Sinus Venosus

(redirected from Venosus)
Also found in: Dictionary, Medical.
Related to Venosus: sinus venosus, Ligamentum venosum

sinus venosus

[′sī·nəs və′nō·səs]
(embryology)
The vessel in the transverse septum of the embryonic mammalian heart into which open the vitelline, allantoic, and common cardinal veins.
(vertebrate zoology)
The chamber of the lower vertebrate heart to which the veins return blood from the body.

Sinus Venosus

 

(1) In the lancelet, which has no heart, an unpaired vessel that gathers venous blood from the portal vein and the ducts of Cuvier and passes into the abdominal aorta.

(2) In lower vertebrates—cyclostomes, fishes, and amphibians—a division of the heart; a thin-walled sac serving as a reservoir for venous blood, which, when the sinus venosus contracts, is driven into the auricle of the heart; the sinoatrial valves, located in the opening between the sinus venosus and the auricle, prevent reverse flow of blood. In the sinus venosus is found the sinus node (Remak’s ganglion), the center in which the primary impulses of heart contraction originate. In reptiles (except for Hatteria) the sinus venosus loses complete independence and enters, to one degree or another, into the structure of the right auricle. In birds and mammals the sinus venosus is formed in the embryo and subsequently (except in unkeeled birds) is completely incorporated in the wall of the right auricle, together with the sinus node; only in Monotremata are the sinoatrial valves preserved.

(3) In a number of invertebrates, the same as venous lacunae.

References in periodicals archive ?
Screening for chromosomal abnormalities at 10-14 weeks: The role of the ductus venosus blood flow.
5 days after conception, cells from an embryonic cardiac structure called the sinus venosus, which directs blood into the developing heart, began to migrate across the surface of the muscle.
As seen in Rumex venosus the wings are chartaceous; venation forms a reticulum with main veins running laterally into each wing, straight to sinuous, interconnecting to form polygonal areoles that diminish in size toward the margin; festooned brochidodromous.
After delivery, three important circulatory pathways, the ductus venosus, the foramen ovale, and the ductus arteriosus, are closed, which leads to an increase in pulmonary blood flow in response to lung expansion.
During normal development, the anterior cardinal veins, which drain the head, neck, and arm, unite with the posterior cardinal vein in the very early embryonic stage and enter the heart as the right and left horns of the sinus venosus.
Partial nodular transformation of liver in an adult with persistent ductus venosus.
The AHR is required for developmental closure of the ductus venosus in the neonatal mouse.
Additionally, Doppler assessment of blood flow measurement - specifically of tricuspid regurgitation and of flow through the ductus venosus, a small fetal blood vessel that leads to the heart - can provide valuable information about fetal cardiac status and can easily be done in the context of the first-trimester ultrasound evaluation.
Pigeons have a venous subcutaneous plexus in the neck zone (plexus venosus subcutaneus collaris),
Recently, new ultrasound markers have been described in the first trimester, including an absent nasal bone, the presence of tricuspid regurgitation and abnormal flow in the ductus venosus which may all be usefully combined with NT assessment to give a similar efficiency of screening but avoiding biochemical testing.
The blood returning to the fetus through the umbilical vein mostly passes through the ductus venosus and therefore only a small amount goes to the liver.