about blood pressure

1. BLOOD PRESSURE
Blood pressure:
It means the force exerted by/given the blood against any unit area of the vessels
wall.
Blood pressure :
Blood pressure is the lateral pressure exerted by the moving column of the blood on
the vessels wall per unit area while flowing through it.
Bp=CO x TPR
Types of Blood pressure :
1. Systemic pressure : 100-140 mm of Hg
2. Diastolic pressure : 60-90 mm of Hg
3. Pulse pressure : 30-40 mm of Hg
4. Mean pressure : 78-98 mm of Hg
(diastolic pressure - 1/3 of pulsus pressure
diatonic pressure -1/3 of systolic pressure-Diastolic pressure)
Systolic Blood pressure :
This is the maximum blood pressure during the Ventricular systole.
Diastolic pressure :
This is the minimum blood pressure during the Ventricular diastole.
Pulse pressure :
This is the difference between systolic and diastolic blood pressure.
Mean pressure : average
Hypertension :
Rised blood pressure is known as hypertension.
Hypotension:
Decrease blood pressure is known as Hypotension.

2. Factors controlling Blood pressure :
1. Cardiac output -Cardiac output depends on:
i. venous return
ii. force of construction
iii. Frequency of heart rate
iv. Peripheral resistance
2. Peripheral Resistance -Peripheral resistance depends on:
i. Velocity of blood
ii. Viscosity of blood
iii. Elasticity of arterial wall
iv. Lumen of blood vessels
3. Age- usually after 60 years,blood pressure rised
(Decrease elasticity of arterial wall)
Q.How Blood pressure within physiological range?
Ans:
There are different pressure control mechanism in our body. They are divided into -
1. Rapidly acting pressure control mechanism or short term mechanism -
a. mechanism which acts within seconds -
i. Baroreceptor feed back mechanism
ii. CNS ischemic response
iii. chemoreceptor mechanism
b. Mechanism which acts within minute -
i. Ranin angiotensis vasocontrictor mechanism
ii. Stress-relaxation of the vasculacture
iii. capillary fluid shift mechanism
2. Long term pressure control mechanism
i. Renal body fluid mechanism
ii. Renin angiotensis aldosterone mechanism
Baroreceptor mechanism:

3. Baroreceptor:
Baroreceptor are the pressure receptor that located in the great vessels.Mainly in the
area of aorta→aor c sinus →get the impulse by the vagus nerve.And just above the
bifercation of the common carotid artery in the internal carotid artery→caro d
sinus→get the impulse by herring's nerve then glossopharyngeal nerve.
I. Glossopharyngeal nerve- 30 mm of Hg (below)
II. Vagus nerve- 60 mm of Hg (below)
Long term mechanism :
Renin angiotensinn asldosterone mechanism :
Decreased blood pressure
Renin blood flow
secretion of Renin
(Renin acts on)
Angiotensinogen(8 globutin)
Angiotensin-I (10 amino acid)
(Angiotensin converting enzyme in lungs)
Angiotensin-II (8 amino acid)
Vasocontriction salt water retention Secretion of aldosterone
(in kidney)
TPR (increase) salt and water retention
(from kidney)
ECF (increase)
CO (increase)
BP (increase)
• Vesomotor center present in between medulla and pons,
which has 3 part/area-
i. Veso constricted area
ii.Veso dialated area
iii.Sensory area

4. Increase Blood pressure
stimulation to the aortic sinus and carotid sinus
From aortic sinus impulse goes From carotic sinus impulse
through vagus nerve to the goes through glossopharyngeal
vesomotor center nerve to the Vesomotor
(to the vegal center) center(to the vesodialated area)
HR & force of contruction to the vesoconstricted area
not produce impulse
CO (Decrease) Generalized vesodialation
TPR (decrease)
BP (Decrease)
(BP=CO X TPR)