HESI A2 2023

Which of these statements is true regarding the way light travels? A. Sound travels faster than light. B. The speed of light is always the same regardless of the medium through which it travels. C. Light travels as both a wave and a particle. D. Light can not travel through a vacuum. - C. Light travels as both a wave and a particle. Light is a curiosity in that it acts as both a wave and a particle. It only changes direction via reflection (bouncing off of something) or refraction (passing from one medium to another). In a vacuum, the speed of light is constant, but when passing through a medium that has an index of refraction different from a vacuum, light's speed slows. Which of these elements is liquid at room temperature? A. mercury B. zinc C. manganese D. magnesium - A. mercury Mercury is the only one of the elements listed here that is liquid at room temperature. The element bromine also has this property. Where is the hyoid bone located? A. neck B. pelvis C. rib cage D. leg - A. neck The hyoid bone is located between the chin and thyroid cartilage. A person with AB- blood should not receive blood from which other blood type? A. B- B. A- C. O- D. AB+ - D. AB+ Those with an AB- blood type should not receive blood from those with AB+ blood. Although both AB+ and AB- blood have A and B antigens, the person with AB- blood lacks a special protein, or "Rhesus" Factor (Rh), circulating in their blood. If they are given blood that has the Rh factor present, their body will make antibodies to this foreign substance and complications will occur. This is especially true in pregnancy situations where the mother is Rh- and the baby she is carrying is Rh+. Which blood type is considered the universal donor? A. O- B. O+ C. AB- D. AB+ - A. O- O- blood lacks both A and B antigens and the Rh factor, making it the only blood type that can donate to everyone. Note the correct use of the terms antibody and antigen: O- is the best donor because it does not have A, B or Rh antigens. AB+ is the universal receiver because it does not have A, B or Rh antibodies.