how might the headrest on a car prevent traumatic injury

HESI A2

Anatomy HESI A2

1. How might the headrest on a car prevent traumatic injury?

A. By limiting hyperflexion of the neck
B. By limiting hyperextension of the neck
C. By reducing vertebral compression
D. By preventing disc degeneration

Correct answer: B

Rationale: The headrest on a car is designed to prevent traumatic injury by limiting hyperextension of the neck during a rear-end collision. This helps reduce the risk of whiplash and other neck injuries that may occur when the head is forcefully thrown backward. Choice A is incorrect because hyperflexion is not the primary concern in rear-end collisions. Choice C is incorrect as the headrest does not directly reduce vertebral compression. Choice D is incorrect because the headrest is not directly involved in preventing disc degeneration.

2. Which type of muscle tissue is found in the heart?

A. Smooth muscle
B. Cardiac muscle
C. Skeletal muscle
D. Striated muscle

Correct answer: B

Rationale: Cardiac muscle tissue, represented by choice B, is the correct answer. Cardiac muscle tissue is unique to the heart and responsible for its involuntary contractions that pump blood throughout the body. Smooth muscle (choice A) is found in the walls of hollow organs, skeletal muscle (choice C) is attached to bones for movement, and striated muscle (choice D) is a general term that can refer to both cardiac and skeletal muscle but is not specific to the heart.

3. What is the function of parathyroid hormone?

A. Increasing energy levels
B. Stimulating cell reproduction
C. Speeding up metabolism
D. Activating vitamin D

Correct answer: D

Rationale: The correct answer is D. Parathyroid hormone plays a crucial role in activating vitamin D. This activation occurs in the kidneys, where parathyroid hormone stimulates the conversion of inactive vitamin D to its active form. Active vitamin D is essential for maintaining proper levels of calcium and phosphorus in the body, which are important for bone health and other physiological functions. Choices A, B, and C are incorrect because parathyroid hormone is not involved in increasing energy levels, stimulating cell reproduction, or speeding up metabolism. Its primary function is related to calcium and phosphorus homeostasis through the activation of vitamin D.

4. Which organ in the body is responsible for insulin production?

A. Pancreas
B. Liver
C. Gallbladder
D. Kidneys

Correct answer: A

Rationale: The correct answer is the pancreas. The pancreas is responsible for producing insulin, a hormone crucial for regulating blood glucose levels. Insulin plays a key role in allowing cells to take in glucose, thereby helping to keep blood sugar levels in check. The liver (choice B), gallbladder (choice C), and kidneys (choice D) do not produce insulin. The liver is involved in glycogen storage and glucose regulation, the gallbladder stores bile, and the kidneys filter blood and regulate fluid balance.

5. Which organelle is responsible for generating energy within a cell?

A. Nucleus
B. Ribosome
C. Mitochondria
D. Golgi apparatus

Correct answer: C

Rationale: Mitochondria are commonly referred to as the powerhouses of the cell as they are primarily responsible for generating energy through cellular respiration. This process involves converting nutrients into adenosine triphosphate (ATP), which is the main energy currency of the cell. The nucleus is responsible for storing the cell's genetic material, the ribosome is involved in protein synthesis, and the Golgi apparatus is responsible for packaging and distributing molecules produced by the cell; therefore, they are not directly involved in energy generation.