what is the name of the radioactive isotope commonly used in medical imaging techniques like pet scans

ATI TEAS 7

TEAS 7 practice test science

1. Which radioactive isotope is commonly used in medical imaging techniques such as PET scans?

A. Uranium-235
B. Plutonium-239
C. Potassium-40
D. Fluorine-18

Correct answer: D

Rationale: Fluorine-18 is the radioactive isotope commonly used in medical imaging techniques such as PET scans. It is frequently used in the form of fluorodeoxyglucose (FDG) to locate areas of heightened metabolic activity in the body, such as in cancer cells. Uranium-235 and Plutonium-239 are not typically employed in medical imaging, and Potassium-40, while a naturally occurring radioactive isotope found in the human body, is not commonly used in medical imaging techniques.

2. Which of the following statements is NOT true about DNA?

A. DNA contains the nucleotides A, T, C, G and is read 5' to 3'.
B. DNA contains genetic information and is tightly coiled with proteins to form chromosomes.
C. DNA contains the nucleotides A, T, C, G and is read 3' to 5'.
D. DNA is a double-stranded molecule connected by hydrogen bonds.

Correct answer: C

Rationale: The correct answer is C because DNA is typically read from the 5' end to the 3' end, not from 3' to 5'. Choices A, B, and D are all true statements about DNA. DNA contains the nucleotides A, T, C, G and is read in a 5' to 3' direction. DNA also contains genetic information and is tightly coiled with proteins to form chromosomes. Additionally, DNA is a double-stranded molecule connected by hydrogen bonds.

3. Which type of capillary is the most permeable?

A. Continuous capillaries
B. Sinusoidal capillaries
C. Fenestrated capillaries
D. Vascular capillaries

Correct answer: B

Rationale: Sinusoidal capillaries are indeed the most permeable type. They are characterized by large gaps between endothelial cells, allowing for the passage of large molecules and cells. These capillaries are commonly found in organs like the liver, bone marrow, and spleen where high permeability is required for specialized functions such as filtration and exchange of substances. Continuous capillaries have tight junctions and are the least permeable, found in muscles, lungs, and the central nervous system where strict control over permeability is needed. Fenestrated capillaries, on the other hand, have small pores or fenestrations and are intermediate in permeability, found in organs like the kidneys, endocrine glands, and intestines where selective permeability is necessary. Vascular capillaries is not a specific type of capillary and is not a valid choice.

4. Why is maintaining good muscle strength and flexibility as we age important?

A. To prevent headaches
B. To prevent falls
C. To reduce anxiety
D. To avoid the common cold

Correct answer: B

Rationale: Maintaining good muscle strength and flexibility as we age is crucial to prevent falls. Strong muscles and good flexibility help improve balance and stability, reducing the risk of falls, which can lead to serious injuries, especially in older adults. Falls are a significant concern for the elderly population, and preventing them through muscle strength and flexibility can enhance overall quality of life. Headaches are not directly related to muscle strength and flexibility; they can have various causes such as stress, dehydration, or underlying health conditions. Anxiety is a mental health condition and not directly prevented by muscle strength and flexibility. Similarly, the common cold is a viral infection and is not influenced by muscle strength and flexibility.

5. What is the most common cause of hospital-acquired infections (HAIs)?

A. Viruses
B. Bacteria
C. Fungi
D. Parasites

Correct answer: B

Rationale: Hospital-acquired infections (HAIs), also known as nosocomial infections, are infections that patients acquire during the course of receiving treatment in a healthcare facility. Among the options provided, bacteria are the most common cause of HAIs. Bacteria such as Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa are known to cause a wide range of infections in healthcare settings. While viruses, fungi, and parasites can also cause HAIs, bacteria are the most prevalent and significant pathogens responsible for these infections. Proper infection control measures, including hand hygiene, environmental cleaning, and antimicrobial stewardship, are essential in preventing and controlling HAIs caused by bacteria.