| frontal region of head | The surface region of the head corresponding to the outlines of the frontal bone. Synonym: regio frontalis capitis. (05 Mar 2000) |
|---|---|
| frontal section | A cross section attained by slicing, actually or through imaging techniques, the body or any part of the body or any anatomic structure in the coronal or frontal plane, i.e., in a vertical plane perpendicular to the median or sagittal plane. Since actual sectioning in the coronal plane results in an anterior and a posterior portion, an anatomical coronal section may be a two-dimensional view of the cut surface of the posterior aspect of the anterior portion, or of the anterior aspect of the posterior portion. Synonym: frontal section. (05 Mar 2000) |
| frontal sinus | One of the paired, but seldom symmetrical, air spaces located between the inner and outer compact layers of the frontal bone. (12 Dec 1998) |
| frontal sinus aperture | One of a pair of openings in the floor of the frontal sinuses in the nasal part of the frontal bone, through which the frontal sinuses communicate with the ethmoidal infundibulum via the frontonasal duct. Synonym: apertura sinus frontalis. (05 Mar 2000) |
| frontal sinusitis | Inflammation of the frontal sinus; in most cases the infection is caused by the bacteria streptococcus pneumoniae and haemophilus influenzae. This condition may be acute or chronic. (12 Dec 1998) |
| frontal squama | The tabular or squamous portion of occipital bone. Synonym: squama occipitalis, occipital squama, frontal squama. (05 Mar 2000) |
| frontal suture | The suture between the two halves of the frontal bone, usually obliterated by about the sixth year; if persistent it is called a metropic suture. Synonym: sutura frontalis. (05 Mar 2000) |
| frontal triangle | A triangle bounded above by the maximum frontal diameter and laterally by lines joining the extremities of this diameter with the glabella. (05 Mar 2000) |
| frontal tuber | The most prominent portion of the frontal bone on either side. Synonym: tuber frontale, eminentia frontalis, frontal tuber. (05 Mar 2000) |
| frontal veins | The superficial veins draining the frontal cortex and emptying into the superior sagittal sinus. Synonym: supratrochlear veins. (05 Mar 2000) |
| frontal zone contraction theory | Model proposed to account for the movement of giant amoebae in which cytoplasmic contraction at the front of the leading pseudopod (fountain zone) pulls viscoelastic cytoplasm forward in the centre of the cell and forms a tube of more rigid cytoplasm immediately below the plasma membrane behind the active region. The peripheral contracted cytoplasm relaxes into a weaker gel at the rear and is pulled forward in its turn. Contrasts with the ectoplasmic tube contraction model. (18 Nov 1997) |
| accessory cephalic vein | <anatomy, vein> A variable vein that passes along the radial border of the forearm to join the cephalic vein near the elbow. Synonym: vena cephalica accessoria. (05 Mar 2000) |
| accessory hemiazygos vein | <anatomy, vein> Formed by the union of the fourth to seventh left posterior intercostal veins, passes along the side of the bodies of the fifth, sixth, and seventh thoracic vertebrae, then crosses the midline behind the aorta, oesophagus, and thoracic duct, and empties into the azygos vein, sometimes in common with the hemiazygos vein. Synonym: vena hemiazygos accessoria, vena azygos minor superior. (05 Mar 2000) |
| accessory saphenous vein | <anatomy, vein> An occasional vein running in the thigh parallel to the great saphenous vein which it joins just before the latter empties into the femoral vein. Synonym: vena saphena accessoria. (05 Mar 2000) |
| accessory vertebral vein | <anatomy, vein> A vein that accompanies the vertebral vein but passes through the foramen of the transverse process of the seventh cervical vertebra and opens independently into the brachiocephalic vein. Synonym: vena vertebralis accessoria. (05 Mar 2000) |