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 blood cell is involved in clotting?

A. Red blood cells
B. White blood cells
C. Platelets
D. Plasma

Correct answer: C

Rationale: Platelets, also known as thrombocytes, are cell fragments that play a crucial role in blood clotting and wound healing. They are responsible for forming blood clots to stop bleeding when a blood vessel is injured, making them the correct choice in this context. Red blood cells (Choice A) are primarily involved in oxygen transport, white blood cells (Choice B) are part of the immune system, and plasma (Choice D) is the liquid component of blood that carries various substances.

3. When an individual is under stress, hormones are released. Which of the following is not one of the locations in which hormones are released when under stress?

A. Posterior pituitary
B. Hypothalamus
C. Adrenal cortex
D. Parathyroid

Correct answer: D

Rationale: During stress, hormones are released from the adrenal cortex, posterior pituitary, and hypothalamus to help the body respond. The parathyroid gland, however, is not typically involved in the stress response by releasing hormones. The posterior pituitary releases hormones like oxytocin and vasopressin, the hypothalamus secretes corticotropin-releasing hormone (CRH) and vasopressin, while the adrenal cortex releases cortisol and aldosterone in response to stress. Therefore, the correct answer is 'Parathyroid.'

4. What condition might result from a lack of vitamin C?

A. Kwashiorkor
B. Pellagra
C. Rickets
D. Scurvy

Correct answer: D

Rationale: Scurvy is the correct answer. Scurvy is a condition caused by a deficiency of vitamin C in the diet. Vitamin C is essential for collagen synthesis, and its deficiency leads to symptoms such as weakness, swollen and bleeding gums, joint pain, fatigue, and easy bruising. If left untreated, scurvy can lead to more severe complications. Choices A, B, and C are incorrect. Kwashiorkor is a severe form of malnutrition due to insufficient protein intake, pellagra is caused by a deficiency of niacin (vitamin B3), and rickets results from a deficiency of vitamin D, calcium, or phosphate.

5. What is the primary function of platelets in the blood?

A. To carry oxygen
B. To fight infections
C. To clot blood
D. To transport nutrients

Correct answer: C

Rationale: The correct answer is C: To clot blood. Platelets, also known as thrombocytes, have a primary function in blood clotting. They help in the process of coagulation, forming clots to prevent excessive bleeding when injuries occur. Platelets play a crucial role in maintaining the integrity of the circulatory system by sealing off damaged blood vessels and promoting wound healing. Choices A, B, and D are incorrect because platelets do not carry oxygen, fight infections, or transport nutrients in the blood.