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In the name of God
Physiology: Circulation
Moradian MD, MPH, PhD candidate
Tehran University of Medical Sciences
2015
Blood Circulation
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 11.3
http://www.sums.ac.ir/~moradij/wp
تئوريهبيپبيهگزدشخون
:اعت تافت ياس تا هتاعة تافت خى جزياى1. كچك ػزق تز دفؼي هاد غذا ،O2، CO2 تاثيز
خى گزدػ ػصثي كتزل هظؼي جزياى اي و هجوع تا للة د تزى2.
.هي ؽد كتزل ػصثي پيام تافتي خى جزياى كتزل اس هغتمل ؽزياي فؾار كتزل3.
:اعت د للة تزى كتزل يا هظؼي ا ريذي هخاسى امثاض للة، پوپي لذرت) ؽزياچ
ا (كلي
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Vascular system possesses different mechanisms for promoting continuous flow of
blood to the capillaries:
Elastic recoil smooth m. regulation of diameter sphincters
valves
Muscular arteries
:نكبت ظزفيتي هماهتي ػزق هذت خى كوتز عزػت :هيزگ سياد همؽغ عؽح تثادل تزاي تيؾتزي
5) دليم در ػثري خى همذار :خى جزياى هيشاى (دليم ليتزدر
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VEINS
CAPACITY
VESSELS
HEART
80 mmHg 120 mmHg
SYSTOLE
DIASTOLE
ARTERIES (LOW COMPLIANCE)
CAPILLARIES
http://www.sums.ac.ir/~moradij/wp
محل درصد
گردش سيستميم 84
وريد 64
شريانچه و مىيرگ 13
ريىي 9
قلب 7
توزيع خون در بدن
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Even though there are many mechanisms for altering the radius of the vascular
system, pressure still drops as blood moves further away from the heart.
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(فيزيكجزيبنخون)اصولهمودينبميك
Ohm Law لاى ان اي اي/جزياى لاي Laminar تيغ Turbulent گزدتادي/جزياى هتلاؼن
لاى پآسي لاى لاپلاط
كوپلياظ
http://www.sums.ac.ir/~moradij/wp
P1 P2
P1 > P2
FLOW
FLOW = P
R
P = FLOW x R
R =
mm Hg
L/min
or
ml/sec
mm Hg
ml/sec
Peripheral Resistance Units (PRU)
P
FLOW
Ohm Law قانون اهم
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Blood flows down a pressure gradient
The absolute value of the pressure is not important to flow, unlike
the difference in pressure (DP or gradient)
P directly proportional to F
http://www.sums.ac.ir/~moradij/wp
(Poiseuille's equation) اگي -پاسي لاى
Q خى، جزياى هيشاى Pفؾار رگ ؽؼاع r رگ، ؼل L يغكسيت،
ؽؼاع چارم تاى تا خى جزياى هيشاى هغتمين راتؽ آى تا رگ هماهت ػكظ راتؽ
خى 18 پلاعوا) دارد ارتثاغ جزياى هماهت تا يغكسيت (آب تزاتز 3-4
η
P r4
8L Q =
http://www.sums.ac.ir/~moradij/wp
v = Pr2 /8L
Q = vr2
Poiseuille's Law
Pr4
8L Q =
P
R Flow =
R = 8L/r4
http://www.sums.ac.ir/~moradij/wp
Resistance = tendency of the vascular system to oppose flow; Flow =
• Influenced by: length of the tube (L), radius of the tube (r), and viscosity of the
blood () Poiseuille’s Law R = L/r
4
• In a normal human, length of the system is fixed, so blood viscosity and radius of
the blood vessels have the largest effects on resistance
1
R
All four tubes have the same driving pressure. Which tube has the
greatest flow? The least flow?
