Chapter 16 Respiratory System Function – supply oxygen to & eliminate carbon dioxide from lungs

Thoracic Cage Ribs Sternum Costal cartilages Thoracic vertebra Top – clavicle Bottom – diaphragm Sternum – manubrium, body, xyphoid 12 pairs of ribs – 7 true, 3 false – costal cartilage to rib 7, 2 floating

Joints and Articulations – Costovertebral Joints Facet Demifacet Costovertebral & Costotransverse Joints – nonaxial, diarthrodial, gliding joints (costocartilage joints also this type) - Ribs attachment to thoracic spine

Movements of the Thorax Elevation Depression Elevation – inspiration; up & out; increase medial/lateral diameter; bucket handle Depression - - expiration; down & in; decrease medial/lateral diameter; Pump handle – change in anterior/posterior diameter

Structures of Respiration Nose Nasal cavity Oral cavity Pharynx Larynx Trachea Main stem bronchi Lobar bronchi Bronchioles Alveolus All made of cartilage material Upper respiratory tract – nose to larynx; pharynx = throat; larynx = voice box; larynx = anterior to C4-C6 Lower Respiratory tract – trachea to alveoli; - trachea- C6-T4 - R & L main stem bronchi - Lobar bronchi – 3 R & 2 L - Bronchioles - Alveolus

Mechanics of Respiration Inspiration Expiration Pressure Change – air will flow from areas of higher pressure to areas of lower pressure Inspiration – thoracic cavity increases which decreases pressure, causing air to flow in Expiration – thoracic cavity decreases in size, causing pressure to increase, causing air to flow out

Phases of Respiration/Breathing Quiet inspiration Deep inspiration Forced inspiration Quiet expiration Forced expiration Quiet inspiration – resting; diaphragm & external intercostals Deep inspiration – breathing harder; may recruit some accessory muscles Forced inspiration – air hunger; use of accessory muscles Quiet expiration – relaxing diaphragm; passive; no muscle action Forced expiration – use of accessory muscles

Muscles of Quiet Respiration Diaphragm External intercostals Internal intercostals 2 ways to change thoracic volume: Move ribs Lower diaphragm Diaphragm – descends when it contracts; lowers 4” External Intercostals – elevate ribs by pulling up on inferior one; V shaped anteriorly; inverted V shape posteriorly Internal Intercostals – depress ribs by pulling down on superior one; inverted V shape anteriorly; V shaped posteriorly - Orientation of muscles same as obliques anteriorly

Accessory Inspiratory Muscles Sternocleidomastoid Scalenes Pectoralis Major - Accessory muscles work in a reversal of muscle action – hands on hips – CKC breathing; allows pectoralis major to pull sternum to humerus

Accessory Expiratory Muscles Rectus abdominus Quadratus lumborum Pull down on rib cage; reversal of muscle action; Rectus abdominus – sternum to pelvis Quadratus Lumborum – ribs to iliac crest; Transverse Abdominus – forces air out by compression (coughing) Tables 16.1 & 16.2 page 243

Respiratory System Anatomical relationships Diaphragmatic versus chest breathing Summary of innervation of the muscles of respiration Valsalva’s maneuver Diaphragmatic breathing – most efficient; least energy expenditure; easiest in standing or sitting with gravity assisted Chest Breathing – requires more effort and more energy; smaller volume of air is produced with more rapid breathing Innervation – diaphragm = phrenic nerve C3-C5 Valsalva – increases BP & HR with a reflexive decrease in HR; may lead to cardiac arrest

Common Respiratory Conditions or Pathologies Upper respiratory infection Pneumonia Bronchitis Emphysema Asthma Pleurisy Pneumothorax URI – nose, throat, larynx; cold, flu Pneumonia – LRI; inflammation of alveoli caused by bacterial or viral infection Bronchitis – LRI Emphysema – LRI – chronic bronchial obstruction; lose elasticity of alveoli Asthma – LRI – spasm of bronchial walls; difficult exhalation Pleurisy – inflammation of pleura Pneumothorax – collapsed lung Stitch – cramp of diaphragm Hiccups – spasm of diaphragm Rib Pathology Separation – between ribs & cartilage Dislocation – cartilage from sternum Flail chest – 4+ ribs fractured – collapsed chest wall