Respiratory System

Respiratory System The job of your respiratory system is very simple. To bring oxygen into your body, and remove the carbon dioxide from your body. Your body needs oxygen to survive.

Development of Lungs The respiratory system lies dormant in the human fetus during pregnancy. At birth, the respiratory system becomes fully functional upon exposure to air, although some lung development and growth continues throughout childhood. Pre-term birth can lead to infants with under-developed lungs.

Development of Lungs These lungs show incomplete development of the alveolar type II cells, cells that produce surfactant. The lungs of pre-term infants may not function well because the lack of surfactant leads to increased surface tension within the alveoli.

Respiratory System As developed humans and other mammals, for example, the anatomical features of the respiratory system include airways, lungs, and the respiratory muscles. Molecules of oxygen and carbon dioxide are passively exchanged, by diffusion, between the gaseous external environment and the blood. This exchange process occurs in the alveolar region of the lungs.

Respiratory System Other animals, such as insects, have respiratory systems with very simple anatomical features, and in amphibians even the skin plays a vital role in gas exchange. Plants also have respiratory systems but the directionality of gas exchange can be opposite to that in animals. The respiratory system in plants also includes anatomical features such as holes on the undersides of leaves known as stomata.

Oxygen Oxygen is used by your cells as it performs the functions of life. As your body uses oxygen, your cells produce another gas known as carbon dioxide. Too much carbon dioxide can be toxic, even deadly. For this reason, it is important that your body have a way to get ride of it.

Oxygen Problems As gas exchange occurs, the acid-base balance of the body is maintained as part of homeostasis. If proper ventilation is not maintained, two opposing conditions could occur: respiratory acidosis, a life threatening condition, and respiratory alkalosis.

Human Respiration Works together with the circulatory system Exchange of gases between atmosphere, blood, and cells If respiratory system and/or circulatory system fails, death will occur Cells need O2 for work; release CO2 as a waste product Accumulation of excess CO2 is toxic to cells and MUST be removed

Breathe in….Breathe out The main organs in your respiratory system are your lungs. Your lungs are in their simplest form nothing more than sacks. As you breath in, you fill these sacs with fresh oxygen rich air. Your heart pumps blood into the walls of your lungs, where it absorbs oxygen, and releases carbon dioxide. As you exhale, or breath out, you release the carbon dioxide rich air into the space around you. Each breath you take, you are taking oxygen in, and putting carbon dioxide out.

Respiratory System Intakes oxygen Releases carbon dioxide waste Circulatory system Transports gases in blood between lungs and cells

Respiratory Structures and Organs

Respiratory Structures and Organs Nose – made of cartilage and bone and is designed to warm, moisten, and filter air as it comes into the system Pharynx – (throat) conducts food and air; exchanges air with Eustachian tube to equalize pressure

Respiratory Structures and Organs Larynx – (voice box) connects the pharynx and the trachea; made of cartilage; contains vocal cords Epiglottis – flap of tissue that covers trachea; ensures food travels down the esophagus

Trachea – (windpipe) tubular passage way for air; carries air to the lungs Bronchi – pair of tubes that branch from trachea and enter lungs; have cartilage plates; lining is ciliated & secretes mucus larynx trachea bronchi bronchioles

Respiratory Structures and Organs Bronchioles – tiny tubes lacking cartilage and cilia; possess smooth muscle bronchiole smooth muscle

Respiratory Structures and Organs Alveoli – cup shaped structures at the end of the bronchioles that resemble bunches of grapes; are in direct contact with capillaries (gas exchange);

Alveoli

Mechanics of Breathing Inhaling (active process) – Air moves in. Why?? Gases move from an area of high pressure to low pressure During inspiration – diaphragm pulls down and lungs expand When lungs expand, it INCREASES the VOLUME, which DECREASES the PRESSURE inside lungs Lung pressure is lower than outside pressure, so air moves in

Mechanics of Breathing Exhaling (passive process) – breathing out Diaphragm and muscles relax Volume in lungs and chest cavity decreases, so now pressure inside increases Air moves out because pressure inside is HIGHER than OUTSIDE atmosphere

Mechanics of Breathing Inhalation is initiated by the diaphragm and supported by the external intercostal muscles. Normal resting respirations are 10 to 18 breaths per minute, with a time period of 2 seconds. During vigorous inhalation (at rates exceeding 35 breaths per minute), or in approaching respiratory failure, accessory muscles of respiration are recruited for support.

