Respiratory system
Major functions of the respiratory system
Organs of the respiratory system and locations (upper and lower)
Breathing Mechanism
Lung capacity terminology
Disorders of the respiratory system
Upper: nose: air enters nose through external nares (nostrils)
Lower: trachea (wind pipe) that connects larynx with bronchi, fairly rigid because of the c-shaped rings made of hyaline cartilage to keep airway open at all times
Gas exchanges between blood and external environment
Passage ways to lungs purify, warm and humidify the incoming air
Nasal cavity: olfactory receptors (sense of smell) located in mucosa on superior surface
Rest line with respiratory mucosa
Moistens air, traps incoming foreign particles, lateral walls have conchae
Paranasal sinuses-cavities within bones: frontal, sphenoid ethmoid, maxillary bone; lighten the skull
Pharynx (throat): Muscular passage from nasal cavity to larynx, 3 regions of the pharynx
Nasopharynx- Superior region behind nasal cavity (passage of the air only)
Oropharynx- Middle region behind mouth
Laryngopharynx- Inferior region attached to larynx
Primary bronchi: formed by divisions of trachea, enters the lungs at hilus, right bronchus is wider, shorter and straighter than the left due to the presence of the heart on the left side
Lungs (Major organ in the resp. system) occupy most of thoracic cavity, apex is near clavical, base rests on diaphram, each lung is divided into lobes by fissures
Breathing patterns
Lung volume
Tidal volume
Respiratory cycle = 1 respiration = 1 inhalation and 1 exhalation
Adults breathe about 12 breaths/min
Measured by using a spirometer to test lung function
Air moved by 1 respiration, about 500mL, during normal breathing at rest
Inspatory reserve volume; additional air taken in during maximal inhalation
Expiratory reserve volume; additional air expired during forced exhalation
Residual volume; amount of air left in alveoli after forced expiration, keeps them inflated
Dead space volume; air remaining in conducting zone; doesn't reach alveoli
Respiratory capacities
Inspirational capacity- tidal volume + inspiratory reserved volume
Functional residual capacity- residual volume + expiratory reserve volume
Chronic obstructive pulmonary disease; patients almost always have a history of smoking, labored of difficulties breathing (dyspnea) becomes aggressive and severe, coughing and frequent infections are common
Emphesyma (only disorder that has a problem exhaling); alveoli enlarge as adjacent chambers breakthrough, chronic inflammation promotes lung fibrosis, airways collapse during expiration, patients use a large amount of energy to exhale
Chronic bronchitis; mucosa becomes inflamed and mucus production increases, risk of lung infection increases
Lung cancer; 1/3 of all cancer deaths in the U.S
associated with smoking
Euphea; normal, quiet breathing Aphea; temporary cessation of breathing
Dysphea; painful or labored breathing
Trachyphea; rapid breathing
Control of respiration
Respiratory center = groups of neurons in medulla oblangata and pons
Chemical factors = higher carbon-d higher respiration; acts directly on medulla oblangata (carbon dioxide levels in blood is the main regulatory chemical for respiration)
Lower oxygen = higher respiration
Chemoceptors in aorta & caratoid artery