Respiratory System. December 20, 2011

Transcription

1 Respiratory System December 20, 2011

2 Nasal Cavity: Contains cilia (hair cells) to prevent particles from entering the respiratory tract Mucus does the same, in addition to warming and moistening the air Pharynx: (Throat)

3 Trachea: Also contains mucus and cilia Debris swept back into pharynx Supported by bands of cartilage Epiglottis: Covers the glottis (opening of trachea) Reflex action closes the epiglottis when eating / drinking Trachea Sample Larynx: Enlarged segment of tracheal cartilage (Adam's Apple) AKA: Voice box Contains two thin sheets of elastic ligaments (vocal cords) The larger the larynx, the deeper the voice (ex. puberty, inflammation etc)

4 Bronchi: Also contain cartilage Branch to L and R lungs Bronchioles: No cartilage Smooth muscle in walls of bronchioles (like arteries) that can constrict / dilate Alveoli: 0.1 to 0.2 um in diameter Site of gas exchange O2 and CO2 diffuse along concentration gradient across a single layer of cells Alveoli contain fat & lipoproteins which lubricate the alveoli reducing surface tension and allowing them to open easily. Premature babies sometimes lack this protein and extreme force is required to overcome the surface tension - Respiratory Distress Syndrome (RDS)

5 Pleural Membrane A double fluid-filled membrane that lines the outer surface of the lungs & inner wall of the thoracic cavity. Breathing Movements Inhalation & Exhalation depend on differences in air presure Gases move from high pressure areas to lower pressure areas

6 Breathing Movements Pressure depends on the actions of the diaphragm and intercostal muscles December 20, 2011 Lung Demo

7 Pneumothorax Air enters the pleural cavity and it becomes mechanically impossible to inflate the lung: - can be open (from the outside) or closed (from the lung) Hiccups Spasms in the diaphragm cause hiccups. Charles Osborne, of the USA, hiccuped for 68 years from 1922 to 1990 (Guiness World Record holder) In 2007 a teenager in Florida hiccuped around 50 times a minute for more than 5 weeks (believed to have been caused by Tourette's Syndrome)

8 Lung Volumes Tidal Volume: air inhaled / exhaled in each regular breath (approx. 500 ml) Inspiratory Reserve Volume: air that can be inhaled above TV (greater in athletes due to stronger respiratory muscles) Expiratory Reserve Volume: air that may be exhaled following normal expiration Residual Volume: volume in lungs after maximal exhalation Vital Capacity: volume difference between maximum exhalation and maximum inhalation.

9 Class Lab - using your text, complete procedure steps 1-7 on page 251. Record your results on the computer. Complete Analysis & Conclusions questions as well as well as application question #7 for homework. Class Spreadsheet Regulation of Breathing Controlled by CO 2 chemoreceptors in the medulla oblongata (brain) high CO 2 normal CO 2 low CO 2 Some drugs like morphine, barbiturates, marijuana etc make these receptors less sensitive. Back-up O 2 sensors are located in the Aorta & Carotid Arteries

10 December 20, 2011 Oxygen and Carbon Dioxide Transport - O2 dissolves into blood plasma and is then picked up by hemoglobin. - CO2 is transported in the following ways: - 9% dissolved in plasma - 27% binds to deoxygenated hemoglobin forming carbaminohemoglobin - 64% combines with water from plasma to form carbonic acid (H CO ) 2 3 Respiratory Health - Air quality and personal lifestyle are the two biggest factors.

11 Bacterial & Viral Infections Tonsilitis Bacterial & Viral Infections Laryngitis

12 Bacterial & Viral Infections Acute Bronchitis (Short Term) Pneumonia - can be caused by bacteria, viruses, or fungi - results in abnormal filling of the alveoli - cough, chest pain, difficulty breathing, fever - a leading cause of death of children under 5 and seniors

13 Pleurisy - an inflammation of the pleural membranes - pain during each breath, extreme pain while coughing or sneezing - can be caused by bacteria or by injury Emphysema / COPD - structures of the lungs are damaged preventing air exchange - caused by smoking, genetic deficiency, or air pollution - barrel chested, shortness of breath, difficulty breathing

14 Cystic Fibrosis - genetic condition resulting in increased mucus production in the digestive system and lungs - increased mucus in lungs leads to increased bacteria and more frequent lung infections Asthma

15 Smoking & Lung Cancer December 20, 2011