which component of the nervous system is responsible for controlling voluntary movements such as the contraction of skeletal muscles

ATI TEAS 7

TEAS 7 practice test science

1. Which component of the nervous system is responsible for controlling voluntary movements, such as the contraction of skeletal muscles?

A. Autonomic nervous system
B. Peripheral nervous system
C. Somatic nervous system
D. Sympathetic nervous system

Correct answer: C

Rationale: The correct answer is C: Somatic nervous system. The somatic nervous system is responsible for controlling voluntary movements, such as the contraction of skeletal muscles. This system consists of motor neurons that send signals from the central nervous system to the skeletal muscles, allowing for conscious control over movement. The autonomic nervous system (A) controls involuntary functions like heart rate and digestion, the peripheral nervous system (B) includes all nerves outside the central nervous system, and the sympathetic nervous system (D) is a division of the autonomic nervous system responsible for the fight-or-flight response. Therefore, choices A, B, and D are incorrect as they do not specifically regulate voluntary movements of skeletal muscles, which is a function of the somatic nervous system.

2. How do isotopes affect the atomic mass of an element?

A. Isotopes have no effect on the atomic mass of an element.
B. Isotopes cause the atomic mass of an element to vary slightly.
C. Isotopes cause the atomic mass of an element to be exactly the same for all isotopes of that element.
D. Isotopes cause the atomic mass of an element to vary greatly.

Correct answer: B

Rationale: Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons. Since the atomic mass of an element is the weighted average of the masses of its isotopes, the presence of isotopes causes the atomic mass of an element to vary slightly. This variation occurs because different isotopes have different masses due to their varying numbers of neutrons. The atomic mass is affected by the abundance of each isotope, leading to a slight fluctuation in the overall atomic mass of the element. Choice A is incorrect because isotopes do influence the atomic mass. Choice C is incorrect because isotopes have different masses, affecting the overall atomic mass. Choice D is incorrect as isotopes typically do not cause a significant variation in atomic mass, but rather a slight fluctuation.

3. Which of the following systems does not include a transportation network throughout the body?

A. Cardiovascular system
B. Endocrine system
C. Immune system
D. Nervous system

Correct answer: B

Rationale: The endocrine system does not include a transportation network throughout the body. While the cardiovascular system transports blood, oxygen, and nutrients, the immune system has lymphatic vessels for immune cell transportation, and the nervous system transmits signals via neurons. In contrast, the endocrine system coordinates bodily functions by releasing hormones directly into the bloodstream, which then act on target organs or tissues. This delivery mechanism is different from the continuous transportation networks found in the other systems listed, making the endocrine system the correct choice for this question.

4. What causes varicose veins to occur?

A. Atherosclerosis.
B. Incompetent valves.
C. Loss of skin turgor.
D. Loss of blood vessel elasticity.

Correct answer: B

Rationale: Varicose veins occur when the valves within the veins become incompetent, leading to blood pooling in the veins instead of being efficiently pumped back to the heart. This causes the veins to become enlarged, twisted, and visible under the skin. Factors such as genetics, aging, pregnancy, and prolonged standing or sitting can contribute to the development of incompetent valves and the resulting varicose veins. Atherosclerosis is the buildup of plaque in arteries, not veins, and does not directly cause varicose veins. Loss of skin turgor is related to skin elasticity and not a direct cause of varicose veins. Loss of blood vessel elasticity is a general term and does not specifically address the mechanism behind varicose veins, which is primarily due to incompetent valves.

5. What is the term for the energy released during a chemical reaction?

A. Kinetic energy
B. Potential energy
C. Heat energy
D. Exothermic energy

Correct answer: D

Rationale: The correct answer is 'Exothermic energy.' During an exothermic reaction, energy is released in the form of heat. The term 'exothermic' signifies that energy is moving outward, typically in the form of heat, throughout the reaction, leading to a decrease in the system's internal energy. Choice A, 'Kinetic energy,' refers to the energy of motion and is not specifically related to chemical reactions. Choice B, 'Potential energy,' is the energy stored within an object due to its position or state and is not directly related to energy released in a chemical reaction. Choice C, 'Heat energy,' is a form of energy but does not specifically describe the energy released during a chemical reaction.