Central and Autonomic Regulation of Cardiac Function Flashcards
Which of the following areas in the brain are involved in the central control of cardiac function?
A. Substantia nigra
B. Rostral ventrolateral medulla
C. Hypothalamus
D. Limbic system
All except A.
Regarding cardiac intrinsic autorhythmicity (true or false):
The SAN is said to have dominance
True
Regarding cardiac intrinsic autorhythmicity (true or false):
The intrinsic rate of the SAN is 40–60 bpm
False. This is the intrinsic rate of the AVN.
Regarding cardiac intrinsic autorhythmicity (true or false):
The rate of decay of the pacemaker potential determines HR
True
Regarding cardiac intrinsic autorhythmicity (true or false):
Sodium is the principal ion responsible for Phase 4 of the SAN action potential
False. Whilst sodium permeability increases in Phase 4 of the SAN action potential it is actually the fall in potassium permeability and increase in calcium permeability that is most important.
Regarding cardiac intrinsic autorhythmicity (true or false):
Activation of L-type voltage gated calcium channels and calcium flux occurs in Phase 0 of the SAN action potential
True
Regarding baroreceptors (true or false):
They are mechanoreceptors
True
Regarding baroreceptors (true or false):
The carotid sinus baroreceptors are high pressure baroreceptors
True
Regarding baroreceptors (true or false):
The glossopharyngeal nerve relays afferent impulses from the aortic arch baroreceptors
False. The glossopharngeal nerve relays afferent impulses from the carotid sinus baroreceptors.
Regarding baroreceptors (true or false):
The vagus nerve relays afferent impulses from the aortic arch baroreceptors
True
Regarding baroreceptors (true or false):
The Bainbridge Reflex describes a paradoxical increase in heart rate seen with increased preload
True
Regarding CNS control of cardiac function (true of false):
The NTS is the main relay centre
True
Regarding CNS control of cardiac function (true of false):
The RVLM is the main group of central sympathetic premotor cells
True
Regarding CNS control of cardiac function (true of false):
The Nucleus Ambiguus increases parasympathetic output to the heart in periods of high blood pressur
True
Regarding CNS control of cardiac function (true of false):
The NTS receives modulation for higher cortical structures
True
Regarding CNS control of cardiac function (true of false):
The PAG is important in the flight and fight response
True
Regarding to autonomic regulation of cardiac function (true or false):
The SNS predominates at rest
False. PNS inhibition of intrinsic cardiac pacemaker activity predominates.
Regarding to autonomic regulation of cardiac function (true or false):
The PNS has a more rapid onset and offset action than the SNS
True. The PNS has is faster in onset and offset than the SNS because Ach is the principle post ganglionic neurotransmitter and is broken down by the widely available and rapid acting enzyme acetylcholinesterase.
Regarding to autonomic regulation of cardiac function (true or false):
The SNS originates from the intermediolateral columns of the upper thoracic spinal cord T1-T7
False. It originates from T1 – T5.
Regarding to autonomic regulation of cardiac function (true or false):
SNS stimulation increases cardiac lusitropy
True
Regarding to autonomic regulation of cardiac function (true or false):
Ach is the principle preganglionic neurotransmitter in the SNS and PNS
True
