cardio control2 (1)
TRANSCRIPT
-
8/6/2019 Cardio control2 (1)
1/18
CARDIOVASCULAR
CONTROL, PART 2Bio Sci E109
Human Physiology
-
8/6/2019 Cardio control2 (1)
2/18
-
Integratingcenter
Effector
Sensor
Stimulus
What matters tocardiovascular homeostasis?
Blood pressure Exercise: commands from themotor cortex
Baroreceptors
Proprioceptors, muscle
spindle organs
Medulla oblongata
Heartrate
Strokevolume
Peripheralresistance
Autonomic pathways
-
8/6/2019 Cardio control2 (1)
3/18
Ganglion
Smooth & cardiac muscle
Glands & adipose tissue
Spinalcord
Effectororgan
EFFERENT PATHWAYS
AChNicotinicreceptor
NE
receptor1 receptor
Autonomic
SympatheticAdrenal
sympathetic
Adrenalgland
EBlood
stream
2 receptor
Parasympathetic
Ganglion
AChNicotinicreceptor
ACh
Muscarinicreceptor
-
8/6/2019 Cardio control2 (1)
4/18
AUTORHYTHMIC CELLS
Time (ms)
Vm(mV)
-60
0 600
0
+20
-40
Out
In
If
Na+
K+
Opens at Vm = -60 mV
Ca2+
Ca2+
Opens at Vm = -40 mV
Slow K+Opens at high Vm
K+
-
8/6/2019 Cardio control2 (1)
5/18
CONTROL OF HEART RATE
Vm(mV)
0 ms 800 ms
-60
0
+20
-40
Pacemaker potential
WithNorepinephrine
H
eart rate
NE release
1in SA Node
Sympathetic
Ifduration
Membrane potential of
autorhythmic cell inSA Node
-
8/6/2019 Cardio control2 (1)
6/18
PCa2+
CONTROL OF HEART RATE
Vm(mV)
0 ms 800 ms
-60
0
+20
-40
Pacemaker potential
WithNorepinephrine
H
eart rate
NE release
1in SA Node
Sympathetic
Ifduration
With ACh
H
eart rate
ACh release
Musc. receptorin SA Node
Parasympathetic
PK+
Stroke volume
?
Membrane potential of
autorhythmic cell inSA Node
-
8/6/2019 Cardio control2 (1)
7/18
FRANK-STARLING LAW
Ventricular end-diastolic volume (mL)
Strokevolume(mL)
0 4000
70
300
With Norepinephrine
(sympathetic pathway)
Heart increases forceproduction to clear all blood
that enters the heart
135Resting value
Effects of NE on myocardial cells (1 - receptors)1. increases [Ca2+] when activated2. shortens duration of activation
Increases contractility
-
8/6/2019 Cardio control2 (1)
8/18
?
Peripheral resistance
1in ventricularmyocardium
EFFERENT PATHWAYS
Heart rate
NE release
1in SA Node
Sympathetic
Ifduration
Heart rate
ACh release
Musc. receptorin SA Node
Parasympathetic
PK+ PCa2+
Stroke volume
Contractility
-
8/6/2019 Cardio control2 (1)
9/18
?
