for dental students

1. THE ARTERIAL BLOOD
PRESSURE
REGULATION
DR JOICE P JIJI
DEPT OF PERIO

2. DEFINITION
The arterial blood pressure (BP) is the
pressure of the column of the blood in the
arterial system

3. COMPONENTS
• SYSTOLIC BLOOD PRESSURE
• DIASTOLIC BLOOD PRESSURE
• PULSE PRESSURE
• MEAN BLOOD PRESSURE

4. SYSTOLIC PRESSURE
• it is the maximum pressure exerted during systole
• Range 110-140 mm Hg
• Average 120 mmHg
• It increased by excitement, exercise, meals etc
• The height of SBP indicate extent of work done by the
heart

5. DIASTOLIC BLOOD PRESSURE
• It is the minimum pressure exerted during diastole
• Range 60-80 mmHg
• Average 70 mmHg
• It undergoes minimum fluctuations
• It indicate the constant load against which the heart
has to work
• It measure of total peripheral resistance

6. PULSE PRESSURE
•Systolic blood pressure - diastolic blood
pressure
•Average 40mmHg
•It determines the pulse volume

7. MEAN BLOOD PRESSURE
• It is the average pressure throughout the cardiac
cycle
• Diastolic blood pressure + 1/3 pulse pressure
• Range 95-100 mmHg
• It is same for each organ and determines the
pressure head
• All cardiovascular reflexes are sensitive to changes in

8. FACTORS AFFECTING BP
• AGE
• SEX
• BODY BUILT
• CLIMATE
• DIURENAL VARIATION
• EXERCISE
• EMOTIONS
• GRAVITY
• HEREDIATARY
• MEALS
• SLEEP
• POSTURE

9. AGE
Both SBP and DBP increases
Decreased distensibility of arteries

10. SEX
• in females before menopause SBP is 4-5 mmHg less
than that in males of same age
• After menopause reverse
• Oestrogen effect

11. BODY BUILT
• In obese individual brachial arterial blood pressure
gives high reading because there is more tissue
between cuff and artery

12. CLIMATE
• COLD- HIGH BP
• WARM- LOW BP
• HYPOTHALAMUS PRODUCE VASOCONSTRICTION

13. DIURNAL VARIATION
• 5-10 mmHg difference in SBP
• Peak values in the afternoon
• Revese rhythm is observed in night workers

14. EXERCISE
Type of individual mild moderate severe
SBP DBP SBP DBP SBP DBP
trained - - - - + -
untrained + +/- ++ + +++
+++
Intensity of exercise

15. EMOTIONS
• Sexual or other type of excitement fear, anger, rage etc.
increase sympathetic activity producing pressure effect
that is increase in heart rate, blood pressure
• Conversely sudden shock ,grief, apprehension etc
decrease sympathetic activity causing fall in BP and
heart rate

16. GRAVITY
• The pressure in any vessels below heart level is
increased
• Above heart level decreased
• The magnitude of the gravitation effect is .77mmHg
for each cm vertical distance above or below the
heart

17. HEREDITARY
•Familial tendency present

18. MEALS
• SBP increase by 5-6 mmHg up to 1 hour after
meals
• Epinephrine effect
• DBP slightly decreases or no change

19. SLEEP
• SBP falls in early hours of sleep by 15-30mmHg
• General vasodailation
• Disturbed sleep increases bp- increased sympathetic discharge

20. POSTURE
•Sudden standing increases DBP due to
baroreceptor activity

21. FACTORS CONTROLLING BP
•CARDIAC OUT PUT
•PERIPHERAL RESISTANCE
•BP =CO * PR

22. ROLE OF CARDIAC OUTPUT
• Cardiac output is the volume of blood ejected from
each Ventricle per minute ,it is about 5L/M
• C0 = HR * SV
• If increase in cardiac output is due to increase in HR ,that
increases DBP
• If increase in CO due to increase in Stroke Volume ,it
increases systolic BP

23. ROLE OF PERIPHERAL RESISTANCE
•The resistance of the arteries to blood flow
•The chief site of peripheral resistance is the
arterioles
•The total PR is inversely related to the
velocity of blood flow and elasticity of vessel
wall
•Increases in blood volume increases both

24. REGULATION OF ARTERIAL BLOOD PRESSURE
Main aim _ maintain normal MBP -95-100
mmHg
•Rapidly acting regulatory
mechanism(Nervous mechanism)
•Intermediate acting regulatory mechanism
•long acting regulatory mechanism(renal

25. RAPIDLY ACTING REGULATORY MECHANISM
• Nervous regulatory mechanism
• The nervous mechanism regulating bp operates through the
vasomotor system
• Vasomotor centres regulates BP by causing vasoconstriction or
vasodilation
• These are primarily the circulatory reflexes which begin to act
within seconds of bp becoming abnormal
• e.g. :Sudden posture body change, Profusely bleeding person
• Most of these mechanism lose their capability for pressure control

26. RAPIDLY ACTING REGULATORY MECHANISM
• Vasomotor centre depends on reflexes from baroreceptors,
chemoreceptors, higher centres, respiratory centres

27. BARORECEPTOR
• Baroreceptors are the receptors , which give response to
change in blood pressure
• Baroreceptors are also called presso receptors, because
sensitive to stretch
• They are operate between 60-200mmHg range of MBP
and correct 2/3 fall in Bp
• Baroreceptors are situated in the carotid sinus and wall
of aorta
• Carotid baroreceptors are supplied by Hering nerve

28. BARORECEPTOR
• Aortic baroreceptors are supplied by aortic nerve ,branch
of vagus
• Nerve fibres from baroreceptors reach the nucleus of
tractus solitarius ,which is situated adjacent to
vasomotor centre in medulla oblongata

29. BARORECEPTOR
BP RAPIDLY INCREASES
baroreceptors are activated and send stimulatory
impulses to nucleus
of tractus solitarius through glossopharyngeal and vagus
nerve.
It inhibits vasoconstrictor area and excite vasodilation
area
Inhibition of vasoconstrictor area reduces vasomotor tone
Reduction in vasomotor tone cause vasodilation, resulting

30. BARORECEPTOR
Fall in bp
Blood pressure reduces in carotid sinus
Inactivation of baroreceptors
No inhibition of vasoconstrictor area or excitation of
vasodilator area

31. CHEMORECEPTORS
• Chemoreceptors are the receptors giving response to
change in chemical constituents of blood
• Peripheral chemoreceptors are situated in the carotid
body and aortic body
• Supplied by same nerves as baroreceptors
• Peripheral chemo receptors are sensitive to lack of
oxygen ,excess of carbon dioxide and hydrogen ion
concentration in blood

32. CHEMORECEPTORS
BP reduces
Blood flow to chemoreceptors reduces
Lack of oxygen, excess of carbon dioxide
Excite chemoreceptors
Send impulse to stimulate vasoconstrictor centre
Inhibit vasodilation area and activation of vasoconstrictor
Blood pressure rise

33. SINO AORTIC MECHANISM
• Mechanism of action of baroreceptors and
chemoreceptors in carotid and aortic region
constitute sino aortic mechanism
• Nerves supplying baroreceptors and
chemoreceptors are called buffer nerves ,because
these regulates heart rate ,blood pressure and
respiration

34. HIGHER CENTRES
Vasomotor centre is also controlled by the impulses from
the two higher enters in the brain
Cerebral cortex– emotional disturbance in area 13 –
activate VMC-RAISE BP
Hypothalamus-stimulation of posterior and lateral nuclei-
vasoconstriction
Stimulation of preoptic area-vasodilation

35. RESPIRATORY CENTRES
During the beginning of expiration arterial BP increases
slightly i.e. by 4-6 mmHg ,it decreases during later part of
expiration and during inspiration

36. LONG TERM REGULATION OF BP
• Renal mechanism of regulation
• By regulation of extracellular fluid volume
• Through renin- angiotensin mechanism

37. LONG TERM REGULATION OF BP
By regulation of extracellular fluid volume
When the BP
Kidney excrete large amount of water and salt( diuresis,
natriuresis)
Leads to ECF and blood volume

