Baroreflex Flashcards
(15 cards)
what is blood pressure
pressure of blood that is exerted on arterial walls
what is systolic blood pressure
peak pressure in the arteries, occurs during cardia contractions (90-120mmHg)
what is diastolic blood pressure
minimum pressure in the arteries, occurs when the heart is not actively contracting and ventricles are filled with blood
(60-80mmHg)
how to calculate blood pressure
cardiac output x Total peripheral resistance
how to calculate cardiac output
stroke volume x heart rate
how to calculate total peripheral resistance
contractility/ radius vessels + circulating volume
what is short term neural control and how does it work
allows an increase in blood pressure in response to immediate changes in physical activity/stress etc.
-baroreceptors responds to pressure changes and stimulates impulses to be sent to cardiovascular centre to activate the sympathetic or parasympathetic nervous system
what is long term renal/hormonal regulation
mechanisms that help to maintain blood pressure, fluid balance etc.
-works through the kidneys in the renal systems to ensure stable blood volume
what are baroreceptors, where are they found and how do they work
found in the carotid sinus in neck and the aortic arch on the aorta
-in high blood pressure, the baroreceptors sense the stretching of the blood vessels and they send impulses to the medulla of the brain to reduce the blood pressure e.g. decreased heart rate
opposite for the decrease of high blood pressure which causes less stretching of the blood vessels
what is the cardiovascular centre
region in the medulla oblongata of the brain and plays a role in regulating heart rate, blood pressure
what are the 3 distinct components of the cardiovascular centre
-cardioaccelerator centre, regulates the heart rate and blood pressure
-cardioinhibitory centre slows heart rate
-vasomotor centre controls the vessel diameter
what is the afferent pathway
pathway that transmits sensory info from the sensory neurones/ peripheral receptors (that detects stimuli like temp change) to the central nervous system
what is efferent pathways
-transmission of motor signals from the CNS to the peripheral effectors e.g. muscles or glands
what are effectors
-responds to nervous system signals to produce a response or actions1
how is arterial pressure regulated and restored back to normal
Increased blood pressure
1) stretched arterial walls
2)baroreceptors sends more signals via carotid sinus to the medulla oblongata of the brain
3) parasympathetic output increases to the heart to reduce heart rate and blood pressure and decreases sympathetic output
Decreased arterial pressure
1) baroreceptors detect the less stretch in the arterial wall
2) sends less signals to the carotid sinus nerve
3) increases the sympathetic activity to increase heart rate and contractility and TPR
4) decrease in the parasympathetic activity
