Related Experiment Video
Updated: Aug 15, 2026

Heart Dissection in Larval, Juvenile and Adult Zebrafish, Danio rerio
Published on: September 30, 2011
Anatomical position of heart in snakes with vertical orientation: a new hypothesis
1Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE 68178, USA.
Abstract:
It has been observed that climbing arboreal snakes have hearts closer to the head than nonclimbing terrestrial or aquatic snakes. The closeness to the head is said to minimize the work of the heart in pumping blood to the head. However, there is ample evidence that the gravitational pressure in the arteries going to the head is counterbalanced (neutralized) by the gravitational pressure of the blood in the veins going down to the heart. Hence, the heart does not do extra work so, another explanation must be sought. It is proposed that the position of the heart may be related to the filling pressure of the heart which is influenced by the compliance of the vessels above and below the heart. Some observations suggest that the caudal vessels in climbing snakes are less compliant than that of aquatic snakes. This tends to move the hydrostatic indifferent point closer to the head and provides an adequate filling pressure in climbing snakes in the vertical position.
Related Concept Videos
Anatomy of the Heart
Anatomical Positions
The body is upright, facing forward, and standing erect.
The feet are parallel and flat on the floor.
The arms are hanging by the...
Location and Orientation of the Heart
Chambers of the Heart
Deoxygenated blood from the body is received in the right...
Development of the Heart
As the embryo undergoes lateral folding, these paired tubes approach each other, merging into a single primitive heart tube by...
Anatomy of the Heart
The heart has three layers: the innermost endocardium, the muscular myocardium, and the outer epicardium, all working together for optimal cardiac function.
Chambers of the Heart
The heart is made up of four...

