The Respiratory System - Quia · PDF file · 2014-03-28Respiratory System! ......
Transcript of The Respiratory System - Quia · PDF file · 2014-03-28Respiratory System! ......
Respiratory System
! Lungs and air passages
! Takes oxygen in and removes carbon dioxide
! Carbon Dioxide is considered metabolic waste from cells, that occurs after cells convert food to energy
! Works continuously or death occurs in ���4–6 minutes
Respiratory Structures Nose Sinuses Pharynx—throat Larynx—voice box Trachea—windpipe Bronchi Alveoli Lungs
Respiratory System ! Nose: has 2 nostrils that
lead to the nasal cavities
! As air enters the cavity, it is warmed, filtered, and moistened
! The mucous membrane produces mucous that helps to trap pathogens and dirt
! Contains Cilia: hairlike structures that trap dirt
! Olfactory sensors are in the nose (sense of smell)
! Sinuses: Cavities in the skull around the nasal area
! Connected to nasal cavity by short ducts
! Lined with mucous membrane that warms and moistens air
! Provides resonance for the voice
Respiratory Structures
! Pharynx or throat: Lies directly behind the nasal cavities
! As air leaves the nose it enters the pharynx
! 3 sections:
! Nasopharynx: upper portion behind nasal cavities
! Adenoids and auditory tube openings are here
! Oropharynx: Middle section located behind the oral cavity
! Receives air from nasopharynx and food and air from mouth
! Laryngopharynx: Bottom of pharynx
! Branches in to trachea, which carries air to and from the lungs, and the esophogus that carries food to the stomach
Respiratory Structures
! Larynx: Voice Box
! Lies between pharynx and trachea
! Has framework of cartilage commonly known as the Adam’s apple
! Contains two folds called vocal cords
! Opening between the vocal cords is the glottis
! Epiglottis: piece of cartilage that closes the opening during swallowing to prevent food from entering the lungs
! Trachea: wind pipe
! Tube extending from larynx to center of chest
! Carries air between pharynx and bronchi
! Series of C-shaped cartilage that are open at the back to allow them to flex
Respiratory Structures
! Bronchi:
! 2 divisions of trachea near the center of the chest, right and left bronchus
! Each bronchus enters the lung and carries air from the trachea to the lung
! Inside the lungs, the bronchus divide in to smaller and smaller branches called bronchioles
! Smallest bronchioles end in air sacs called alveoli
! Alveoli: Air sacs that resemble a bunch of grapes
! Adult lung contains approximately 500 million alveoli
! Contains a rich network of blood capillaries
! Capillaries allow oxygen and carbon dioxide to be exchanged between blood and lungs
! Inner surface of alveoli is covered with surfactanct
! Lipid substance
! Helps prevent alveoli from collapsing
Respiratory Structures
! Lungs: Organs that containing divisions of alveoli and bronchi
! Right lung has 3 sections, or lobes: superior, middle, and inferior
! Left lung is smaller because of the heart being on the same side
! Pleura: membranes or sac enclosing each lung
! Consists of 2 layers of membrane:
! Visceral Pleura: outside of lung
! Parietal Pleura: chest wall
! Pleural space: Located between the 2 layers
! Filled with a thin layer of fluid that lubricates the membranes and prevents friction as lung expand for breathing
Ventilation
! Process of breathing:
! Inspiration—inhalation: taking air in the lungs ! Diaphragm and intercostal muscles in chest wall contract to expand
rib cage for lungs to fill with air: gas exchange occurs in alveoli
! Expiration—exhalation: air leaves lungs ! Diaphragm and intercostal muscles relax: air is forced out of lungs
Respiration
! Process of respiration is controlled by the medulla oblangata
! This process is typically involuntary, however, people can control breathing faster or slower
! A decreased amount of oxygen as seen in certain diseases (asthma, CHF, & emphysema) or increased CO2 will cause the center in increase respiration
! External Respiration: Exchange of O2 and CO2 between lungs and blood stream
! Internal Respiration: Exchange of CO2 and O2 between cells and blood stream