Regulation of Blood Pressure.pptx

1. Regulation of
Blood Pressure
Dr. Irtaza Rehman
(Author of the book “The Extraordinary Life”)

3. Learning Objectives
• To understand the short term control of B.P
• To understand the long term control of B.P

7. Q. Why blood pressure needs to be
regulated?

8. Regulation of B.P
Two methods
FASTER
NEURAL
SLOWER
HORMONAL
Baroreceptor
reflex
RAAS

9. Baroreceptor Reflex
Stretch
receptors
Negative
feedback
system

10. Tractus Solitarius 

11. Baroreceptor Reflex

12. Q. Which one of the
baroreceptors only respond
to INCREASE in B.P??
• A. Aortic Baroreceptors
• B. Carotid sinus Baroreceptors
• Ans. A

13. Cardiovascular
centers
Baroreceptor Reflex

15. • The set point for mean arterial pressure in
the vasomotor center is about 100 mm Hg.
• Baroreceptors respond much more to a
rapidly changing pressure than to a
stationary pressure.
• Immediately increases the B.P when we
stands up.
• Also called Pressure Buffer system
• Reset in 1 to 2 days to the pressure level to
which they are exposed. (Not for long term)
Baroreceptor Reflex

17. Chemoreceptors
• Carotid body and aortic body
• Sensitive to Decreased O2, Increased CO2,
Increased H+
• Only effective to raise lower blood pressure
<80mm of Hg

19. Cardiopulmonary Receptors
• Also called Low pressure receptors
• In atria and pulmonary artery
• detect increases in pressure in the low-pressure
areas of the circulation caused by increase in
volume

20. Inc. ANP  Inc. water
excretion from kidneys
1
2
3

23. • Emergency pressure control system
“acts rapidly and powerfully to prevent further decrease
in arterial pressure whenever blood flow to the brain
decreases dangerously close to the lethal level
(15-20 mm of Hg)”
LAST DITCH STAND

26. Abdominal compression reflex

28. Exercise
During Exercise  Skeletal muscles contraction
 Compression of Blood vessels
 Increase venous return
 Increase Cardiac output

29. Respiration
• B.P Rises during early expiration and falls
during rest of respiration

30. • Q. Why Systolic
Blood pressure
falls during
Inspiration?
Respiration
Ans. During inspiration  Decreased Intrathoracic pressure
 Expansion of pulmonary vessels  Pooling of blood in lungs
 Dec. Pulmonary venous return  Reduced blood flow to left heart
 Decreased Stroke volume output  Decrease SBP

33. Q. Why
Angiotensin-II
levels decline in
1-2 minutes?
• Ans. because it is rapidly
inactivated by multiple blood and
tissue enzymes collectively called
angiotensinases.

34. “Thanks to RAAS, because we can
eat very small or large amount of
salt without causing great change
in our blood pressure”
Renin Angiotensin Aldosterone System

36. Q. Is there any
angiotensin-III ??
• Ans. YES, having some
of the biological activity
of angiotensin-II

39. Jazakumullahu Khair ♥
(May ALLAH swt reward you with goodness)