Podcast
Questions and Answers
What happens to the impulses that originate at the SA node during atrial contraction?
What happens to the impulses that originate at the SA node during atrial contraction?
- They are blocked by the atrioventricular node
- They are delayed for about 0.1 second before spreading to the heart apex (correct)
- They are conducted directly to the ventricular walls
- They are transmitted directly to the Purkinje fibers
What is the function of the bundle branches and Purkinje fibers?
What is the function of the bundle branches and Purkinje fibers?
- To conduct signals from the AV node to the ventricular walls (correct)
- To secrete hormones that influence the pacemaker
- To regulate the pace of the SA node
- To detect changes in body temperature
What is the role of the parasympathetic division in regulating heart tempo?
What is the role of the parasympathetic division in regulating heart tempo?
- It has no effect on the pacemaker
- It slows down the pacemaker (correct)
- It increases the force of contraction
- It speeds up the pacemaker
What is the effect of an increase in body temperature on heart rate?
What is the effect of an increase in body temperature on heart rate?
What is the role of epinephrine in regulating heart rate?
What is the role of epinephrine in regulating heart rate?
What happens to the atria during atrial contraction?
What happens to the atria during atrial contraction?
What is a characteristic of some cardiac muscle cells?
What is a characteristic of some cardiac muscle cells?
Where is the pacemaker located in vertebrates?
Where is the pacemaker located in vertebrates?
What is the function of the sinoatrial node?
What is the function of the sinoatrial node?
What is the purpose of an electrocardiogram (ECG or EKG)?
What is the purpose of an electrocardiogram (ECG or EKG)?
What is special about the impulses produced by the sinoatrial node?
What is special about the impulses produced by the sinoatrial node?
What is the term for the cluster of autorhythmic cells that sets the rate and timing of cardiac muscle cell contractions?
What is the term for the cluster of autorhythmic cells that sets the rate and timing of cardiac muscle cell contractions?
Where in the heart does the heartbeat originate?
Where in the heart does the heartbeat originate?
What allows impulses from the SA node to spread rapidly within heart tissue?
What allows impulses from the SA node to spread rapidly within heart tissue?
What is recorded by electrodes placed on the skin in an electrocardiogram?
What is recorded by electrodes placed on the skin in an electrocardiogram?
What is the shape of the graph representing the stages in the cardiac cycle?
What is the shape of the graph representing the stages in the cardiac cycle?
What is unique about the rhythmic contractions of autorhythmic cardiac muscle cells?
What is unique about the rhythmic contractions of autorhythmic cardiac muscle cells?
In which vertebrates is the pacemaker located in the nervous system?
In which vertebrates is the pacemaker located in the nervous system?
What is the primary function of the AV node?
What is the primary function of the AV node?
What happens to the heart rate when the body temperature increases?
What happens to the heart rate when the body temperature increases?
What is the primary function of the bundle branches and Purkinje fibers?
What is the primary function of the bundle branches and Purkinje fibers?
What is the result of the sympathetic division stimulating the pacemaker?
What is the result of the sympathetic division stimulating the pacemaker?
What is the primary function of the SA node?
What is the primary function of the SA node?
What is the result of the parasympathetic division stimulating the pacemaker?
What is the result of the parasympathetic division stimulating the pacemaker?
