RESPIRATORY SYSTEM EXCHANGE OF GASES PowerPoint® Lecture Slide Presentation by Robert J. Sullivan, Marist College RESPIRATORY SYSTEM EXCHANGE OF GASES Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.

What is Human Respiration? The human respiratory system allows one to obtain oxygen, eliminate carbon dioxide. Breathing consists of 2 phases: Inspiration- the process of taking in air Expiration- the process of blowing out air

Cellular Respiration O2 needed in conversion of glucose to cellular energy (ATP) in all body cells Carbon dioxide (CO2) is produced as a waste product The body’s cells die if either the respiratory or cardiovascular system fails = NO ATP!

Human Respiratory System Figure 10.1

Organs in the Respiratory System STRUCTURE FUNCTION nose / nasal cavity  warms, moistens, & filters air as it is inhaled pharynx (throat)  passageway for air, leads to trachea larynx  the voice box, where vocal chords are located trachea (windpipe)  keeps the windpipe "open"  trachea is lined with fine hairs called cilia which filter air before it reaches the lungs bronchi  two branches at the end of the trachea, each lead to a lung bronchioles  a network of smaller branches leading from the bronchi into the lung tissue & ultimately to air sacs alveoli  the functional respiratory units in the lung where gases are exchanged

Structures of Thoracic Cavity Cartilage rings support pressure from breathing & maintain open pathways of trachea and bronchi Pleural membranes(2) –fluid filled to reduce friction from movement Smooth muscle that relaxes and contracts (absence of cartilage) Figure 10.3

Bronchial tree (Brochi) Right main bronchus Each bronchus runs into a lung, behind pulmonary vessels (pulmonary artery/vein from heart) (Wikipedia)

Bronchial “tree” and associated Pulmonary arteries

Trachea and Brochi lined with Respiratory Mucosa Ciliated epithelium Scattered goblet cells – produce mucin (mucus) and watery fluid Macrophages - digestive enzymes, e.g. lysozyme Together all these produce a quart/day Dead junk is swallowed

smaller tubes, tubes smaller than 1 mm called bronchioles Bronchi divide into smaller tubes, tubes smaller than 1 mm called bronchioles Brochioles: tissue changes as becomes smaller Cartilage disappears No mucus or cilia in tissue of cells Smooth muscle - relaxation (“bronchodilation”) and contraction (“bronchoconstriction”)

Alveoli End-point of respiratory tree Structures that contain air-exchange chambers are called alveoli Respiratory bronchioles lead into alveolar ducts: walls consist of alveoli Ducts lead into terminal clusters called alveolar sacs – are microscopic chambers There are 3 million alveoli! Alveoli

Gas Exchange Between the Blood and Alveoli Figure 10.8A

Microscopic detail of alveoli Single layer thick- diffusion surrounded by fine elastic fibers Alveolar macrophages – free floating “dust cells”

Practice! Ch. 10 Gas Exchange: Free Response Questions #6 & #7 p. 180

Respiratory Cycle Figure 10.9

Smoking and Human Health Threats: Tar and carcinogens Carbon monoxide nicotine Passive smoking (2nd hand smoke)- breathing someone else’s smoke Atmospheric pollution and industrial emissions – lead to respiratory diseases

Chronic (long term) obstructive pulmonary diseases (COPD) Asthma Chronic bronchitis Emphysema

SEM image of alveoli normal emphysema

Chronic bronchitis - Tar stimulates goblet cells Destroys cilia; bacteria & viruses collect Smoker’s cough; pneumonia

Emphysema Inflammation of constantly infected lung causes phagocytes (white blood cells) to leave blood and line airways Release elastase which destroys elastin walls of alveoli (can’t stretch/recoil) Air is trapped, alveoli can burst Reduces surface area for gas exchange – less O2 in blood Wheezing, breathlessness, heart enlargement

Lung Capacity Figure 10.10A

Collapsed Lung

Lung Cancer Substances in tobacco smoke produce mutations in DNA of lung epithelial cells lose control of cell reproduction tumor Tumor can spread through lymphatic system and other parts of body = metastasis Coughing up blood = tissue damage

Smoker’s lung

Malfunctions & Diseases of the Respiratory System asthma severe allergic reaction characterized by the constriction of bronchioles  bronchitis inflammation of the lining of the bronchioles emphysema condition in which the alveoli deteriorate, causing the lungs to lose their elasticity pneumonia condition in which the alveoli become filled with fluid, preventing the exchange of gases lung cancer irregular & uncontrolled growth of tumors in the lung tissue

Cardiovascular Disease