ATI TEAS 7 Science

Correct Answer: D

Rationale: Certainly! The correct answer is D because saltatory conduction is faster than normal nerve conduction (A), occurs from one node of Ranvier to the next (B), and only occurs in myelinated neurons (C). This process involves the rapid transmission of action potentials in myelinated axons, where the impulse "jumps" from one node of Ranvier to the next, skipping the myelinated regions in between. This allows for faster conduction speeds compared to continuous conduction in unmyelinated neurons. Therefore, all of the statements in options A, B, and C are accurate descriptions of saltatory conduction, making option D the correct choice.

Correct Answer: A

Rationale: The primary function of the coronary arteries is to carry oxygenated blood to the heart muscle. This is essential for providing the heart muscle with the oxygen and nutrients it needs to function properly. Without adequate oxygen supply, the heart muscle can become damaged, leading to conditions like heart attacks. The other choices are incorrect because: B: Coronary arteries do not carry deoxygenated blood from the heart muscle; they supply oxygenated blood to it. C: Pumping blood to the lungs for oxygenation is the function of the pulmonary arteries, not the coronary arteries. D: Regulating blood pressure in the systemic circulation is primarily the function of the arteries and arterioles throughout the body, not specifically the coronary arteries.

Correct Answer: B

Rationale: The correct answer is B: Cardiac muscle. Cardiac muscle is found exclusively in the heart, allowing it to contract rhythmically and involuntarily to pump blood throughout the body. Smooth muscle (A) is found in organs like the intestines and blood vessels, not in the heart. Skeletal muscle (C) is attached to bones and responsible for voluntary movements, while voluntary muscle (D) is a general term that refers to skeletal muscle controlled voluntarily. Therefore, the unique characteristics of cardiac muscle make it the correct answer for this question.

Correct Answer: C

Rationale: The correct answer is C: Holding urine in the bladder for long periods is NOT recommended for optimal urinary system health. When urine is held for a long time, it can increase the risk of urinary tract infections and bladder issues. It can also lead to bladder distension and potential damage to the bladder muscles. To maintain urinary system health, it is crucial to empty the bladder regularly to prevent bacterial growth and support proper bladder function. Choices A, B, and D are recommended practices for optimal urinary system health. Limiting high-sodium foods helps reduce the risk of kidney stones and hypertension, consuming cranberry juice can help prevent urinary tract infections, and regular moderate-intensity exercise promotes overall health, including the urinary system.

Correct Answer: D

Rationale: The correct answer is D: tRNA. Transfer RNA (tRNA) carries amino acids to ribosomes during protein synthesis. tRNA has an anticodon that pairs with the mRNA codon, ensuring the correct amino acid is added to the growing polypeptide chain. A: DNA carries genetic information but does not directly participate in protein synthesis. B: mRNA carries the genetic information from DNA to the ribosomes but does not carry amino acids. C: rRNA is a structural component of ribosomes and helps in protein synthesis but does not carry amino acids to the ribosomes.