Denise Juarez P.2 Respiratory System
Internal vs. external respiration
Layers of the pleurae
Lower respiratory structures and functions
Respiratory volumes and capacities
Disorders of the respiratory system
Compare and contrast the mechanism of inspiration and expiration
Major functions of the respiratory system
Upper respiratory structures and functions
Volume and Pressure relationships in thoracic cavity
supply body with O2 for cellular respiration
dispose of CO2, a waste product of cellular respiration
Paranasal sinuses
Pharynx
Nose and nasal cavity
Bronchi and branches
Lungs and alveoli
Trachea
Diaphragm
Larynx
Nasal cavity is divided by midline nasal septum and lined with mucosa.
Lightens skull; may also warm, moisten, and filter
incoming air
Connecting nasal cavity to larynx and oral cavity to
esophagus.
Produces mucus; filters, warms, and moistens
incoming air; resonance chamber for speech
Roof of nasal cavity contains olfactory epithelium.
Mucosa-lined, air-filled cavities in cranial bones surrounding nasal cavity
Passageway for air and food
Connects pharynx to trachea.
Holds true vocal cords, voice production
Air passageway; prevents food from
entering lower respiratory tract
Tube running from larynx and dividing inferiorly into
two main bronchi.
Air passageway; cleans, warms, and
moistens incoming air
Consists of right and left main bronchi,
Air passageways connecting trachea, with alveoli; cleans, warms, and moistens incoming air
Main sites of gas exchange
Paired composite organs that flank mediastinum in thorax.
Microscopic chambers at termini of bronchial tree.
House respiratory passages smaller
than the main bronchi
Serous membranes. Parietal pleura lines thoracic cavity;
visceral pleura covers external lung surfaces.
Produce lubricating fluid and
compartmentalize lungs
Serves as resonating chamber for speech
Filters and cleans inspired air
Nasopharynx
Air passageway (only air) posterior to nasal cavity
Oropharynx
Laryngopharynx
Passageway for food and air from level of soft palate to epiglottis
Passageway for food and air
Laryngitis: inflammation of the vocal folds that causes the vocal folds to swell, interfering with vibrations
Parietal pleura: membrane on thoracic wall, superior face of diaphragm, around heart, and between lungs
Visceral pleura: membrane on external lung surface
Pleurae: thin, double-layered serosal membrane that divides thoracic cavity into two pleural compartments and mediastinum
Pleural fluid fills slitlike pleural cavity between two pleurae
Pleurisy: inflammation of pleurae that often results from pneumonia
Inspiration: gases flow into lungs
Expiration: gases exit lungs
Intrapulmonary pressure (Ppul)
Transpulmonary pressure
Atmospheric pressure (Patm)
Pressure exerted by air surrounding the body
Fluctuates with breathing
Ppul −Pip
Intrapleural pressure (Pip)
Pressure in pleural cavity
Two inward forces promote lung collapse
Fluctuates with breathing
One outward force tends to enlarge lungs
Lungs’ natural tendency to recoil
Surface tension of alveolar fluid
760 mm Hg at sea level = 1 atmosphere
Always eventually equalizes with P atm
Pressure in alveoli
Pressure that keeps lung spaces open
Atelectasis: lung collapse due to plugged bronchioles, which cause collapse of alveoli, or pneumothorax, air in pleural cavity
As thoracic cavity volume increases, lungs are stretched as they are pulled out with thoracic cage
Active process involving inspiratory muscles (diaphragm and external intercostals)
Forced expiration is an active process that uses oblique and transverse abdominal muscles, as well as internal intercostal muscles
Quiet expiration normally is passive process
Forced (deep) inspirations can occur during vigorous exercise or in people with COPD
Inspiration
Expiration
Action of intercostal muscles: when external intercostals contract, rib cage is lifted up and out, much like when handle on a bucket is raised (outward as it moves upward)
Inspiratory muscles relax, thoracic cavity volume decreases, and lungs recoil
Action of the diaphragm: when dome-shaped diaphragm contracts, it moves inferiorly and flattens out
Volume decrease causes intrapulmonary pressure (Ppul) to increase
thoracic cavity volume increases causes intrapulmonary pressure to drop
Volumes
Capacities
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Tidal volume (TV): amount of air moved into and out of lung with each breath ( average 500ml)
Inspiratory reserve volume (IRV): amount of air that can be inspired forcibly beyond the tidal volume (2100–3200 ml)
Residual volume (RV): amount of air that always remains in lungs (keeps alveoli open)
Expiratory reserve volume (ERV): amount of air that can be forcibly expelled from lungs (1000–1200 ml)
Functional residual capacity (FRC): sum of RV + ERV
Vital capacity (VC): sum of TV + IRV + ERV
Inspiratory capacity (IC): sum of TV + IRV
Total lung capacity (TLC): sum of all lung volumes (TV + IRV+ ERV + RV
COPD: chronic obstruction pulmonary disorder, includes chronic bronchitis, emptysema, and asthma, asthmatic bronchitis, tobacco smoke, dust exposure, age, genetics
TUBERCULOSIS: bacterial infection in the respiratory system caused by mycobacterium tuberculosis, contagious inhaled weakened immune system
Pneumonia : bacterial or viral infection of the lungs, exposure to infected individuals, impacted immune system
Lung cancer: uncontrolled cell growth & development of the tumors in the lungs, smoking, genetics, air pollution
seasonal flu: a viral infection many variations of this virus changes every year, weakened immune system, chronic illness, living conditions