how many neurons generally make up a sensory pathway

ATI TEAS 7

ATI TEAS Science

1. How many neurons typically comprise a sensory pathway?

A. 1
B. 2
C. 3
D. 4

Correct answer: C

Rationale: A sensory pathway generally consists of three neurons: a first-order neuron, a second-order neuron, and a third-order neuron. The first-order neuron carries sensory information from the periphery to the spinal cord or brainstem. The second-order neuron then transmits this information to the thalamus or cerebellum. Finally, the third-order neuron projects the sensory input to the cerebral cortex for processing and perception. Therefore, the correct answer is 3 (C). Choices A, B, and D are incorrect as they do not align with the typical structure of a sensory pathway involving three neurons.

2. Which of the following is a characteristic phenomenon associated with Cherenkov radiation?

A. Alpha particle emission
B. Beta particle emission
C. Gamma ray emission
D. Charged particles exceeding the speed of light in a medium

Correct answer: D

Rationale: Cherenkov radiation is produced when charged particles travel through a medium at speeds greater than the speed of light in that medium. It is not specific to a particular type of particle emission but rather to the speed of the charged particles. This phenomenon results in the emission of a characteristic blue light, which is a visual indicator of charged particles exceeding the speed of light in that medium. Choices A, B, and C are incorrect because Cherenkov radiation is not limited to a specific type of particle emission but is based on the speed of the charged particles relative to the speed of light in the medium.

3. Which of the following nutrients is correctly matched with its foundational components?

A. Carbohydrates are formed when glucose molecules bond together.
B. Lipids consist of fatty acids and glycerol.
C. Nucleic acids consist of nitrogenous bases, sugar, and phosphate groups.
D. Proteins consist of strings of amino acids.

Correct answer: D

Rationale: Proteins consist of strings of amino acids. Amino acids are the basic building blocks of proteins, and they are linked together in a specific sequence to form a protein structure. This is a correct match between the nutrient (proteins) and its foundational components (amino acids). Choices A, B, and C are incorrect as they do not accurately match the foundational components of the respective nutrients. Carbohydrates are not formed by glucose molecules bonding together; they are made up of sugar molecules. Lipids consist of fatty acids and glycerol, but they are not nutrients typically associated with bonding for formation. Nucleic acids do consist of nitrogenous bases, sugar, and phosphate groups, but they are not the correct match for the question.

4. Which of the following is a condition characterized by a loss of bone density and increased risk of fractures?

A. Osteoarthritis
B. Rickets
C. Osteoporosis
D. Scoliosis

Correct answer: C

Rationale: Osteoporosis is a condition characterized by a loss of bone density, leading to fragile bones and an increased risk of fractures. Osteoarthritis is a degenerative joint disease affecting cartilage, Rickets is caused by a deficiency in vitamin D leading to impaired bone development, and Scoliosis is an abnormal sideways curvature of the spine. Therefore, the correct answer is osteoporosis as it specifically pertains to decreased bone density and fracture risk, distinguishing it from the other conditions listed.

5. What are the four chambers of the heart?

A. Right atrium, left atrium, right ventricle, left ventricle
B. Right atrium, left atrium, right ventricle, left atrium
C. Left atrium, right ventricle, left ventricle, right atrium
D. Left atrium, right atrium, left ventricle, right ventricle

Correct answer: A

Rationale: The correct answer is A: Right atrium, left atrium, right ventricle, left ventricle. The heart consists of four chambers: the right atrium, left atrium, right ventricle, and left ventricle. Blood flows from the body into the right atrium, then to the right ventricle, where it is pumped to the lungs for oxygenation. Oxygenated blood returns to the left atrium, passes to the left ventricle, and is then pumped out to the body. Choice B is incorrect because it incorrectly lists the left atrium twice. Choice C is incorrect as it rearranges the order of the chambers. Choice D is incorrect as it mistakenly switches the atria and ventricles in their positions.