alveolar arch

Examples of alveolar arch in the following topics:

• Mouth

  • This process begins with the mechanical breakdown of food by the teeth, which fit into the alveolar arches.

• Structures Used in Voice Production

  • The alveolar ridge, the gum line just behind the teeth (alveolar).
  • Alveolar (front part of alveolar ridge), 5.
  • Post-alveolar (rear part of alveolar ridge & slightly behind it), 6.
  • Pre-palatal (front part of hard palate that arches upward), 7.

• Great Vessels of the Heart

  • The aortic arch contains peripheral baroreceptors (pressure sensors) and chemoreceptors (chemical sensors) that relay information concerning blood pressure, blood pH, and carbon dioxide levels to the medulla oblongata of the brain.
  • The ascending aorta lies between the heart and the arch of aorta.
  • The arch of aorta is the peak of the aorta, which breaks off into the left carotid artery, brachiocephalic trunk, and the left subclavian artery.
  • The descending aorta is  the section from the arch of aorta to the point where it divides into the common iliac arteries.
  • The pulmonary arteries carry deoxygenated blood from the right ventricle into the alveolar capillaries of the lungs to unload carbon dioxide and take up oxygen.

• Arches, Vaults, and Domes

  • This is sometimes referred to as arch action.
  • As the forces in the arch are carried to the ground, the arch will push outward at the base; this is called thrust.
  • Circular arches, also referred to as rounded arches, were commonly employed by the builders of ancient, heavy masonry arches.
  • The advantage of using a pointed arch rather than a circular arch is that the arch action in a pointed arch produces less thrust at the base.
  • Of any arch type, the parabolic arch produces the most thrust at the base, but can span the largest areas.

• Arch of the Aorta

  • The arch of the aorta follows the ascending aorta and begins at the level of the second sternocostal articulation of the right side.
  • The arch of the aorta, or the transverse aortic arch, is continuous with the upper border of the ascending aorta and begins at the level of the upper border of the second sternocostal articulation of the right side.
  • Three vessels come out of the aortic arch: the brachiocephalic artery, the left common carotid artery, and the left subclavian artery.
  • In approximately 20% of individuals, the left common carotid artery arises from the brachiocephalic artery rather than the aortic arch, and in approximately 7% of individuals the left subclavian artery also arises here.
  • This diagram shows the arch of the aorta and its branches.

• Arches and Domes

  • As the forces in an arch are carried toward the ground, the arch will push outward at the base (called thrust).
  • As the height of the arch decreases, the outward thrust increases.
  • The most common true arch configurations are the fixed arch, the two-hinged arch and the three-hinged arch.
  • The two-hinged arch is most often used to bridge long spans.
  • This type of arch has pinned connections at the base.

• Arches of the Feet

  • The arches of the foot are formed by the tarsal and metatarsal bones.
  • The longitudinal arch of the foot can be broken down into several smaller arches.
  • The main arches are the antero-posterior arches, which may, for descriptive purposes, be regarded as divisible into two types—a medial and a lateral.
  • In contrast, the lateral longitudinal arch is very low.
  • In addition to the longitudinal arches, the foot presents a series of transverse arches.

• Dental Anesthesia

  • The most common local anesthetic technique, effective for the lower teeth and jaw, is inferior alveolar nerve anesthesia.
  • Several non-dental nerves are usually anesthetized during an inferior alveolar block.
  • When the inferior alveolar nerve is blocked, the mental nerve is blocked also, resulting in a numb lip and chin.
  • Nerves lying near the point where the inferior alveolar nerve enters the mandible often are also anesthetized during inferior alveolar anesthesia.
  • A dentist injects a local anesthetic into the inferior alveolar nerve before extracting a tooth.

• Development of the Respiratory System

  • The canalicular period spans weeks 16 to 26, during which the lumens of the bronchi enlarge, lung tissue becomes highly vascularized, and respiratory bronchioles and alveolar ducts develop from the terminal bronchioles.
  • Specialized cells of the respiratory epithelium appear, including type II alveolar cells that secrete pulmonary surfactant.
  • This surfactant is important in reducing the surface tension at the air-alveolar surface, allowing expansion of the terminal saccules.
  • Preterm birth can lead to infants with under-developed alveolar type II cells.
  • Lastly, the alveolar period spans from birth to eight years of age, during which the terminal saccules, alveolar ducts, and alveoli increase in number.

• Alveoli

  • Found in the lung parenchyma, the pulmonary alveoli are the terminal ends of the respiratory tree that outcrop from either alveolar sacs or alveolar ducts; both are sites of gas exchange with blood.
  • The alveolar membrane is the gas-exchange surface.
  • The alveoli are located in the respiratory zone of the lungs, at the distal termination of the alveolar ducts.
  • Type I (Squamous Alveolar) cells: These form the structure of an alveolar wall.
  • The alveoli are the site of alveolar ventilation, and are not normally considered dead space.