| third and fourth pharyngeal pouch syndrome | <syndrome> Also called the digeorge syndrome (dgs), this disorder is characterised by (1) low blood calcium levels (hypocalcaemia) due to underdevelopment (hypoplasia) of the parathyroid glands which control calcium; (2) underdevelopment (hypoplasia) of the thymus, an organ behind the breastbone in which lymphocytes mature and multiply; and (3) defects of the heart involving the outflow tracts more than from the heart. most cases of dgs are due to a microdeletion in chromosome band 22q11.2. A small number of cases have defects in other chromosomes, notably 10p13. Named after the american paediatric endocrinologist angelo digeorge. Another name for dgs is hypoplasia of the thymus and parathyroids. (12 Dec 1998) |
|---|---|
| ultimobranchial pouch | A transient fifth pharyngeal pouch; it is now considered to be incorporated into the caudal pharyngeal complex, the cells of which become the parafollicular cells (C cells) of the thyroid. Uterovesical pouch, a pocket formed by the deflection of the peritoneum from the bladder to the uterus in the female. Synonym: excavatio vesicouterina, cavum vesicouterinum, vesicouterine pouch. (05 Mar 2000) |
| laryngeal pouch | A small diverticulum provided with mucous glands extending upward from the ventricle of the larynx between the vestibular fold and the lamina of the thyroid cartilage; it is a vestigial structure, being a much larger structure interdigitating with the neck musculature in some of the great apes where it serves as a resonating chamber. Synonym: sacculus laryngis, appendix ventriculi laryngis, Hilton's sac, laryngeal pouch. Origin: L. Sacculus (05 Mar 2000) |
| antidepressive agents, second-generation | A structurally and mechanistically diverse group of drugs that are not tricyclics or monoamine oxidase inhibitors. The most clinically important appear to act selectively on serotonergic systems, especially by inhibiting serotonin reuptake. (12 Dec 1998) |
| burns, second degree | Second degree burns look similar to the first degree burns in that it is red and sensation is intact; however, the damage is severe enough to cause blistering of the skin and the pain is usually somewhat more intense. (12 Dec 1998) |
| centimeter-gram-second system | The scientific system of expressing the fundamental physical units of length, mass, and time, and those units derived from them, in centimeters, grams, and seconds; currently being replaced by the International System of Units based on the meter, kilogram, and second. (05 Mar 2000) |
| centimeter-gram-second unit | <unit> An absolute unit of the centimeter-gram-second system. (05 Mar 2000) |
| Mendel's second law | Different hereditary factors assort independently when the gametes are formed; traits at linked loci are an exception. Synonym: Mendel's second law. (05 Mar 2000) |
| meter-kilogram-second system | An absolute system based on the meter, kilogram, and second; the basis of the International System of Units. (05 Mar 2000) |
| meter-kilogram-second unit | An absolute unit of the meter-kilogram-second system. (05 Mar 2000) |
| cycles per second | The number of successive compressions and rarefactions per second of a sound wave. The preferred designation for this unit of frequency is hertz. Acronym: cps (05 Mar 2000) |
| pregnancy trimester, second | Period of pregnancy from the beginning of the 15th through the 28th completed week (99 to 196 days) of gestation. (12 Dec 1998) |
| healing by second intention | Delayed closure of two granulating surfaces. Synonym: secondary adhesion, secondary union. (05 Mar 2000) |
| Scanzoni's second os | A constriction located at the junction of the thinned lower uterine segment with the thick retracted upper uterine segment, resulting from obstructed labour; this is one of the classic signs of threatened rupture of the uterus. Synonym: Bandl's ring, Baudelocque's uterine circle, Scanzoni's second os. (05 Mar 2000) |
| second | 1. Immediately following the first; next to the first in order of place or time; hence, occuring again; another; other. "And he slept and dreamed the second time." (Gen. Xli. 5) 2. Next to the first in value, power, excellence, dignity, or rank; secondary; subordinate; inferior. "May the day when we become the second people upon earth . . . Be the day of our utter extirpation." (Landor) 3. Being of the same kind as another that has preceded; another, like a protype; as, a second Cato; a second Troy; a second deluge. "A Daniel, still say I, a second Daniel!" (Shak) Second Adventist. See Adventist. Second cousin, the child of a cousin. Second-cut file. See File. Second distance, the House of Peers. Second girl, a female house-servant who does the lighter work, as chamber work or waiting on table. Second intention. See Intention. Second story, Story floor, in America, the second range of rooms from the street level. This, in England, is called the first floor, the one beneath being the ground floor. Second thought or thoughts, consideration of a matter following a first impulse or impression; reconsideration. "On second thoughts, gentlemen, I don't wish you had known him." (Dickens) Origin: F, fr. L. Secundus second, properly, following, fr. Sequi to follow. See Sue to follow, and cf. Secund. 1. One who, or that which, follows, or comes after; one next and inferior in place, time, rank, importance, excellence, or power. "Man an angel's second, nor his second long." (Young) 2. One who follows or attends another for his support and aid; a backer; an assistant; specifically, one who acts as another's aid in a duel. "Being sure enough of seconds after the first onset." (Sir H. Wotton) 3. Aid; assistance; help. "Give second, and my love Is everlasting thine." (J. Fletcher) 4. An article of merchandise of a grade inferior to the best; especially, a coarse or inferior kind of flour. 5. [F. Seconde. See Second] The sixtieth part of a minute of time or of a minute of space, that is, the second regular subdivision of the degree; as, sound moves about 1,140 English feet in a second; five minutes and ten seconds north of this place. 6. In the duodecimal system of mensuration, the twelfth part of an inch or prime; a line. See Inch, and Prime. 7. The interval between any tone and the tone which is represented on the degree of the staff next above it. The second part in a concerted piece; often popularly applied to the alto. Second hand, the hand which marks the seconds on the dial of a watch or a clock. Source: Websters Dictionary (01 Mar 1998) |