1. Regulation of the cardiovascular activity
-- Nervous regulation
-- Humoral regulation
-- Autoregulation

2. Nervous regulation The role of nervous regulation :
-- redistributing of blood flow
-- increasing of heart activity
-- providing very rapid control of arterial pressure
-- realized by autonomic nervous system

3. sympathetic fibers from the thoracic and lubar regions of the spinal cord; the parasympathetic fibers from the brain and the sacral portion of the spinal cord.
sympathetic ganglia lie close tho the spinal cord and form the two chains of ganglia-one on each side fo the cord.
celiac 腹部的，腹的
ACh is thethe major neurotransmitter released between pre- and postgangllionic neuronsin autonomic ganglia.
Anatomy of sympathetic and parasympathetic nervous control of the circulation

4. Autonomic nervous system
Sympathetic nervous system
sympathetic innervation of the blood vessels
-- small arteries and arterioles:
increase the resistance
decrease the blood flow
-- vein: increase the venous return
sympathetic innervation of the heart
-- artium and ventricles : increasing the heart activity

5. Heart rate
Sympathetic stimulation
Heart CO BP
Contractile strength of heart SV
arterioles
vasoconstriction
Total peripheral resistance BP
vein
Vasocon-striction
Venous return SV CO BP
Summary of the effects of the sympathetic nervous systems on cardiovascular system

6. Autonomic nervous system
Parasympathetic nervous system
parasympathetic innervation on the atrium
-- control the heart rate

7. Cardiovascular center
A collection of functionally similar neuron that help to regulate the HR, SV and blood vessel tone
cranial nerve

8. Cardiovascular center
cardioacceleratory and cardioinhibitory centers , vasoconstrictor and
vasodilator areas
located in the medulla within the brain stem. the center alters the ratio between sympathetic and parasympathetic activity to the effector organs.

9. The cardiovascular reflex
Baroreceptor reflex
Cardiopulmonary reflex

10. The baroreceptor reflex includes
Afferent pathway
An integrating center
Efferent pathway
Effector organs

11. Baroreceptor reflex
Receptor: carotid sinus and aortic arch baroreceptors, they are mechanoreceptors
Sensitive to the stretching of vessel wall (not directly to the blood pressure change)
Afferent pathway: for carotid sinus (Hering’s nerve)
for aortic arch baroreceptors (vagus nerve)

12. Location of the arterial baroreceptors

13. Afferent pathway:
for carotid sinus (Hering’s nerve)
for aortic arch baroreceptors (vagus nerve)

14. Baroreceptor reflex
Baroreceptor continuously generate AP in response to the ongoing pressure within the arteries (constantly provide information about BP to the center)
BP increase, the receptor potential of the Baroreceptor increase, the rate of firing in the afferent neurons increase

15. Firing rate in the afferent neurons from the carotid sinus baroreceptor in relation to the magnitude of mean arterial pressure

16. Baroreceptor reflex
The integrating center : cardiovascular control center (cardioacceleratory and cardioinhibitory centers , vasoconstrictor and vasodilator areas) located in the medulla within the brain stem
The efferent pathway : the autonomic nervous system (sympathetic nerve and parasympathetic nerve)
Effectors : heart and blood vessels

17. Reflex pathway

18. The process of baroreceptor reflex
When arterial pressure becomes elevated above normal
BP becomes above normal
Carotid sinus and aortic arch receptor potential
Rate of firing in afferent nerves
Cardiovasc-ular center HR SV
and arteriolar and venous vasodilation
Sympathetic cardiac nerve activity
Sympathetic vasoconstriction nerve activity
Parasympathetic nerve activity CO
Total peripheral resistance
Blood pressure decreased toward normal

19. The process of baroreceptor reflex
BP becomes below normal
Carotid sinus and aortic arch receptor potential
Rate of firing in afferent nerves
Cardiovasc-ular center HR SV
and arteriolar and venous vasoconstriction
Sympathetic cardiac nerve activity
Sympathetic vasoconstriction nerve activity
Parasympathetic nerve activity CO
Total peripheral resistance
Blood pressure increased toward normal
When arterial pressure becomes below normal

20. baroreceptor reflex The feature:
1. sensitive to stretching of vessels wall
2. firing rate is directly proportional to the extend of stretch
3. response to BP ranging from mm Hg
4. receptor within the aortic arch are less sensitive than the carotid sinus receptor

21. The significance: Maintenance of the relatively constant of blood pressure

22. If clamp both common carotid ,
how does BP change?

23. Typical carotid sinus reflex
Both common carotid clamp
Typical carotid sinus reflex

24. Vasoconstrictor agents
Humoral regultaion
Vasoconstrictor agents
Vasodilator agents

25. 1. Renin - angiotensin system

26. 1. Renin - angiotensin system
Juxtaglomerular
cell
renin
nephron

27. Physiological role of Angiotensin
(NE )

28. 2. Epinephrine and norepinephrine
Epinephrine : adrenal medulla
binding toβ1 and β2 receptor
(usage: strengthening the heart activity)
Norepinephrine : adrenal medulla and sympathetic nerve terminal binding the α receptor (usage: increasing the BP)

29. +++ －

30. 3.Vasopressin (antidiuretic hormone, ADH)

31. 4. Atrial natriuretic peptide (ANP)
Physiological role : produces natriuresis and diuresis
－Decrease renin release
－Reduce total peripheral resistance via vasodilatation
－Decreases HR, CO

32. 5. Kinin and Histamine Bradykinin, Kallidin– plasma
Histamine – mast cells
Similar effects:
Causes vasodilatation
Increases capillary permeability
bradykinin:缓急跆 kallidin：. 胰激肽

33. 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
Possible mechanism:
-- myogenic mechanism
-- metabolic mechanism