The Respiratory System

 The cardiovascular system and the respiratory system are responsible for supplying the body of oxygen and disposing of carbon dioxide  Respiratory system deals the gas exchange  Cardiovascular system deals with transportation Organ System Connections

 Organs of the respiratory system (in order of air passage)  Nose/Mouth  Pharynx  Larynx  Trachea  Bronchi and their smaller branches  Lungs and alveoli Functional Anatomy

 Air enters the nose by passing through the nostrils  Separated by a nasal septum  The interior of the nose is called the nasal cavity  Lined with respiratory mucosa  Rests on a rich network of thin-walled veins that function to warm the air as it flows past  These are what cause nosebleeds Nose

 Review  True or false: This organ is a part of the digestive system and the respiratory system  TRUE! Remember: the pharynx is for PHood, PHluids, AND air Pharynx

 “Voicebox”  Formed by 8 rigid hyaline cartilage rings  The epiglottis is also located in this organ and separates the larynx from the esophagus  What was the epiglottis again?  Flap of cartilage that prevents food from “going down the wrong tube” Larynx

 “Windpipe”  Walls are reinforced with C- shaped rings of hyaline cartilage  Dual functions  The open part of the C allows the esophagus to expand anteriorly when we swallow  The solid portions keep it open during the pressure changes that occur during breathing Trachea

 There are 2 main bronchi plus many pairs of shorter branching bronchioles Bronchi

 Flank the heart  Lungs are covered with serous membrane  Visceral pleura  Parietal pleura  Pleural fluid in between (basically plain old serous fluid)  Sound familiar? This is JUST like how the heart is set up! Lungs

 The primary bronchi (the two main branches) enter the lungs and then subdivide into smaller and smaller branches  Called bronchioles  The terminal set of bronchioles lead into respiratory zone structures  Eventually terminate into alveoli, small air sacs Lungs

 The walls of the alveoli are composed of a single, thin layer of squamous epithelial cells  External surface of the alveoli are covered with a “cobweb” of pulmonary capillaries  Alveoli + capillary walls = respiratory membrane  Air (containing gases) flows past on one side and blood flows on the other side  This is also known as the air-blood barrier Lungs: Alveoli

 Gas exchange  Oxygen passes from the alveolar air into the capillary blood  Carbon dioxide leaves the blood to enter the gas- filled alveoli Gases

 Respiratory zone  Includes respiratory bronchioles and alveolar sacs  Conducting zone  All other respiratory zone structures Zones

 List the organs that are considered to be in each zone  Respiratory zone:  Bonchioles, alveoli  Conducting zone:  Nose, pharynx, larynx, trachea, bronchi Zones

 Diaphragm: muscle that helps to inflate the lungs Accessory Organ