Hemorrhage is defined as excess loss of blood due to ruptured blood vessels. There are several types of hemorrhage including accidental, capillary, internal, postpartum, and hemorrhage due to premature placenta detachment. The effects of hemorrhage depend on whether it is acute or chronic. Acute hemorrhage involves a sudden large loss of blood and can cause hypovolemic shock, while chronic hemorrhage is a slow loss of blood over a long period from sources like ulcers or hemophilia. Immediate effects of hemorrhage include reduced blood volume, venous return, and cardiac output, potentially leading to lower blood pressure. Mild hemorrhage maintains blood

1. Hemorrhage:
*Definition: is the excess loss of blood due to rupture of blood vessels
*Types and causes of hemorrhage:
1-Accidental hemorrhage: occurs in road accidents and industrial accidents , accidental
hemorrhage is two type:
a-primary hemorrhage: which occurs immediately after the accident
b- secondary hemorrhage: which occurs about few hours after accident.
2-capillary hemorrhage :is bleeding due to the rupture of blood vessels particularly
capillaries , it is very common in brain (cerebral hemorrhage)
3-Internal hemorrhage: is the bleeding in viscera , it is caused by rupture of blood vessels
in the viscera , the blood accumulates in viscera
4-postpartum hemorrhage: excess bleeding that occurs immediately after labor
5-Hemorrhage due to premature detachment of placenta
*Compensatory effects of hemorrhage: different in acute or chronic
hemorrhage:
1-acute hemorrhage: is the sudden loss of large quantity of blood, it occurs in conditions
like accidents,↓ in blood volume →hypovolemic shock
2-chronic hemorrhage: is the loss of blood either by internal or external bleeding over a
long period of time, internal bleeding occurs in condition like ulcer, external occurs in
condition like hemophilia
*Immediate compensatory effects of hemorrhage:
1-On cardiovascular system: reduced blood volume after hemorrhage ↓ venous
return , ventricular filling and cardiac output, in severe hemorrhage , there is fall in blood
pressure also ,
#Mechanism involved in maintenance of blood pressure during mild
hemorrhage: when there is loss of a small amount of blood up 350 to 500 ml
1- Usually when arterial blood pressure increase → stimulation of carotid and
aortic baroreceptors →send impulses to brain →↓ in blood pressure , during

2. hemorrhage falls in arterial blood pressure , baroreceptors become in activated
and stop discharging impulses
2- This increase the vasomotor tone leading to vasoconstriction in all regions of
body except brain and heart
3- Vasoconstriction result in increase in peripheral resistance
4- Loss of blood causes reflex constriction of veins
5- Venoconstriction enhance the venous return , ventricular filling
6- Because of ↑peripheral resistance the arterial blood pressure is restored
7- One more factor is involved in this mechanism vasoconstriction occurs in organs
having reservoir function such as skin , liver , and spleen , blood from these
reservoir organs is directed in to systemic circulation , this my compensate the
volume of blood that is lost during hemorrhage.
*Mechanism involved in maintenance of blood pressure during sever
hemorrhage:
1-when hemorrhage is severe with loss of about 1,500 to 2,000 ml of blood
2-the arterial blood pressure falls to great extend, it is because venous return and stroke
volume
3-in the heart , the reflex tachycardia increase the quantity of metabolic products in
myocardium
4-these metabolic products causes coronary vasodilatation
2- on skin: