The Respiratory System Section 37-3 Pages 956-963

Respiration Process of gas exchange The release of carbon dioxide and the Uptake of oxygen between the lungs and the environment

Function To exchange oxygen & carbon dioxide between the blood, the air, and tissues

Structures Nose & mouth Pharynx Larynx Epiglottis Trachea Bronchi lungs

carbon dioxide exchange at Flowchart Movement of Oxygen and Carbon Dioxide In and Out of the Respiratory System Section 37-3 Nasal cavities Oxygen-rich air from environment Pharynx Trachea Bronchi Oxygen and carbon dioxide exchange at alveoli Bronchi Bronchioles Alveoli Bronchioles Nasal cavities Carbon dioxide-rich air to the environment Trachea Pharynx

Cilia & Mucus To keep lung tissue healthy, air entering the body must be warmed, moistened, & filtered Mucus – moistens air & traps particles of dust and/or smoke Cilia – sweeps trapped particles & mucus away from lungs & pharynx Mucus & tapped particles are either swallowed or spit out This process keeps the lungs clean & open for gas exchange

Hemoglobin Oxygen-carrying protein in blood When blood goes into the lungs, the hemoglobin picks up oxygen and carries it to all the tissues in our body It binds with so much oxygen that it increases the oxygen-carrying capacity of blood more than 60 times

Breathing – movement of air into & out of lungs Breathing – movement of air into & out of lungs - no muscles connected to lungs - air pressure drives air into & out of lungs Air exhaled Air inhaled Rib cage descends Rib cage rises Diaphragm Diaphragm Inhalation Exhalation

How Breathing is Controlled Only have partial control over breathing Medulla Oblongata controls breathing Autonomic nerves are connected to diaphragm & chest muscles They automatically stimulate them to contract to allow for breathing Medulla Oblongata monitor CO2 levels - when levels get high – send message to breath

Tobacco & the Respiratory System Dangerous substances in tobacco: 1. Nicotine – stimulant drug, increases heart rate & blood pressure 2. Carbon Monoxide – poisonous gas that blocks the transport of oxygen by hemoglobin in blood - decrease blood flow to tissues - deprives heart & tissue of oxygen needed to function 3. Tar – contains compounds known to cause cancer

Effects on Respiratory System Nicotine & Carbon Monoxide paralyze cilia Unable to moved particles out of lungs So particles stick on lungs & walls of trachea Mucus becomes trapped in airways Causes “Smokers Cough” Leads to respiratory diseases

Diseases Caused by Smoking Bronchitis – swollen & clogged bronchi - unable to do simple activities without loss of breath Emphysema – loss of elasticity of lungs - unable to get enough air into lungs - not enough oxygen gets to tissues - unable to do any physical activities Cancer – 160,000 people diagnosed every year - once diagnosed usually die within 5 years - preventable by not smoking - lung cancer can spread to other areas in body Heart Disease – smoking causes blood vessels to narrow – which causes the heart to work harder & rises blood pressure - leads to heart attack & damage to heart tissue

Smoking & the Nonsmoker Tobacco smoke is dangerous to anyone who inhales it – even if you do not smoke Passive Smoking – inhaling smoke of others - damaging to kids - lungs still developing – damage is greater - kids of smokers are twice as likely to develop respiratory problems like asthma than kids of nonsmokers

Dealing With Tobacco No matter what age or the length of time a person smoked – they can improve their health by quitting Lungs can heal themselves as long as the tissue is not completely damaged Smoking is hard to quit because of Nicotine – it is a very additive & powerful drug So best solution is to not start to smoke in the first place