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Greek alphabet Αα Alpha Νλ Nu
Ββ Beta Ξμ Xi
Γγ Gamma Ον Omicron
Γδ Delta Ππ Pi
Δε Epsilon Ρξ Rho
Εδ Zeta ζο Sigma
Ζε Eta Ση Tau
Θζ Theta Τπ Upsilon
Ηη Iota Φθ Phi
Κθ Kappa Υρ Chi
Λι Lambda Φς Psi
Μκ Mu Χσ Omega
غثت :واتكزيت ك خى حجن درصذ ا تعػ اؽغال گيچ
اس يكي ك ؽد هي تز هثز فاكتراي .اعت يغكسيت
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گزدببدي/لايهايجزيبن پيذايؼ احتوال :ريلذس
گزدتادي جزياى يغكعيت، چگالي، V خى، عزػت d رگ لؽز
پاييي احتوال 2000 تالا احتوال 3000
كرتكف صذاي
η
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:(لاپلاسقبنون)رگياشببعقببليت اي فيثزاي ؽذى كؾيذ تزاي هحيؽي يزي هايچ
.تواذ تالي اتغاع حالت ت رگ ك تؽري رگ ديار در .اعت اؽثاع لاتل ؽزياى اس تيؾتز تز 8 ريذ
لاتليت اؽثاع رگي ; افشايؼ حجن
افشايؼ فؾار × حجن الي
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(رگيپذيزش)كمپليبنس افشايؼ جي هيلي ليتز ز اساي ت هي تاذ ك خي همذار .ؽد اثاؽت خى گزدػ اس هؼيي تخؼ در فؾار
لاتليت اؽثاع رگي; كهپلياظ /حجن الي
تاتزايي ، ؽزياى اعت تزاتز 3 ريذا در خى حجن .اعت ؽزياى تزاتز 24 ريذا كهپلياظ
C = V
P
كهپلياظ رگي ; افشايؼ حجن
افشايؼ فؾار
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VASCULAR COMPLIANCE
C = V
P P
RE
SS
UR
E (
mm
Hg
)
VOLUME (L)
1 2 3 4
Arteries
Veins
100-
Cv = 24 x Ca
Ca = =2.5 ml/mmHg
Cv = = 60 ml/mmHg
250 ml 100 mmHg
300 ml 5 mmHg
http://www.sums.ac.ir/~moradij/wp
DIFFUSION BETWEEN BLOOD
& INTERSTITIAL FLUID
Plasma Proteins BLOOD
O2 CO2 Glucose
INTERSTITIAL
FLUID
CELL
active transport
http://www.sums.ac.ir/~moradij/wp
FLUID BALANCE
40-
30-
20-
10-
0-
PR
ES
SU
RE
(m
mH
g)
Filtration vs. Reabsorption
Outward Forces:
1. Capillary blood pressure
(Pc = 35 to 15 mmHg)
2. Interstitial fluid pressure
(PIF = 0 mmHg)
3. Interstitial fluid colloidal
osmotic pressure
(IF = 3 mmHg) TOTAL = 38 to 18 mmHg
Inward Force:
1. Plasma colloidal osmotic
pressure (C = 28 mmHg)
http://www.sums.ac.ir/~moradij/wp
The lymphatic system is a “scavenger”
system that removes excess fluid, excess
protein molecules, debris, and other matter
from the tissue spaces. Normally, when fluid
enters the terminal lymphatic capillaries, the
lymph vessel walls automatically contract for
a few seconds and pump the fluid into the
blood circulation slight negative pressure
that has been measured for fluid in the
interstitial spaces
http://www.sums.ac.ir/~moradij/wp
“PUMP”
Compression
Smooth muscle contraction
2 - 3 L/day ( 120 ml/hr)
LYMPHATIC CAPILLARY
Special structure of the lymphatic capillaries that permits
passage of substances of high molecular weight into the
lymph.
