Thymus
- Lungs
What lines the thoracic wall?
parietal pleura
What covers the lungs?
visceral pleura
The parietal and visceral pleura are normally pushed together, with a potential space between called the what?
intrapleural space
Gas exchange in the lungs occurs via what?
diffusion
Describe how O2 is diffused into the blood.
O2 concentration is higher in the lungs than in the blood, so O2 diffuses into blood.
Describe how C02 is diffused out of the blood (into the lungs).
CO2 concentration in the blood is higher than in the lungs, so CO2 diffuses out of blood.
When talking about ventilation, in what way does air move?
Air moves from higher to lower pressure.
What are 3 important physical properties of the lungs?
- Compliance
- Elasticity
- Surface Tension
Pressure differences between the two ends of the conducting zone occur due to changing what?
lung volumes
What is atmospheric pressure?
pressure of air outside the body
What is Intrapulmonary pressure?
pressure in the lungs
What is Intrapleural pressure?
pressure within the intrapleural space (between parietal and visceral pleura)
During inhalation, is intrapulmonary pressure or atmospheric pressure lower?
Intrapulmonary pressure is lower than atmospheric pressure
What is pressure below that of the atmosphere called?
subatmospheric or negative pressure
During exhalation, is intrapulmonary pressure or atmospheric pressure lower?
Intrapulmonary pressure is greater than atmospheric pressure.
During inhalation/exhalation, how does the Intrapleural pressure relate to the intrapulmonary and atmospheric pressure?
Lower than intrapulmonary and atmospheric pressure in both inhalation and exhalation
The difference between intrapulmonary and intrapleural pressure is called what?
transpulmonary pressure
How does the Intrapleural pressure physically affect the lungs?
Keeps the lungs against the thoracic wall
What does boyles law state?
States that the pressure of a gas is inversely proportional to its volume
During inhalation, lung volume increases. What happens next?
An increase in lung volume during inspiration decreases intrapulmonary pressure to subatmospheric levels. Air goes in.
During inhalation does the lung volume increase or decrease?
Increase
During exhalation does the lung volume increase or decrease?
Decrease
During exhalation , lung volume decreases. What happens next?
A decrease in lung volume during exhalation increases intrapulmonary pressure above atmospheric levels. Air goes out.
Can lungs expand when stretched? What is this referred to?
Yes. Lung compliance.
What is lung compliance defined as?
Defined as the change in lung volume per change in transpulmonary pressure (ΔV/ΔP)
What disease decreases lung compliance and how?
Reduced by infiltration of connective tissue proteins in pulmonary fibrosis
Summarize what lung elasticity is.
Lungs return to initial size after being stretched.
Do lungs have a low or high amount of elastin fiber?
Lungs have lots of elastin fibers.
The lungs are always under elastic tension because?
Because the lungs are stuck to the thoracic wall, they are always under elastic tension
Surface tension allows the lungs to resist what?
distension
What is surface tension exerted by?
Exerted by fluid secreted in the alveoli
Surface tension raises the pressure of the alveolar air as it acts to ____ __ ____.
collapse the alveolus
What does the law of laplace state?
Pressure is directly proportional to surface tension and inversely proportional to radius of alveolus.
Would smaller or larger alveoli be at greater risk of collapse without surfactant?
Small alveoli would be at greater risk of collapse without surfactant
What is surfactant secreted by?
type II alveolar cells
What is surfactant composed of?
Consists of hydrophobic protein and phospholipids
What is the function of surfactant?
- Reduces surface tension between water molecules
2. Prevents collapse
Is surfactant more concentrated in smaller or larger alveoli?
More concentrated in smaller alveoli
When does production of surfactant begin?
Production begins late in fetal life
Since production of surfactant begins in fetal life, what are premature babies at risk of?
premature babies may be born with a high risk for alveolar collapse called respiratory distress syndrome (RDS)
What is respiratory distress syndrome (RDS)
premature babies may be born with a high risk for alveolar collapse due to insufficient concentrations of surfactant called respiratory distress syndrome (RDS)
What is another name for breathing?
pulmonary ventilation
What are the two types of breathing/pulmonary ventilation and describe what they do.
- Inspiration: breathe in
2. Expiration: breathe out
How is breathing/pulmonary ventilation accomplished?
Accomplished by changing thoracic cavity/ lung volume
During inspiration, how does the volume of the thoracic cavity (and lungs) increase when the diaphragm contracts (flattens)?
Volume of thoracic cavity (and lungs) increases vertically when diaphragm contracts (flattens)
During inspiration, how does the volume of the thoracic cavity (and lungs) increase when parasternal and external intercostals raise the ribs?
