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