Registration and regulation of companies Registration and regulation of companies.
Regulation of Cardiovascular Activities
-
Upload
addison-bright -
Category
Documents
-
view
25 -
download
2
description
Transcript of Regulation of Cardiovascular Activities
![Page 1: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/1.jpg)
Regulation of Cardiovascular Activities
Qiang XIA ( 夏强 ), PhDDepartment of Physiology
Room C518, Block C, Research Building, School of MedicineTel: 88208252
Email: [email protected]
![Page 2: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/2.jpg)
Lecture Outline
•Nervous Regulation
•Humoral Regulation
•Autoregulation
![Page 3: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/3.jpg)
Nervous Regulation
![Page 4: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/4.jpg)
Innervation of the heart
• Cardiac sympathetic nerve• Cardiac vagus nerve
1. 起源 origin
2. 节前纤维 preganglionic fiber
3. 外周神经节 ganglion
4. 节后纤维 postganglionic fiber
5. 支配 distribution
6. 递质 neurotransmitter
![Page 5: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/5.jpg)
![Page 6: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/6.jpg)
![Page 7: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/7.jpg)
Cardiac sympathetic actions
• Positive chronotropic effect 正性变时作用• Positive dromotropic effect 正性变传导作用• Positive inotropic effect 正性变力作用
![Page 8: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/8.jpg)
Cardiac mechanisms of norepinephrine
![Page 9: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/9.jpg)
Mechanisms of norepinephrine
—increase Na+ & Ca2+ permeability
• If , phase 4 spontaneous depolarization,
autorhythmicity
• Ca2+ influx (ICa,L) , phase 0 amplitude & velocity ,
conductivity
• Ca2+ influx (ICa,L) , Ca2+ release , [Ca2+ ]i , contractility
(CICR)
![Page 10: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/10.jpg)
Asymmetrical innervation of sympathetic nerve
![Page 11: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/11.jpg)
Cardiac parasympathetic actions
• Negative chronotropic effect 负性变时作用• Negative dromotropic effect 负性变传导作用• Negative inotropic effect 负性变力作用
![Page 12: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/12.jpg)
Cardiac mechanisms of acetylcholine
![Page 13: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/13.jpg)
Mechanisms of acetylcholine
—increase K+ & decrease Ca2+ permeability
• K+ outward , |MRP| , phase 4 spontaneous
depolarization , autorhythmicity
• Inhibition of Ca2+ channel, phase 0 amplitude &
velocity , conductivity
• Ca2+ influx , [Ca2+ ]i , contractility
![Page 14: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/14.jpg)
Cardiac effect of parasympathetic stimulation
![Page 15: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/15.jpg)
Vagal Maneuvers
• Valsalva maneuver
– A maneuver in which a person tries to exhale forcibly with a closed glottis (the windpipe) so that no air exits through the mouth or nose as, for example, in strenuous coughing, straining during a bowel movement, or lifting a heavy weight. The Valsalva maneuver impedes the return of venous blood to the heart.
– Named for Antonio Maria Valsalva, a renowned Italian anatomist, pathologist, physician, and surgeon (1666-1723) who first described the maneuver.
![Page 16: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/16.jpg)
![Page 17: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/17.jpg)
Physiological response in Valsalva maneuver
• The normal physiological response consists of 4 phases
![Page 18: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/18.jpg)
Physiological response in Valsalva maneuver
• The normal physiological response consists of 4 phases– Initial pressure rise: On application of expiratory force, pressure rises inside the chest forcing
blood out of the pulmonary circulation into the left atrium. This causes a mild rise in stroke volume.
– Reduced venous return and compensation: Return of systemic blood to the heart is impeded by the pressure inside the chest. The output of the heart is reduced and stroke volume falls. This occurs from 5 to about 14 seconds in the illustration. The fall in stroke volume reflexively causes blood vessels to constrict with some rise in pressure (15 to 20 seconds). This compensation can be quite marked with pressure returning to near or even above normal, but the cardiac output and blood flow to the body remains low. During this time the pulse rate increases.
– Pressure release: The pressure on the chest is released, allowing the pulmonary vessels and the aorta to re-expand causing a further initial slight fall in stroke volume (20 to 23 seconds) due to decreased left ventricular return and increased aortic volume, respectively. Venous blood can once more enter the chest and the heart, cardiac output begins to increase.
– Return of cardiac output: Blood return to the heart is enhanced by the effect of entry of blood which had been dammed back, causing a rapid increase in cardiac output (24 seconds on). The stroke volume usually rises above normal before returning to a normal level. With return of blood pressure, the pulse rate returns towards normal.
![Page 19: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/19.jpg)
![Page 20: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/20.jpg)
Interaction of sympathetic and parasympathetic nerves
![Page 21: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/21.jpg)
Predominance of autonomic nerves
![Page 22: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/22.jpg)
Tonus 紧张• Cardiac vagal tone 心迷走紧张• Cardiac sympathetic tone 心交感紧张
![Page 23: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/23.jpg)
Innervation of the blood vessels
• Vasoconstrictor nerve 缩血管神经– Sympathetic vasoconstrictor nerve 交感缩血管
神经• Vasodilator nerve 舒血管神经
– Sympathetic vasodilator nerve 交感舒血管神经– Parasympathetic vasodilator nerve 副交感舒血
管神经– Dorsal root vasodilator nerve 脊髓背根舒血管神
经
![Page 24: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/24.jpg)
![Page 25: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/25.jpg)
Cardiovascular Center
A collection of functionally similar neurons that
help to regulate HR, SV, and blood vessel tone
![Page 26: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/26.jpg)
Vasomotor center
Located bilaterally mainly in the reticular substance of the medulla and of the lower third of the pons
– Vasoconstrictor area– Vasodilator area– Cardioinhibitor area – dorsal nuclei of the
vagus nerves and ambiguous nucleus
– Sensory area – tractus solitarius
![Page 27: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/27.jpg)
![Page 28: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/28.jpg)
![Page 29: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/29.jpg)
![Page 30: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/30.jpg)
Vasomotor center
![Page 31: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/31.jpg)
– Reticular substance
of the pons
– Mesencephalon
– Diencephalon
– Hypothalamus
– Cerebral cortex
– Cerebellum
Higher cardiovascular centers
![Page 32: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/32.jpg)
Baroreceptor Reflexes
• Arterial baroreceptors– Carotid sinus receptor– Aortic arch receptor
• Afferent nerves (Buffer nerves)
• Cardiovascular center: medulla• Efferent nerves: cardiac sympathetic nerve,
sympathetic constrictor nerve, vagus nerve• Effector: heart & blood vessels
![Page 33: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/33.jpg)
Baroreceptor neurons function as sensors in the homeostatic maintenance of MAP by constantly monitoring pressure in the aortic arch and carotid sinuses.
![Page 34: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/34.jpg)
![Page 35: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/35.jpg)
Characteristics of baroreceptors:
Sensitive to stretching of the vessel walls
Proportional firing rate to increased
stretching
Responding to pressures ranging from 60-
180 mmHg
Receptors within the aortic arch are less
sensitive than the carotid sinus receptors
![Page 36: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/36.jpg)
![Page 37: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/37.jpg)
The action potential frequency in baroreceptor neurons is represented here as being directly proportional to MAP.
![Page 38: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/38.jpg)
Baroreceptor neurons deliver MAP information to the medulla oblongata’s cardiovascular control center (CVCC);the CVCC determines autonomic output to the heart.
