Circulation of the blood

(Physiol.) The course of the blood through the body, from the heart to the capillaries, and from the capillaries back again to the heart. This, after respiration, is the most important function performed by the body, if between the two there can be any difference in the degree of their imp or tance, as one cannot exist for a moment without the other. That this most interesting vital function should be clearly and thoroughly understood, we must anticipate, in a slight degree, some of our remarks on the heart. Though the ancients had some vague idea about the up and down motion of the blood, and had acquired a tolerably correct opinion of the course of that fluid as far as the abdominal organs and particularly the liver was concerned, yet the knowledge of the great and beautiful fact that the blood performed a perfect circuit through the body, was left to the immortal Harvey (q.v.) to discover. The heart (see fig. 201), which may be called the great reservoir of the blood, is divided into a right and left side, each side having two cavities or receptacles, one being situated above the other. The two upper cavities are called respectively the right and left auricle ; and the two lower receptacles the right and left ventricle. All the impure blood coursing in the veins of the lower extremities is collected in one large vein, the vena cava ascendens; and all the venous blood in the upper extremities, including that from the head, neck, arms, and chest, is received also in one large ve el, called the vena cava descend ens. These two large tubes, carrying all the venous or purple blood of the body, pour their contents into the upper chamber on the right side of the heart the right auricle; by means of a valve between the upper and lower chamber, the blood pa es from the auricle into the right ventricle. From the side of this latter cavity rises a large ve el called the pulmonary artery , - though in reality a vein. which, receiving all the blood from the right ventricle, carries it to the lungs, where it becomes purified by absorbing oxygen from the air and giving off its carbon in the form of carbonic acid, and being re-collected by the pulmonary vein (properly artery), is brought back to the heart in the form of a bright scarlet fluid, loaded with all the elements of vitality; but instead of returning to the locality from which the pulmonary artery started, it terminates in the third chamber, or left auricle , thus completing one circle the le er, or, as it is called, the pulmonic circulation. The arterial blood poured into the left auricle from the lungs, pa es by means of a valve into the space below it, or the left ventricle , from the upper side of which arises the great parent artery of the body, the aorta (see figs. 120 and 201), by which the blood is conveyed upwards and downwards to every portion of the body, to build up the frame, repair deficiencies, give heat to the system, and supply those fluid secretions so perpetually required to maintain the healthy economy of the system. The arteries having carried their blood to the skin, muscles, bones, and every ti ue of the body, and expended in the journey all its vital and constructive properties, the capillaries collect the refuse blood, and then, merging into the veins. these in turn, after collecting the impure stream from all quarters, bring it back by the two large veins, the ascending and descending vena cava, to the right auricle of the heart, from which, as before stated, it pa es into the right ventricle, the opposite cavity to that from which the aorta started, thus completing the second great circle, or the systematic circulation of the blood. -See ARTERY, AORTA, BRONCHI, BLOOD, HEART, LUNGS, RESPIRATION, . Circulative, a. Circulating; tending to increase circulation. (R.) Circulator, n. The person who, or thing which, cir culates. Circulatory, a. [Fr. circulatoire .] Circular; as a cir- culatory letter. Affecting the organs of circulation. -n. A chemical ve el, in which that which rises from the ve el on the fire is collected and cooled in another fixed upon it, and falls down again. Circulus, n. [Dim. of Lat. circus, a circle.) (Anat.) Any part of the body, which is round or annular, as C. oculi , the globe or orb of the eye. It is also applied to objects which by no means form a circle, as to the C. of Will is , which is an anastomotic circle at the base of the brain formed by the anterior and the posterior cerebral arteries, and the communicating arteries of Will is. Cir'cum, prep . [Lat., around.] Used as a prefix in Circumag'itate, v . a . [Lat. circum , and Eng, agitate .] many English words. Circumambiency, n . The act of encompa ing. To shake round; to agitate on all sides. Circumam'bient, a. going round, from ambio -am; Gr. amphi , round, and eo, to go.] Going round about; surrounding, encom- pa ing, inclosing, or being on all sides; as, "circumam- bient coldne ." - Wilkins . [Lat. circum, and ambiens, Circumambula'tion, n. The act of walking round Circumben'dib us, n. A vulgarism, denoting a cir- about. about. cuitous route. cut off the prepuce or foreskin, according to the Jewish law. "They came to circumcise the child."