Pulmonary Apparatus and Chest Wall

Pulmonary Apparatus and Chest Wall

1. chest wall

   • Rib cage
     • ribs and costal cartilage
     • sternum
     • pectoral girdle
     • vertebral column (thoracic)
     • Muscles of Rib Cage Wall
       • muscles of anterolateral neck
         • Sterno Cliedo Mastoid
           • origin- sternum and clavicle
           • insertion- mastoid process of skull
           • function- unilateral contraction, brings sternum and clavicle closer to mastoid process
             • innervation- Cranial nerve 11 accessory nerve
           • Class 1 Lever
             • bilateral contraction, flexes neck, raises sternum
         • Anterior Scalene
           • origin- C3-C6 vertebrae (cervical)
             • insertion- 1st rib
           • function- flexes neck forward and laterally into and out of lungs
           • innervation- 4th-6th Cervical spinal nerves
         • Middle Scalene Muscle
           • origin- C2-C7 vertebrae
           • insertion- 1st rib
           • same function as ASM
           • innervation- 3rd cervical spinal nerves
             • Lever type 3
         • Posterior Scalene
           • origin- C4-C6 or C7
           • insertion- 2nd rib
           • function- rotate neck, raise 2nd rib
           • innervation- 6th-8th cervical spinal nerves
       • muscles of anterolateral chest
       • muscles of posterior neck
   • Superficial
     • pectoralis major
       • origin- medial half of clavicle, ribs 2-6, sternum, aponeuroses of external oblique
       • insertion- humerus
       • function- adduct and rotate arm medially, raises ribs 2-6, and raises sternum
     • pectoralis minor
       • origin- scapula
       • insertion- rib 2-5
       • functions- protracts scapula, elevates ribs 2-5
       • innervation- medial pectoral nerve (8th cervical and 1st thoracic spinal nerves
     • serratus anterior
       • origins- ribs 1-8 or 9
       • insertion- scapula
       • innervation- long thoracic nerve (5th-7th Cervical spinal nerves
       • functions- protracts and rotates scapular, rely on muscle to hold close to thoracic wall
   • Deep
     • diaphragm
       • Muscles of diaphragm
         • central tendon
           • origins at xiphoid process of sternum, cartilage of ribs 7-12 and upper lumbar vertebrae
           • flattens when it contracts, increases volume of thoracic cavity controlled by phrenic nerve (3rd-5th Cervical spinal nerves
     • external and internal intercostals
       • occupy spaces between ribs (11)
       • downward and medially
       • innervated by intercostal muscles
         • function- muscles of inhalation and raise and lateralize ribs
       • deep to external
         • interosseous- stiffen spaces between ribs and lower ribs
           • raise ribs
     • transverse thoracic
       • origin- sternum, xiphoid process, cartilage of ribs 5-7
       • insertion- ribs 2-6
       • innervation- intercostal muscles

2. diaphragm

   • shaped like inverted bowl (open parachute)
     • separates thorax from abdomen, flexible

3. Abdominal Wall

   • abdominal muscles
   • connective tissues
   • vertebral column (lumbar, sacral, coccygeal)
   • pelvic girdle
   • abdominal Contents:
     • stomach
     • intestines
     • internal organs
     • compressible- creates pressure in abdominal cavity- intra-abdominal pressure
       • make it possible to shunt pressure between rib cage and abdomen