When we flung our arms around on the first day of class our heart rate increased to meet the demands of our exercising muscles. What was the mechanism by which this occurred? O Norepinephrine bound to receptors on the SA and AV nodes of the heart O The excess CO2 in the plasma generated by our skeletal muscles directly stimulated our cardiomyocytes to contract more frequently O Parasympathetic postganglionic neurons released acetylcholine onto the SA and AV nodes of the heart

The atrioventricular node is located in the: A. right atrium B. right ventricle C. septum between the right and left atrium D. juncture between the right atrium and ventricle       Preganglionic parasympathetic neurons release NT that binds to: A. nicotinic acetylcholine ligand-gated receptors B. muscarinic acetylcholine GPCRs C. beta-1 norepinephrine GPCRs D. norepinephrine ligand-gated receptors

Which of the following provides parasympathetic input to the SA and AV nodes of the heart? Adrenal gland (suprarenal) O Vagus nerve O all of these choice are correct O Cervical paravertebral ganglia

answer all questions don't need explanation 1) Multiple answers: Which of the following would cause a decrease in heart rate? Group of answer choices a)Increase in sympathetic input to the SA node b)Decrease in sympathetic input to the SA node c)Increase in parasympathetic input to SA node d)Decrease in parasympathetic input to SA node   2) Where would you expect there to be a receptor to detect the increased MAP during exercise? Group of answer choices (Hypothalamus, Capillaries, Arterioles, Carotid sinus, Vein)   3)Multiple answers: Which of the following mechanisms may have occurred to explain Jose's elevated MAP? Group of answer choices a)An increased total peripheral resistance b)A decreased stroke volume c)An inecrased heart rate d)An increased cardiac output e)A sudden increase in water volume in arteries