Anchoring Filaments
http://www.sums.ac.ir/~moradij/wp
Colloid Osmotic Pressure of the Plasma
http://www.sums.ac.ir/~moradij/wp
Filtration Reabsorption
Via lymphatics
http://www.sums.ac.ir/~moradij/wp
Mean Pressures of the Capillary
http://www.sums.ac.ir/~moradij/wp
CAPILLARY FLUID SHIFT
Pout > c Pout < c
Pc Pc
FAVORS FILTRATION FAVORS REABSORPTION
PULMONARY CIRCULATION http://www.sums.ac.ir/~moradij/wp
كتزل جزياى خى
:هظؼي (پيؼ هيزگي اعفكتزاي) آرتزيل :حاد
آدسيي، :رگي كذ گؾاد هاد :هتاتليك يذرصى، پتاعين، يغتاهيي، كزتي، دي اكغيذ
اكغيضى فمذاى (خى فؾار) جزياى تظيوي خد :هيصيك
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كتزل جزياى خى :هظؼي
تافت اعولاريت درج تا رگ تؼذاد :هذت دراس
رگي اذتليال رؽذ :خي رگ رؽذ فاكتراي
(VEGF)، آپيصيي فيثزتلاعتي، رؽذ
رهى ،(تصل الخاع اسهتر) عوپاتيك :ػوهي
http://www.sums.ac.ir/~moradij/wp
Chemical Physiologic role Source Type
NE (a ) Baroreceptor reflex Sympathetic neurons Neural
Endothelin Paracrine Vascular endothelium Local
Serotonin Platelet aggregation, smooth
muscle contraction
Neurons, digestive
tract, platelets
Local, neural
Substance P Pain, increased capillary
permeability
Neurons, digestive
tract
Local, neural
Vasopressin Increase blood pressure during
hemorrhage
Posterior pituitary Hormonal
Angiotensin II Increase blood pressure Plasma hormone Hormonal
Prostacyclin Minimize blood loss from
damaged vessels before
coagulation
endothelium local
Substances causing contraction in vascular
smooth muscle
http://www.sums.ac.ir/~moradij/wp
Chemical Physiologic role Source Type
Nitric oxide Paracrine mediator Endothelium Local
Atrial natriuretic
peptide
Reduce blood pressure Atrial myocardium,
brain
Hormonal
Vasoactive intestinal
peptide
Digestive secretion, relax
smooth muscle
Neurons Neural, hormonal
Histamine Increase blood flow Mast cells Local, systemic
Epinephrine (b2) Enhance local blood flow
to skeletal muscle, heart,
liver
Adrenal medulla Hormonal
Acetylcholine
(muscarinic)
Erection of clitoris, penis Parasympathetic
neurons
neural
Bradykinin Increase blood flow via
nitric oxide
Multiple tissues Local
Adenosine Enhance blood flow to
match metabolism
Hypoxic cells local
Substances that mediate vascular smooth muscle
relaxation
What Is Blood Pressure?
Blood pressure is the
force of blood pushing
against the arteries.
Blood is carried to all
parts of your body in
vessels called arteries.
Each time the heart beats
(about 60-70 times a minute
at rest), it pumps out blood
into the arteries.
What Is Blood Pressure?
Your blood pressure is at its
highest when the heart beats,
pumping the blood.
When the heart is at
rest, between beats,
your blood pressure
falls. This is called SYSTOLIC pressure. 120/ 80
This is called DIASTOLIC pressure.
Bottom number
http://www.hsfpe.org/
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Arterial Blood Pressure (continued)
Diastolic pressure is more important, because diastolic
period is longer than the systolic period in the cardiac
cycle. است تر مهم دياستىل فشار
Pulse pressure = Systolic BP – Diastolic BP. فشار نبض
Mean arterial pressure = Diastolic BP + 1/3 Pulse press.
In normal adult 120/80 mmHg
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ثط فؾار
عيغتل فؾار تيي تزاختلاف هثز ػاهل :(ثط فؾار)دياعتل
اي حجن عمغ - عيغتل فؾار رفتي تالا :ظزت دياعتل فؾار
فؾار افشايؼ هؼاي ت تدى كوتز :كهپلياظ حجن رفتي تالا تا اعت
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Effects of gravity on arterial
and venous pressures.
Each cm of distance
produces a 0.77 mmHg
change.