-Luke. ing an idea does not naturally and immediately occur, or when a person wishes to avoid expre ing in direct terms something disagreeable or inconvenient. Circumlocu'tional, a. Periphrastic; circuitous; containing circumlocutions. Circumloc'utory, a . Pertaining to circumlocution; periphrastic; as, circumlocutory language. Circummured', a . [Lat. circum , and Eng. mured.] Walled round, or encompa ed with a wall. Circumnavigable, a. That may be sailed around. Circumnavigate, v . a . [Lat. circumnavigo-circum, and navigo , navigatus , to sail over, to navigate.] To nav- igate or sail round; to pa round by water; as, to cir- cum navigate the globe. -Minutene ; particularization; detail. Circumstantially, adv . According to circum- stances; not e entially; accidentally. - Minutely; with exactne ; in every particular or circumstance. "Lucian agrees with Homer in every point circumstantially." Circumnavigation, n. Act of circumnavigating, or of sailing round; usually applied to the act of sailing round the world. The first to circumnavigate the world was Magellan, or Magalhaens, a Portuguese, Circumstantiate, v. a. To place in particular cir- in 1519. Fifty years ago the C. of the globe was still looked upon as a great enterprise, but it is now become a matter of common performance. and Persians, on the females. - The Jews esteemed un- circumcision as a very great impurity; and the greatest Circumnavigator, n. One who sails around the offence they could receive was to be called uncircumcised. Paul frequently mentions the Gentiles under this term, Cir cum plica'tion, n. [Lat. circumplicare - circum . Circumpolar, a. [Lat. circum, and Eng. polar .] Sit- uated about or near the pole. (Astron.) C. stars are stars which are so near the pole, N. or S., as to revolve around it without setting. Their number varies according to the latitude of the observer. Circumposition, n . [Lat. circumpositio .] The act of placing anything in a circular position. "Now is your season for circumposition , by tiles or baskets of earth." Evelyn. Circumrota'tion, n. [Lat. circum, and rotatio , from roto, rotatus, to turn round, as a wheel, from rota , a wheel.] Act of turning, rolling, or revolving round, as a wheel; circumvolution; the state of being whirled round. Circumro'tatory, Circumro'tary, a . Turning, rolling, or whirling round, as a wheel. Circumscis's ile, a. [Lat. circumscindere .] ( Bot . ) Ap- plied to pods which open by a circular horizontal line cutting off the upper part of a lid, as in the fruit of the Purslane (fig. 607). A pod character- ized by this mode of dehiscence is called Pyxis or Pyzidium . Circumscrib'able, a. Capable of being circumscribed. Circumscribe', v. a. [Lat. cir- cumscribo - circum, and scribo , to write.] To write or inscribe around; to draw a line or lines round. - To inclose within a certain limit; to limit; to bound; to confine; to re- FRUIT OF PURSLANE. strict. The little forms which circumscribe your sex."-Southern. Circumscrib'er, n. He who, or that which, circum- Cir cum scrip'tible, a. That which may be limited or circumscribed. Cir cum scrip'tion, n. Act of circumscribing; a circular inscription. (R.) -The line that limits; deter- min at i on of particular form or magnitude. "In the circumscription of many leaves... nature affects a regular figure." - Ray. -Limitation; bound; confinement; margin. "I would not any unhoused free condition Put into circumscription and confine." -a. Moving or turning round. (R.) Circumflex'ion, n. The act of giving a circular di- Cir cum scrip'tive, a . Defining the outward form rection or figure. IMG:content-0201.png:[blocks in formation] Circum'fluent, Circum'fluous, a. [Lat. cir- cumfluens-circum, and fluo , to flow.] Flowing round; surrounding, as a fluid. Cir cum for a'nean, Cir cum for a'neo us, a. Lat, cir cum forane us circum, and forum , a market.] Walking, wandering, or strolling about from market to market, or from house to house. Circumfuse', v . a . [Lat. circumfusus - circum , and fun