Difference between revisions of "Blood Vessels"
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==Introduction== | ==Introduction== | ||
| − | Blood vessels are responsible for supplying the | + | Blood vessels are responsible for supplying the petrol that runs all of mammalian physiology. Without the vasculature to carry blood to and from tissues, they will die in the absence of nutrition and waste removal. It is therefore crucial to consider their structural integrity and utilize their availability when considering any disease process requiring on blood-borne healing factors, whether indigenous or introduced. |
==Anatomy== | ==Anatomy== | ||
| − | The vasculature makes up the highway network of the body, carrying nutrients to and waste products from all tissues. From the left side of the | + | The vasculature makes up the highway network of the body, carrying nutrients to and waste products from all tissues. From the left side of the heart, the aorta exits to empty into the larger arteries, which become arterioles, and then disseminate into the capillary bed that feeds the periphery. It is in this place of least resistance where most of the crucial work concerning gas exchange and waste removal takes place. Capillaries then filter into the venous system, with venules feeding veins until blood reaches the vena cava, which carries unoxygenated blood to the right side of the heart. This blood travels an identical, though shorter, circulatory route through the lungs, where oxygen is picked up in rich capillary system surrounding alveoli, and then returned to the left heart for circulation around the body. |
==Physiology== | ==Physiology== | ||
| − | The development of the vascular system | + | The [[Vascular Development - Anatomy & Physiology|development of the vascular system]] occurs following three distinct processes: |
*Vasculogenesis: the formation of blood vessels during the third week of gestation in domestic mammals, initially in the yolk sac and afterwards in the allantois from endothelial progenitor cells. | *Vasculogenesis: the formation of blood vessels during the third week of gestation in domestic mammals, initially in the yolk sac and afterwards in the allantois from endothelial progenitor cells. | ||
*Angiogenesis: the sprouting of new capillaries from pre-existing vessels. | *Angiogenesis: the sprouting of new capillaries from pre-existing vessels. | ||
*Arteriogenesis: the remodelling of newly formed or pre-existing vascular channels into larger and more muscular arterioles. | *Arteriogenesis: the remodelling of newly formed or pre-existing vascular channels into larger and more muscular arterioles. | ||
| − | In the adult animal, the physiology of blood vessels is predominantly associated with the maintenance of [[Blood Pressure Physiology|blood pressure and blood flow]]. Arterial blood pressure is created by the combined forces and complex interactions of cardiac output, systemic vascular resistance (resistance produced mainly in the arterioles), and viscosity of the blood. | + | In the adult animal, the physiology of blood vessels is predominantly associated with the maintenance of [[Control of Blood Pressure & Blood Flow - Anatomy & Physiology|blood pressure and blood flow]]. Arterial blood pressure is created by the combined forces and complex interactions of cardiac output, systemic vascular resistance (resistance produced mainly in the arterioles), and viscosity of the blood. In summary, Blood Pressure (BP) = Cardiac Output (CO) x Systemic Vascular Resistance (SVR). |
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| − | In summary, Blood Pressure (BP) = Cardiac Output (CO) x Systemic Vascular Resistance (SVR). | ||
==Response to Injury== | ==Response to Injury== | ||
| − | When blood vessels are injured, the process of [[Haemostasis|haemostasis]] begins to prevent [[Haemorrhage|blood loss]] from ruptured vessels. Normal haemostasis depends on a combination of events | + | When blood vessels are injured, the process of [[Haemostasis|haemostasis]] begins to prevent [[Haemorrhage - Pathology|blood loss]] from ruptured vessels. Normal haemostasis depends on a combination of events: the vascular response, which occurs mainly at capillary and small vessel level, the platelet (or thrombocyte) response, which also occurs in capillaries and small vessels, and the blood coagulation response which takes place in the arteries and veins. |
[[Category:WikiBlood]] | [[Category:WikiBlood]] | ||
Revision as of 10:34, 4 August 2010
Introduction
Blood vessels are responsible for supplying the petrol that runs all of mammalian physiology. Without the vasculature to carry blood to and from tissues, they will die in the absence of nutrition and waste removal. It is therefore crucial to consider their structural integrity and utilize their availability when considering any disease process requiring on blood-borne healing factors, whether indigenous or introduced.
Anatomy
The vasculature makes up the highway network of the body, carrying nutrients to and waste products from all tissues. From the left side of the heart, the aorta exits to empty into the larger arteries, which become arterioles, and then disseminate into the capillary bed that feeds the periphery. It is in this place of least resistance where most of the crucial work concerning gas exchange and waste removal takes place. Capillaries then filter into the venous system, with venules feeding veins until blood reaches the vena cava, which carries unoxygenated blood to the right side of the heart. This blood travels an identical, though shorter, circulatory route through the lungs, where oxygen is picked up in rich capillary system surrounding alveoli, and then returned to the left heart for circulation around the body.
Physiology
The development of the vascular system occurs following three distinct processes:
- Vasculogenesis: the formation of blood vessels during the third week of gestation in domestic mammals, initially in the yolk sac and afterwards in the allantois from endothelial progenitor cells.
- Angiogenesis: the sprouting of new capillaries from pre-existing vessels.
- Arteriogenesis: the remodelling of newly formed or pre-existing vascular channels into larger and more muscular arterioles.
In the adult animal, the physiology of blood vessels is predominantly associated with the maintenance of blood pressure and blood flow. Arterial blood pressure is created by the combined forces and complex interactions of cardiac output, systemic vascular resistance (resistance produced mainly in the arterioles), and viscosity of the blood. In summary, Blood Pressure (BP) = Cardiac Output (CO) x Systemic Vascular Resistance (SVR).
Response to Injury
When blood vessels are injured, the process of haemostasis begins to prevent blood loss from ruptured vessels. Normal haemostasis depends on a combination of events: the vascular response, which occurs mainly at capillary and small vessel level, the platelet (or thrombocyte) response, which also occurs in capillaries and small vessels, and the blood coagulation response which takes place in the arteries and veins.