Bronchi: The two main air passages into the lungs. Diaphragm: The main muscle used for breathing; separates the chest cavity from the abdominal cavity. Epiglottis: A flap of cartilage that prevents food from entering the trachea (or windpipe). Esophagus: The tube through which food passes from the mouth down into the stomach. Heart: The muscular organ that pumps blood throughout the body.

Intercostal muscles: Thin sheets of muscle between each rib that expand (when air is inhaled) and contract (when air is exhaled). Larynx: Voice box. Lungs: The two organs that extract oxygen from inhaled air and expel carbon dioxide in exhaled air. Muscles attached to the diaphragm: These muscles help move the diaphragm up and down for breathing.

Nasal cavity: Interior area of the nose; lined with a sticky mucous membrane and contains tiny, surface hairs called cilia. Nose hairs: Located at the entrance of the nose, these hairs trap large particles that are inhaled. Paranasal sinuses: Air spaces within the skull. Pharynx: The throat.

Pleural membrane: Covering the lung and lining the chest cavity, this membrane has 2 thin layers. Pulmonary vessels: Pulmonary arteries carry deoxygenated blood from the heart and lungs; pulmonary veins carry oxygenated blood back to the heart. Respiratory center: Area of the brain that controls breathing. Ribs: Bones attached to the spine and central portion of the breastbone, which support the chest wall and protect the heart, lungs, and other organs in the chest. Trachea: Tube through which air passes from the nose to the lungs (also known as the windpipe).

Protists: diffusion through skin Cnidarians: diffusion through skin Annelids, Nematodes, Flatworms: diffusion through skin

Mollusks: breathe through gills Arthropods: (sea dwellers) gills, (land)-trachea Echinoderms: water vascular system

Vertebrates: lungs or gills

Three things needed: a big respiratory surface area (such as gills or lungs) a way for ventilating the respiratory surface area a circulatory system to move the gas throughout the rest of the body

Simplest respiration surface is the skin amphibians get almost all of their gas exchange through their skin nearly all animals gain some gas exchange through diffusing through the skin

Very small animals can do the necessary gas exchange using diffusion through their skin.

Bigger animals need to diffuse gases through their skin and use internal tissues such as lungs or gills.

Are split into thin layers of tissue H 2 O enters through mouth, exits through layers of gills O 2 from water diffuses into capillaries Blood flows opposite of the water flow

 Evolved from tiny pouches in the gut  Aquatic tetrads were essential in the transition from gills to lungs  Capillaries lace around lungs and circulates oxygen throughout body

 Carbon dioxide removal is necessary for maintaining a proper pH level in the bloodstream

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Neurons of the Medullary center set the pace for inhalation Control centers maintain the partial pressure of O 2 and CO 2 Chemoreceptors detect shifts in pH and signal the Medullary centers for regulation

So that too much oxygen or carbon dioxide buildup does not occur in the bloodstream

 Asthma-severe allergic reaction that cause the bronchioles to contract. Treated with inhalers, breathing machines, anti-inflammatory drugs.  Bronchitis – alveoli swell and clog with mucous and bronchioles swell. Treated with antibiotics, breathing machines, OTC cough suppressants.  Emphysema – lungs lose elasticity, alveoli are damaged, can not be cured.

 Pneumonia – alveoli filled with fluid. Treated with antibiotics.  Lung cancer – tumors in the lungs interrupt breathing. Treated with surgery, chemotherapy, radiation.  COPD- aka emphysema and chronic bronchitis, is a very serious disease, and the fourth leading cause of death in the United States. Treated with medication, rehabilitation, and sometimes surgery.

 "Breathing - Anatomy Video: MedlinePlus Medical Encyclopedia." National Library of Medicine - National Institutes of Health. Web. 12 Apr  "Gas Exchange - Anatomy Video: MedlinePlus Medical Encyclopedia." National Library of Medicine - National Institutes of Health. Web. 12 Apr  Lungs. Web..  "Respiration." Web..  "Respiratory System." American Medical Association - Physicians, Medical Students & Patients (AMA). Web. 12 Apr  "Respiratory System Function." National Heart, Lung and Blood Institute. Web. 12 Apr