Volume of thoracic cavity (and lungs) increases horizontally when parasternal and external intercostals raise the ribs
During expiration, how does the volume of the thoracic cavity (and lungs) decrease when the diaphragm relaxes (dome)?
Volume of thoracic cavity (and lungs) decreases vertically when the diaphragm relaxes (dome)
During expiration, how does the volume of the thoracic cavity (and lungs) decrease when internal intercostals lower the ribs in forced expiration?
Volume of thoracic cavity (and lungs) decreases horizontally when internal intercostals lower the ribs in forced expiration
What is an example of a Pulmonary Function Test?
Spirometry
How is a spirometry conducted?
Subject breathes into and out of a device that records volume and frequency of air movement on a spirogram.
What type of graph does a spirometry produce?
spirogram
What is a spirometry measuring?
Measures lung volumes and capacities
What can a spirometry diagnose?
Can diagnose restrictive and disruptive lung disorders
Lung Capacity Measurements:
What is vital capacity?
maximum amount of air that can be forcefully exhaled after a maximum inhalation
Lung Capacity Measurements:
What is total lung capacity?
amount of gas in the lungs after a maximum inspiration
Lung Capacity Measurements:
What is inspiratory capacity?
amount of gas that can be inspired after a normal expiration
Lung Capacity Measurements:
What is functional residual capacity?
amount of gas left in lungs after a normal expiration
Lung Capacity Measurements:
What is tidal volume?
amount of air expired or inspired in quiet breathing
Lung Capacity Measurements:
What is expiratory reserve volume?
amount of air that can be forced out after tidal volume
Lung Capacity Measurements:
What is inspiratory reserve volume?
amount of air that can be forced in after tidal volume
Lung Capacity Measurements:
What is residual volume?
amount of air left in lungs after maximum expiration
In a restrictive lung disorder, describe the:
- Lung tissue
- Vital capacity
- Forced Expiration
- Lung tissue is damaged
- Vital capacity is reduced
- Forced expiration is normal
In a obstructive lung disorder, describe the:
- Lung tissue
- Vital capacity
- Forced Expiration
- Lung tissue is normal
- Vital capacity is normal
- Forced expiration is reduced
What are 2 examples of a restrictive lung disorder?
- Pulmonary Fibrosis
2. Emphysema
What is an example of an obstructive lung disorder?
Asthma
How are obstructive lung disorders usually diagnosed?
by doing forced expiratory volume tests (FEV test)
What are the symptoms of asthma?
dyspnea (shortness of breath) and wheezing
What is dyspnea?
shortness of breath
What are 3 things asthma is caused by?
Caused by inflammation, mucus secretion, and constriction of bronchioles
What is another name for asthma?
airway hyperresponsiveness
What is allergic asthma triggered by?
- Allergens stimulating T lymphocytes to secrete cytokines and recruit eosinophils and mast cells, which contribute to inflammation
- Cold or Dry Air
Is allergic asthma reversible?
YES
What is allergic asthma reversible with? (give an example)
bronchodilator (albuterol)
What symptoms are characterized by Chronic Obstructive Pulmonary Disease (COPD)?
- Chronic inflammation
- excessive mucus production
- narrowing of the airways
- Alveolar destruction
What two other diseases are included with COPD?
emphysema and chronic obstructive bronchiolitis
In an FEV test, a patient with COPD would show what?
Accelerated decline in FEV
Inflammation from COPD is due to/involved what?
- Macrophages
- Neutrophils
- Cytotoxic T cells
With COPD, what can smoking trigger?
Excessive mucus production and inflammation
Is COPD common to people who do or do not smoke?
Most people with COPD smoke
Is there a cure for COPD?
NO
What is the 5th leading cause of death?
COPD
In addition to the excessive mucus production and inflammation that smoking triggers in COPD, what else does it trigger?
Smoking also promotes the infiltration of obstructing fibrous tissue and muscle in the airways and remodeling of blood vessels in the lungs, leading to pulmonary hypertension
What is emphysema?
Destruction of alveoli
How does emphysema affect surface area for gas exchange?
Reduces surface area for gas exchange
How does the destruction of alveoli in emphysema physically affect the bronchioles during expiration?
With fewer alveoli to put pressure on bronchioles, they collapse during expiration.
What is the most common cause of emphysema? What does this cause trigger?
Smoking is the most common cause. It triggers inflammation and destruction of alveoli by immune cells
What is pulmonary fibrosis?
accumulation of fibrous tissues in the lungs when alveoli are damaged.
What may pulmonary fibrosis be due to?
inhalation of small particles
What is an example of pulmonary fibrosis?
black lung in miners