郑 煜（Zheng Yu）
Department of Physiology
West China School of Preclinical
and Forensic Medicine
Sichuan University
Tel: 8550 2389
E-mail: yzheng@scu.edu.cn
QQ: 1595486138
华西校区 逸夫楼 4-19
循环生理学课件网址：
http://cc.scu.edu.cn/G2S/Template/View.aspx?courseT
ype=1&courseId=43&topMenuId=118511&menuType
=1&action=view&type=&name=&linkpageID=118560
循环生理学
Circulatory Physiology
or
心血管生理学
Cardiovascular Physiology
教材和参考书
姚 泰主编
生理学（八年制规划教材）
第二版，人民卫生出版社，2010。
朱大年主编
生理学（五年制规划教材）
第八版，人民卫生出版社，2013。
Guyton & Hall
Textbook of Medical Physiology
12 Ed, Saunders, 2011.
William Harvey
1578-1657
1628
实验生理学的起源 !!!
现代医学的开端 !!!
2 parts and 2 circulations
Main Topics to be Discussed
Bioelectrical Activity and Physiological
Properties of Cardiac Myocyte
（心肌细胞的生物电活动和生理特性）
Heart as a Pump
（心脏的泵血功能）
Functions of Blood Vessels
（血管的功能）
Regulation of Cardiovascular Activity
（心血管功能的调节）
Coronary Circulation
（冠脉循环）
Part One
心肌细胞的
生物电活动和生理特性
(Bioelectrical Activity
and Physiological Properties
of Cardiac Myocyte)
I. 心肌细胞的生物电活动
（Bioelectrical Activity）
自律细胞
工作细胞
1
0
-70
3
2
0
3
4
4
Atrial M.
Ventricular M.
Purkinje C.
-90
Skeletal M.C.
Neuron
1
2
0
3
4
Sinus Node
A-V Node
(not Node
Region)
0
4
Node Region
Autorhythmic Nonautorhythmic
Fast Response C.
Purkinje
Slow Response C.
Sinus N.
A-V N.
(not Node
Region)
3
Atrial Muscle
Ventricular M.
Node Region
1.心室肌细胞的生物电活动
1
2
0 mV
0
﹣90 mV
3
4
Pattern
Mechanism
Permeability of cell membrane to ions
Driving force (electro-chemical gradient)
– 90 mV
1) Resting Potential
1
0 mV
2
3
0
4
﹣90 mV
[K+]i  [K+]o
Higher PK+
K+ outward flow
(IK1)
electrogenic Na+-K+ pump
Na+ inward flow
EK+
pump current
background current
2) Action Potential
1
0 mV
2
3
0
﹣90 mV
0
1
Phase 2
3
4
4
depolarization
initial rapid repolarization
plateau (slow repolarization)
final rapid repolarization
polarization (“resting”)
spike
Phase 0:
rapid depolarization
–90 ～ +30 mV
200 ～ 400 V/s
1 ～ 2 ms
(fast response potential)
Na+ channels open
[Na+]o  [Na+]i
→ Na+ flow in (INa)
→ ENa+
blocked by TTX
Phase 0
Phase 1:
initial rapid repolarization
+ 30 ～ 0 mV
10 ms
Na+ channels inactivation
K+ channels open
→ K+ flow out
→ transient outward
current (Ito)
activated at –30 mV
blocked by 4-aminopyridine
Phase 1
Phase 2:
around 0 mV
plateau (phase of slow
repolarization)
100 ～ 150 ms
L-type Ca++ channels open
Ca++ flow in ( ICa-L )
at –30 ～ –40 mV
slow
blocked by Mn++
IK ↑ (activated at –40 mV dep. ,
inactivated at –40 ～ –50 mV rep.)
