The main responsible for the delay among the atrial and
ventricular contractions is the action potential conduction velocity of the AV
node cells. If the atria and ventricles contract simultaneously, atria cannot
give any help in filling the ventricles, which is needed, especially in those
with stiff ventricles as in the elderly. Hence atria have to contract first and
then the ventricles.
Answer:
Barroreceptors are specific type of receptors that are present within the membrane or wells of the blood vessels and monitor the changes occur in blood pressure.
The major and important barroreceptors are located in carotid sinus and the aorta for detecting fluctuation in the blood pressure. If blood pressure falls these receptors firing rate decreases and barroceptors reflexes act to increase heart rate in order to restore blood pressure in an individual.
Thus, the correct answer would be - increasing heart rate.
B) They should test their hypothesis before coming to that conclusion.
Answer: the proper number of chromosomes.
Explanation:
