Neural Control Of Circulation Flashcards
Where is the medullary cardiovascular centre located?
In the medulla, within there is a region called pressor and depressor region
What is the pressor region responsible for?
Raising BP - it is sympathetic
How does the pressor region increase BP?
By increasing:
Vasoconstriction
Cardiac output ( by increasing heart rate and stroke vol)
Contractility
What pathway does it go from the pressor region to the heart?
Pressor region Sympathetic route Medulla Spinal cord Synapses at T1 to L2 Heart
Describe the sympathetic effect on cardiovascular system
Sympathetic postganglionic fibers innervation the entire heart
Controlled by adrenaline and nor adrenaline (which binds to beta 1 receptors in the heart)
Increase heart rate and cardiac output
Increase force of contraction
What is the depressor region responsible for?
Lowering BP- parasympathetic
How does the depressor region decrease BP?
Inhibits the pressor region
What is the pathway from depressor region to heart?
Depressor region Parasympathetic route Medulla Vagus nerve Heart
What is the parasympathetic effect on the cardiovascular system?
Fibers transmitted via vagus nerve Controlled by acetyl choline which binds to muscarinic type 2 receptors Decrease heart rate Decrease force of contraction Decreased cardiac output
What do central chemoreceptors in the medulla respond to and why?
A decrease in pH
Due to CO2 diffusing across blood brain barrier reducing pH of CSF
Peripheral chemoreceptors
Where are they found?
What are they sensitive to?
What is the response?
Aortic arch and carotid sinus
Increase CO2, decrease O2 and decrease pH
Impulses to pressor region of the medulla
Sympathetic NS
Increase BP
Arterial Baroreceptors
Where are they found?
What are they sensitive to?
How do they respond?
Aortic arch and carotid sinus
Stretch receptors, increase BP
Increased BP = increased firing rate (more distorted baroreceptor)
Increased impulses to the depressor centre of medulla
Parasympathetic NS
Decrease BP
What is the route of the arterial baroreceptor in the aortic arch?
Aortic arch, vagus nerve, medulla, decrease sympathetic, increase parasympathetic, decrease BP
What is the route of the arterial baroreceptor in the carotid sinus ?
Two receptors where left and right common carotid divide into 2 smaller arteries (internal and external carotid)-this part of the artery is known as the carotid sinus
Carotid sinus, sinus nerve, glossopharyngeal, medulla, decrease sympathetic, increase parasympathetic, decrease BP
Cardiopulmonary baroreceptor
Where are they found?
What are they sensitive to?
What is the response?
Atria, ventricles, pulmonary artery
Increased blood volume
Increase BV = increase BP = more distorted baroreceptor
Increased impulses sent to the depressor region of medulla
Parasympathetic route, decrease BP
