| 释义 |
sagittal, a.|səˈdʒɪtəl|
[ad. mod.L. sagittālis, f. L. sagitta arrow: see -al1. Cf. F. sagittal.]
1. Anat.
a. sagittal suture († sagittal addition, † sagittal commissure): ‘the median antero-posterior suture between the two parietal bones on the vertex of the skull’ (Syd. Soc. Lex. 1891).
1541R. Copland Guydon's Quest. Chirurg. F ij, There commeth .ix. [muscles to the tongue] that brede of the addycyon called sagitall of the bone named Lapheoides. 1597A. M. tr. Guillemeau's Fr. Chirurg. 40 b/2 The sagittal suture, where she ioyneth her self with the Coronalle suture. 1653Urquhart Rabelais i. xliv, The sagittal commissure or dart-like seame which distinguisheth the right side of the head from the left. 1882Wilder & Gage Anat. Technol. 183 In Human Anatomy the sagittal suture is confined to the articulation of the two parietals with each other, the two frontals uniting so early that they are considered as a single bone.
b. Pertaining to the sagittal suture; pertaining to or lying in ‘the median longitudinal anteroposterior plane of the body, or to any plane parallel with this’ (Syd. Soc. Lex. 1891).
1831R. Knox Cloquet's Anat. 57 Four Edges. The upper or sagittal (margo sagittalis) is the longest. 1854Owen Skel. & Teeth in Orr's Circ. Sci., Org. Nat. I. 250 The sagittal and occipital crests.
2. Pertaining to an arrow; resembling an arrow or an arrow-head in shape. rare.
1656Blount Glossogr., Sagittal..; Also belonging to an Arrow. 1772Pennant Genera of Birds (1781) 16 Hoopoe... Tongue, short, sagittal. 1785― Arctic Zool. II. 207 Feathers of the thighs long, white, crossed with sagittal bars of yellow. 1886R. F. Burton Arab. Nts. (abr. ed.) I. 148 Sagittal shots from eyelids Sagittarius threw. 1887Sollas in Encycl. Brit. XXII. 416/2 (Fig. 13) [Forms of sponge-spicules] h, sagittal triod.
3. Optics. Pertaining to or designating the plane that contains the chief ray from an off-axis point source and those rays that are brought to a point in the further (radial) line image formed by an astigmatic system (in a plane at right angles to the sagittal plane).
1902Mann & Millikan tr. Drude's Theory of Optics iii. 50 All the rays emitted by P..cross the axis at the same point P2. The beam made up of such rays is called a sagittal beam. It has a focal point at P2. 1910J. P. C. Southall Geom. Optics vii. 333 Following the usage of most modern writers, we shall call the incident and refracted rays lying in the planes π , π′ , respectively, the Sagittal Rays. [Note] ‘Sagittal’ is a term borrowed from Anatomy... Some writers..prefer..the word ‘equatorial’ instead of sagittal. 1936H. T. Flint Geom. Optics vii. 150 This line and P2P21 are the focal lines of the astigmatic reflected pencil,..the sagittal and tangential lines respectively. 1972O. N. Stavroudis Optics of Rays xii. 266 These skew rays, called sagittal rays, also pass through opposite sides of both the circle on the exit pupil and the ellipse on the image plane... Any fan of sagittal rays from the fixed object point will converge to..the sagittal focus... The tangential focus and the sagittal focus are the astigmatic foci.
Hence saˈgittally adv., Anat., ‘in the direction of the sagittal plane’ (Cassell's Suppl. 1902).
1895in Funk's Standard Dict. 1950Jrnl. Compar. Neurol. XCII. 142 The right postcentral sulcus..its lower limb running almost sagitally. 1977Lancet 29 Oct. 930/2 The pineals were removed, bisected sagitally, homogenised, and stored at -20°C. |