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111 terms

Respiratory system

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respiratory system
consists of the nose, pharynx, larynx, trachea, bronchi, and lungs
upper respiratory system
includes only the nose, pharynx, and associated structures
lower respiratory system
includes the larynx, trachea, bronchi, and lungs
conducting zone
consists of a series of interconnecting cavities and tubes both outside and within the lungs that function to filter, warm, and moisten air and conduct it into the lungs
respiratory zone
consists of tissues within the lungs where gas exchange occurs, including the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli
external nose
the portion of the nose visible on the face consisting of a supporting framework of bone and hyaline cartilage covered with muscle and skin and lined by a mucous membrane
external nares
the two openings of the nose also called the nostrils
internal nose
a large cavity beyond the nasal vesitbule in the anterior skull that lies inferior to the nasal bone and superior to the mouth; lined with muscle and mucous membrane
internal nares
two openings that connect the internal nose with the pharynx; also called the choanae
nasal cavity
the space within the internal nose
nasal vestibule
the anterior portion of the nasal cavity just inside the nostrils that is surrounded by cartilage
nasal septum
a vertical partition that divides the nasal cavity into right and left sides
meatus
a groovelike passageway found on the side of the nasal cavity, formed by the nasal conchae
olfactory epithelium
a region of the membrane lining the superior nasal conchae and septum which contains recpetors for the sense of smell
pharynx
a funnel-shaped tube that starts at the internal nares and extends to the cricoid cartilage of the inferior larynx; also called the throat
nasopharynx
the superior portion of the pharynx that extends to the soft palate
soft palate
the posterior portion of the roof of the mouth; arch-shaped muscular partition between the nasopharynx and oropharynx
adenoid
also called the pharyngeal tonsil; located on the posterior wall of the pharynx
oropharynx
the intermediate pharynx, lying posterior to the oral cavity and extending from the soft palate inferiorly to the hyoid bone
laryngopharynx
the inferior portion of the pharynx; also called the hypopharynx; extends from the hyoid bone to the opening into the esophagus and larynx
larynx
a short passageway that connects the laryngopharynx with the trachea; also called the voicebox
thyroid cartilage
two fused plates of hyaline cartilage that forms the anterior wall of the larynx; also called the Adam's apple
epiglottis
a large, leaf-shaped piece of elastic cartilage that is covered with epithelium; moves down and forms a lid over the glottis, the opening into the trachea
glottis
consists of a pair of vocal folds (true vocal cords) and the sapce between them (rima glottidis)
cricoid cartilage
a ring of hyaline cartilage that forms the inferior wall of the larynx
cuneiform cartilage
a pair of club- or wedge-shaped elastic cartilages anterior to the corniculate cartilages that support the vocal folds and lateral aspects of the epiglottis
ventricular folds
superior mucous membrane folds of the larynx; also called the false vocal cords
vocal folds
inferior membrane and connective tissue folds of the larynx; also called the true vocal cords
trachea
a tubular passageway for air that is anterior to the esophagus and extends from the larynx to the left and right primary bronchi; also called the windpipe
primary bronchus
a pair of branches of the trachea that lead to the right and left lung; consist of incomplete rings of cartilage and are lined by pseudostratified ciliated columnar epithelium
secondary bronchi
branches of the primary bronchi that lead to each lobe of the lung; also called lobar bronchi
tertiary bronchi
branches of the secondary bronchi that divide into bronchioles; also called segmental bronchi
bronchioles
branches of the tertiary bronchi that repeatedly branch into smaller terminal bronchioles
terminal bronchioles
branches of the bronchioles
bronchial tree
the extensive branching of airways from the trachea which resembles an inverted tree
lungs
paired, cone-shaped organs in the thoracic cavity that lie on either side of the heart; the primary organs of respiration
pleural membrane
double-layered serous membrane that encloses and protects each lung
parietal pleura
superficial layer of membrane that lines the wall of the thoracic cavity
visceral pleura
deep layer of membrane that covers the lungs themselves
pleural cavity
a small space between the visceral and parietal pleura which contains a small amount of lubricating fluid secreted by the membranes
pleuritis
inflammation of the pleural membrane that causes pain in its early stages due to friction between the parietal and visceral layers of the pleura
base
the broad, concave, inferior portion of the lung that fits over the convex area of the diaphragm
apex
the narrow superior portion of the lung
costal surface
the lung surface that lies against the ribs, matching the rounded curvature of the ribs
hilum
the region of the mediastinal surface through which bronchi, pulmonary blood vessels, lymphatic vessels, and nerves enter and exit the lungs
cardiac notch
a concave space on the left lung in which the heart lies
respiratory bronchiole
branches of the terminal bronchioles that subdivide into several alveolar ducts
alveolar duct
branches of the respiratory bronchioles that lead directly to the alveoli
alveolus
an air sac in the lungs lined by simple squamous epithelium and supported by a thin elastic basement membrane
type I alveolar cell
simple squamous epithelial cell that forms a nearly continuous lining of the alveolar wall; the main sites of gas exchange
type II alveolar cell
cuboidal epithelial cells that secrete alveolar fluid; also called septal cells
surfactant
a complex mixture of phospholipids and proteins found in the alveolar fluid; lowers the surface tension of alveolar fluid, which reduces the tendency of alveoli to collapse
alveolar macrophages
phagocytes associated with the alveolar wall that remove fine dust particles and other debris from the alveolar spaces; also called dust cells
respiratory membrane
the combined alveolar and capillary walls where gas exchange between the air spaces in the lungs and blood takes place
