Respiratory System Chapter 23

Superficial To Deep  Nose  Produces mucus; filters, warms and moistens incoming air

Superficial To Deep  Pharynx  Passageway for air and food

Superficial To Deep  Larynx  Air passageway; prevents food from entering lower respiratory tract  Houses vocal cords

Superficial To Deep  Trachea  Air passageway; cleans, warms and moistens incoming air

Superficial To Deep  Pleurae  Produce lubricating fluid and compartmentalizes lungs

Superficial To Deep  Lungs  House passageways of bronchial tree and alveoli

Superficial To Deep  Bronchial Tree  Air passageway connecting trachea with alveoli; warms and moistens incoming air

Superficial To Deep  Alveoli  Main sites of gas exchange

Who is the Main Player?  ALVEOLI  Site of gas exchange  Oxygen and Carbon Dioxide

Inspiration and Expiration  Atmospheric pressure at sea level is equal to 760 mmHg.  In order to inhale, pressure inside the lungs must decrease by at least 1.

Inspiration and Expiration  Inspiratory muscles contract (diaphragm descends; rib cage rises)

Inspiration and Expiration  Thoracic cavity volume increases

Inspiration and Expiration  Lungs stretched; intrapulmonary pressure drops

Inspiration and Expiration  Intrapulmonary pressure drops (at least 1 mmHg relative to the atmosphere)

Inspiration and Expiration  Air (gases) flows into lungs down its pressure gradient until intrapulmonary pressure is 0 (equal to atmospheric pressure)

Inspiration and Expiration  In order to exhale, pressure must be greater in the lungs than outside.

Inspiration and Expiration  Inspiratory muscles relax (diaphragm rises; rib cage descends due to gravity)

Inspiration and Expiration  Thoracic cavity volume decreases

Inspiration and Expiration  Elastic lungs recoil passively; intrapulmonary volume decreases.

Inspiration and Expiration  Intrapulmonary pressure rises (at least 1 mmHg relative to the atmosphere)

Inspiration and Expiration  Air (gases) flows out of lungs down its pressure gradient until intrapulmonary pressure is 0

Inspiration and Expiration  Intrapleural pressure is always  -4mmHg compared to intrapulmonary pressure  Pleural fluid secures the pleurae together, similar to two slides held together by water.

Inspiration and Expiration  The importance of the negative pressure is:  Any condition that equalizes the intrapleural pressure with intrapulmonary pressure (or atmospheric) causes lung collapse.

Inspiration and Expiration  The presence of air in the intrapleural space is called pneumothorax  One lung can be fine and the other be collapsed since they are in separate cavities

Structure and Function  External respiration, or ventilation, brings oxygen into the lungs  Internal respiration exchanges oxygen and carbon dioxide between blood and body cells  Cellular respiration changes acid produced during metabolism into harmless chemicals in the cells

Mechanics of Breathing

Following the Inhalation Process  Air enters the respiratory system through the nose or mouth  Air from the nose or mouth is then funneled through the throat and into the trachea  The trachea branches into two tubes called bronchi

Following the Inhalation Process  Each bronchus enters one of the lungs and then branches into smaller tubes called bronchioles  The bronchioles have small sacs at their ends called alveoli  Capillaries in the walls of the alveoli exchange oxygen and carbon dioxide by the process of diffusion

Assessment Techniques  Rate  The normal rate of respiration varies with age, gender, posture, exercise, temperature, and other factors  Character  Respirations should have a regular rhythm, occurring at regular intervals  Sounds  Breath sounds can be heard by using a stethoscope

Assessment Techniques (continued)  Lung volume  The amount of air that can be brought into the lungs is called respiratory capacity  Blood gases  Studies measure how much oxygen (O 2 ) and carbon dioxide (CO 2 ) are in the blood, the blood's pH and other gases

Respiratory Capacity

Disorders of the Respiratory System  Anthrax  Caused by spores of the bacterium  Asthma attack  May result from exposure to an allergen, cold temperature, exercise, or emotion  Atelectasis  A collapse of part or all of a lung, caused by a tumor in the thoracic cavity, pneumonia, or injury

Disorders of the Respiratory System (continued)  Bronchitis  An infection of the bronchi  Carbon monoxide poisoning  Occurs from breathing carbon monoxide  Chronic obstructive pulmonary disease  A group of chronic respiratory disorders including asthma, chronic bronchitis, and pulmonary emphysema

Disorders of the Respiratory System (continued)  Cold  A respiratory infection  Cystic fibrosis  A genetic disorder of the exocrine glands  Emphysema  The alveoli lose elasticity and become dilated and do not exchange gases well

Disorders of the Respiratory System (continued)  Hay fever  A respiratory inflammation caused by allergens such as plants, dust, and food  Lung cancer  Directly linked to smoking and smoke products

Disorders of the Respiratory System (continued)  Pleural effusion  A condition in which air or fluid enters the pleural cavity  Pleurisy  An inflammation of the membranes that line the lungs  Pneumonia  An inflammation of the lungs, in which a buildup of excessive moisture impairs breathing

Disorders of the Respiratory System (continued)  Respiratory distress syndrome  A condition that occurs when the alveoli do not inflate properly  Sinusitis  An inflammation of one or more of the paranasal sinuses  Sudden infant death syndrome (SIDS)  A respiratory disorder of newborns

Disorders of the Respiratory System (continued)  Tuberculosis  Caused by bacteria that are difficult to destroy, and it can be transmitted through the air  Upper respiratory infection  Caused by a virus or bacteria in the nose, pharynx, or larynx