which nervous system controls voluntary motor movement

ATI TEAS 7

ATI TEAS Science Test

1. Which nervous system controls voluntary motor movement?

A. Parasympathetic
B. Sympathetic
C. Autonomic
D. Somatic

Correct answer: D

Rationale: The correct answer is D: Somatic. The somatic nervous system is responsible for controlling voluntary motor movements. It includes the motor neurons that innervate skeletal muscles and allows us to consciously control our movements. The parasympathetic and sympathetic nervous systems are part of the autonomic nervous system, which controls involuntary functions such as heart rate and digestion. Therefore, choices A, B, and C are incorrect as they are components of the autonomic nervous system and are not primarily responsible for voluntary motor movements.

2. Which property of matter remains constant regardless of changes in gravity?

A. Mass
B. Weight
C. Volume
D. Density

Correct answer: A

Rationale: Mass is a measure of the amount of matter in an object and remains constant regardless of changes in gravity. Weight, on the other hand, is the force of gravity acting on an object and can vary depending on the strength of gravity. Volume is the amount of space an object occupies, and density is the mass per unit volume of a substance, both of which can change with changes in gravity. Therefore, mass is the property that remains the same regardless of variations in gravitational force. Choice B, Weight, changes with gravity as it is a force dependent on gravity. Choices C and D, Volume and Density, can be affected by changes in gravity as they are related to the space an object occupies and the mass per unit volume, respectively.

3. Why is the lining of the stomach covered with rugae?

A. Rugae increase the output of gastric juices.
B. Rugae increase the surface area of the stomach.
C. Rugae increase the permeability of the stomach walls.
D. Rugae increase the types of nutrients that can diffuse.

Correct answer: B

Rationale: Rugae are folds in the stomach lining that increase its surface area. This increased surface area allows for more efficient digestion and absorption of nutrients in the stomach. Choice A is incorrect because rugae do not directly affect the output of gastric juices. Choice C is incorrect because rugae do not impact the permeability of the stomach walls. Choice D is incorrect because rugae do not influence the types of nutrients that can diffuse.

4. What is the primary function of the atrioventricular (AV) node within the heart?

A. Generate the electrical impulse for contraction (pacemaker function)
B. Transmit the electrical impulse from the atria to the ventricles, regulating the timing of contraction.
C. Increase blood pressure within the ventricles during systole.
D. Separate oxygenated and deoxygenated blood flow in the heart.

Correct answer: B

Rationale: The correct answer is B: Transmit the electrical impulse from the atria to the ventricles, regulating the timing of contraction. The primary function of the atrioventricular (AV) node is to coordinate the transmission of electrical signals between the atria and the ventricles. It ensures proper timing between atrial and ventricular contractions, allowing for efficient blood pumping through the heart. Choice A is incorrect because the AV node does not generate the initial electrical impulse; that role is typically attributed to the sinoatrial (SA) node. Choice C is incorrect as the AV node does not directly influence blood pressure within the ventricles. Choice D is also incorrect as the separation of oxygenated and deoxygenated blood is primarily achieved by the anatomical structure of the heart (e.g., atria and ventricles) and not the AV node.

5. Which of these body parts does not contain melanin?

A. Hair
B. Nails
C. Skin
D. Iris

Correct answer: D

Rationale: The iris is the colored part of the eye that determines the eye's color. Melanin is not present in the iris, unlike hair, nails, and skin. Melanin gives color to hair, nails, and skin, but not to the iris. Therefore, the correct answer is the iris (Choice D). Choices A, B, and C contain melanin and are incorrect.