do, fusus , to pour.] To pour around, as a fluid; to spread around; to surround. or limit; inclosing the superficies of a body. Cir cum scrip'tively, adv . In a limited manner. Circumspect, a . [Fr. circonspect , from Lat. circum- and specio, spectus , to look or view.] spectus - circum, Looking around cautiously; watchful on all sides; cau- tious; prudent; wary; thoughtful; as, circumspect behavior. Circumspection, n. [Fr. cir con spec tion , from Lat. circumspectio.] A looking around cautiously; caution; watchfulne ; deliberation: warine ; thoughtfulne ; as, "with sly circumspection." Circumspective, a . Looking around every way; attentive; wary; vigilant; cautious. "All sly, slow things, with circumspective eyes." - Pope. Cautiously; warily; Circumspectively, adv . watchfully; vigilantly; carefully. Circumspectly, adv . With watchfulne every way; cautiously; attentively; warily; as, to examine a matter circumspectly. Circumspectne , n. Quality of being circum- spect: caution; vigilance; circumspection. Circumstance, n . [Fr. cir con stance; It. circostanza ; Lat. circumstantio-circum, and sto , stans, to stand.] Something attending, appendant, or relative to a main fact or case; adjunct of a fact; something adventitious; accident; incident; event. "And breasts the blows of circumstance."-Tennyson. -Condition of things surrounding or attending an event. "Pride, pomp, and circumstance of glorious war." -Shaks. Circumja'cence, n . Condition of being circumjacent. Circumjacent, a. [Lat. circumjacens- circum , and jaceo , to lie. Lying round about; bordering on every -pl . State of affairs; one's state or condition in life; sta- tion; situation; as, to be in good circumstances. certain things. IMG:content-0202.png:[blocks in formation] -v.i. To roll around; to revolve. Cir'cus, n.; pl . Eng. CIRCUSES, pl . Lat. CIRCI. Gr. kirkos . See CIRCLE.] ( Roman Antiq .) A round or oval-shaped edifice, which was used for the exhibiting of games and shows called circuses. The C. was more especially adapted for races, an amusement of which the Romans were pa ionately fond. The Ludus Troje was a mock conflict between young men on horseback. A regular battle was sometimes represented ( Pugna Eques- tris et Pedestris). By the formation of canals and the in- troduction of ve els, a Naumachia , or sea-fight, was oc- cas i on ally e x hibited; IMG:content-0203.png:[blocks in formation] Cirencester, (sis'is-ter,) a town of England, in Glou- cestershire, on the Churn, 16 m.S.E. of Gloucester. Manf. Carpets, woollens, and cutlery. Pop , 6,326. Cirl-bunting, n. (Zool.) See PLECTROPHANES. Cirque ( sērk ), n. [Fr.] a circular space; a circus; as, the Cirque Olympique, Paris. Cirrhose, Cir'rho us, CIR'ROSE. See CIRROUS. Cirriferous, a. [Lat. cirrus, a curl, and ferre, to bear.) Producing tendrils, as a plant. Cirrig'erous, a. [Lat. cirrus, and gerere, to carry.] Having curled locks of hair. of the cube, or the insertion of two mean proportions Ci'tal, n. [From CITE, q. v.] A summons to appear in between two given straight lines. Cis's us, AMPELOPSIS, n. [Gr. ki os , ivy.) ( Bot .) A genus of plants, order Vitaceae . The Woodbine, C. quin- quefolia , found wild in woods and thickets, is a vigorous climber, supporting itself firmly upon trees by means of its radiating tendrils, and ascending to the height of 50 ft. In the same manner it ascends and overspreads walls and buildings. The large quinate leaves const i- tute a luxuriant foliage of dark, glo y green. Flowers inconspicuous, greenish, in dichotomous clusters. Ber- ries dark blue, smaller than peas, acid. Cist, (sist,) n. [Gr. kiste . See CHEST.) ( Archæol .) A stone coffin of the Bronze period, or place of interment, formed of two parallel rows of stones placed on their ends, and covered by similar flat stones, in length about 7 feet. Cist, Cis'ta, n. [Lat.; from Gr. kiste .] ( Rom . Antiq .) A small box or chest, carried in proce ion in the fest i- vals of Ceres or Bacchus. These boxes, which were al- ways kept closed in the public proce ions, contained sacred things connected with the worship of these dei- ties. In the representations of Dionysiac proce ions on ancient vases, women carrying ciste are frequently introduced. The C. was also the name of the ballot- box, into which those who voted in the comitia and in the courts of justice cast their tabellæ. - See CYST. Cista'ceæ, n . pl . [Gr. kiste , a CIST, q. v.] (Bot.) The Rock-rose family, an order of plants, alliance Cistales . DIAG. Trimerous or pentamerous flowers, stamens never tetradynamous, closed fruit, and albuminous seeds.