In the experiment where both common carotids are clamped, what is the immediate effect on the vasomotor center and aortic arterial pressure?
Explanation
This question tests the understanding of a classic physiological experiment (carotid clamping) used to demonstrate the function and mechanism of the baroreceptor reflex.
Other questions
Which part of the autonomic nervous system is considered the most important for regulating the circulation?
What is the principal effect of sympathetic stimulation on the small arteries and arterioles?
What is the most important circulatory effect of the parasympathetic nervous system?
Where is the vasomotor center, which controls the sympathetic vasoconstrictor system, located in the brain?
What is the term for the continuous firing of sympathetic vasoconstrictor nerve fibers that maintains a partial state of constriction in blood vessels?
What is the observed effect on arterial pressure after administering a spinal anesthetic that blocks all sympathetic nerve impulses, as shown in Figure 18-4?
Which neurotransmitter is primarily secreted at the endings of sympathetic vasoconstrictor nerves?
What is the condition called vasovagal syncope primarily caused by?
What is the speed of the nervous system's response in controlling arterial pressure?
During strong sympathetic stimulation, by how much can the heart rate and blood pumping capacity increase?
What is the alarm reaction, and what is the typical rise in arterial pressure associated with it?
Where are baroreceptors, the stretch receptors that initiate the baroreceptor reflex, most abundantly located?
At what range of arterial pressure are the carotid sinus baroreceptors typically not stimulated at all?
What are the net effects of the circulatory reflex initiated by the baroreceptors when they are excited by high pressure?
What is the primary purpose of the 'pressure buffer' function of the arterial baroreceptor system?
Why has the importance of baroreceptors in long-term blood pressure regulation been considered controversial by some physiologists?
At what pressure level does the chemoreceptor reflex become an important controller of arterial pressure?
What is the Bainbridge reflex?
What is the primary trigger for the powerful CNS ischemic response?
At what arterial pressure does the CNS ischemic response become a significant factor in regulating arterial pressure, acting as a 'last-ditch stand' mechanism?
What is the Cushing reaction?
What is the abdominal compression reflex?
What causes the arterial pressure to rise and fall by 4 to 6 mm Hg with each cycle of respiration, creating respiratory waves?
What are vasomotor waves, also known as Mayer waves, characterized by?
What is the underlying cause of vasomotor (Mayer) waves?
Which three major changes occur simultaneously to rapidly increase arterial pressure under nervous control?
In which body tissues is the sympathetic vasoconstrictor effect especially powerful?
What is the typical rate of firing for sympathetic vasoconstrictor tone under normal conditions?
The sensory area of the vasomotor center, which receives signals from the circulatory system, is located in which structure?
How do the operating pressure levels of the aortic baroreceptors compare to those of the carotid receptors?
What is the effect of the baroreceptors on blood pressure variability in a normal dog, as shown in the comparison in Figure 18-9?
At what pressure do the carotid sinus baroreceptors reach their maximum rate of impulse transmission?
The reflex initiated by low-pressure receptors in the atria that leads to reflex reductions in renal sympathetic nerve activity and decreased ADH secretion is known as what?
By how much can the Bainbridge reflex increase the heart rate?
What is the primary substance believed to cause the powerful stimulation of the vasomotor center during the CNS ischemic response?
To what level can the mean arterial pressure rise during a CNS ischemic response?
What is the primary function of the vasodilator area located in the lower half of the medulla?
During muscle exercise, what causes the rise in arterial pressure?
What is a key characteristic of how baroreceptors respond to a rapidly changing pressure compared to a stationary pressure?
The nerves from the carotid baroreceptors are transmitted through Hering’s nerves to which larger nerve?
How much can sudden inhibition of nervous cardiovascular stimulation decrease arterial pressure within 10 to 40 seconds?
After denervation of the baroreceptors in a dog, the pressure range was observed to increase by how much?
What is the primary role of the sympathetic vasodilator system in humans believed to be mediated by?
Which part of the brain is the principal area controlling the sympathetic vasodilator system?
What happens to the arterial pressure during heavy exercise?
The chemoreceptors that initiate the chemoreceptor reflex are primarily sensitive to what changes in the blood?
The purpose of the Cushing reaction is to:
How long does a typical cycle of a vasomotor (Mayer) wave last in an unanesthetized human?
In the final analysis, why do nervous pressure control mechanisms like the baroreceptor reflex oscillate to cause vasomotor waves?