axis (ak'sis) [L. axis, axle, axis]
1. A real or imaginary line that runs through the center of a body or about which a part revolves.
The second cervical vertebra (epistropheus). It bears the odontoid process (dens), about which the atlas rotates. Synonym: odontoid vertebra
The axis connecting the basion and gonion.
The axis from the subnasal point to the gonion.
The axis between the two auricular points.
A graphic representation of the main conduction vector of the heart, determined through measurements of direction and amplitude of the complexes in several leads on a 12-lead electrocardiogram. Normal axis is zero to +90°.
The axis between the celiac artery and the abdominal aorta.
The central nervous system.
A projected line connecting the condyles of the mandible. Movement of the mandible is rotation around this imaginary line. Synonym: hinge axis; mandibular axis; transverse mandibular axis
coronal axisFrontal axis.
The hormones and neurotransmitters from the gastrointestinal tract that regulate the secretion of hormones by the pancreas (esp. insulin).
An imaginary line, running from side to side in the frontal plane, about which the anterior to posterior movement occurs. Synonym: coronal axis
hinge axisCondylar axis.
mandibular axisCondylar axis.
neural axisCentral nervous system.
A line that connects the anterior and posterior poles of the eye.
An anatomic reference point on the surface of the body, used to approximate the position of the right atrium and pulmonary artery in critical care.
The line is identified by drawing two lines on the supine body: one, in the right mid-axillary position, descending from head to foot; and the other, from the anterior to the posterior of the chest, at the level of the fourth intercostal space. The intersection of the these two lines constitutes the axis. It is used in critical care to provide a reproducible location for the zeroing and leveling of hemodynamic monitoring systems such as pulmonary artery catheters.
In optics, a line that passes through the optical center or nodal point of a lens perpendicular to the surface of the lens.
Imaginary line running anterior-posterior, about which frontal plane motion occurs.
transverse mandibular axisCondylar axis.
The line of vision from the object seen through the pupil's center to the macula lutea.