- Cirro-cu'mulus, n. [Lat. cirrus , and cumulus .] ( Me- teor.) See CLOUD. Cir'rose, a . See CIRROUS. Cirro-str a'tus, n. [Lat. cirrus, and stratus, q. v.] (Meteor.) The wave-cloud. See CLOUD. Cir'rous, a. [Lat. cirrus , a curl.] ( Bot .) Terminating in a curl or tendril, as a leaf. Also written Cirrhose, Cirrhous, and Cirrose. Europe and North of Afri- ca. The leaves are entire; the sepals and petals have a ternary or quinary ar- range ment, and are twisted in æstivation, the former being persistent and the latter caducous; the sta- mens are hypogynous and distinct; the ovary has parietal placentas, and a single style with a simple stigma; the fruit is capsu- lar; the seeds have mealy albumen and embryos in- verted, curved, or spiral. The Cistaceæ have resinous and balsamic properties. From species of the typical genus Cistus, a fragrant resinous substance, called Ladanum, is obtained in the Fig . 609. ROCK-ROSE. ( Cistus purpurens.) Levant. This is used medicinally as an expectorant and emmenagogue, and is much esteemed by the Turks as a perfume. A gum called Kuteera , which is sometimes substituted in India for tragacanth, is the produce of a plant of this order, named Coch los per mum Go ypium. Cistus purpurens , a sub-evergreen low bush of the Le- vant, is one of the most beautiful species in this order. It is 3-4 feet high, and has large bright-reddish purple flowers, with a yellow spot at the base. The order con- sists of 7 genera and 185 species. Cista'les, n . pl. ( Bot .) An alliance of hypogynous ex- ogen plants. DIAG. Mono dichlamydeous flowers, par i- etal or sutural placentæ, and a curved or spiral embryo, with little or no albumen. The cistal alliance consists of the 4 orders Cistaceæ, Bra icaceæ, Resedaceæ, and Capparidacece. Cist'ed, a . Inclosed in a cist, or bag. Cister'cians, Cister'cian Monks, n. pl . ( Eccl . Hist .) This religious order was founded in 1098, by Rob- ert, a Benedictine abbot of Molesme, in Burgundy, and received its name from Citeaux, in which forest, near Dijon, the first convent was situated. Its members in- creased rapidly, although their rules were extremely severe. They had a dispute with the Cluniacs or Clunia- censians, who acoused them of too great austerity, while the C. in return taxed the Cluniacs with having aban- doned their regular discipline. The C. followed the rule of St. Benedict, and having been reformed early in the 12th cent., by Bernard, Abbot of Clairvaux, were afterwards called BERNARDINES, (q. v.) There were nuns of this order. Cis'tern, n. [Lat. cisterna , from cist a ; Gr. kistě , a chest or box.) An artificial reservoir or receptacle for holding water or other liquids. -A natural reservoir; a hollow place containing water. "In the wide cisterns of the lakes confined." - Black more. (Steam Engineering .) The ve el which surrounds the condenser of a steam-engine, and contains the injection IMG:content-0204.jpg:[blocks in formation] "Your family will dwindle into cits or squires, or run up into wits or madmen." Tatler . Cit'able, a . That which may be cited or quoted. Citadel, n. [Fr. citadelle ; İt. cittadella , dim. of citta , a city. A fortre or castle in or near a city, intended for keeping the inhabitants in subjection; or, in case of a siege, to form a place of retreat for the defenders, and enable them to hold out after the rest of the town has been captured. A C. must command the other fortifi- cations of the city. Citadel'la, a town of N. Italy, on the Bren tell a, 14 m. N.E. of Vicenza; pop . 7,742. Cita'tor, n. One who cites. (R.) Citatory, a. Citing; calling; having the power or form of citation. Cit'er, n. One who cites or summons into court. -One who quotes or repeats from another. -(U. States.) A person, whether native-born or natural- ized, who, under the Constitution and laws of this country, has a right to vote for representatives in Con- gre , and other public officers, and who is qualified to fill offices in the gift of the people. Native C. may fill any office; naturalized C. may be elected or appointed to any office under the Constitution of the U. States, ex- cept the offices of president and vice-president. The Constitution provides that "the citizens of each State shall be entitled to all the privileges and immunities of citizens in the several States." -U. S. Const ., Art. 4, s. 2.. -a. Having the qualities of a citizen; as, a citizen -guard. Citizene , n. A female citizen. (R.) Citizenship, n . State of being vested with the rights and privileges of a citizen. Cit'rate, n . [From Lat. citrus , citron.] (Chem.) A salt formed by the combination of citric acid with a base. See