Respiratory Tract

Functions 1. Air Distribution 2. Gas Exchange • O2 supplied to cells, CO2 removed 3. Homeostasis • Types of Respiration • External respiration: exchange of gases between atmosphere and blood. Gas exchange 4. Filters, warms, & humidifies “air” 5. Speech/Sound production 6. Olfaction (smell) Respiratory Mucosa • Mucus membrane that lines the air distribution tubes – Air purification & filtration – 125 mL of mucus produced daily • Cilia – Hair-like structures – Move in 1 direction: pushes mucus out of lower tract, toward pharynx • Internal Respiration: exchange between blood and cells. Respiratory Mucosa Upper Respiratory Tract • • • • Lower Respiratory Tract Nose & Sinuses Oral Cavity Pharynx Larynx • • • • The Nose: Structure The Nose: Functions • Septum divides right & left sides • Sinuses: – Frontal (1) – Maxillary (2) – Sphenoid (3) – Ethmoid (4) 1 4 2 Trachea Bronchi Bronchioles Lungs/Alveoli • Warms & moistens inhaled air • Filters out some dust and debris • Sense organs of smell 3 Pharynx: Structure • Tube, ~ 5 inches long • 3 sections – Nasopharynx • Behind nasal cavity – Oropharynx • Behind oral cavity Pharynx: Structure • Tonsils – Masses of lymphatic tissue embedded in the mucus membrane – Palatine: in the oropharynx – Pharyngeal (adenoids): in nasopharynx – Lingual: behind tongue – Laryngopharynx • Leading into trachea Pharynx: Functions • Passage for air to the lungs • Passage for food & liquids to the esophagus Larynx: Structure • aka “Voice Box” – Vocal Cords: 2 fibrous bands across the larynx • Several pieces of cartilage – Epiglottis • Partially covers opening of larynx • Trapdoor action during swallowing to prevent food/liquid from entering the trachea – Thyroid cartilage: “Adam’s Apple” – Cricoid cartilage Larynx: Functions • Air passage • Voice production Trachea: Structure • C-shaped rings of cartilage hold the tube open • Ciliated mucous lining Trachea: Function • Passage for air to move to/from lungs • Obstruction can cause death in minutes! – More than 4,000 deaths in US each year – Heimlich maneuver can be used to free the trachea of obstruction Bronchi & Bronchioles: S Bronchi & Bronchioles: F • Bronchi: two branches from trachea: smooth muscle and cartilage lined with cilia and mucus. • Bronchioles: branch off bronchi; cilia and mucus • Air distribution; air moves to & from alveoli Alveoli: Structure Alveoli: Function • Single layer thick • Grape-like clusters • Exchange of gases between air & blood – Large surface area Lungs: Structure Diffusion • Fills most of the chest cavity (middle space for the heart) • Right has 3 lobes, Left has 2 • Pleura: moist, smooth, slippery membrane that reduces friction while breathing 3 things happen to the air we inhale: – Parietal pleura lines chest cavity – Visceral pleura covers lungs 1.oxygen is removed 2.carbon dioxide is added 3.water vapor is added Mechanism of Breathing Pulmonary Ventilation • Inspiration: moving air into lungs – Active process • Expiration: movement of air out of lungs – Passive process Regulation of Breathing • • • • • Controlled by brain Regulated by cell activity High CO2 = increase rate/depth Low CO2 = slower rate Can consciously override the brain temporarily Pulmonary Ventilation • Changes in size & shape of thorax cause changes in air pressure in the cavity – (Inspiration) Diaphragm flattens, increasing length of thorax, reducing pressure & drawing air IN to lungs – (Expiration) Diaphragm relaxes, decreasing size of cavity, increasing pressure & air leaves the lungs Common Respiratory Disorders Emphysema • Is a long-term, progressive disease of the lung that primarily causes shortness of breath • Involves the lung tissues necessary to support the physical shape and function of the lung being destroyed • Include: – emphysema – asthma – influenza – lung cancer – pneumonia – tuberculosis – carbon dioxide poisoning emphysema affects over three million people in the United States 31 Emphysema 32 Asthma • Makes the affected bronchioles unable to hold their shape properly when you exhale • Is primarily caused by cigarette smoking • Is treated with medications, surgery or transplantation • Is a chronic disease that affects your airways • Involves the inside walls of your airways being swollen due to an irritant • Cannot be cured, but can be controlled • Is treated with medication and inhalers three to six percent of the United States population has asthma 33 34 Lung Cancer Lung Cancer • Is a disease where tissue in the lung grows out of control • Can arise in any area of the lung • Is the most common form of cancerrelated death in men and the second most common in women • Can be treated with the removal of the affected area or chemotherapy lung cancer causes 1.3 million deaths per year 35 Pneumonia 36 Pneumonia • Is an illness of the lungs and respiratory system in which the alveoli become inflamed and flooded with fluid • Can result from a variety of causes, including: – infection with bacteria – viruses – fungi or parasites – chemical or physical injury to the lungs pneumonia is a leading cause of death among the elderly and people who are chronically and terminally ill 37 38 Pneumonia Tuberculosis • Occurs in all age groups • Is treated according to cause • Is a common and deadly infectious disease caused by mycobacterium • Attacks the lungs but can also affect almost any part of the body – if bacterial, it can be treated with antibiotics tuberculosis is commonly called consumption because it seems to consume people from the inside out 39 Tuberculosis 40 Carbon Dioxide Poisoning • Is spread through the air from one person to another • Can be found by a skin test • Is also called hypercapnia • Is a condition where there is too much carbon dioxide (CO2) in the blood • Is generally caused by hypoventilation, lung disease or diminished consciousness – placing a small amount of a substance under the skin and determining if a bump grows • Can be treated with medication the average American car releases 300 pounds of carbon dioxide into the air per tank of gas 41 42 Carbon Dioxide Poisoning • Can be caused by exposure to environments containing abnormally high concentrations of carbon dioxide (usually due to volcanic or geothermal causes) or by rebreathing exhaled carbon dioxide 43