38. LONG TERM REGULATION OF BP
Through renin angiotensin mechanism
• When BP and ECF
• Renin secretion in kidney
• It convert angiotensinogen into angiotensin 1
• By angiotensin converting enzyme angiotensin 1 convert to
angiotensin 2

39. LONG TERM REGULATION OF BP
Through renin angiotensin mechanism
• Angiotensin 2 cause constriction of arterioles
• Leads to increase peripheral resistance and increase BP
• It causes constriction of afferent arterioles in kidney ,so that
GFR reduce
• That cause retention of water and salt
• Increase ECF volume to normal level

40. LONG TERM REGULATION OF BP
Through renin angiotensin mechanism
• Simultaneously angiotensin 2 stimulate the adrenal cortex to
secrete aldosterone
• This hormone increases reabsorption of sodium from renal
tubules, water resorption resulting in increase ECF and blood
volume

41. HORRMONAL MECHANISM FOR REGULATION
OF BP
• Hormone which increases BP
• Adrenalin
• Noradrenalin
• thyroxine
• Aldosterone
• Vasopressin
• Angiotensin 2,3,4
• serotonin

42. HORMONAL MECHANISM FOR REGULATION
OF BP
• Hormone which decreases BP
• Vasoactive intestinal polypeptide
• Bradykinin
• Histamine
• Prostaglandin
• Acetylcholine
• Atrial natriuretic peptide
• C-type natriuretic peptide

43. LOCAL MECHANISM FOR REGULATION OF BP
• Local vasoconstrictors
• Local Vasodilators
Endothelium derived
constricting factors
like endothelin 1,2
and 3
Vasodilators of metabolic origin-
carbon dioxide, lactate, hydrogen
ions, adenosine
Vasodilators of endothelial origin—
nitric oxide

44. BP AND A DENTIST
• HYPERTENSION
• Blood pressure should be controlled before elective dental treatment or the
opinion of a physician should be sought first
• Hypertension ASA GRADING AND DENTAL MANAGEMENT CONSIDERATION
Blood pressure
(mmHg; systolic,
diastolic)
ASA
grade
Hypertensi
on stage
Dental aspects
140, < 90 I - Routine dental care
140-159,
90-99
Il 1 Recheck BP before starting routine dental care
160-179,
95-109
III 2 Recheck BP and seek medical advice before
routine dental care Restrict use of
adrenaline/epinephrine Conscious sedation
may help
> 180, > 110 IV 3 Recheck BP after 5 min quiet rest Medical

45. • Preoperative assurance is important, sedation
using temazepam may be helpful
• Best treated in late morning time : early morning:
adrenalin/epinephrine level peak
• Short and minimally stressful appointments
• It is essential to avoid anxiety and pain-
adrenalin/epinephrine level increases cause
arrhythmias
• Aspirating syringe should be used to give LA

46. • LA is not contraindicated unless the systolic BP is
higher than 200 mm Hg
• Lidocaine should be used with caution in patient
using beta blockers
• Gingival retraction cord containing
adrenalin/epinephrine should be avoided
• Raising the patients suddenly from supine position
may cause postural hypertension and loss of
consciousness if the patient is taking drugs like
thiazide, furosemide, calcium- channel blockers

47. • All antihypertensive drugs are potentiated by GA
agents, which can induce dangerous hypotension
• Some NSAIDs (indomethacin ,ibuprofen and
naproxen) can reduce the efficacy of
antihypertensive agents
• Antihypertensive drugs cause xerostomia(like
clonidine), salivary gland swelling, pain, lichenoid
reaction, erythema multiforme, angioedema,
gingival swelling, sore mouth, paresthesia .

48. • HYPOTENSION
• CAUSE OF ORTHOSTATIC HYPOTENSION
•
Primary autonomic causes Secondary autonomic causes Non-autonomic causes
Familial dysautonomia (Riley-
Day syndrome)
B vitamin deficiency Hypovolemia
Pure autonomic failure
(idiopathic orthostatic
hypotension)
Alcoholism Ageing
Shy-Drager syndrome Diabetes Prolonged bedrest
Dopamine Parkinsonism Pregnancy
Beta-hydroxylase deficiency Porphyria Drugs (e.g. anti hypertensives)

49. THANK YOU