Control of Systemic Blood Pressure Flashcards
Which of the following do you think are effects of the baroreceptor reflex in response to a fall in blood pressure?
A. Adrenaline secretion
B. Arterial vasoconstriction
C. Increased secretion of vasopressin
D. Sodium retention
E. Splanchnic venoconstriction
F. Tachycardia and increased myocardial contractility
All of them.
A. Adrenaline secretion by the adrenal glands is stimulated by increased sympathetic activity.
B. Vasoconstriction of peripheral vessels is a result of sympathetic vasomotor activity.
C. Increased secretion of vasopressin occurs when the brain responds to a fall in the blood pressure.
D. Sodium retention occurs when increased sympathetic activity leads to renin secretion.
E. Increased sympathetic vasomotor activity also causes splanchnic venoconstriction.
F. Reduced vagal activity mediates tachycardia, together with adrenaline secretion this increases myocardial contractility.
Regarding the sympathetic control of BP (true or false):
The single most important physiological regulator of vascular tone is sympathetic vasoconstriction
True
Regarding the sympathetic control of BP (true or false):
The sympathetic fibres release adrenaline
False. The sympathetic fibres release noradrenaline.
Regarding the sympathetic control of BP (true or false):
The transmitter release is quantal
True
Regarding the sympathetic control of BP (true or false):
Arterioles are the most densely sympathetically innervated blood vessels
True
Regarding hormonal control of blood pressure (true or false):
Adrenaline has both metabolic and cardiovascular effects
True
Regarding hormonal control of blood pressure (true or false):
Vasopressin is synthesized in the kidney
False. Vasopressin is synthesized in the magnocellular neurons of supraoptic and paraventricular nuclei.
Regarding hormonal control of blood pressure (true or false):
Angiotensin II production is mediated by renin and endothelial ACE
True
Regarding hormonal control of blood pressure (true or false):
Angiotensin II is a direct vasoconstrictor
True
Regarding hormonal control of blood pressure (true or false):
Natriuretic peptides increase the plasma volume
False. Natriuretic peptides reduce the plasma volume.
Regarding baroreceptors (true or false):
Baroreceptors respond to hypoxic stimuli
False. Baroreceptors are stretch receptors.
Regarding baroreceptors (true or false):
Baroreceptors have only dynamic sensitivity
False. Baroreceptors have static and dynamic sensitivity.
Regarding baroreceptors (true or false):
The baroreceptor reflex provides short-term homeostasis of blood pressure
True
Regarding baroreceptors (true or false):
The baroreceptor reflex does not affect cardiac output
False. The baroreceptor reflex does affect cardiac output.
Regarding baroreceptors (true or false):
Peripheral chemoreceptors are excited by hypoxia and acidosis and elicit hypotension through peripheral vasodilatation
False. Peripheral chemoreceptors are excited by hypoxia and acidosis and elicit hypertension through vasoconstriction.
Regarding the Valsalva manoeuvre (true or false):
Valsalva manoeuvre is forced inspiration against a closed glottis
False. The Valsalva manoeuvre is forced expiration against a closed glottis.
Regarding the Valsalva manoeuvre (true or false):
In Phase I arterial blood pressure decreases as the thoracic aorta is compressed by the high intrathoracic pressure
False. In Phase I arterial blood pressure increases as the thoracic aorta is compressed by high intrathoracic pressure.
Regarding the Valsalva manoeuvre (true or false):
In Phase IV there is a transient bradycardia
True
Regarding the Valsalva manoeuvre (true or false):
In patients with autonomic neuropathy the blood pressure continues to fall in Phase II and does not overshoot in Phase IV
True
Regarding the Valsalva manoeuvre (true or false):
On terminating the Valsalva manoeuvre, intrathoracic pressure falls to normal and the thoracic aorta is decompressed, so arterial blood pressure falls abruptly
True
Regarding substances secreted by the endothelium (true or false):
Adenosine, bradykinin and histamine are vasodilators
True
Regarding substances secreted by the endothelium (true or false):
Thromboxane A2 inhibits platelet aggregation
False. Thromboxane A2 encourages platelet aggregation.
Regarding substances secreted by the endothelium (true or false):
Prostacyclin inhibits platelet aggregation and produces vasodilatation
True
Regarding substances secreted by the endothelium (true or false):
Endothelins are the most potent naturally occurring vasoconstrictors in the body
True
Regarding substances secreted by the endothelium (true or false):
Nitric oxide is synthesized by the endothelium from L-Arginine and is a potent vasodilator
True