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Click to edit Master title style How to Measure Blood
Pressure
Vital Signs in the Ambulatory Setting: An Evidence-Based Approach
Cecelia L. Crawford
RN, MSN
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Sphygmomanometer
Automated
BpTRU™ BP Devices
Blood Pressure – An Overview
Equipment for accurate BP
measurement
Functional & calibrated machine
Right-sized cuff
Pen or pencil
Flowsheet, chart, or medical record
Clean hands and fingers!
Patient in a comfortable & relaxed
position
Wait 5 minutes if patient was active
Right Cuff in the Right Place
Cuff width = 20% more than upper arm
diameter
Cuff width = 2/3 of upper arm length
Cuff bladder length encircles 80% of upper arm
Cuff arrow aligned with brachial artery
Inside of the elbow
http://connection.lww.com/products/evans-smith
Blood Pressure Procedure
1. Wash hands & put on gloves, if appropriate
2. Provide privacy
3. Assist patient to a comfortable & relaxed position
4. Back supported, legs uncrossed
Blood Pressure – An Overview CAUSE SYSTOLIC BP CORRECTIVE ACTION
Sit without back support + 6 to 10 Support back (sit in chair)
Full bladder + 15 Empty bladder before BP taken
Tobacco/caffeine use + 6 to 11 Don’t use before clinic appointment
BP taken when arm is:
Parallel to body
Unsupported
Elbow too high
Elbow too low
+ 9 to 13
+ 1 to 7
+ 5
False low
While seated in chair, patient’s arm
must be straight out and supported,
with elbow at heart level
“White coat” reaction + 11 to 28 Have someone else take the BP
Talking or hand gestures + 7 No talking or use of hands during BP
Cuff too narrow/small + 8 to 10
Right-sized cuff properly placed over
bare upper arm Cuff too wide/large False low
Cuff not centered + 4
Cuff over clothing + 5 to 50 (Pickering et al., 2005; Perry & Potter, 2006)
Blood Pressure Procedure 4. Unplug & roll machine near the patient
5. Ensure connecter hose will reach
6. Turn on machine to self-test
7. Select proper arm cuff size
– Small adult cuff
– Medium adult cuff
– Large adult cuff
– Pediatric cuff
http://www.pharmj.com/Hospital/Editorial/200501/meetings/p27ashp.html
Blood Pressure Procedure
8. Expose upper arm completely – Do not put cuff over clothing! – Machine can’t “hear” the pulse with clothing
9. Upper arm properly supported at level 10. Squeeze air from cuff & attach connector hose and Check for kinks 11. Wrap flat cuff snugly around the upper arm 12. Arrow mark on cuff is at inside of elbow
Blood Pressure Procedure 13. Set machine for adult or pediatric BP
14. Press start button
15. No talking or hand gestures by you or the patient
16. Check digital display for BP when cuff is fully deflated
17. Repeat BPs may be taken if 2 minutes apart
18. Remove cuff and replace clothing
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http://www.sums.ac.ir/~moradij/wp 3
RECOMMENDED BLOOD PRESSURERECOMMENDED BLOOD PRESSUREMEASUREMENT TECHNIQUEMEASUREMENT TECHNIQUE
2.
• The cuff must be level with heart.
• If arm circumference exceeds 33 cm,a large cuff must be used.
• Place stethoscope diaphragm over
brachia l artery.
2.2.
•• The cuff must be level with heart.The cuff must be level with heart.
•• If arm circumference exceeds 33 cm,If arm circumference exceeds 33 cm,a large cuff must be used.a large cuff must be used.
•• Place stethoscope diaphragm overPlace stethoscope diaphragm over
brachia l artery.brachia l artery.
1.
• The patient shouldbe relaxed and the
arm must besupported.
• Ensure no tight
clothing constrictsthe arm.
1.1.
•• The patient shouldThe patient shouldbe relaxed and thebe relaxed and the
arm must bearm must besupported.supported.
•• Ensure no tightEnsure no tight
clothing constrictsclothing constrictsthe arm.the arm.
3.
• The column ofmercury must be
vertical .
