Chapter 22 Respiratory System Flashcards
The Respiratory system consists of the
respiratory and conducting zones
Respiratory zone
- site of gas exchange
* consists of bronchioles, alveolar ducts, and alveoli
COnducting zone
- conducts the air to reach the sites of gas exchange
* includes all other respiratory structures (e.g., nose, nasal cavity, pharynx, trachea)
Respiratory muscles
diaphragm and other muscles that promote ventilation (the supply of air to the lungs, especially by artificial means)
Respiratory System
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Major functions of the respiratory system are to supply the body with
oxygen and dispose of carbon dioxide
Respiration (the action of breathing) has four distinct processes that must happen. Those 4 processes are:
- pulmonary ventilation
- external respiration
- transport
- internal respiration
Pulmonary ventilation (breathing)
moving all the air into and out of the lungs
*includes inhalation and expiration
External respiration
gas exchange between the lungs and the blood
*occurs in the lungs where oxygen diffuses into the blood and carbon dioxide diffuses into the alveolar air
Transport
transport of oxygen and carbon dioxide between the lungs and tissues
Internal respiration
gas exchange between systemic blood vessels and tissues
*occurs in the metabolizing tissues, where oxygen diffuses out of the blood and carbon dioxide diffuses out of the cells
The nose is the only
externally visible part of the respiratory system
The nasal cavity lies
in and posterior to the external nose
Nasal Cavity
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Paranasal sinuses are the sinuses in bones that
surround the nasal cavity
Sinuses lighten the skill and help to
warm and moisten the air
The Pharynx is the
funnel-shaped tube of skeletal muscle that connects to the:
- nasal cavity and mouth superiorly
- larynx and esophagus inferiorly
The Pharynx extends from the base of the
skull to the level of the sixth cervical vertebra
The pharynx is divided into three regions:
- nasopharynx
- oropharynx
- laryngopharynx
Nasopharynx lies
posterior to the nasal cavity, inferior to the sphenoid and superior to the level of the soft palate
The nasopharynx is strictly an
air passageway
The nasopharynx closes during
swallowing to prevent food from entering the nasal cavity
the pharyngeal tonsil lies
high on the posterior wall
Oropharynx extends inferiorly from the
level of the soft palate to the epiglottis
The oropharynx opens to the
oral cavity via an archway called the fauces
The oropharynx serves as a common
passageway for food and air
In the oropharynx, the palatine tonsils lie
in the lateral walls of the fauces
The laryngopharynx serves as a common
passageway for food and air
The laryngopharynx lies
posterior to the upright epiglottis
The laryngopharynx extends to the larynx, where the
respiratory and digestive pathways diverge
The larynx is known as the
voice box
The larynx attaches to the
hyoid bone and opens into the laryngopharynx superiorly
The larynx is continuous with
the trachea posteriorly
The three functions of the larynx are:
- to provide a patent airway
- to act as a switching mechanism to route air and good into the proper channels
- to function in voice production
Framework of the Larynx
Laryngeal prominence is known as the
Adam’s apple
Epiglottis is
elastic cartilage that covers the laryngeal inlet during swallowing
Framework of the Larynx
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Movement of Vocal Cords
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The larynx is closed during
coughing, sneezing and Valsalva’s maneuver
The trachea is a flexible and mobile
tube extending from the larynx into the mediastinum
The trachea is composed of three layers
mucosa, submucosa, and adventitia
mucosa
made up goblet cells and ciliated epithelium
submucosa
connective tissue deep to the mucosa
adventitia
outermost layer made of C-shaped rings of hyaline cartilage
Trachea
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Conducting Zone: Bronchi
Bronchi subdivide into
secondary bronchi, each supplying a lobe of the lungs
COnducting Zones
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Respiratory Zone is defined by
the presense of alveoli; begins as terminal bronchioles feed into repiratory bronchioles
Respiratory bronchioles lead to alveolar ducts, then to
terminal clusters of alveolar sacs composed of alveoli
There are approximately 300 million a
alveoli
The 300 million alveoli account for most of the lungs
volume
The alveoli also provide tremendous
surface area for gas exchange
Respiratory Zone
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Respiratory Zone
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Alveoli contain open pores that
- connect adjacent alveoli
* allow air pressure throughout the lung to be equalized
Alveoli house macrophages that keep
alveolar surfaces sterile
Respiratory Membrane
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Lungs occupy all of the
thoracic cavity except for the mediastinum
Root
the site of vascular and bronchial attachments
Costal surface
anterior, lateral, and posterior surfaces in contact with the ribs
Apex
narrow superior tip
Base
an inferior surface that rests on the diaphragm
Hilus
is the indentation that contains pulmonary and systemic blood vessels
Organs in the Thoracic Cavity
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Transverse Thoracic Section
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Left lung
separated into upper and lower lobes by the oblique fissure
Right lung
separated into three lobes by the oblique and horizontal fissures
Lungs are perfused by two circulations:
pulmonary and bronchial
Pulmonary arteries
supply systemic venous blood to be oxygenated
- branch profusely, along with bronchi
- Ultimately feed into the pulmonary capillary network surrounding the alveoli
Pulmonary veins
carry oxygenated blood from respiratory zones to the heart
Breathing or pulmonary ventilation consists of two phases:
inspiration and expiration
Inspiration-
air flows into the lungs
Expiration-
gases exit the lungs
Pulmonary ventilation is a mechanical process that
depends on volume changes in the thoracic cavity
Volume changes lead to pressure changes which lead to
the flow of gases to equalize the pressure
Inspiration is when
the lungs are stretched and intrapulmonary volume increases
Expiration is when
thoracic cavity volume decreases
There are four respiratory volumes
- tidal volume (TV)
- inspiratory reserve volume (IRV)
- Expiratory reserve volume (ERV
- Residual volume (RV)
Tidal volume (TV)-
air that moves into and out of the lungs with each breath (Approximately 500 ml)
Inspiratory reserve volume (IRV)-
air that can be inspired forcibly beyond the tidal volume (2100-3200 ml)
Expiratory reserve volume (ERV)-
air that can be evacuated from the lungs after a tidal expiration (1000-1200 ml)
Residual volume (RV)-
air left in the lungs after strenuous expiration (1200 ml)
Respiratory capacities:
- Inspiratory capacity (IC)
- Functional residual capacity (FRC)
- Vital capacity (VC)
- Total lung capacity (TLC)
*Inspiratory capacity (IC)-
total amount of air that can be inspired after a tidal expiration (IRV+TV)
*Functional residual capacity (FRC)-
amount of air remaining in the lungs after a tidal expiration (RV+ERV)
*Vital capacity (VC)-
the total amount of exchangeable air (TV+IRV+ERV)
*Total lung capacity (TLC)-
the sum of all lung volumes (approximately 6000 ml in males)
Spirometer-
an instrument consisting of a hollow bell inverted over water, used to evaluate respiratory function
Spirometry can distinguish between:
- obstructive pulmonary disease-increased airway resistance
* restrictive disorders-reduction in total lung capacity from structural or functional lung changes
Nonrespiratory air movements mostly result from
reflex action
*Examples include: coughing, sneezing, crying, laughing, hiccuping and yawning
Oxygen transport is when molecular oxygen is
carried in the blood:
* it’s bound to hemoglobin (Hb) within red blood cells
Role of Hemoglobin in oxygen transport; each Hb molecule
binds four oxygen atoms in a rapid and reversible process
Saturated hemoglobin-
when all four hemes of the molecule are bound to oxygen
Partially saturated hemoglobin-
when one to three hemes are bound to oxygen
Lung problems
Chronic obstructed pulmonary disease (COPD)-
a chronic inflammatory lung disease that causes obstructed airflow from the lungs.
Symptoms: difficulty breathing, cough, mucus production, and wheezing
Lung problems
Asthma-
a respiratory condition marked by spasms in the bronchi of the lungs. Characterized by dyspnea (difficult breathing), wheezing, and chest tightness
Lung problems
Tuberculosis-
an infectious disease characterized by the growth of nodules in the tissues. Symptoms include fever, night sweats, weight loss, a racking cough, and a splitting headache. Treatment entails a 12-month course of antibiotics.
Lung problems
Lung cancer-
accounts for 1/3 of all cancer deaths in the U.S. 90% of all patients with lung cancer were smokers
