Select all that applyThe heartbeat originates in the remnant of the sinus venosus known as the sinoatrial node in which of the following animals?Multiple select question.BirdsMammalsFishAmphibians

In a fish, electrical impulses that cause the heart to contract are initiated in theMultiple choice question.sinus venosus.SA node.conus arteriosus.ventricle.

Four-chambered hearts, two atria and two ventricles, are found in all of these animals exceptMultiple choice question.crocodiles.mammals.amphibians.birds.

What is the first structure that contracts in a fish heart?Multiple choice question.The sinus venosusThe atriumThe conus arteriosusThe ventricle

Which of the following structures is found between the right atrium and the right ventricle in a mammal?Multiple choice question.The SA nodeThe aortic valveThe bicuspid valveThe tricuspid valve

The Sinoatrial node is the normal pacemaker of the heart with a rhythm of 70-80 bpm. The SA node has an unstable resting potential. Question 4Answera.Both statements are TRUEb.First statement is TRUE. Second statement is FALSEc.Both statements are FALSEd.First statement is FALSE. Second statement is TRUE.