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Respiratory System. Purpose. Moving air into and out of the lungs Lungs are the site of the exchanges of oxygen and carbon dioxide between the air and the blood All of our cells must obtain oxygen to carry out cell respiration to produce ATP.
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Purpose • Moving air into and out of the lungs • Lungs are the site of the exchanges of oxygen and carbon dioxide between the air and the blood • All of our cells must obtain oxygen to carry out cell respiration to produce ATP. • Works to eliminate the CO2 produced as a waste product of cell respiration. • Tied into the Circulatory System which transports these gases in the blood.
Divisions of the Respiratory System • Divided into the upper respiratory tract and the lower respiratory tract. • Upper respiratory tract consists of the parts outside the chest cavity • Air passages of the nose • Nasal cavities • Pharynx • Larynx • Upper trachea
Divisions of the Respiratory System • Lower respiratory tract consists of parts found within the chest cavity • Lower trachea • The lungs themselves which include • Bronchial tubes • Alveoli • Also part of the respiratory system are the pleural membranes and the respiratory muscles that form the chest cavity • Diaphragm • Intercostal muscles
Nose and Nasal Cavities • Air enters and leaves the respiratory system through the nose. • The two nasal cavities are within the skull, separated by the septum • Nasal mucosa (lining) is ciliated epithelium, containing goblet cells that produce mucous • Three shelf like bones called conchae project from the lateral wall of each nasal cavity • Conchae increase the surface area on the nasal mucosa. • Air passes through the nasal cavities and is warmed and humidified
Nose and Nasal Cavities • Bacteria and particles of air pollution are trapped on the mucus • Cilia continuously sweep the mucus toward the pharynx • Most mucus is eventually swallowed, and most bacteria present will be destroyed by the hydrochloric acid in the stomach • Upper nasal cavity contains the olfactory receptors which detect vaporised chemicals that have been inhaled. • Nasal cavities also lighten the skull and provide resonance for the voice.
Pharynx • Is a muscular tube posterior to the nasal and oral cavities, and anterior to the cervical vertebrae • Divided into three parts • Nasopharynx • Oropharynx • Laryngopharynx • Participates in swallowing, contains several tonsils that are part of the immune system and directs food and air into the appropriate channels.
Larynx • Also called the voice box • Functions include speaking as well as an air passageway • Contains rings of cartilage connected by ligaments. • Cartilage maintains a firm structure to allow the passage of continuous air flow
Trachea and Bronchial Tree • Trachea extends from the larynx to the primary bronchi. • Wall of trachea contains C-shaped pieces of cartilage for support • Mucosa of the trachea is ciliated epitheluim which sweep upward toward the pharynx. • Bronchial tree is divided into the left and right primary bronchi and are the branches of the trachea that enter the lungs. • Also have C-shaped pieces of cartilage. • Within the lungs each primary bronchi branches into secondary bronchi leading to the lobes of the lung • Smaller branches become bronchioles. There is no cartilage in the bronchioles
Lungs and Pleural Membranes • Lungs are located on either side of the heart in the chest cavity • Encircled and protected by the rib cage. • The base of each lung rests on the diaphragm • Pleural Membranes are the serous membranes of the thoracic cavity. • Parietal Pleura lines the chest wall • Visceral Pleura is on the surface of the lungs • Between the pleural membranes is serous fluid which prevents friction and keeps the two membranes together when breathing
Exchange of Gas • Two sites of gas exchange within the body • Lungs • Tissue • External respiration – the exchange of gases between the body and the external environment ie: lung alveoli and blood • Internal Respiration – the exchange of gases between blood and tissue fluids • Exchange of gases occurs through diffusion – the movement of a gas from an area of greater concentration to an area of lesser concentration.
Pulmonary Volumes • 1. Tidal Volume – the amount of air involved in one normal inhalation and exhalation. • 2. Minute respiratory volume (MRV) – the amount of air inhaled and exhaled in 1 minute. • 3. Inspiratory reserve – the amount of air, beyond tidal volume, that can be taken in with the deepest possible inhalation. • 4. Expiratory reserve – the amount of air, beyond tidal volume, that can be expelled with the most forceful exhalation. • 5. Vital Capacity – sum of tidal volume, inspiratory reserve and expiratory reserve. • 6. Residual air – the amount of air that remains in the lungs after the most forceful exhalation.