Control Blood Pressure
of
120180 mmHg normal blood pressure
High systemic pressure is needed
To drive glomerular filtration rate
To control 1 regulate ionic balance fluid volume
To optimise kidney function
10x higher systemic pressure than pulmonary pressure
Pressure gradient same for most mammals
120180
not due to distance e
g same in mice and humans
systemic circulation
Stretch and elastic recoil in vessels controls
pressure
Pressuredrop driving force forward
Pulse Pressure
Time average mean arterial pressure
MAP DP t 113 SP Dp
determined by
1 Cardiac output 3 Blood distribution
HR diameter of veins
Sv pooling of blood in venous
affects systolic pressure system reservoir
reduce venous return 1 CO
2 Resistance to blood flow anaphylactic shock
diameter of arterioles
contractile state of smooth muscle 4 Blood volume
affects diastolic pressure fluid intake 1 loss
elasticity prevents pressure dropping to O e g dehydration burns
haemorrhage
, Change in blood pressure
A cute response slow response
Baroreceptor reflex Endocrine
v v
cardiovascular Renal
compensation compensation
V V
Change in Change in Alteration of
blood vessel
tone
cardiac output fluid loss via
urine
short term
desensitizes
Recovery of blood pressure
Baroreceptor reflex
Responds to changes in arterial pressure
Located in carotid sinus and aortic arch
Stretch receptors sensitive to changes in blood pressure
mechanosensitive
Respond rapidly
Relay information to cardiovascular control centre
of medulla oblongata
Buffer short term changes
Adapt to sustained changes
Individual baroreceptors are sensitive to different pressure ranges
C fibres small diameter
unmyelinated silent 100mmHg
slow conducting
higher pressure threshold
less regular discharge
A fibres large diameter
myelinated
fast
lower
conducting
threshold
pressure
regular firing in normal pulsatileflow
range
sensitive to static and dynamic pressure changes
Parasympathetic and sympathetic contributions
of
120180 mmHg normal blood pressure
High systemic pressure is needed
To drive glomerular filtration rate
To control 1 regulate ionic balance fluid volume
To optimise kidney function
10x higher systemic pressure than pulmonary pressure
Pressure gradient same for most mammals
120180
not due to distance e
g same in mice and humans
systemic circulation
Stretch and elastic recoil in vessels controls
pressure
Pressuredrop driving force forward
Pulse Pressure
Time average mean arterial pressure
MAP DP t 113 SP Dp
determined by
1 Cardiac output 3 Blood distribution
HR diameter of veins
Sv pooling of blood in venous
affects systolic pressure system reservoir
reduce venous return 1 CO
2 Resistance to blood flow anaphylactic shock
diameter of arterioles
contractile state of smooth muscle 4 Blood volume
affects diastolic pressure fluid intake 1 loss
elasticity prevents pressure dropping to O e g dehydration burns
haemorrhage
, Change in blood pressure
A cute response slow response
Baroreceptor reflex Endocrine
v v
cardiovascular Renal
compensation compensation
V V
Change in Change in Alteration of
blood vessel
tone
cardiac output fluid loss via
urine
short term
desensitizes
Recovery of blood pressure
Baroreceptor reflex
Responds to changes in arterial pressure
Located in carotid sinus and aortic arch
Stretch receptors sensitive to changes in blood pressure
mechanosensitive
Respond rapidly
Relay information to cardiovascular control centre
of medulla oblongata
Buffer short term changes
Adapt to sustained changes
Individual baroreceptors are sensitive to different pressure ranges
C fibres small diameter
unmyelinated silent 100mmHg
slow conducting
higher pressure threshold
less regular discharge
A fibres large diameter
myelinated
fast
lower
conducting
threshold
pressure
regular firing in normal pulsatileflow
range
sensitive to static and dynamic pressure changes
Parasympathetic and sympathetic contributions