• Infla te to occlude thepulse. Deflate at 2 to
3 mm/s. Measure
systolic (first sound)and diastolic
(disappearance) tonearest 2 mm Hg.
3.3.
•• The column ofThe column ofmercury must bemercury must be
vertical .vertical .
•• Infla te to occlude theInfla te to occlude thepulse. Deflate at 2 topulse. Deflate at 2 to
3 mm/s. Measure3 mm/s. Measure
systolic (first sound)systolic (first sound)and diastolicand diastolic
(disappearance) to(disappearance) tonearest 2 mm Hg.nearest 2 mm Hg.
StethoscopeStethoscope
MercuryMercury
machinemachine
MEASURING BLOOD PRESSURE
TURBULENT FLOW
1. Cuff pressure > systolic blood pressure--No sound.
2. The first sound is heard at peak systolic pressure.
3. Sounds are heard while cuff pressure < blood pressure.
4. Sound disappears when cuff pressure < diastolic pressure.
http://www.sums.ac.ir/~moradij/wp
Factors affecting ABP: Sex … M > F …due to hormones/ equal at menopause.
Age … Elderly > children …due to atherosclerosis.
Emotions … due to secretion of adrenaline &
noradrenaline.
Exercise … due to venous return.
Hormones … (e.g. Adrenaline, noradrenaline, thyroid H).
Gravity … Lower limbs > upper limbs.
Race … Orientals > Westerns … ? dietry factors, or
weather.
Sleep … due to venous return.
Pregnancy … due to metabolism. http://www.sums.ac.ir/~moradij/wp
What factors influence blood pressure?
Cardiac Output (Stroke volume×HR)
(عزػت ظزتاى×اي ظزت حجن)د للة تزى
Total Peripheral Resistance
هماهت ػزلي
Co= BP× TPR
http://www.sums.ac.ir/~moradij/wp
Factors determining ABP:
Blood Pressure = Cardiac Output × Peripheral Resistance
(BP) (CO) Flow
(PR) Diameter of arterioles
BP depends on:
1. Cardiac output CO = SV X HR.
2. Peripheral resistance.
3. Blood volume.
http://www.sums.ac.ir/~moradij/wp
Regulation of ABP
Maintaining B.P. is important to ensure a steady blood flow (perfusion) to tissues.
B.P. is regulated neurally through centers in medulla oblongata:
1. Vasomotor Center (V.M.C.), or (pressor area):
Sympathetic fibers.
2. Cardiac Inhibitory Center (C.I.C.), or (depressor area):
Parasympathetic fibers (vagus).
http://www.sums.ac.ir/~moradij/wp
Regulation of ABP
حفظ جزياى خى تزاي تزلزاري جزياى هذام خى ت تافت ا لاسم اعت
جزياى خى اس ؼزيك هزاكشي در تصل الخاع ت ؽكل ػصثي :تظين هي ؽد
كاؼ تزى د هماهت هار عوپاتيك هزكش اسهتر ػزق
گيزذ فؾار كن در جذار دليشا ؽزياى ا ريي
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cardiac control centers in medulla oblongata
Regulation of ABP (continued)
1. Cardiacaccelerator center (V.M.C)
2. Cardiacinhibitory center (C.I.C)
Sympathetic n. fibers Parasympathetic n. fibers
Regulatory mechanisms depend on: a. Fast acting reflexes: Concerned by controlling CO (SV, HR), & PR.
b. Long-term mechanism: Concerned mainly by regulating the blood volume.
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افشايؼ ظزتاى للة
تزگؾت تيؾتز خى ت دليش
اتغاع ديار دليش
گؾادي رفلكغي آرتزيل ا
هار تزؽح رهى ظذ ادراري
افشايؼ حجن ادرار
خى فؾار كاؼ حجن خى
http://www.sums.ac.ir/~moradij/wp
Blood pressure Controls Mechanisms
Fast Acting (Neural) ( لي)هكايغن عزيغ
Baro receptor feedback تاررعپتر
Chemo receptors ( تفظ-افت سياد فؾار)گيزذ ؽيوايي
CNS Ischemia كوثد اكغيضى دعتگا ػصثي هزكشي
http://www.sums.ac.ir/~moradij/wp
1. Baroreceptors reflex:
Baro receptors are receptors found in carotid
sinus & aortic arch.