IK1 ↓ (inward rectification)
Phase 2
Phase 3:
final rapid repolarization
0 ～ – 90 mV
100 ～ 150 ms
K+ flow outward
( IK ) till –50 mV
IK1 recover gradually
Phase 3
Phase 4:
– 90 mV
1
0 mV
2
3
IK1 recovered
Na+
K+
0
﹣90 mV
4
pump
(3Na+ outward,
2K+ inward)
(Na+ - K+ pump current)
Na+ - Ca++ exchanger
(3Na+ inward, 1Ca++ outward)
(Na+ - Ca++ exchange current)
Ca++ pump
(a few Ca++ outward)
(Ca++ pump current)
Membrane
more active
Summary
1(10 ms)
2 (100-150 ms)
30
mV
0
3 (100-150 ms)
(1-2
ms)
-90 mV 4
outside
+
K
inside
4
Na+ Ca2+ Ca2+
K+ K+
4 0 1
INa Ito
2K+
K+ K+
2
3
IK
ICa-L
IK1
IK
3Na+
Ca2+
+
3Na
K+
4
IK1
INa+ - K+ pump
INa+ - Ca++ exchange
ICa++ pump
2.窦房结起搏细胞的生物电活动
（Sinus Pacemaker Cell）
1) 特点（Properties）
3 phases
(no phases 1 and 2)
lower maximal
repolarization p.
(-70 mV)
lower threshold
potential (-40 mV)
lower amplitude (70 mV)
1
2
0 mV
3
0
4
-90 mV
-70 mV
0 mV
0 mV
0
-40 mV
-70
-70mV
mV
0
3
3
4 4 -40 mV
longer duration of depolarization (7 ms)
slower velocity of depolarization (10V/s)
automatic depolarization (0.1 V/s)
2) 机制（Mechanism）
Phase 0:
L-type Ca++ channels open (ICa-L)
Phase 3:
K+ channels open (IK)
Phase 4:
IK decreases gradually
If (funny current)
(Na+, a few K+)
(pacemaker current)
ICa-T increases
IK activated
ICa-T
IK inactivated
If
ICa-L
Summary
0 mV
0
3
– 40 mV
– 70 mV
outside
inside
4
Ca2+ (ICa-L)
K+(IK)
Na+ (If)
Ca2+ (ICa-T)
Importance of maintenance of
ions concentration in the activity
of cardiac cells
II. 心肌细胞的生理特性
（Physiological Properties）
Electrophysiological Properties
Excitability（兴奋性）
Autorhythmicity（自动节律性）
Conductivity（传导性）
Mechanical Property
Contractility（收缩性）
自律性细胞
工作细胞
兴奋性 
兴奋性 
自律性 
自律性 
传导性 
传导性 
收缩性 
收缩性 
1.兴奋性（Excitability）
1) Factors affecting excitability
RP or maximal repolarization potential
Threshold potential
State of ion channels
resting
↓
activation
↓
inactivation
↓
reactivation
2) Changes in Excitability during Excitation
(1) Effective Refractory Period (ERP)（有效不应期）
Phase 0 ~ –60 mV (Rep) Excitability 0
Absolute Refractory Period（绝对不应期）
Phase 0 ~ –55 mV rep.
Local Response Period （局部反应期）
– 55 ~ –60 mV rep.
Local response
ERP
RRP
ERP
(2) Relative Refractory Period (ERP)（相对不应期）
–60 ~ –80 mV rep.
Excitability 
SNP
RRP
ERP
(3) Supranormal Period (SNP)（超常期）
–80 ~ –90 mV rep.
Excitability 
3) Relation of Changes in Excitability
to Mechanical Contraction
ERP
(1) 特点：ERP特别长，直到机械收缩的舒张早期。
(2)意义：保证舒缩交替进行，不会发生强直收缩，
以利于血液充盈和射血。
骨骼肌呢？
4) Premature Systole and Compensatory Pause
（期前收缩与代偿间歇）
Premature Systole
(Extrasystole)
Sinus AP
Extra St.
