Anatomy Test

• Nasal airflow pathway

  Passes through the vestibular area of the nasal cavity along the nasal vestibule, then enlarges into the nasal fossa containing the conchae in the lateral walls. Air passes through the meati, inferior to the respective conchae, increasing the surface area. Posterior to the nasal fossa is the nasopharynx, containing the opening of the Eustachian/auditory tube and the tubal and pharyngeal tonsils. Air passes from the nasopharynx to the oropharynx to enter the larynx. Air passes through the five spaces of the larynx (laryngeal vestibule, rima vestibuli, laryngeal ventricle, rima glottidis, infraglottic space) to enter the trachea
• Floating ribs have no articulation with the transverse vertebral process. The exit of the thorax can enlarge laterally during deep inspiration to accommodate upper abdomen
• Difference in rib shape between baby and adult

  Influences the manner of respiration; babies and pregnant women use only diaphragmatic respiration, while adults use diaphragmatic and intercostal respiration. People in old age usually use diaphragmatic respiration due to decreased extrinsic thoracic compliance
• Ribs of a baby have one uniform curve, no angle, and lie horizontally. The rib of an adult has two curves, two angles, and the axis is twisted so that the anterior end lies lower than the posterior end. Gravity changes the position of the anterior ends as the child assumes an increasingly more erect posture
• It is difficult to feel the 12th rib of a patient/person because the erector spinae muscle covers it, especially if a short 12th rib is present. Usually, the pleural cavity is in danger at the costovertebral angle. The whole inferior pleural cavity is in danger when the 11th rib is mistaken for the 12th during a procedure like a biopsy of the kidney
• Vertebral articulation of the floating ribs

  Floating ribs have no articulation with transverse vertebral process. The exit of the thorax can enlarge laterally during deep inspiration to accommodate upper abdominal organs, pressed down by diaphragm
• Insertion of a chest tube

  Simulate how to correctly place an intercostal drain to the pleural cavity by identifying and listing sequentially the structures penetrated by the needle when placed just anterior to the midaxillary line, 6th intercostal space into the pleural cavity
• Suprapleural membrane (Sibson’s fascia) serves to withstand pressure changes preventing the structures in the neck’s root from being drawn into the thoracic cavity during inspiration
• Structures penetrated by the needle at the right and left side in the midaxillary line, 8th intercostal space


  Right: Costal pleura, Pleural cavity, Lung during deep inspiration, Diaphragmatic pleura, Diaphragm, Liver | Left: Costal pleura, Pleural cavity, Lung during deep inspiration, Diaphragmatic pleura, Diaphragm, Spleen or stomach
• Structures deep and anterior to the 11th and 12th ribs

  • Right: Subcostal neurovascular bundle, Costodiaphragmatic recess and pleura, 11th rib: right adrenal gland and liver, 12th rib: right kidney, Lung during deep inspiration | Left: Subcostal neurovascular bundle, Costodiaphragmatic recess and pleura, 11th rib: upper pole of left kidney and adrenal gland and spleen, 12th rib: left kidney, Lung during deep inspiration
• Increase in thoracic dimensions enlarging the thoracic volume during deep inspiration

  1. Scaleni muscles elevate the thoracic cavity

  2. Quadratus lumborum stabilizes and lowers the 12th ribs, facilitates diaphragm action

  3. Intercostals contribute to the "Bucket-handle" effect

  4. Serratus anterior and sternocleidomastoid contribute to the "Pump-handle" effect
• Nasal flaring is a symptom of breathing difficulties or an attempt to widen the nasal opening to reduce airway resistance
• Structures making expiration possible

  • Gravity
  • Relaxation of inspiratory muscles
  • Thoracic compliance
  • Elastic recoil of rib cartilages
  • Pulmonary compliance
  • Elastic recoil of lung tissue
  • Internal & innermost intercostals
  • Subcostal
  • Transversus thoracic
  • Abdominal muscles (Internal obliques, transverse abdominis)
  • Rectus abdominis
  • External oblique
• Division and structures in each part of the mediastinum

  1. Superior mediastinum: Trachea, Aortic arch, Brachiocephalic trunk, Left common carotid artery, Left subclavian artery, Superior vena cava, Azygos vein, Ligamentum arteriosum, Left recurrent laryngeal nerve

  2. Middle mediastinum: Pulmonary trunk, Pulmonary arteries, Phrenic nerve

  3. Posterior mediastinum: Esophagus, Sympathetic trunk, Vagus nerve, Descending thoracic aorta

  4. Intercostal spaces
• Anatomical basis for thoracoabdominal rhythm: anterior abdominal muscles relax during inspiration to facilitate diaphragm contraction
• Mechanisms of movement of the thoracic wall that changes the diameter/volume of the thoracic cage

  1. "Piston" effect by the diaphragm

  2. "Bucket-handle" effect by external intercostals, pectoralis major, pectoralis minor

  3. "Pump-handle" effect by serratus anterior, sternocleidomastoid
• Levator costarum assist with inspiration by lifting the ribs
• Thoraco-abdominal rhythm in a relaxed person lying on his back reflects primarily the action of the diaphragm driving both thoracic and abdominal movements
• Accessory respiratory muscles like sternocleidomastoid or scalenes indicate respiratory stress
• Widening of the nostrils and use of accessory respiratory muscles can indicate respiratory stress
• Re-identify structures in the mediastinum

  1. Phrenic nerve

  2. Vagus nerve

  3. Esophagus

  4. Aortic arch

  5. Pulmonary veins

  6. Pulmonary arteries

  7. Superior vena cava
• Structures in the mediastinum

  • Azygos vein
  • Ligamentum arteriosum
  • Left recurrent laryngeal nerve
  • Middle mediastinum
  • Pulmonary trunk
  • Pulmonary arteries
  • Phrenic nerve
  • Posterior mediastinum
  • Esophagus
  • Sympathetic trunk
  • Vagus nerve
  • Descending thoracic aorta
  • Intercostal spaces
  • Intercostal muscles
  • Subcostal muscle
  • Intercostal neurovascular structures