RESPIRATORY SYSTEM Madison Martin and Heather Handberry 3 rd Cook

FUNCTION OF THE RESPIRATORY SYSTEM  The Respiratory System includes the nose, pharynx, larynx, trachea, bronchi and their smaller branches, and the lungs, which contain the terminal air sacs.  The basic structure of the Respiratory System is to take in oxygen and expel carbon dioxide.

LARYNX  The larynx, also called the “voice box” routes air and food into the proper channels and plays a role in speech.  It is located inferior to the pharynx.  Formed by 8 rigid hyaline cartilages ad a spoon shaped flap of elastic cartilage.

PHARYNX  The pharynx is a muscular passage way about 13 cm long that looks like a red garden hose.  Commonly called the “throat”  This cavity is behind the nose and mouth, connecting them to the esophagus.

BRONCHI  The bronchi are main passage ways into the lungs.  It is split into the right and left bronchi and form the division of the trachea.  The right is shorter, straighter, and wider than the left.  When air reaches the bronchi it is warm, cleansed of its impurities, and well humidified.

TRACHEA  The trachea is more commonly known as the “wind pipe”.  Air entering the trachea travels down its length (10-12 cm, or about 4 in) to the level of the 5 th thoracic.  It is fairly rigid because its walls are reinforced with c-shaped rings of hyaline cartilage.

SINUS  Nasal cavity is surrounded by a ring of paranasal sinuses located in the frontal, sphenoid, ethmoid, and maxillary bones.  Lightens skull and acts as resonance chambers for speech.  Produces mucus  Basically air filled cavities in cranial bones surrounding nasal cavity.

ALVEOLI  Microscopic chambers at termini of bronchial tree.  Special alveolar cells produce surfactant.  Main sites of gas exchange  Helps to prevent lung collapse

DIAPHRAGM  Primary muscle used in the process of inhalation.  Separates abdominal cavity from the thoracic cavity.  Contraction of this muscle expands the lungs during inspiration when one breaths.

TIDAL VOLUME  When breathing at a normal rate it moves 500 ml air into and out of the lungs  Tidal volume is the lung volume representing the normal volume of air displaced between each inhale and exhale.

INHALATION  Action of inhaling or breathing in.  Involves contraction of diaphragm and muscles in thoracic cavity, it expands creating a negative pressure.

INSPIRATORY RESERVE VOLUME  This is the amount of air that can be taken in forcibly over the tidal volume.  Volume is typically between 2100 and 3200 ml.

EXPIRATORY RESERVE VOLUME  This is the amount of air than can be forcibly exhaled after a tidal expiration.  Approximately 1200 ml.

RESIDUAL VOLUME  No matter how hard you try, 1200 ml of air stays in your lungs.  It is important because it allows you exchange continuously and helps to keep the alveoli open (inflated)

REVIEW 1.The respiratory system includes the stomach. T/F 2.The pharynx is also called the “voice box”. T/F 3.The bronchi are main passage ways into the lungs. T/F 4.The diaphragm is the primary muscle used for exhalation. T/F 5.The alveoli are the main sites of gas exchange. T/F 6.The sinus does NOT produce mucus. T/F 7.The sinus lightens skull. T/F 8.The trachea is more commonly known as the “wind pipe”. T/F 9.The larynx is superior to the pharynx. T/F 10.When breathing at a normal rate it moves 800 ml of air into and out of the lungs (tidal volume) T/F