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Ch. 18 The Cardiovascular System II: The Blood Vessels
Amerman - Human Anatomy & Physiology 2nd Edition
Amerman2nd EditionHuman Anatomy & PhysiologyISBN: 9780136873822Not the one you use?Change textbook
Chapter 18, Problem 1c

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.
The tunica media consists of smooth muscle cells innervated by vasomotor nerves.

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1
Step 1: Understand the structure of blood vessel walls. Blood vessels have three layers: tunica intima (inner layer), tunica media (middle layer), and tunica externa (outer layer). The tunica media is primarily composed of smooth muscle cells and elastic fibers.
Step 2: Recall the function of the tunica media. The smooth muscle cells in the tunica media are responsible for vasoconstriction and vasodilation, which regulate blood vessel diameter and blood flow.
Step 3: Identify the role of vasomotor nerves. Vasomotor nerves are part of the autonomic nervous system and innervate the smooth muscle cells in the tunica media to control contraction and relaxation.
Step 4: Evaluate the statement: 'The tunica media consists of smooth muscle cells innervated by vasomotor nerves.' Based on the anatomy and physiology of blood vessels, this statement is true.
Step 5: If the statement were false, the correction would involve ensuring the description of the tunica media includes its smooth muscle composition and innervation by vasomotor nerves, as these are key features of this layer.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Tunica Media

The tunica media is the middle layer of blood vessel walls, primarily composed of smooth muscle cells and elastic fibers. This layer is crucial for regulating blood vessel diameter and blood flow through vasoconstriction and vasodilation, which are controlled by the autonomic nervous system.
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Vasomotor Nerves

Vasomotor nerves are part of the autonomic nervous system that control the contraction and relaxation of smooth muscle in blood vessels. These nerves play a key role in regulating blood pressure and distribution of blood flow by signaling the tunica media to adjust the vessel diameter.
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Innervation of Smooth Muscle

Smooth muscle cells in the tunica media are innervated by autonomic nerves, which means they receive signals from the nervous system to contract or relax. This innervation is essential for the dynamic regulation of blood vessel tone and is distinct from voluntary muscle control, as it operates involuntarily.
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