which of the following neurons has the longest axon in the human body

ATI TEAS 7

Practice Science TEAS Test

1. Which of the following nerves has the longest axon in the human body?

A. Dorsal root ganglion
B. Laryngeal nerve
C. Sciatic nerve
D. None of the above

Correct answer: C

Rationale: The sciatic nerve contains the longest axon in the human body, extending from the lower back down the leg. This nerve is responsible for innervating the muscles of the lower limb. The dorsal root ganglion and laryngeal nerve do not possess axons as long as the sciatic nerve, making them incorrect choices. Therefore, the correct answer is C, the sciatic nerve.

2. Which hormone, produced by the pituitary gland, stimulates the growth and development of bones, muscles, and organs?

A. Growth hormone (GH)
B. Thyroid-stimulating hormone (TSH)
C. Prolactin
D. Follicle-stimulating hormone (FSH)

Correct answer: A

Rationale: The correct answer is Growth hormone (GH). GH, produced by the pituitary gland, is responsible for stimulating the growth and development of bones, muscles, and organs. It plays a critical role in regulating growth during childhood and adolescence by promoting cell division, protein synthesis, and tissue growth. Thyroid-stimulating hormone (TSH) functions to stimulate the thyroid gland to produce thyroid hormones, while prolactin is involved in milk production. Follicle-stimulating hormone (FSH) is primarily responsible for reproductive functions like egg development in females and sperm production in males.

3. When a blockage forms in a coronary artery, reducing blood flow to the heart muscle, this condition is called:

A. Atherosclerosis
B. Myocardial infarction
C. Angina pectoris
D. Heart murmur

Correct answer: B

Rationale: A myocardial infarction, commonly known as a heart attack, occurs when a blockage forms in a coronary artery, leading to reduced blood flow to the heart muscle. Atherosclerosis refers to the buildup of plaque in the arteries, which can lead to blockages but is not the name for this specific condition. Angina pectoris is chest pain or discomfort due to inadequate blood supply to the heart muscle, which is a precursor to a heart attack but not the name for this condition. A heart murmur is an abnormal sound heard during a heartbeat, often due to turbulent blood flow, and is not related to a blockage in a coronary artery.

4. Why are noble gas elements generally unreactive?

A. They are too large and cannot form bonds easily.
B. They lack valence electrons in their outermost shell.
C. They have strong bonds within their own molecules.
D. They have already achieved stable electron configurations.

Correct answer: D

Rationale: The correct answer is D. Noble gas elements are generally unreactive because they have already achieved stable electron configurations by having a full outer electron shell. This full shell makes them very stable and unlikely to gain, lose, or share electrons with other elements. Choices A, B, and C are incorrect because noble gases are not unreactive due to being too large to form bonds easily (A), lacking valence electrons in their outermost shell (B), or having strong bonds within their own molecules (C).

5. Which types of glial cells are in the PNS?

A. Schwann cells, satellite cells
B. Astrocytes, oligodendrocytes
C. Microglia, ependymal cells
D. Satellite cells, oligodendrocytes

Correct answer: A

Rationale: The correct answer is A, which includes Schwann cells and satellite cells as the types of glial cells found in the peripheral nervous system. Schwann cells support neurons and myelinate axons, while satellite cells provide structural support and regulate the microenvironment around neurons in the PNS. Options B, C, and D are incorrect as they refer to glial cell types that are typically found in the central nervous system, not the peripheral nervous system. Astrocytes and oligodendrocytes are primarily located in the CNS, where they perform functions such as providing structural support and forming the blood-brain barrier. Microglia are immune cells found in the CNS responsible for immune defense and maintenance of neural environment, while ependymal cells line the cerebral ventricles and the central canal of the spinal cord, contributing to the production and circulation of cerebrospinal fluid.