BIO271H1 : BIO271 - Circulatory Section.docx
Document Summary
Type method none none muscular contractions move h2o none muscular contractions move isf. Ciliated cells move isf and muscle contractions closed ciliated cells move isf and muscle contractions open heart and blood vessels closed heart and blood vessels. Hearts and tracheal system closed single circuit closed double circuit. Yes, but kept fairly separate (trabeculae and spiral. Ventricle pumps blood into pulmonary and systemic circuits. Chambers arranged in series, two primary, two auxillary. Valves are passive except for when ventricle is filling (atria must contract) Non-contractile bulbus serves as volume and pressure reservoir. Pressure in atria exceeds ventricular pressure, av valves open and the ventricles fill passively: atrial systole. Atrial contraction forces additional blood into ventricles: ventricular systole. Ventricular contraction pushes the av valves closed and increases pressure in the ventricle: ventricular sytole, ventricular diastole. Ventricles relax and semilunar valves close increased ventricular pressure forces the semilunar valves open and blood is ejected.
