Vascular spasm is the first response as the blood vessels constrict to allow less blood to be lost. In the second step, platelet plug formation, platelets stick together to form a temporary seal to cover the break in the vessel wall. The third and last step is called coagulation or blood clotting.
What is a vascular spasm?
When a vessel is severed or punctured, or when the wall of a vessel is damaged, vascular spasm occurs. In vascular spasm, the smooth muscle in the walls of the vessel contracts dramatically. This smooth muscle has both circular layers; larger vessels also have longitudinal layers.
What is the function of a vascular spasm?
Vascular spasm is much more effective at slowing the flow of blood in smaller blood vessels. Vasoconstriction also causes an increase in blood pressure for affected blood vessels. Smooth muscle in the vessel wall goes through intense contractions that constrict the vessel.
How do vascular spasms contribute to the process of hemostasis?
What do vascular spasms contribute to the process of hemostasis? Vascular spasms decrease blood vessel diameter to limit blood loss. Medications known as anticoagulants interfere with: the coagulation cascade.
What factors trigger a vascular spasm?
Cocaine use and cigarette smoking can cause severe spasms of the arteries. This causes the heart to work harder. In many people, coronary artery spasm may occur without any other heart risk factors (such as smoking, diabetes, high blood pressure, and high cholesterol).
What is arterial vasospasm?
A vasospasm is the narrowing of the arteries caused by a persistent contraction of the blood vessels, which is known as vasoconstriction. This narrowing can reduce blood flow. Vasospasms can affect any area of the body including the brain (cerebral vasospasm) and the coronary artery (coronary artery vasospasm).
What is the benefit of a vascular spasm at the onset of hemostasis?
Vascular spasm is when smooth muscle contracts, causing vasoconstriction. The benefit is that it slows blood down. This is a negative feedback event because it closes off damaged vessels, keeps blood in a fluid state, and removes clots after restoration of blood vessel.
Does degranulation promote hemostasis?
In platelet plug formation, a large mass of platelets AGGREGATE and undergo degranulation. Degranulation PROMOTES hemostasis. COAGULATION finishes the process by clotting the blood and protecting the body from excess blood loss.
What is vascular spasm quizlet?
Vascular spasm (vasoconstriction) Immediate but temporary constriction of blood. vessel (Vasoconstriction) Damage to blood vessels activate the nervous system reflexes that cause vascular spasms.
What are the three stages of hemostasis?
1) Constriction of the blood vessel. 2) Formation of a temporary “platelet plug.” 3) Activation of the coagulation cascade. 4) Formation of “fibrin plug” or the final clot.
What do vascular spasms contribute to the process of hemostasis quizlet?
How do vascular spasms contribute to the process of hemostasis? Vascular spasms cause platelets to adhere to exposed collagen. vascular spasm limits blood loss. Thrombin converts fibrinogen into fibrin, a mesh that glues together the platelet plug and helps seal the damaged vessel.
What is the function of a vascular spasm quizlet?
(1) vascular spasm, (2) platelet plug formation, and (3) coagulation. is the immediate but temporary constriction of a blood vessel. occurs when smooth muscle within the wall of the vessel contracts. This constriction can close small vessels completely and stop the flow of blood through them.
What is myogenic spasm?
Local myogenic contraction (spasm) which is initiated by direct damage to the wall of the blood vessel. Local humoral factors from the damaged tissues and the platelets (for example, thromboxane A and serotonin)
What happens during vasospasm?
Overview. Vasospasm refers to the sudden contraction of the muscular walls of an artery. It causes the artery to narrow, reducing the amount of blood that can flow through it. The tissue receiving blood from the artery may develop ischemia (injury due to lack of oxygen).
Which of the following enhances vascular spasm?
A Vascular spasm – constriction of the damaged blood vessel. 1 1st step is platelet adhesion – they stick to collagen in the layers of CT below the endothelial cells. b) empty contents of granules – ADP and Thromboxane A2 activate nearby platelets, serotonin and thromboxane A2 enhance vascular spasm.