Are stimulated by changes in BP.
BP
+ Baroreceptors
= V.M.C ++ C.I.C
= Sympathetic
Vasodilatation & TPR
+ Parasympathetic
Slowing of SA node ( HR) & CO
http://www.sums.ac.ir/~moradij/wp
2. Chemoreceptors reflex: Chemoreceptors are receptors found in carotid & aortic bodies.
Are stimulated by chemical changes in blood mainly hypoxia ( O2), hypercapnia ( CO2), & pH changes.
BP
+ Chemoreceptors ++ V.M.C = C.I.C
+ Sympathetic
Vasoconstriction & TPR
= Parasympathetic
HR
Haemorrhage
Hypoxia
+ Adrenal medulla
http://www.sums.ac.ir/~moradij/wp
Peripheral chemoreceptors
regulating respiration
Aortic bodies* On aorta
Send sensory info to medulla
through X (vagus n)
Carotid bodies+ At fork of common carotid
artery
Send info mainly through IX
(glossopharyngeal n)
*
+
http://www.sums.ac.ir/~moradij/wp
Blood pressure Controls Mechanisms
Short term (Minutes) كتا هذت
Renin-Angitensin
Vessels Relaxation كؾيذ ؽذؽل ؽذى رگ
Fluid Shift هيزگي تغييز هحل هايغ
http://www.sums.ac.ir/~moradij/wp
Renin
Aldosterone
Adrenal cortex
Corticosterone
Angiotensinogen
(Lungs)
renal blood flow &/or Na+
++ Juxtaglomerular apparatus of kidneys (considered volume receptors)
Angiotensin I
Converting enzymes
Angiotensin II (powerful
vasoconstrictor)
Angiotensin III (powerful
vasoconstrictor)
Renin-Angiotensin System:
Aldosterone is the main regulator of Na+ retention. http://www.sums.ac.ir/~moradij/wp
Blood pressure Controls Mechanisms
Long term (Hours) دراسهذت
Kidnyes ا ديرس فؾاري كلي
Renin- Angiotensin-Aldostrone
http://www.sums.ac.ir/~moradij/wp
Regulation of Blood Volume:
A long-term regulatory mechanism.
Mainly renal:
1. Renin-Angiotensin System.
2. Anti-diuretic hormone (ADH), or
vasopressin.
3. Low-pressure volume receptors.
http://www.sums.ac.ir/~moradij/wp
HORMONAL REGULATION
Epinephrine & Norepinephrine
From the adrenal medulla
Renin-angiotensin-aldosterone
Renin from the kidney
Angiotensin, a plasma protein
Aldosterone from the adrenal cortex
Vasopressin (Antidiuretic Hormone-ADH)
ADH from the posterior pituitary
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3. Other Vasomotor Reflexes:
1. Atrial stretch receptor reflex:
Venous Return ++ atrial stretch receptors
reflex vasodilatation & BP.
2. Thermoreceptors: (in skin/or hypothalamus)
• Exposure to heat vasodilatation.
• Exposure to cold vasoconstriction.
3. Pulmonary receptors:
Lung inflation vasoconstriction.
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ػاهل هثز تز تزگؾت خى در عيازگ ا
ا پوپ (جي هيلي ليتز 3 تا 6) عي
ػعلاي پوپ
عوپاتيك امثاض
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گزدػ خى كززي
للة چپ عوت ت عيازگي خى رد :تثشيي ؽت
(O2 104 ← 95 فؾار)
دياعتلي خزعاي
عي افشيؼ تا آاعتهس
ػزق گؾادي β تگي α آدرزصيك گيزذ
كزز گؾادي :للة هايچ اس ؾت :آدسييhttp://www.sums.ac.ir/~moradij/wp