i.e., MAP is above
homeostatic set point
i.e., reduce cardiac output
![Page 39: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/39.jpg)
Reflex pathway
![Page 40: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/40.jpg)
Click here to play theBaroreceptor Reflex Control
of Blood PressureFlash Animation
![Page 41: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/41.jpg)
Typical carotid sinus reflex
![Page 42: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/42.jpg)
Maintaining relatively
constant arterial
pressure, reducing the
variation in arterial
pressure
Physiological Significance
![Page 43: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/43.jpg)
Other Cardiovascular Reflexes
Click here to play theChemoreceptor Reflex Control
of Blood PressureFlash Animation
![Page 44: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/44.jpg)
Humoral Regulation
• Vasoconstrictor agents• Vasodilator agents
![Page 45: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/45.jpg)
Renin-angiotensin system
![Page 46: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/46.jpg)
Juxtaglomerular cell
Renin
![Page 47: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/47.jpg)
– Constricts resistance vessels
– Acts upon the adrenal cortex to release aldosterone
– Stimulates the release of vasopressin
– Facilitates norepinephrine release from sympathetic nerve endings
– Stimulates thirst centers within the brain
Physiological effects of angiotensin II
![Page 48: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/48.jpg)
Epinephrine & Norepinephrine
• Sources
Epinephrine----
adrenal medulla
Norepinephrine----
adrenal medulla
sympathetic nerves
![Page 49: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/49.jpg)
Catecholamines
Norepinephrine
Epinephrine
![Page 50: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/50.jpg)
Effects Epinephrine Norepinephrine
Receptor -adrenoceptor ++ +++
-adrenoceptor ++ +
Heart heart rate + + (in vitro)
- (in vivo)
cardiac output +++ ±
Vessels constriction (skin, visceral) + +++
relaxation (SM, liver) - +++
total peripheral resistance ± +++
Blood pressure systolic +++ +++
diastolic ± ++
MAP + ++
Clinical application positive inotropic pressor agent
agent
![Page 51: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/51.jpg)
![Page 52: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/52.jpg)
Vasopressin (antidiuretic hormone, ADH)
![Page 53: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/53.jpg)
![Page 54: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/54.jpg)
Endothelium-derived vasoactive substances
•Vasodilator factors
PGI2--prostacyclin
EDRF, NO--endothelium-derived relaxing factor, nitric oxide
EDHF--endothelium-dependent hyperpolarizing factor
•Vasoconstrictor factors Endothelin
![Page 55: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/55.jpg)
Atrial natriuretic peptide (ANP)
•Produces natriuresis and diuresis •Decreases renin release•Reduces total peripheral resistance via vasodilatation•Decreases heart rate, cardiac output
![Page 56: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/56.jpg)
Autoregulation
Definition:
Intrinsic ability of an organ to maintain a constant
blood flow despite changes in perfusion pressure,
independent of any neural or humoral influences
![Page 57: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/57.jpg)
![Page 58: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/58.jpg)
![Page 59: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/59.jpg)
Myogenic mechanism
• The myogenic mechanism is how arteries and arterioles react to an increase or decrease of blood pressure to keep the blood flow within the blood vessel constant
• The smooth muscle of the blood vessels reacts to the stretching of the muscle by opening ion channels, which cause the muscle to depolarize, leading to muscle contraction. This significantly reduces the volume of blood able to pass through the lumen, which reduces blood flow through the blood vessel. Alternatively when the smooth muscle in the blood vessel relaxes, the ion channels close, resulting in vasodilation of the blood vessel; this increases the rate of flow through the lumen.
![Page 60: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/60.jpg)
From: http://www.umm.uni-heidelberg.de/inst/cbtm/kphys/research-schubert.html
Universität Heidelberg > Fakultäten > Medizinische Fakultät Mannheim > CBTM: Kardiovaskuläre Physiologie >
![Page 61: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/61.jpg)
From: AJP - Heart October 2008 vol. 295 no. 4 H1505-H1513
![Page 62: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/62.jpg)
Metabolic mechanism
• Any intervention that results in an inadequate oxygen (nutrient) supply for the metabolic requirements of the tissues results in the formation of vasodilator substances which increase blood flow to the tissues
![Page 63: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/63.jpg)
Metabolic mechanism
![Page 64: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/64.jpg)
Lack of oxygen? Formation of vasodilators?
Combination of both??
Metarteriole
Precapillary Sphincter
Capillary
Relaxation of smooth muscle
Increased Blood Flow
![Page 65: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/65.jpg)
Metabolic mechanism
• Hypoxia• Tissue metabolites and ions
– Adenosine– Potassium ions– Carbon dioxide– Hydrogen ion– Lactic acid– Inorganic phosphate
![Page 66: Regulation of Cardiovascular Activities](https://reader035.fdocument.pub/reader035/viewer/2022062720/56813597550346895d9d0c08/html5/thumbnails/66.jpg)
The End.