The ventricle leads into a single anterior median aorta.
Ventricle of the heart.
A, Pericardium opened dorsally a, Ventricle of the heart.
It consists of a median ventricle with muscular walls and a cavity traversed by muscular strands.
These differences of gill-struc v, Ventricle of the heart.
The openings of the auricles into the ventricle vary in different forms. In many of the lower forms (Lepidopleuridae, Mopalidae, Ischnochitonidae) the opening on each side is single and anterior.
In Anodonta the blood is driven by the ventricle through the arteries into vessel-like spaces.
On either side of the ventricle, in the primitive condition, is a thinwalled auricle, opening into the ventricle by a valved opening.
The ventricle and auricles of Anodonta lie in a pericardium which is clothed with a pavement endothelium (d, fig.
Rectum traversing the ventricle of the heart.
The rectum traverses the pericardium, and has the ventricle of the heart wrapped, as it were, around it.
And of two auricles which open into the ventricle by orifices protected by valves.
In the primitive form a single anterior aorta is given off from the ventricle, the two together representing the dorsal blood-vessel of Chaetopods.
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 right ventricle occupies the ventral portion of the heart.
The communication with the atrium is guarded by a valvula cardiaca dextra, which only in function represents the mammalian tricuspid; it consists of an oblique reduplication of the muscular fibres together with the endocardiac lining of the right ventricle, while the opposite wall is convex and forms neither a velum nor papillary muscles, nor chordae tendineae.
Heart with two auricles; ventricle traversed by the rectum, except in the Helicinidae.
The heart in Patella consists of a single auricle (not two as in Haliotis and Fissurella) and a ventricle; the former receives the blood from the branchial vein, the latter distributes it through a large aorta which soon leads into irregular blood-lacunae.
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.
In more specialized forms a posterior aorta passes backwards from the ventricle, as in Gastropods and the majority of Lamellibranchs.
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.
In Anodon and the majority of lamellibranchs the ventricle surrounds the intestine; in the oyster the two are quite independent, the intestine passing above the pericardium.
The cardiac contractions become irregular, the ventricle assumes curious shapes - "hour-glass," &c. - becomes very pale and bloodless, and finally the heart stops in a state of spasm, which shortly afterwards becomes rigor-mortis.