Compensatory Pause
2.自动节律性（Autorhythmicity）
1) Definition
the ability of the cardiac myocyte to produce
automatically rhythmic excitation without
external stimuli
2) Mechanism
automatic depolarization
in phase 4
3) Autorhythmic Tissues
in the Heart
the special conduction
system of the heart except
for the node region of the
A-V node
Normal
Sinus node —100 impulses/min — pacemaker
Sinus rhythm
A-V node —
50 impulses/min
Bundle of His — 40 impulses/min Ectopic pacemaker
Ectopic rhythm
Purkinje F —
25 impulses/min
Preocupation (Capture)
Overdrive Suppression
4) Factors affecting autorhythmicity
(1) velocity of automatic depolarization
in phase 4
(2) maximal repolarization potential
(3) threshold potential
Sinus rhythm
窦性心律
Ectopic rhythm
异位心律
Arrhythmia
心律失常
Tachycardia
Bradycardia
Cardiac arrest
Coupled rhythm
Trigeminal rhythm
……
心动过速
心动过缓
心跳骤停
二联律
三联律
Artificial Pacemaker
（人工起搏器）
3.传导性（Conductivity）
Principle of conduction
local current in a single cell
like a single cell for atria or ventricles
蛋白亚单位
连接蛋白
（connexin）
Na+
Na+
连接子
（connexon）
Na+
Na+
Na+
Na+
细胞膜
与骨骼肌比较
1) Conduction pathway
2) Properties and their significances
Sinus node
Atria (1 m/s)
A-V node (0.02-0.05 m/s)
Bundle of His
Purkinje F. (1.5-4 m/s)
Ventricle (1 m/s)
(1) fast in the atrial and ventricular muscles,
but very slow in the A-V node
functional syncytium（功能合胞体）
important for pumping blood
Properties and their significances of conduction
(2) atrioventricular delay（房-室延搁）
important for a
successive
contraction of
atria and
ventricles and
then for the
pumping function
of the heart
3) Factors affecting conductivity
(1) Structural property
diameter of cell
number of gap junction
(2) Velocity and amplitude of depolarization
in phase 0
depending on the open velocity
and number of Na+ channels
(efficiency of Na+ channels)
and affected by resting potential
(3) Excitability of adjacent cell or adjacent
portion of membrane of a cell
RP, TP, state of ion channels
4.收缩性的特点
（Properties of Contractility）
Ca++ induced Ca++ release (CICR) in
cardiac cell（钙诱导钙释放）
atria or ventricles as a functional
syncytium (“all or none”)
no tetanus
Summary
about Bioelectrical Activity
and Physiological Properties
Part Two
心脏的泵血功能
（The Heart as a Pump）
Topics to be discussed in this part :
Cardiac Cycle
Mechanism of Pumping Blood
Evaluation of Pumping Function
Factors Affecting Pumping Function
Heart Sounds
I. 心动周期（Cardiac Cycle）
1. 定义（Definition）
the period from the
beginning of heart
contraction to the
beginning of next,
consisting of a period
of contraction called
systole followed by a
period of relaxation
called diastole
2. 时间过程 （Time Course）
heart rate – 75 beats/min
cardiac cycle – 0.8 s
3. 特点（Properties）
1) sequential
the atria contract first,
then the ventricles;
simultaneous
relaxation, but never
simultaneous contraction
important for filling
and pumping
2) the diastole is longer than the systole
the diastole shortens more when the heart
rate increases
meaning that the heart works more and that
the coronary blood flow decreases
II. 泵血机制
（ Mechanism of Pumping Blood）
1. 动力（Driving Force）
the pressure difference produced
by contraction and relaxation of the
heart
2. 方向（Direction）
depending on the state of the valves and
the direction of the pressure difference
3. 泵血过程（Pumping Process）
Process
Pressure
Atria Ventr Art
Blood
Flow
Volume of
Ventricles
25%
O
C
Atr V
<
C
C
—
Rapid EP
>
C
O
V
Reduced EP
<
C
O
V
Atrial Systole
Ventr Systole Vetr Diastole
Isovol CP
>
Valves
A-V Art
<
—
Ar
70%
Ar
30%
<
Isovol RP
Rapid FP
Reduced FP
>
>
—
—
C
C
O
C
Atr
V
O
C
Atr
V
III. 心脏泵血功能的评价
（Evaluation of Pumping
Function of the Heart）
1. 每搏输出量（搏出量）
（Stroke Volume）（SV）
the volume of
blood ejected by
each ventricle
per beat
SV = V End-diastolic Volume – V End-systolic Volume
SV = 125 ml – 55 ml = 70ml（in adult at rest）
2. 射血分数（ Ejection Fraction）
the ratio of the SV to the ventricular enddiastolic volume, about 55 ~ 65 %
3. 每分输出量（心输出量）
（Minute Cardiac Output）（CO）
the volume of blood ejected by each ventricle
per minute
CO = SV × HR
5 ～ 6 L/min in adult at rest
4. 心指数（Cardiac Index）
the CO per square meter of body surface area
about 3.0 ~ 3.5 L / (min · m2) in adult at rest
5. 心力贮备（Cardiac Reserve）
5 - 6 L/min  30 L/min
1) Definition
the ability of the heart to increase its output
as the metabolism of the body increases
2) Mechanism
Reserve of Stroke Volume
Diastolic: 125 ml  140 ml (15 ml)
Systolic: 55 ml  15 ml (40 ml)
Reserve of Heart Rate
75 beats/min  180 beats/min
(2 ~ 2.5 folds)
6. 心做功量（Work of Heart）
stroke work
minute work
cardiac efficiency
... ...
