24 Questions
Which part of the nervous system is primarily responsible for regulating heart rate under resting conditions?
Vagal tone
Which of the following reflexes is responsible for the increase in heart rate due to increased venous return?
Bainbridge reflex
According to Marey's Law, what is the relationship between heart rate and arterial blood pressure?
Heart rate is inversely proportional to arterial blood pressure
Which of the following is the correct pathway for the Bainbridge reflex?
Increased venous return → increased right atrial pressure → stimulation of atrial stretch receptors → increased cardiac filling → increased heart rate
Which part of the hypothalamus is responsible for stimulating the Cardiac Acceleratory Center (CAC) and increasing heart rate?
Posterior hypothalamus
What is the effect of deep inspiration on heart rate according to the text?
Deep inspiration increases heart rate
What is the mechanism by which stimulation of the carotid sinus baroreceptors can lead to bradycardia?
Stimulation of the Cardiac Inhibitory Center (CIC)
Which of the following is a direct mechanism by which the respiratory center can influence heart rate?
Respiratory sinus arrhythmia
What is the effect of sympathetic stimulation on the heart?
Increases the heart rate
Which of the following statements about heart rate is true?
The average heart rate for adults is around 70 beats per minute
Which factor does NOT contribute to physiological variations in heart rate?
Body mass index (BMI)
Which of the following statements about the regulation of heart rate is true?
The parasympathetic nervous system decreases the SA nodal discharge and heart rate
Which of the following heart rates would be considered bradycardia?
50 beats per minute
What is the typical heart rate for an infant?
Around 120 beats per minute
Which of the following factors contributes to a lower heart rate in athletes?
Their heart is stronger and more efficient
What is the primary mechanism by which the autonomic nervous system regulates heart rate?
By controlling the SA nodal discharge
What is the effect of voluntary contraction of skeletal muscles on heart rate?
Tachycardia
Which of the following accurately describes the effect of hypoxia (low oxygen) on heart rate?
Mild to moderate hypoxia causes tachycardia, while severe hypoxia causes bradycardia
Which hormone is associated with an increase in heart rate?
All of the above
What is the effect of applying pressure on the eyeball (oculo-cardiac reflex) on heart rate?
Bradycardia
How does moderate hypercapnia (increased carbon dioxide) affect heart rate?
Causes tachycardia
Which of the following substances causes bradycardia (decreased heart rate)?
Morphine
What is the approximate increase in heart rate for every 1°C rise in body temperature?
10-13 beats per minute
Which of the following is NOT a factor that regulates heart rate?
Dietary habits
Test your knowledge on heart rate regulation with questions on the impact of sympathetic and parasympathetic stimulation, physiological variations, factors regulating heart rate, and different methods of regulation like nervous, chemical, and physical mechanisms.
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