The Respiratory System Medical Terminology
The respiratory system is where gas exchange occurs via respiration; inhalation/exhalation. pick up oxygen from inhaled air expels carbon dioxide and water sinus nose mouth epiglottis trachea pharynx larynx lungs
Respiratory Systems: A Closer Look A system of branching ducts conveys air to the lungs Pathway of air Air inhaled through the following structures: Nares of the nose through Nasal cavity nasopharynx oropharynx laryngopharynx passed the epiglottis larynx trachea bronchi bronchioles alveoli (where gas exchange occurs) Mouth oropharynx laryngopharynx passed the epiglottis larynx trachea bronchi bronchioles alveoli (where gas exchange occurs)
Pharynx Larynx Trachea Right lung Bronchus Nasal septum Branch from pulmonary vein (oxygen-rich blood) Nasal cavity Oral cavity Left lung Terminal bronchiole Branch from Pulmonary artery (oxygen-poor blood) Alveoli Bronchiole SEM Colorized SEM
Epiglottis Other important structures: Epiglottis - covers the trachea when you swallow in order to prevent choking
Epiglottis Esophagus Pleural membranes (pleurae) Other important structures: Epiglottis - covers the trachea when you swallow in order to prevent choking Pleural membranes - Layers surround the lungs and line the rib cage in order to reduce friction - From superficial to deep - Parietal pleura - Interpleural space - Visceral pleura - Also plays a role in breathing Diaphragm - Large, flat muscle that divides the thoracic and abdominal cavities - Important in breathing Diaphragm
The process that ventilates the lungs is breathing, the alternate inhalation and exhalation of air Humans ventilate their lungs by negative pressure breathing, which pulls air into the lungs Breathing involves the diaphragm and intercostal muscles. Lung volume increases as the rib muscles and diaphragm contract which causes suction of air into lungs Air inhaled. Air exhaled. Muscles contract and thoracic cavity expands. Muscles and thoracic cavity becomes small. Diaphragm flattens by contraction and moves downward. Diaphragm relaxes and rises.
The respiratory system moves gases into and out of the blood. The lungs contain the bronchi, bronchioles, and alveoli. Millions of alveoli give the lungs a large surface area. The alveoli absorb oxygen from the air you inhale. alveoli bronchiole
Gas exchange occurs across specialized respiratory surfaces Gas exchange supplies oxygen for cellular respiration and disposes of carbon dioxide Animals require large, moist respiratory surfaces for adequate diffusion of gases between their cells and the respiratory medium, either air or water
Gas exchange occurs in the alveoli of the lungs. Oxygen and carbon dioxide are carried by the blood to and from the alveoli. oxygen diffuses from alveoli into capillary oxygen binds to hemoglobin in red blood cells carbon dioxide diffuses from capillary into alveoli ALVEOLI GAS EXCHANGES capillary alveolus Co 2 diffuses into alveolus. co 2 capillaries o 2 O 2 diffuses into blood.
Control of Breathing in Humans In humans, the main breathing control centers are in two regions of the brain, the medulla oblongata and the pons The medulla regulates the rate and depth of breathing in response to ph changes in the cerebrospinal fluid ph changes are caused by concentration of CO2 in the blood The medulla adjusts breathing rate and depth to match metabolic demands
Sensors in the aorta and carotid arteries monitor O 2 and CO 2 concentrations in the blood These sensors exert secondary control over breathing Breathing control centers Cerebrospinal fluid Pons Medulla oblongata Carotid arteries Aorta Diaphragm Rib muscles
Negative Feedback Loop Holding breath causes CO 2 levels to rise O 2 / CO 2 level returns to normal Control system forces exhale, inhale