how do efferent fibers exit the spinal cord

ATI TEAS 7

ATI TEAS Science Practice Test

1. How do efferent fibers exit the spinal cord?

A. Through the anterior aspect
B. Through the dorsal aspect
C. Through the ventral aspect
D. Through the lateral aspect

Correct answer: C

Rationale: Efferent fibers, which carry motor commands, exit the spinal cord through the ventral aspect, also known as the anterior aspect. The correct answer is C, 'Through the ventral aspect.' Efferent fibers exiting through the ventral aspect are responsible for carrying motor commands from the spinal cord to the muscles and glands. Choices A, B, and D are incorrect. Efferent fibers do not exit through the dorsal, lateral, or anterior aspects of the spinal cord.

2. If Silicon (Si) has an atomic mass of 28.1 AMU (atomic mass units), which of the following is the most likely number of neutrons an atom of Silicon would have?

A. 28.1
B. 14
C. 28
D. 14.2

Correct answer: B

Rationale: Silicon has an atomic number of 14, indicating it has 14 protons. The atomic mass of 28.1 AMU accounts for both protons and neutrons in the nucleus. By subtracting the atomic number from the atomic mass, we can estimate the number of neutrons in the atom. Thus, 28.1 - 14 = 14 neutrons. Choice A is incorrect as it represents the total atomic mass, not the number of neutrons. Choice C is incorrect; it is the atomic number (protons) rather than the number of neutrons. Choice D is incorrect as it is a value that does not reflect the number of neutrons in the silicon atom.

3. Which of the following is NOT a major function of the respiratory system in humans?

A. It provides a large surface area for gas exchange of oxygen and carbon dioxide.
B. It helps regulate the blood's pH.
C. It helps cushion the heart against jarring motions.
D. It is responsible for vocalization.

Correct answer: C

Rationale: Option C, 'It helps cushion the heart against jarring motions,' is NOT a major function of the respiratory system in humans. The primary functions of the respiratory system include gas exchange, regulation of blood pH, and vocalization. The respiratory system does not play a role in cushioning the heart; that function is primarily carried out by the pericardium and other protective structures around the heart. Choices A, B, and D are major functions of the respiratory system in humans. Choice A refers to the respiratory system's role in gas exchange, Choice B highlights its involvement in regulating blood pH, and Choice D points out its responsibility for vocalization.

4. Where is the scaphoid bone located in the body?

A. Wrist
B. Shoulder
C. Spine
D. Face

Correct answer: A

Rationale: The correct answer is A: Wrist. The scaphoid bone is one of the carpal bones located in the wrist. It is a small boat-shaped bone that is frequently involved in wrist injuries, such as falls onto an outstretched hand resulting in a scaphoid fracture. Choices B, C, and D are incorrect as the scaphoid bone is not located in the shoulder, spine, or face. Understanding the anatomical location of bones is crucial for diagnosing and treating injuries accurately.

5. What is the independent variable in the botanist's experiment?

A. Temperature
B. Root tissue
C. Light exposure
D. Root length

Correct answer: A

Rationale: In an experiment, the independent variable is the factor that is deliberately manipulated or changed by the researcher. The botanist is likely altering the temperature to observe its effect on the plants. Therefore, temperature is the independent variable in the botanist's experiment. Choice B, root tissue, is not the independent variable as it is not the factor being intentionally changed in the experiment. Choice C, light exposure, and choice D, root length, are also not the independent variables as they are not the factors being purposely manipulated by the researcher in this scenario.