**Prolonged high blood pressure is a major cause of:
heart failure, vascular disease, renal failure, and stroke
List some causes of high blood pressure:
heredity, diet, obesity, age, stress, diabetes mellitus, and smoking
The speed of blood flow is slowest through the capillaries. Why is this a good thing? Explain.
allows adequate time for exchange between blood and tissues
What substance is the major factor that causes dilation of the blood vessels (vasodilation)? Where does that substance come from?
Vasodilation of arterioles and relaxation of precapillary sphincters occur in response to
Declining tissue O2
Substances from metabolically active tissues (H+, K+, adenosine, and prostaglandins) and inflammatory chemicals
What is "angiogenesis"? Give an example.
The number of vessels to a region increases and existing vessels enlarge. Common in the heart when a coronary vessel is occluded, or throughout the body in people in high-altitude areas
What effect does an abnormally high or low MAP (mean arterial pressure) have on the brain? Explain.
The brain is vulnerable under extreme systemic pressure changes . MAP below 60 mm Hg can cause syncope (fainting). MAP above 160 can result in cerebral edema (fluid in brain)
How does blood regulate body temperature? Explain.
Blood flow through the skin
Supplies nutrients to cells
Helps maintain body temperature
Provides a blood reservoir
List and describe three types of circulatory shock.
Hypovolemic shock: results from large-scale blood loss
Vascular shock: results from extreme vasodilation and decreased peripheral resistance
Cardiogenic shock results when an inefficient heart cannot sustain adequate circulation
List three situations in which blood vessel formation occurs.
To support body growth
For wound healing
To rebuild vessels lost during menstrual cycles
dignostic technique involving the infusion of radioscope substance into the circultion for X-ray examination of specific blood vessels