IV. 影响心输出量的因素
（Factors Affecting Cardiac Output）
（Factors Affecting Pumping
Function of the Heart）
Preload
Stroke After Load
Volume
Cardiac
Myocardial Contractility
Output
Heart Rate
1. 前负荷（Preload）
1) Effect
Left Ventricular
Performance
no falling limb
0
10
20
30
Left Ventricular EDP（cmH2O)
Ventricular Function Curve (Frank-Starling Curve)
2) Mechanism
100
Contraction
Performance
80
b c
a
a
60
b
40
20
0
1.0
1.5
2.0
2.5
3.0
c
Initial Length
Ventricular EDP  Preload  Initial Length  Performance
Heterometric Autoregulation（异长自身调节）
（Frank-Starling Mechanism）
In Heart Failure
3) Factors Affecting Preload (Initial Length)
filling duration of ventricle (heart rate)
velocity of venous return (venous pressure
difference)
pressure in pericardium
compliance of ventricle
2. 后负荷（After Load）
1) Effect
5
CO L/min)
4
（ 3
2
1
0
0
50
100
150
200
250
Aortic Pressure（mmHg)
2) Mechanism
after load (arterial BP)↑
↓
isovolumic contraction phase↑
ejection phase ↓
shortening velocity and degree ↓
↓
stroke volume ↓
↓
ventricular end-diastolic volume ↑
↓
preload↑
↓
heterometric autoregulation
↓
recovery of stroke volume
3. 心肌收缩能力（Myocardial Contractility）
1) Phenomena
the intrinsic property
of myocardium to change
its contraction
performance
not depending on the
preload and after-load
(inotropic state)
（变力状态）
Ventricular
Performance
2) Definition
0
10
20
30
Left Ventricular EDP（cmH2O)
Ventricular Function Curve
(Frank-Starling Curve)
Homeometric Autoregulation
（等长自身调节）
3) Factors Affecting Myocardial Contractility
[Ca2+] in the extracellular fluid
affinity of troponin for Ca2+
number of active cross-bridge
activity of ATPase
4. 心率（Heart Rate）
HR in a normal adult at rest:
60 — 100 beats/min
HR  CO （40 ~ 180 beats/min）
HR   contractility 
Starecase Phenomenon (Treppe)
(due to an increase in [Ca++]i )
HR ＞180 beats/min
＜40 beats/min
 CO 
sympathetic N, E, NE, TH
temperature 
 HR 
vagus N, ACh
 HR 
V. 心音（Heart Sounds）
Four sounds
generally two
Sound Locations
Differences and Generation of Sounds
tune
duration
phase
generation
S1 40—60 Hz
longer
systole
A-V valves, arteries
S2 60—100 Hz
shorter
diastole
semilunar valves
Significance of Sounds
Rate
Rhythm
Strength
Murmur
Summary
about
the Heart as a Pump
Part Three
血管的功能
（Functions of Blood Vessels）
Topics to be discussed in this part
Functional Categories of Blood Vessels
Arterial Blood Pressure
Microcirculation
Formation and Return of Interstitial Fluid
Venous Pressure and Venous Return
I. 血管的功能分类
（Functional Categories of Blood Vessels）
1. Windkessel V
（弹性贮器血管）
2. Distribution V
Aorta ArterioleCapillary Vein
Artery Sphincter Venule Cavum
（分配血管）
3. Resistance V
（阻力血管）
4. Exchange V
（交换血管）
5. Capacitance V
（容量血管）
6. Shunt V
（短路血管）
Inner D
Wall T
Endothelium
Elastic F
Smooth M
Collagenic F
II. 动脉血压（Arterial Blood Pressure）
1. Definitions
Blood Pressure:
the force exerted
by the flowing blood
against any unit area
of the blood vessel
wall
arterial BP
venous BP
capillary BP
2. Formation of Arterial BP
1) sufficient blood filling in the circulatory
system (prerequisite)
mean circulatory filling p. (7 mm Hg)
2) ejection of blood by the heart
(determinant factor 1)
3) peripheral resistance (determinant factor 2)
4) elasticity of aorta and large artery
to buffer the blood pressure
to maintain a continuous blood flow in
