which part of the brain is responsible for regulating involuntary functions such as breathing and heart rate

HESI A2

Anatomy HESI A2

1. Which part of the brain is responsible for regulating involuntary functions such as breathing and heart rate?

A. Cerebrum
B. Cerebellum
C. Medulla oblongata
D. Frontal lobe

Correct answer: C

Rationale: The medulla oblongata, located in the brain stem, is responsible for regulating involuntary functions such as breathing and heart rate. It contains vital centers that control these essential functions to maintain life. The cerebrum is primarily involved in higher brain functions like thinking and voluntary movements; the cerebellum plays a crucial role in coordinating movement and balance; and the frontal lobe is responsible for functions such as decision-making, problem-solving, and voluntary muscle movements. Therefore, the correct answer is the medulla oblongata (Choice C).

2. The cheekbones are positioned ___________ to the nose.

A. anterior
B. proximal
C. deep
D. lateral

Correct answer: D

Rationale: The term 'lateral' refers to the direction away from the midline of the body. In this case, the cheekbones are situated to the sides of the nose, making them lateral to the nose. Therefore, 'lateral' correctly describes the position of the cheekbones in relation to the nose. Choices A, B, and C are incorrect: A. 'Anterior' means situated at or towards the front, which is not the correct description of the cheekbones in relation to the nose. B. 'Proximal' means situated nearer to the center of the body, which is not the correct description of the cheekbones' position in relation to the nose. C. 'Deep' refers to being situated further away from the surface, which is not the appropriate term to describe the cheekbones' position in relation to the nose.

3. A medication must be taken twice daily, 12 hours apart. If the first dose is at 8:00 AM, what is the most convenient time for the second dose to avoid disrupting sleep?

A. 4:00 PM
B. 6:00 PM
C. 8:00 PM
D. 10:00 PM

Correct answer: B

Rationale: To take the medication 12 hours apart from the first dose at 8:00 AM, the second dose should be taken at 8:00 PM. However, to avoid disrupting sleep, it is recommended to take the second dose a bit earlier. Taking the second dose at 6:00 PM ensures that the medication is still being taken 12 hours apart while allowing for a buffer before bedtime to avoid any potential disruptions to sleep. Choice A (4:00 PM) is too early, not maintaining the 12-hour interval. Choice C (8:00 PM) aligns with the 12-hour interval but might be too close to bedtime, potentially causing sleep disruptions. Choice D (10:00 PM) is too late and exceeds the 12-hour interval.

4. Which is not part of a nucleic acid?

A. Sulfate
B. Phosphate
C. Carbon
D. Nitrogen

Correct answer: A

Rationale: Sulfate is not part of a nucleic acid. Nucleic acids, such as DNA and RNA, are composed of nucleotide units, which consist of a phosphate group, a sugar molecule (ribose in RNA and deoxyribose in DNA), and a nitrogenous base. Carbon and nitrogen are essential elements found in nucleic acids, while sulfate is not a component of nucleic acid structure. Therefore, the correct answer is A: Sulfate.

5. What does 'Discrete' mean?

A. Continuous
B. Distinct or separate
C. Mixed
D. Combined

Correct answer: B

Rationale: The correct answer is B, 'Distinct or separate.' Discrete refers to something that is individually separate and distinct, not continuous (choice A), mixed (choice C), or combined (choice D). In mathematics and other fields, discrete items are countable and distinct from each other.