Define hemostasis and describe its three phases
What will be an ideal response?
Hemostasis refers to the stopping of bleeding, and it involves three phases. (1) Vascular spasm is an automatic constriction of blood vessels when they are cut or torn. (2) Platelet plug formation occurs when platelets aggregate and stick to collagen fibers that are exposed in damaged vessels. The aggregated platelets release various chemicals, some of which cause more platelets to aggregate, while others cause vasoconstriction. (3) Clot formation involves a series of reactions in which a soluble plasma protein, fibrinogen, is converted into an insoluble form, fibrin. The fibrin threads intertwine to form a net that traps blood cells and stops the loss of blood.
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The figure illustrates the autonomic reflexes and the heart. What does "E" represent?
A. sympathetic nerve B. increase in blood pressure detected by carotid baroreceptors C. glossopharyngeal nerve D. decrease in blood pressure detected by carotid baroreceptors E. vagus nerve
The postnatal period extends from
A. birth to death. B. the beginning of the fetal period until the beginning of childhood. C. fertilization to birth. D. the fertilized egg until the end of life.
The peripheral nervous system has two subdivisions: the sympathetic and the parasympathetic nervous systems
a. True b. False Indicate whether the statement is true or false
A pump is attached to the common carotid artery and red ink is pumped in. Which structures of the body will show the red ink?
A. The intercostal muscles and chest area B. The large intestine and portions of the small intestine C. The arms and the hands D. The neck and the head