Page 168 - Physiology and Pathophysiology MNU 2024-2025 نظرى

Clinical pharmacy 2024/2025 Level 2 Pharm D Physiology and Pathophysiology (MD303)
Arterial pressure

Not constant during a cardiac cycle

➢ It is the highest arterial pressure during a cardiac cycle.
1. Systolic Pressure
➢ Pressure in the artery  After blood has been ejected from the left ventricle
[120]
during systole.
 It is the lowest arterial pressure during a cardiac cycle.
2. Diastolic Pressure
 It is pressure in the artery  During ventricular relaxation.
[80]
(When no blood is being ejected from the left ventricle).
 It is the difference between systolic pressure & diastolic pressure. تباث
 Determined by  Stroke volume. (Mainly depend on systolic BP which
3. Pulse Pressure
depend on contraction)
[40]
 It is the change in arterial pressure that occurs when Blood is ejected from the
left ventricle in the aorta.
☺ It is the average pressure in a complete cardiac cycle.
4. Mean Arterial Mean arterial pressure = Diastolic pressure + 1/3 pulse pressure
Pressure ➢ Not normal Mean as Relaxation 0.7 of heart take more time than
Contraction 0.3.

Regulation of blood flow مهم

Example  cerebral & coronary circulation. بلقلاو خملل
1. Intrinsic
(local) * The sympathetic nerves play a minor role in these circulations. * Blood flow is regulated by local metabolic factors.
control of Coronary circulation (to Heart) Cerebral circulation (To Brain)

blood flow
Blood flow is mainly regulated by hypoxia ➔ (level of o2)➔ Blood flow is mainly regulated by Co2 level.
ىعضوم مكحت
 ↓ O2 (over work of the heart) ➔ V.D but ↑ O2 ➔ V.C  ↑ CO2 in brain ➔ V.D
2. Extrinsic A) Sympathetic * VC is the dominant effect of sympathetic nerves (α1 receptor)➔ the most affected blood vessels are
control of innervations of arterioles
blood flow *  Sympathetic tone  VC. *  Sympathetic tone  VD.

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