Summary
Taxonomy
Physical Description
Ecology
Life History & Behaviour
Anatomy & Physiology
Torsion and the mantle cavity
Nervous system
Sensory systems
Reproduction
Internal transport
Feeding mechanisms
Digestive system
Respiration
Excretion
Foot anatomy
Evolution & Systematics
Conservation & Threats
References & Links |
Internal transport
Internal transport in gastropods are similar to that of the general molluscs with the exception that the pericardial cavity and heart were moved by torsion from the primitive posterior location to within the anterior visceral mass. The heart of higher gastropods consists of a muscular ventricle and atrium, with the ventricle having more muscle mass than that of the atrium. The ventricle receives oxygenated blood from the atrium and pumps into the aortae, where the posterior (visceral) aorta supplies the visceral hemocoel and the anterior (cephalic) aorta supplies the cephalopedal hemocoel. Unoxygenated blood passes over the nephridium and gills to remove wastes from it and also to take on a fresh supply of oxygen on the way back to the heart. The arteries and veins are made up of both connective and muscular tissues. They also have open hemocoelic spaces that are not lined by an epidermis which are split into two main spaces, called the visceral and cephalopedal hemocoel. The lack of an epidermis enables the hemocoels to adopt different shapes and sizes, which increases the surface area. This plays an important part in the hydrostatic role that blood plays in addition to that of internal transport. In Prosobranch like C. parthenopeum, the blood plasma carries hemocyanin as its respiratory pigment (Ruppert et al., 2004). |
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