the blood vessels
3. Measurement of Arterial BP
Direct
Indirect
4. Normal Values in Young Adult at Rest
Systolic P: maximal value
100 ～ 120 mmHg
Diastolic P: lowest value
60 ～ 80 mmHg
Pulse P:
difference
30 ～ 40 mmHg
MAP:
100 mmHg
(Diastolic P + 1/3 Pulse P)
Systolic P / Diastolic P
Hypertension（高血压）
类别
收缩压
（mmHg）
舒张压
（mmHg）
正常血压
< 120
< 80
正常高值
120-139
80-89
高血压
 140
 90
单纯收缩期高血压
 140
< 90
Hypotension（低血压）
收缩压 < 90 mmHg，舒张压 < 60 mmHg
5. Factors Affecting Arterial BP
1) Stroke Volume
2) Heart Rate
3) Peripheral Resistance
8L
R= 
 r4
4) Arterial Elasticity
5) Circulatory Blood Volume
/ Capacity of Circulatory System
Factors Affecting Arterial BP
Factors
Systolic P
Diastolic P
Pulse P
Stroke V

 
 
 
HR

 
 
 
Periphl R

 
 
 
Elasticity


 ()

Circ B V /
Capacity of
Circ Syst




III. 微循环（Microcirculation）
1. Definition
the blood flow from the arterioles
to the venules
2. Composition
1) 7 parts morphologically
2) 3 pathways functionally
7 parts
arteriovenous shunt
venule
arteriole
metarteriole
true capillary
sphincter
thoroughfare channel
3 pathways
tortuous thoroughfare
arteriole  metarteriole  precapillary sphincter  capillary  venule
thoroughfare channel
shortcut thoroughfare
arteriovenous shunt
arteriovenous shunt
3. Properties and Functions
of the 3 Pathways
Tortuous Thoroughfare
Properties: tortuous, network, thin,
high permeability, slow blood flow,
alternate opening
Function: substance exchange
(diffusion, filtration, reabsorption,
pinocytosis)
(Nutritious Thoroughfare)
Shortcut Thoroughfare
Properties: extension of metarteriole,
often in open state, fast blood flow,
mainly in skeletal muscle
Function: to have the blood return
rapidly to the vein
Arteriovenous Shunt
Properties: structurally similar to the
arteriole, mainly in the skin
Function: to participate in the
regulation of body temperature
in some extent
IV. 组织液（Interstitial Fluid）
1. 生成与回流（Formation and Return）
Formation
(Filtration)
Plasma
Interstitial Fluid
(Reabsorption)
Return
1) Driving Force: Effective Filtration Pressure (EFP)
A
V
EFP
PC
if
Pif
Capillary
P
Four Forces:
pressure in capillary (Pc)
colloid OP in interstitial fluid (πif)
hydrostatic P in interstitial fluid (Pif)
colloid OP in plasma (πP)
EFP = （PC + if）  （Pif + P）
EFPA =（30+15）（25+10）= +10（mmHg)
EFPV =（12+15）（25+10）= - 8（mmHg)
A
+30mmHg
+15mmHg
-25mmHg
-10mmHg
+10mmHg
PC
if
P
Pif
EFP
V
+12mmHg
+15mmHg
-25mmHg
-10mmHg
 8mmHg
Blood Capillary
Lymphatic
Capillary
2) Volume of Formation and Return
V = Kf  EFP = Kf  [（PC + if） - （Pif + P）]
2. 影响组织液生成与回流的因素
（Factors Affecting Formation
and Return of Interstitial Fluid）
1) blood pressure in capillary
2) colloid OP in plasma
3) permeability of capillary
4) lymphatic return
(filariasis)
V. 静脉血压与静脉回流
（Venous Pressure and Venous Return）
1. 静脉血压（Venous Pressure）
1) Peripheral Venous Pressure (PVP)
pressure of the veins in different organs
low (15 ～ 20 mmHg)
subjected to gravity
subjected to transmural pressure
2) Central Venous Pressure (CVP)
pressure in the right atrium and
venae cava
4 ～ 12 cmH2O
depending on the pumping function of
the heart and the venous return
another index of the pumping function
of the heart
2. 静脉回流（Venous Return）
1) Volume of Return
Q  P / R
( P = PVP – CVP )
2) Factors Affecting Venous Return
(1) mean filling pressure
