The typical pericardium is well developed.
A, Pericardium opened dorsally a, Ventricle of the heart.
The pair of renal organs of Anodonta, called in Lamellibranchs the organs of Bojanus, lie below the membranous floor of the pericardium, and open into it by two well-marked apertures (e and f in fig.
The glands secrete hippuric acid which passes from the pericardium into the renal organs.
In Unionidae and several other forms the pericardial glands are extended into diverti cula of the pericardium which penetrate the mantle and constitute the organ of Heber.
The excretory organs are coelomoducts with an internal ciliated opening into the pericardium and an opening to the exterior.
The gonad is transversely wrinkled and lies between the aorta and the intestine, extending from the pericardium to the anterior end of the body.
The heart is enclosed in the pericardium, and consists of a median elongated ventricle and a pair of lateral auricles, so that the structure somewhat resembles that in the Lamellibranchiata.
The gonads are paired and hermaphrodite, they form a pair of anterior prolongations of the pericardium, extending nearly to the anterior end of the body.
The pericardium is ciliated internally on its dorsal and lateral walls.
The urino-genital tubes arise from the posterior angles of the pericardium, pass first forwards, then backwards, and unite to open by a common opening into the cloaca below the anus except in A 8 C D FIG.
The chief difference is that the gonad or generative portion of the coelom is single and median, opening into the pericardium by a single posterior aperture.
The internal vesicle is already indicated, and is shown in the diagram by the thinner black line: I, gut; 2, somite; 2', nephridial part of coelom; 3, haemocoele; 3', part of haemocoele which will form the heart - the part of the haemocoele on each side of this will form the pericardium; 4, nerve-cord; 4, slime glands.
It contains a closed vesicle regarded by Schepotieff as a right probosciscavity and in any case representing the pericardium of Balangolossus, the glomerulus of which is also probably represented.
The existence of two renal organs in Patella, and their relation to the pericardium (a portion of the coelom), is important.
The connexion with the pericardium of pl, Pleural ganglion.
Heart has only a single auricle, neither heart nor pericardium traversed by rectum.
The heart c lying in the pericardium is seen in close proximity to the renal organ, and consists of a single auricle receiving blood from the gill, and of a single ventricle which pumps it through the body by an anterior and posterior aorta.
Its superficial extent is seen when the folds covering the shell are cut away and the shell removed; the external surface forms a triangle with its base bordering the pericardium, and its apex directed posteriorly and reaching to the lefthand posterior corner of the shell-chamber.
When the pericardium is cut open from above in an animal otherwise entire, the anterior face of the kidney is seen forming the posterior wall of the pericardial chamber; on the deep edge of this face, a little to the left of the attachment of the auricle to the floor of the pericardium, is seen a depression; this depression contains the opening from the pericardium into the kidney.
As so great a part of the whole surface of the kidney lies adjacent to external surfaces of the body, the remaining part which faces the internal organs is small; it consists of the left part of the under surface; it is level with the floor of the pericardium, and lies over the globular mass formed by the liver and convoluted intestine.
The heart lying within the adjacent pericardium has the usual form, a single auricle and ventricle.
The typical character is retained by the heart, pericardium, and the communicating nephridium or renal organ in all Opisthobranchs.
In both animals the wall of the pericardial sinus is connected by vertical muscular bands to the wall of the ventral venous sinus (its lateral expansions around the lung-books in Scorpio) in each somite through which the pericardium passes.
R B A B C must cause a depression of the floor of the pericardium and a rising of the roof of the ventral blood sinus, and a consequent increase of volume and flow of blood to each.
In any case it is clear that we have in these muscles an apparatus'for causing the blood to flow differentially in increased volume into either the pericardium, through the veins leading from the respiratory organs, or from the body generally into the great sinuses which bring the blood to the respiratory organs.
Margaritiferae) occurs in the pericardium of the Ceylon b pearl-oyster (9).
Pore leading from the pericardium into the glandular sac of the left nephridium.
The rectum traverses the pericardium, and has the ventricle of the heart wrapped, as it were, around it.
- Diagrams showing the Relations of Pericardium and Nephridia in a Lamellibranch such as Anodonta.
C, Dorsal wall of the pericardium B, Heart removed and floor of cut and reflected.
The pericardium cut away on e, Reno-pericardial orifice.
C, Ideal pericardium and neph- i, Pore leading from the glandu ridium viewed laterally.
Indicate the course of fluid ab, Posterior, cut remnants of the from the pericardium outintestine and ventricle.
Fr, g, It does not contain blood or communicate directly with the bloodsystem; this isolation of the pericardium we have noted already in Gastropods and Cephalopods.
The heart is not contained in the pericardium, lies dorsad of the rectum and gives off a single aorta anteriorly.
There is usually one pair of coelomic ducts leading from the pericardium to the exterior, and these are the excretory organs or kidneys, formerly known as the organs of Bojanus.
The walls of the pericardium are also excretory in parts, these parts forming the pericardial glands.
The heart is situated in the pericardium on the dorsal side of the intestine and at the posterior end of the animal.
The Prorhipidoglossomorpha are distinguished by the separation of the genital coelom from the pericardium, and by the long visceral commissure passing ventral to the intestine.
As in other molluscs the coelom is represented by a large pericardial cavity, situated above the intestine posteriorly, and a generative sac which is single and median and situated in front of the pericardium, except in the Nuttalochiton hyadesi, where the gonads are in a similar position, but are paired.
There is a heart in the pericardium consisting of a median ventricle attached, except in Neomenia, to the dorsal wall of the pericardium, and in Neomenia a pair of auricular ducts returning blood from the gills to the ventricle.
The pericardium being absent, there are no reno-pericardial apertures.
Peripatus is an Arthropod, as shown by (1) the presence of appendages modified as jaws; (2) the presence of paired lateral ostia perforating the wall of heart and putting its cavity in communication with the pericardium; (3) the presence of a vascular body cavity and pericardium (haemocoelic body cavity); (4) absence of a Derivisceral section of the coelom.
The batrachians they are confined to the vomers pericardium and palatines or to the vomers alone (37).
A ventral vessel occurs on the anterior side of the metasome and forms a loop extending down the entire length of the stalk, while a " heart " projects into the cavity of the pericardium, probably connected on the ventral side of the notochord with the ventral vessel, and on its dorsal side with the dorsal vessel.
The whole ventral surface of the pericardium is exposed when the sternum is removed.
Close to this the small renal organ (i, mediad) and the larger renal organ (k, to the right and posteriorly) are seen, also the pericardium (1) and a coil of the intestine (int) embedded in the compact liver.
Pericardium indicated by a dotted outline - at its right side are seen the two renopericardial pores.
Whether the pericardium and the ventral sinus are made to expand simultaneously or all the movement is made by one only of the surfaces concerned, must depend on conditions of tension.
Floor of the pericardium separating that space from the non-glandular portion of the nephridia.
The ventricle and auricles of Anodonta lie in a pericardium which is clothed with a pavement endothelium (d, fig.
The heart lies in the pericardium and gives off two aortae.
The last is between the pericardium and the foot; from it the blood passes through the renal organs to the ctenidia.
Pericardium, and is therefore a typical o, Olfactory ganglion, nephridium, was not known.