1in ventricularmyocardium
EFFERENT PATHWAYS
Heart rate
NE release
1in SA Node
Sympathetic
Ifduration
Heart rate
ACh release
Musc. receptorin SA Node
Parasympathetic
PK+ PCa2+
Stroke volume
Contractility
Sympathetic neuron
Actionpotentials
Smooth musclearound ar teriole
receptor
NE
Peripheral resistance
-
8/6/2019 Cardio control2 (1)
10/18
Peripheral resistance
in arteriolesm. muscle
Vasoconstriction
1in ventricularmyocardium
EFFERENT PATHWAYS
Heart rate
NE release
1in SA Node
Sympathetic
Ifduration
Heart rate
ACh release
Musc. receptorin SA Node
Parasympathetic
PK+ PCa2+
Stroke volume
Contractility
Sympathetic neuron
Actionpotentials
Smooth musclearound ar teriole
receptor
NE
Increased sympathetic stimulation causesvasoconstriction and high peripheral resistance
-
8/6/2019 Cardio control2 (1)
11/18
Peripheral resistance
in arteriolesm. muscle
Vasoconstriction
1in ventricularmyocardium
EFFERENT PATHWAYS
Heart rate
NE release
1in SA Node
Sympathetic
Ifduration
Heart rate
ACh release
Musc. receptorin SA Node
Parasympathetic
PK+ PCa2+
Stroke volume
Contractility
Sympathetic neuron
Actionpotentials
Smooth musclearound ar teriole
receptor
Decreased sympathetic stimulation causesvasodilatation and low peripheral resistance
-
8/6/2019 Cardio control2 (1)
12/18
Peripheral resistance
in arteriolesm. muscle
Vasoconstriction
1in ventricularmyocardium
INTEGRATION CENTER
Heart rate
NE release
1in SA Node
Ifduration
Heart rate
ACh release
Musc. receptorin SA Node
PK+ PCa2+
Stroke volume
Contractility
MedullaoblongataBlood pressure control
-
8/6/2019 Cardio control2 (1)
13/18
Peripheral resistance
in arteriolesm. muscle
Vasoconstriction
1in ventricularmyocardium
SENSORY ORGANS
Heart rate
NE release
1in SA Node
Ifduration
Heart rate
ACh release
Musc. receptorin SA Node
PK+ PCa2+
Stroke volume
Contractility
Medullaoblongata
Baroreceptors
Aorta
Carotid artery
Baroreceptors
Baroreceptors sense MeanArterial Pressure (MAP)via strain in major arteries
-
8/6/2019 Cardio control2 (1)
14/18
BARORECEPTOR REFLEX
Peripheral resistance
in arteriolesm. muscle
Vasoconstriction
1in ventricularmyocardium
Heart rate
NE release
1in SA Node
Ifduration
Heart rate
ACh release
Musc. receptorin SA Node
PK+ PCa2+
Stroke volume
Contractility
Medullaoblongata
Baroreceptors
Blood pressureBaroreceptors sense MeanArterial Pressure (MAP)via strain in major arteries
-
8/6/2019 Cardio control2 (1)
15/18
-
BARORECEPTOR REFLEX
Peripheral resistance
in arteriolesm. muscle
Vasoconstriction
1in ventricularmyocardium
Heart rate
NE release
1in SA Node
Ifduration
Heart rate
ACh release
Musc. receptorin SA Node
PK+ PCa2+
Stroke volume
Contractility
Medullaoblongata
Baroreceptors
Blood pressure High Blood Pressure
+-
Peripheral resistance
Vasodialation
Reducesympatheticpathways
Activateparasympathetic
pathways
-
8/6/2019 Cardio control2 (1)
16/18
Heart rate
ACh release
Musc. receptorin SA Node
PK+ PCa2+
-
BARORECEPTOR REFLEX
Peripheral resistance
in arteriolesm. muscle
Vasoconstriction
1in ventricularmyocardium
Heart rate
NE release
1in SA Node
Ifduration
Stroke volume
Contractility
Medullaoblongata
Baroreceptors
Blood pressure Low Blood Pressure
+ -
Reduceparasympathetic
pathways
Activatesympatheticpathways
-
8/6/2019 Cardio control2 (1)
17/18
Heart rate
ACh release
Musc. receptorin SA Node
PK+ PCa2+
-
REGULATING BLOOD VOLUME
Peripheral resistance
in arteriolesm. muscle
Vasoconstriction
1in ventricularmyocardium
Heart rate
NE release
1in SA Node
Ifduration
Stroke volume
Contractility
Baroreceptors
Blood pressure
+ -
Blood volume
Thirst
KidneyOsmolarity
of urine
Drink water
Medulla &hypothalamus
Low Blood Pressure
-
8/6/2019 Cardio control2 (1)
18/18
KidneyOsmolarity
of urine
-
Peripheral resistance
in arteriolesm. muscle
Vasoconstriction
1in ventricularmyocardium
Heart rate
NE release
1in SA Node
Ifduration
Heart rate
ACh release
Musc. receptorin SA Node
PK+ PCa2+
Stroke volume
Contractility
Medulla &hypothalamus
Baroreceptors
Blood pressure High Blood Pressure
+-
Peripheral resistance
Vasodialation
Blood volume
REGULATING BLOOD VOLUME