BIOL10002 Lecture Notes - Lecture 14: Ductus Arteriosus, Sinus Venosus, Pulmonary Circulation
Document Summary
Haemolymph is combined blood of oxygentated and deoxygenated blood (in open circulatory systems: fish: single circulation (one a and one v) Problem with single circulation is that it is low pressure therefore metabolic rate a fish can obtain is very low (non-efficient delivery of o2 and nutrients) Split between atria and ventricles = separated circuits. Separate capillaries for lungs when breathing air, and capillaries for gills: amphibians: pulmonary circuit to lungs. Higher pressure in systemic circuit, while retaining lower pressure in the pulmonary circuit. Still some mixing between o blood and do blood so that the exchange surface is not damaged. Septum is a wall that divides chamber into two: reptiles: pronounced separation. Can bypass lungs whilst holding their breathe. Holding breathe= higher resistance in pulmonary circuit. Therefore pushing the blood to bypass this circuit. When breathing, there is lower resistance so the blood goes easily to the circuit: birds and mammals: 4 chambered- hearts.
