The heartbeat Flashcards
What is used to record the electrical activity of the heart in hospitals?
An electrocardiograph (ECG)
Why does the heart beat faster during exercise?
Muscles use up oxygen quicker in respiration to supply energy for movement. Blood can be delivered faster to the muscles, and this supplies oxygen
What is the function of the pace maker?
Controls the heartbeat rate. It sends electrical impulses through the wall of the heart at regular time intervals. causing the muscles to contract.
What causes the pH of the blood to decrease?
During exercise, the concentration of carbon dioxide increases. It dissolves in the blood and forms a weak acid.
How does the brain respond to a decreased blood pH
It sends impulses along the nerves to pacemaker,causing the heart to beat faster.
Describe diastole
Cardiac muscles relax. The heart becomes larger and blood flows into the atria and vetricles.
Describe atrial systole
Muscles of the atria contract. Muscles of the ventricles
remain relaxed. Blood is forced from the atria into the ventricles
Describe vetricular systole
Muscles of the atria relax. Muscles of the vetricles contract. Blood is forced out of the ventricles and into the arteries.
