Respirtory - Sheet1 Flashcards
The two systems that cooperate to supply O2 and CO2 are
the cardiovascular and the respiratory system.
The respiratory system provides for
gas exchange.
The cardiovascular system
transports the respiratory gases.
Failure of either system has the same effect on the body:
disruption of homeostasis and rapid death of cells from starvation and buildup of waste products.
Respiration is the exchange of gases between
the atmosphere and cells.
Respiration takes place in three basic processes:
ventilation (breathing), external (pulmonary) respiration, and internal (tissue) respiration.
The respiratory system consists of
the nose, pharynx, larynx, trachea, bronchi, and lungs.
The upper respiratory system refers to the
nose and pharynx, and associated structures.
The lower respiratory system refers to the
larynx, trachea, bronchi, and lungs.
The conducting system consists of
a series of cavities and tubes - nose, pharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles - that conduct air into the lungs.
The respiratory portion consists of
the area where gas exchange occurs - respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli.
The external portion of the nose is made of
cartilage and skin and is lined with mucous membrane.
Openings to the exterior of the nose are called
external nares.
The bony framework of the nose is formed by the
frontal bone, nasal bones, and maxillae.
The interior structures of the nose are specialized for
warming, moistening, and filtering incoming air; receiving olfactory stimuli; and serving as large, hollow resonating chambers to modify speech sounds.
The internal portion of the nose communicates with the
paranasal sinuses and nasopharynx through the internal nares.
The inside of both the external and internal nose is called the
nasal cavity.
The nasal cavity is divided into right and left sides by the
nasal septum.
The anterior portion of the nasal cavity is called the
vestibule.
The pharynx (throat) is a
muscular tube lined by a mucous membrane.
The anatomic regions of the pharynx are the
nasopharynx, oropharynx, and laryngopharynx.
The nasopharynx functions in
respiration.
Both the oropharynx and laryngopharynx function in
digestion and respiration (serving as a passageway for both air and food).
The larynx (voice box) is a passageway that connects the
pharynx with the trachea.
The larynx contains the thyroid cartilage, commonly known as the
Adam’s apple.
The epiglottis prevents food from
entering the larynx.
The cricoid cartilage connects the
larynx and trachea.
The paired cartilages of the larynx include the
arytenoid, corniculate, and cuneiform cartilages.
The larynx contains vocal folds (true vocal cords), which produce
sound.
Taunt vocal folds produce
high pitches.
Relaxed vocal folds produce
low pitches.
Sound originates from the
vibration of the vocal folds, but other structures are necessary for converting the sound into recognizable speech.
Laryngitis is an
inflammation of the larynx that is usually caused by respiratory infection or irritants.
Cancer of the larynx is almost exclusively found in
smokers.
The trachea (windpipe) is located
anterior to the esophagus.
The trachea extends from the larynx to the
primary bronchi.
The trachea is composed of
C-shaped rings of cartilage and is lined with pseudostratified ciliated columnar epithelium.
The cartilage rings of the trachea keep the airway
open.
The cilia of the epithelium sweep debris
away from the lungs and back to the throat to be swallowed.
The trachea divides into the
right and left primary bronchi.
The bronchial tree consists of the
trachea, primary bronchi, secondary bronchi, tertiary bronchi, bronchioles, and terminal bronchioles.
Changes in histology reflect changes in
function in the structures of the bronchial tree.
The mucus membrane changes from ciliated pseudostratified epithelium with many goblet cells in the largest bronchi to
non-ciliated cuboidal epithelium in the smallest bronchioles.
The C-rings of the trachea are replaced by
plates of cartilage in the bronchi and eventually disappear completely in the bronchioles.
As the amount of cartilage decreases, the amount of
smooth muscle increases.
Lungs are paired organs in the
thoracic cavity.
The lungs are enclosed and protected by the
pleural membrane.
The parietal pleura is the
outer layer which is attached to the wall of the thoracic cavity.
The visceral pleura is the
inner layer, covering the lungs themselves.
Between the pleurae is a small potential space, the
pleural cavity, which contains a serous lubricating fluid secreted by the membranes.
The lungs extend from the
diaphragm to just slightly superior to the clavicles and lie against the ribs anteriorly and posteriorly.
Injuries to the chest wall that allow air to enter the intrapleural space either from the outside or from the alveoli cause
pneumothorax, filling the pleural cavity with air.
The right lung has
three lobes separated by two fissures.
The left lung has
two lobes separated by one fissure and a depression, the cardiac notch.
The secondary (lobar) bronchi give rise to branches called
tertiary (segmental) bronchi, which supply segments of lung tissue called bronchopulmonary segments.
Each bronchopulmonary segment consists of many small compartments called
lobules.
Lobules contain
lymphatics, arterioles, venules, terminal bronchioles, respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli.
Alveolar walls consist of
type I alveolar (squamous pulmonary epithelial) cells, type II alveolar (septal) cells, and alveolar macrophages (dust cells).
Type II alveolar cells secrete
alveolar fluid, which keeps the alveolar cells moist and contains a component called surfactant.
Surfactant reduces the surface tension of alveolar fluid, preventing the
collapse of alveoli with each expiration.
Inadequate surfactant in premature infants can result in
Respiratory Distress Syndrome, which causes blue skin color and labored breathing.
Compliance is the ease with which the
lungs and thoracic wall can be expanded.
Any condition that destroys lung tissue, causes it to become filled with fluid, or produces a deficiency in surfactant results in
decreased compliance.
Any condition that obstructs the air passageway increases
resistance, and more pressure is required to force air through.
Breathing patterns and modified respiratory movements include
normal variations in breathing rate and depth.
Apnea refers to
breath holding.
Dyspnea relates to
painful or difficult breathing.
Tachypnea involves
rapid breathing rate.
Costal breathing requires
combinations of various patterns of intercostal and extracostal muscles, usually during the need for increased ventilation, as with exercise.
Diaphragmatic breathing is the
usual mode of operation to move air by contracting and relaxing the diaphragm to change the lung volume.
Gas exchange occurs across the
alveolar-capillary membrane.
Blood enters the lungs via the
pulmonary arteries (pulmonary circulation) and the bronchial arteries (systemic circulation).
Most of the blood leaves the lungs by the
pulmonary veins, but some drains into the bronchial veins.
In the lungs, vasoconstriction in response to hypoxia diverts pulmonary blood from poorly ventilated areas to well-ventilated areas. This phenomenon is known as
ventilation-perfusion coupling.
Patency helps to maintain the system as the
air passageways are kept free of obstructions.
Respiration occurs in three basic steps:
pulmonary ventilation, external respiration, and internal respiration.
Inhalation (inspiration) is the process of
bringing air into the lungs.
The movement of air into and out of the lungs depends on pressure changes governed in part by
Boyle’s law, which states that the volume of a gas varies inversely with pressure, assuming that temperature is constant.
The first step in expanding the lungs involves contraction of the
main inspiratory muscle, the diaphragm.
Inhalation occurs when alveolar (intrapulmonic) pressure falls below
atmospheric pressure.
Contraction of the diaphragm and external intercostal muscles increases the size of the thorax, thus decreasing the intrapleural (intrathoracic) pressure so that the
lungs expand.
During forced inhalation, accessory muscles of inspiration (sternocleidomastoids, scalenes, and pectoralis minor) are
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