(2) pumping function of the heart
(3) body position (gravity)
(4) activity of skeletal muscle
(“muscular pump”
or “venous pump”)
(5) respiratory activity
Summary about
Functions of Blood Vessels
Part Four
心血管活动的调节
（Regulation of
Cardiovascular Activity）
I. 神经调节（Neural Regulation）
1. 传出神经支配（Efferent Innervation
of the Heart and Blood Vessels）
1) Innervation of the Heart Dual Innervation
(1) Cardiac Sympathetic Nerve
Pathway:
T1-5
ACh
N1
NE
β1
Symp
Parasymp
Effects:
positive chronotropic action
positive dromotropic action
positive inotropic action
Properties:
tonic action (cardiac
sympathetic tone)
asymmetrical innervation
right – mainly affecting heart rate
left – mainly affecting
A-V conduction and contractility
(2) Cardiac Vagus Nerve
Pathway:
dorsal vagus nucleus
ambiguous nucleus
ACh
N1
ACh
M
Otto. Loewi
(3 June 1873 – 25 December 1961)
(德国出生，德籍、美籍、奥地利籍)
chemical transmission, 1921
Father of Neuroscience
Nobel Prize, 1936
Symp
Parasymp
Effects:
negative chronotropic action
negative dromotropic action
negative inotropic action
Properties:
tonic action
(cardiac vagal tone)
asymmetrical innervation
right – mainly affecting heart rate
left – mainly affecting A-V conduction
(3) Peptidergic Neurons
neuropeptide Y
vasoactive intestinal polypeptide (VIP)
calcitonin gene-related peptide
opioid peptide
……
2) Innervation of the Blood Vessels
(1) Sympathetic Vasoconstrictor Fiber
Pathway and Actions:
paravertebral
ganglion
vessels of trunck
T1-12
and limbs
ACh N1
NE , 2
vessels of visceral
L1-3
organs
prevertebral
ganglion
Properties:
all blood vessel smooth muscles
different density
mainly acting on  receptor
sympathetic vasoconstrictor tone
(2) Vasodilator Fibers
Sympathetic Vasodilator Fiber
vessels of
skeletal
muscles
ACh M
Parasympathetic Vasodilator Fiber
vessels of brain,
digestive glands,
ACh M external reproductive
organs
Vasodilator Fibers
Dorsal Root Vasodilator Fiber
skin
Vasoactive Intestinal Polypeptide Fiber
vessels of sweat gland
and submaxilary gland
Summary about Innervation
Cardiac Sympathetic Nerve
Cardiac Vagus Nerve
Tonic, Antagonistic
Sympathetic Vasoconstrictor Nerve
Tonic, Extensive
Vasodilator Nerves
Not Tonic, Local
2. 心血管中枢（Cardiovascular Centers）
widely distributed in the central nervous system
Spinal Cord
Medulla
dorsal vagus nucleus (cardiac vagal tone)
ambiguous nucleus
NTS
caudal
ventrolateral
medulla
rostral
ventrolateral
medulla
spinal cord
(cardiac sympathetic
tone, sympathetic
vasoconstrictor tone)
Hypothalamus
defense area
Cerebral Cortex
3. 心血管反射（Cardiovascular Reflexes）
1) Baroreceptor Reflex (Depressor R)
(1) Definition
the reflex that a fall of
the arterial blood pressure
will be induced when the
baroreceptors located in
the carotid sinus and aortic
arch are stimulated by
stretching
Carotid
Sinus
Aortic
Arch
(2) Process
Carotid
IX
Sinus
Aortic X
Arch
BP
rVLM
NTS
cVLM
Sp C
Dorsal VN
Amb N
C Symp N
Symp Constr N
Heart
C Vagus N
BP
Vessels
Hypothalamus
BP
CO
Vasopressin
BP
R
(3) Properties
sensitive to rapid
change in BP
Arterial BP (mmHg)
most sensitive at the
level of around mean BP
150
100
50
50 100 150
Intrasinus P (mmHg)
sensitive to pulsative
change in BP
BP (mmHg)
always playing a role
in the regulation of BP
50
75
100
125
200
0
0.5
1.0 1.5 2.0
Time (sec)
(4) Significance