Gas Transport in Blood Carbon dioxide 70% as bicarbonate ion (HCO3-) dissolved in plasma 23% bound to hemoglobin 7% as CO2 dissolved in plasma Oxygen 99% bound to hemoglobin 1% as O2 dissolved in plasma Carbon monoxide poisoning occurs because CO binds to hemoglobin more readily than O2

Control of Breathing Ventilation occurs under the control of the autonomic nervous system from parts of the brain stem, the medulla oblongata and the pons. This area of the brain forms the respiration regulatory center, a series of interconnected brain cells within the lower and middle brain stem which coordinate respiratory movements.

Control of Breathing rhytmicity center Breathing is regulated by the rhythmicity center in the medulla of brain Medulla stimulates inspiratory muscles (diaphragm & external intercostal muscles) rhytmicity center

Control of Breathing

Respiratory Disorders Four general areas of Respiratory Disorders: Obstructive conditions (e.g., emphysema, bronchitis, asthma attacks) Restrictive conditions (e.g., fibrosis, sarcoidosis, alveolar damage, pleural effusion) –overall this is the breakdown of connective tissues or organs that cannot repair itself.

Massive left-sided pleural effusion (whiteness) in a patient presenting with lung cancer.

Vascular diseases (e.g., pulmonary edema, pulmonary embolism, pulmonary hypertension) Infectious, environmental and other "diseases" (e.g., pneumonia, tuberculosis, asbestosis, particulate pollutants): Coughing is of major importance, as it is the body's main method to remove dust, mucus, saliva, and other debris from the lungs. Inability to cough can lead to infection. Deep breathing exercises may help keep finer structures of the lungs clear from particulate matter, etc.

Respiratory System Disorders Asthma – muscles of bronchioles constrict, drastically reducing ventilation Emphysema – destruction of alveoli Tuberculosis – highly contagious bacterial infection Lung cancer – 90% of lung cancer victims have a history of smoking

Facts about ETS Smoking causes 20% (or 1 in 5) of all deaths in the United States each year. In 1988, the U.S. Surgeon General reported that nicotine is just as addictive as heroin and cocaine. A "hit" of nicotine reaches the brain in seven seconds, twice as fast as heroin injected into the vein. There are over 19 known carcinogens in cigarette smoke.

Facts about Smoking More deaths are caused each year by tobacco use than by all deaths from human immunodeficiency virus (HIV), illegal drug use, alcohol use, motor vehicle injuries, suicides, and murders combined (CDC, 2008)

Facts about Smoking Compared with nonsmokers smoking increases the risk of— Coronary heart disease by 2 to 4 times Stroke by 2 to 4 times Men developing lung caner by 23 times Women developing lung cancer by 13 times Dying from chronic obstructive lung diseases by 12 to 13 times Source: (USDHSS, 2009)

After quitting smoking At 20 minutes after quitting: Blood pressure decreases Pulse rate drops Body temperature of hands and feet increases.

After quitting smoking At 8 hours: Carbon monoxide level in blood drops to normal Oxygen level in blood increases to normal

After quitting smoking At 24 hours: Chance of a heart attack decreases

After quitting smoking At 48 hours: nerve endings begin regrow

After quitting smoking Between 2 weeks and 3 months: Circulation improves Walking becomes easier Lung function increases The worst of nicotine withdrawal symptoms subside within the first month. Following that, the focus shifts to learning how to decipher and reprogram the psychological tugs or urges to smoke that we've all built up over the years.

After quitting smoking At One Year Smoke-Free: Your excess risk of coronary heart disease is decreased to half that of a smoker after one year.

Tips to Quit Pick a day in advance and prepare Have a buddy/support system Have PLENTY of gum or candy to keep your hand and mouth busy. The short temper will pass 21 days to change habits If you slip, don’t be discouraged…keep going Tomorrow is a new day