alveolar wall
a layer of type I and type II alveolar cells and associated alveolar macrophages
ventilation-perfusing coupling
the phenomenon where blood flow to each area of the lungs matches the extent of airflow to alveoli in that area
respiration
the general process of gas exchange in the body
pulmonary ventilation
the inhalation and exhalation of air that involves the exchange of air between the atmosphere and the alveoli of the lungs; also called breathing
external respiration
the exchange of gases betweent he alveoli of the lungs and the blood in pulmonary capillaries across the respiratory membrane; also called pulmonary respiration
internal respiration
the exchange of gases between blood in systemic capillaries and tissue cells; also called tissue respiration
inhalation
breathing in; also called inspiration
Boyle's law
states that the volume of a gas varies inversely with its pressure
intrapleural pressure
the pressure between the two pleural layers in the pleural cavity, which is always subatmospheric; also called intrathoracic pressure
alveolar pressure
the pressure inside the lungs themselves; also called intrapulmonic pressure
exhalation
breathing out; also called expiration
elastic recoil
property of the chest wall and lungs that causes exhalation; their natural tendency to spring back after they have been stretched
surface tension
arises at all air-water interfaces due to the polar water molecules being more strongly attracted to each other thatn they are to the gas molecules in the air
compliance
refers to how much effort is required to stretch the lungs and chest wall
eupnea
the normal pattern of quiet breathing
costal breathing
a pattern of shallow (chest) breathing due to contraction of the external intercostal muscles
diaphragmatic breathing
a pattern of deep (abdominal) breathing consisting of the outward movement of the abdomen
tidal volume
the volume of one breath
minute ventilation
the total volume of air inhaled and exhaled each minute; equal to respiratory rate multiplied by tidal volume
spirometer
the apparatus commonly used to measure the volume of air exchanged during breathing and the respiratory rate
spirogram
the record of air volume and respiratory rate measured by the spirometer
anatomic (respiratory) dead space
the air in airways that does not undergo respiratory exchange
alveolar ventilation rate
the volume of air per minute that actually reaches the respiratory zone
inspiratory reserve volume
the additional inhaled air taken into the lungs by taking a very deep breath
expiratory reserve volume
the extra air that is pushed out of the lungs during a forcible exhalation
residual volume
air that remains in the lungs, even after the expiratory reserve volume is exhaled; cannot be measured by spirometry
inspiratory capacity
the sum of tidal volume and inspiratory reserve volume
functional residual capacity
the sum of residual volume and expiratory reserve volume
vital capacity
the sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume
total lung capacity
the sum of vital capacity and residual volume
Dalton's law
states that each gas in a mixture of gases exerts its own pressure as if no other gases were present
Henry's law
states that the quantity of a gas that will dissolve in a liquid is proportional to the partial pressure of the gas and its solubility
nitrogen narcosis
excessive amounts of dissolved nitrogen that produce giddiness and other symptoms similar to alcohol intoxication; also called the "rapture of the deep"
decompression sickness
if a scuba diver ascends too rapidly, nitrogen in the blood comes out of solution too quickly and forms gas bubbles in the tissues, causing joint pain, dizziness, shortness of breath, extreme fatigue, paralysis, and unconsciousness; also called "the bends"
deoxygenated blood
blood that is depleted of some oxygen gas
oxygenated blood
blood that is saturated with oxygen gas
oxyhemoglobin
the binding of oxygen and hemoglobin
percent saturation of hemoglobin
the average saturation of hemoglobin with oxygen
affinity
the tightness with which hemoglobin binds oxygen
Bohr effect
phenomenon where lower pH drives oxygen off hemoglobin, making more oxygen available for tissue cells; and elevated pH increases the affinity of hemoglobin for oxygen
carbaminohemoglobin
hemoglobin that has bound carbon dioxide onto its alpha and beta globin chains
bicarbonate ions
how 70% of the carbon dioxide in blood plasma is transported
respiratory center
neurons in the medulla oblongata and pons of the brain that regulate the rate and depth of pulmonary ventilation
medullary rhythmicity area
the neurons of the respiratory center in the medulla oblongata that control the basic rhythm of respiration
central chemoreceptors
located in or near the medulla oblongata in the central nervous system that respond to changes in hydrogen ion (H+) concentration or P-CO2 or both, in cerebrospinal fluid
peripheral chemoreceptors
neurons located in the aortic and carotid bodies that are sensitive to changes in P-O2, H+, and P-CO2 in the blood
hypercapnia
an increase in P-CO2 of arterial blood; also called hypercarbia
hyperventilation
rapid and deep breathing that allows the inhalation of more oxygen gas and the exhalation of more carbon dioxide until P-CO2 and H+ are lowered to normal
hypocapnia
the condition where arterial P-CO2 is lower than 40 mm Hg; also called hypocarbia
hypoxia
a deficiency of oxygen gas at the tissue level
baroreceptors
neurons located in the walls of bronchi and bronchioles that are stretch-sensitive; also called stretch receptors
asthma
a disorder characterized by chronic airway inflammation, airway obstruction, or airway hypersensitivity to a variety of stimuli
emphysema
a disorder characterized by destruction of the alveolar walls, producing abnormally large air spaces that remain filled with air during exhalation
chronic bronchitis
a disorder characterized by excessive secretion of bronchial mucus accompanied by a productive cough that lasts for three months of the year for two successive years
pulmonary edema
an abnormal accumulation of fluid in the interstitial spaces and alveoli of the lungs
pneumonia
an acute infection or inflammation of the alveoli
tuberculosis
an infectious, communicable disease caused by the bacterium Mycobacterium tuberculosis that most often affects the lungs and pleurae