to maintain the arterial BP at a
relatively constant level in a way of
negative feedback
always in action
2) Chemoreceptor reflex
Receptors
carotid body
aortic body
Adequate Stimuli
PO2↓, PCO2↑, [H+] ↑
Effects
respiratory ↑
cardiovascular
direct
 CO
heart rate ↓
BP


vessel constriction  R
(coronary dilation)
indirect (in the state of natural breathing)
 CO BP 
heart rate ↑

vessel constriction  R
Significance
II. 体液调节（Humoral Regulation）
1. Epinephrine and Norepinephrine
Epinephrine
Sources
adrenal medulla (80% E)
Vessels:   constriction
2  dilation
Effects
skin, kidney, gastrointestine:
mainly α
skeletal m., liver: mainly 2
small dose: acting on 2
large dose: on  as well
Heart:
 1  cardiac output 
Clinical
application
cardiac stimulant
Norepinephrine
adrenal medulla (20% NE)
adrenergic nerve terminal
Vessels:
on , weakly on  2
all vessels constrict, BP 
baroreceptor
reflex
(indirect)
Heart:
(direct)
vasoconstrictor
heart 
2. Renin-Angiotensin System
1) Formation of Angiotensins
Angiotensinogen (14 aa, from liver)
Renin
(from kidney)
Angiotensin I (10 aa)
Converting enzyme
(mainly in lungs)
Angiotensin II (8 aa)
Aminopeptidase
(mainly in plasma)
Angiotensin III (7 aa)
2) Actions
Ang. I:
to promote the release of E and NE
from adrenal medulla
Ang. II:
to constrict all the arterioles
to promote the venous return
to promote the release of aldosterone
from the cortex of adrenal gland
to promote the reabsorption of Na+
and H2O by the renal tubules
to promote the release of NE from the
sympathetic nerve
to increase the sympathetic vasoconstrictor
tone through some central areas
to promote the release of vasopressin and
ACTH
Ang. III:
to weakly constrict the blood vessels
to promote the synthesis and
release of aldosterone
3. Vasopressin (Antidiuretic Hormone, ADH)
1) Source
suprachiasmatic n
paraventricular n
hypothalamichypophysial tract
posterior hypophysis
blood
2) Actions
In physiological dose
to increase the permeability of the
distal tubule and collecting duct to H2O
(antidiuretic hormone, ADH)
In large dose
to constrict the blood vessels
(vasopressin)
4. Atrial Natriuretic Peptide
(Cardionatrin, Atriopeptide)
Humoral Regulation
5. Vasoactive Substances from
Vascular Endothelium
Prostacyclin
Endothelium-derived relaxing factor
Endothelin
6. Opioid Peptide
7. Kinin
8. Histamine
9. Prostaglandin
III. 自身调节（Autoregulation）
Myogenic Theory
Metabolic Theory
Neuro-humoral Regulation
Part Five
冠脉循环
（Coronary Circulation）
I. 解剖特点（Anatomical Properties）
1. vertical penetration of small arteries
into the cardiac muscle
2. capillary : myocyte
1:1
3. thin and scarce anastomotic branches
II. 血流特点（Properties of Blood Flow）
1. short pathway
2. high pressure
3. large quantity
225 ml/min
4% ~ 5% CO
4. high level of O2 consumption
65% ~ 70%
5. subjected to the compression of cardiac
contraction, blood supply primarily
during diastole
120
Aortic Pressure
(mmHg)
100
80
100
20
Left Coronary Flow
(ml/min)
15
10
5
0
Right Coronary Flow
(ml/min)
60
S
D
III. 调节（Regulation）
1. local metabolism as the primary
controller of the coronary blood flow
2. neural regulation
cardiac sympathetic nerve
direct and indirect
cardiac vagous nerve
direct and indirect
3. hormone regulation
E, NE
thyroid hormones
large dose of vasopressin
Ang II
Chapter
Summary