Control of Blood Pressure Flashcards
How quickly can arterial pressure increase to twice the normal level?
Within 5-10 seconds
How quickly can arterial pressure decrease to 50% of the normal level?
Within 10-40 seconds
Where are baroreceptors mainly located?
Walls of aorta and carotid artery
What increases the rate of firing of baroreceptors?
Increased blood pressure
What do cardiopulmonary baroreceptors sense?
Central blood volume
What does a decrease in cardiopulmonary barorecptor firing do?
It signals a decrease in blood volume through increased sympathetic activity to the heart and blood vessels and a decrease in parasympathetic activity to the heart.
What is the Bainbridge reflex?
Sympathetic-mediated reflex in response to increased blood in atria. Causes increased HR and contractility.
What takes priority - The Bainbridge reflex or the baroreceptors?
The bainbridge reflex
What does the sensory area of the Medullary cardiovascular control centre (MCVC) “vasomotor” centre sense?
Input from baroreceptors
What does the lateral portion of the Medullary cardiovascular control centre (MCVC) “vasomotor” centre sense?
Efferent sympathetic nerves
What does the medial portion of the Medullary cardiovascular control centre (MCVC) “vasomotor” centre sense?
Efferent parasympathetic (vagal) nerves
What is the CNS ischaemic response?
- Emergency pressure control system
- When blood flow to the CVCC greatly decreased
- Increased peripheral vasoconstriction
- Increased sympathetic stimulation of the heart
- Increased systemic arterial pressure
How is blood flow easier to control safely when blood pressure is increased?
- Myogenic theory - stretch-induced vascular depolarisation of smooth muscle due to increased arterial pressure
- Metabolic theory - increased arterial pressure increases 02 and “washes out” local factors
What nerve gives off the carotid body?
Hering’s nerve which is a branch of the glossopharyngeal nerve
