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1. a stripe, streak, or narrow ridge; sometimes only an imaginary connector between two anatomic landmarks. Called also linea. adj., adj lin´ear.
2. tubing on a catheter.
absorption l's dark lines in the spectrum due to absorption of light by the substance through which the light has passed.
arterial line a monitoring system that uses an artery for access and consists of a catheter in the artery, pressure tubing, a transducer, and an electronic monitoring device. The most common uses of arterial lines are for monitoring of systemic blood pressure and obtaining arterial blood for analysis.
Beau's l's transverse lines or grooves in the nail plate caused by various systemic and local traumatic factors.
bismuth line a thin blue-black line along the gingival margin in bismuth poisoning.
blue line lead line.
cement line a line visible in microscopic examination of bone in cross section, marking the boundary of an osteon (haversian system).
cervical line anatomical designation for the cementoenamel junction.
cleavage l's Langer's lines.
line of Douglas a crescentic line marking the termination of the posterior layer of the sheath of the rectus abdominis muscle.
l's of election lines of expression.
epiphyseal line one on the surface of an adult long bone, marking the junction of the epiphysis and diaphysis.
l's of expression the natural skin lines and creases of the face and neck; the preferred lines of incision in facial and cervical surgery.
1. a line determined by the level to which the gingiva extends on a tooth; called also gum line.
2. any linear mark visible on the surface of the gingiva.
gluteal line any of the three rough curved lines (anterior, inferior, and posterior) on the gluteal surface of the ala of the ilium.
gum line gingival line (def. 1).
hot line see hot line.
iliopectineal line the ridge on the ilium and pubes showing the brim of the true pelvis.
incremental l's lines supposedly showing the successive layers deposited in a tissue, as in the tooth enamel.
intertrochanteric line one running obliquely from the greater to the lesser trochanter on the anterior surface of the femur.
Langer's l's linear clefts in the skin indicative of the direction of the fibers; they correspond closely to the creases of the body but vary with body configuration. Lines of incision made parallel to them are thought to heal more efficiently. Called also cleavage lines.
lead line a purple-blue line at the edge of the gums in chronic lead poisoning; called also blue line.
lip line a line on the teeth at the level to which the margin of either lip extends.
median line an imaginary vertical line dividing the body equally into right and left parts.
milk line the line of thickened epithelium in the embryo along which the mammary glands are developed.
mylohyoid line a ridge on the inner surface of the lower jaw from the base of the symphysis to the ascending rami behind the last molar tooth.
nuchal l's three lines (inferior, superior, and highest) on the outer surface of the occipital bone.
pectinate line one marking the junction of the zone of the anal canal lined with stratified squamous epithelium and the zone lined with columnar epithelium.
semilunar line a curved line along the lateral border of each rectus abdominis muscle, marking the meeting of the aponeuroses of the internal oblique and transverse abdominal muscles.
Shenton's line a curved line seen in radiographs of the normal hip, formed by the top of the obturator foramen; it is used to determine the relationship between the head of the femur and the acetabulum.
temporal l's curved ridges, inferior and superior, on the external surface of the parietal bone, continuous with the temporal line of the frontal bone, a ridge that extends upward and backward from the zygomatic process of the frontal bone.
terminal line one on the inner surface of each pelvic bone, from the sacroiliac joint to the iliopubic eminence anteriorly, separating the false from the true pelvis.
visual line a line from the point of vision of the retina to the object of vision; called also visual axis.
The highest or lowest point the lips reach on the teeth or gums during a broad smile.
See also: line