The Respiratory System, Victoria Gomez, Period 2 (definitions of lung…
The Respiratory System, Victoria Gomez, Period 2
Major functions of the
The main function of the respiratory system is the exchange of oxygen from the atmosphere for carbon dioxide produced by the cells of the body.
Other functions of the respiratory system include participation in the acid-base balance of the body, phonation, pulmonary defense, and metabolism.
organs of the respiratory system and location
(upper and lower respiratory track)
Upper respiratory system
Nose: produces mucus; filters, warms, and moistens incoming air; resonance chamber for speech, receptors for sense of smell
Paranasal sinuses: lighten skull; also warm, moisten, and filter incoming air
Pharynx: facilitates exposure of immune system to inhaled antigens
Lower respiratory system
Larynx: air passageway; prevents food from entering lower respiratory tract
Trachea: voice production, cleans, warms, and moistens incoming air
Bronchial tree: passageways connecting trachea with alveoli; cleans, warms, and moistens incoming air
Alveoli: main sites of gas exchange
Lungs: surfactant reduces surface tension; helps prevent lung collapse; house respiratory passages smaller than the main bronchi
Pleurae: produce lubricating fluid and compartmentalize lungs
anatomy of the respiratory tract
differences between the right and left lung and right and left
Right lung: is shorter because the liver sits high, tucked under the ribcase, but it is broader than the left
Left lung: is smaller because of the space taken up by the heart
Right primary bronchi: is shorter and more vertical than the left, It divides into the three lobes of the right lung.
Left primary bronchi: smaller and longer than the right main bronchus, divides into two lobar bronchi which enter the two lobes of the left lung.
breathing mechanism (physiology)
inspiratory muscles contract (diaphragm descends; ribcage rises)
Thoracic capacity volume increases
Lungs are stretched; intrapulmonary volume increases
Intrapulmonary pressure drops (to -1mm Hg)
Air flows into lungs down its pressure gradient until intrapulmonary pressure is 0
Inspiratory muscles relax (diaphragm rises; ribcage descends)
Thoracic cavity volume decreases.
Elastic lungs recoil passively; intrapulmonary volume decreases
Intrapulmonary pressure rises (to + 1 mm Hg)
Air flows out of lungs down its pressure gradient until intrapulmonary pressure is 0
definitions of lung capacity terminology
Vital capacity: maximum amount of air that can be expired after a maximum inspiratory effort
Inspiratory capacity: maximum amount of air that can be inspired after a normal tidal volume expiration
Total lung capacity: maximum amount of air contained in lungs after a maximum inspiratory effort
Functional residual capacity: volume of air remaining in the lungs after a normal tidal volume expiration
Residual volume: amount of air remaining in the lungs after a forced expiration
Tidal volume: amount of air inhaled or exhaled with each breath under resting conditions
Inspiratory reserve volume: amount of air that can be forcefully inhaled after a normal tidal volume inspiration
Expiratory reserve volume: amount of air that can be forcefully exhaled after a normal tidal volume expiration
internal and external respiration
Internal respiration:occurs in the metabolizing tissues, where oxygen diffuses out of the blood and carbon dioxide diffuses out of the cells
External respiration: occurs in the lungs where oxygen diffuses into the blood and carbon dioxide diffuses into the alveolar air
disorders of the respiratory system
Chronic obstructive pulmonary disease (COPD): Collective term for progressive, obstructive respiratory disorders; includes emphysema, chronic bronchitis.
Dyspnea: Difficult or labored breathing; air hunger.
Emphysema: distinguished by permanent enlargement of the alveoli, accompanied by destruction of the alveolar walls
Asthma: characterized by episodes of coughing, dyspnea, wheezing, and chest tightness—alone or in combination.
Tuberculosis (TB): the infectious disease caused by the bacterium Mycobacterium tuberculosis, is spread by coughing and primarily enters the body in inhaled air.
Adenocarcinoma: originates in peripheral lung areas as solitary nodules that develop from bronchial glands and alveolar cells.
Squamous cell carcinoma: arises in the epithelium of the bronchi or their larger subdivisions and tends to form masses that may hollow out and bleed.
Small cell carcinoma: round lymphocyte-sized cells that originate in the main bronchi and grow aggressively in small grapelike clusters within the mediastinum.
Sleep apnea: is a common disorder that is characterized by the temporary cessation of breathing during sleep.