BIOL 382 Lecture Notes - Lecture 14: Vascular Smooth Muscle, Qrs Complex, Histamine
Document Summary
Conus arteriosus forms pulmonary artery and right and left aorta. Reptiles can bypass either pulmonary or systemic circulation using a shunt. R to l shunt useful for diving since the animal is not breathing. L to r shunt useful for oxygen delivery to spongy right heart. The two aortas are connected at foramen of. Right aorta sends blood to brain and anterior circulation. Left aorta send blood to viscera and posterior parts. When blood pressure in two ventricles is equal, oxygenated blood from the lv goes to the brain via the r-aorta and deoxygenated blood from rv goes to viscera via l-aorta where it may aid digestion. When blood pressure is greater in lv than rv, active and breathing air, r-l shunt is inhibited. The pulmonary valve of crocodile hearts has cog teeth made up of connective tissue. Epinephrine controls the position of the cog teeth. At rest, epinephrine is low and the valve is closed.
