Arch

Examples of Arch in the following topics:

• 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.

• Development of the Cardiovascular System

  • The aortic arches or pharyngeal arch arteries are a series of six paired, embryological vascular structures which give rise to several major arteries .
  • The third aortic arch constitutes the commencement of the internal carotid artery, and is named the carotid arch.
  • The fourth left arch constitutes the arch of the aorta between the origin of the left carotid artery and the termination of the ductus arteriosus.
  • The fifth arch disappears on both sides.The proximal part of the sixth right arch persists as the proximal part of the right pulmonary artery, while the distal section degenerates.
  • A double aortic arch occurs with the development of an abnormal right aortic arch, in addition to the left aortic arch, forming a vascular ring around the trachea and esophagus, which usually causes difficulty breathing and swallowing.

• Roman Architecture under the Republic

  • An arch is a pure compression form.
  • As the forces in the arch are carried to the ground, the arch will push outward at the base, called thrust.
  • Multiple arches can be used together to create a vault.
  • Roman aqueducts are another iconic use of the arch.
  • The arches that make up an aqueduct provided support without requiring the amount of building material necessary for arches supported by solid walls.

• Flatfoot and Clawfoot

  • Flatfoot and crowfoot are medical conditions that appear as flat and high arches, respectively.
  • The appearance of flat feet is normal and common in infants, partly due to "baby fat" which masks the developing arch, and partly because the arch has not yet fully developed.
  • Flat arches in children usually become proper arches and high arches while the child progresses through adolescence and into adulthood.
  • A high arch is the opposite of a flat foot, and somewhat less common.
  • High arch in foot of a person with a hereditary neuropathy.

• Gothic Cathedrals

  • One of the defining characteristics of Gothic architecture is the pointed or ogival arch.
  • The way in which the pointed arch was drafted and utilized developed throughout the Gothic period, and four popular styles emerged: the Lancet arch, the Equilateral arch, the Flamboyant arch, and the Depressed arch.
  • Gothic openings such as doorways, windows, arcades, and galleries have pointed arches.
  • Niches with pointed arches that contain statuary are a major external feature.
  • Ogival, or pointed arches, increased in popularity in the Gothic period.

• Architecture during the Severan Dynasty

  • The Roman Arch of Septimius Severus recalls the triumphal arch of Augustus, also erected to honor his own victory over the Parthians.
  • Like Augustus's arch, that of Septimius is a triple arch--the only surviving one in Rome.
  • The Arch of Septimius Severus at Leptis Magna is architecturally distinct and unique in comparison to the triumphal arches of Rome.
  • This arch is four-sided and acts as a gateway into the city.
  • Despite its very different design, the arch's components are in dialogue with the triumphal arch in Rome.

• Parts of a Vertebra

  • A vertebra consists of two parts: an anterior segment, or the vertebral body; and a posterior part, or the vertebral (neural) arch.
  • A typical vertebra of the upper region of the spine consists of two regions; the anterior vertebral body which is the point of articulation between the vertebrae and the posterior vertebral or neural arch which encloses the spinal cord.
  • The vertebral arch is formed from two short thick processes called pediments which extend posteriorly from the lateral sides vertebral body, before joining together at the midline with the laminae.
  • A single spinous process projects backwards and downwards from the center of the vertebral arch and it serves as a major attachment point for muscles and ligaments of the back.