Nursing Elites

1. How many electrons are typically found in each shell of a neutral aluminum atom with 13 electrons in its electron cloud?

• A. 6 in the first shell, 7 in the second shell
• B. 2 in the first shell, 11 in the second shell
• C. 2 in the first shell, 8 in the second shell, 3 in the third shell
• D. 3 in the first shell, 5 in the second shell, 5 in the third shell

Correct answer: C

Rationale: In a neutral aluminum atom with 13 electrons, the electron distribution typically follows the electron shell filling order based on the Aufbau principle. The first shell can hold a maximum of 2 electrons, the second shell can hold up to 8 electrons, and the third shell can hold up to 8 electrons as well. Therefore, the distribution would be 2 electrons in the first shell, 8 electrons in the second shell, and 3 electrons in the third shell, totaling 13 electrons. Choice A is incorrect as it exceeds the maximum number of electrons the shells can hold. Choice B is incorrect as it does not distribute the electrons correctly among the shells. Choice D is incorrect as it also does not distribute the electrons correctly among the shells.

2. Where is the heart located within the human body cavities?

• A. Dorsal cavity
• B. Ventral cavity
• C. Thoracic cavity
• D. Abdominal cavity

Correct answer: C

Rationale: The heart is located within the thoracic cavity, specifically in the mediastinum, which is the central compartment of the thoracic cavity. The thoracic cavity is part of the ventral cavity, which also includes the abdominal cavity. The dorsal cavity refers to the posterior side of the body and does not contain the heart. The heart is situated in the thoracic cavity between the lungs and above the diaphragm, making option C the correct choice. Therefore, the correct answer is the thoracic cavity (option C). The ventral cavity (option B) includes the thoracic and abdominal cavities, but the heart is specifically situated in the thoracic cavity. The dorsal cavity (option A) is located on the posterior side of the body, not where the heart is positioned. The abdominal cavity (option D) is below the thoracic cavity and houses organs such as the stomach, liver, and intestines, but it does not contain the heart.

3. What is the name of the muscular ring that controls the passage of food from the esophagus to the stomach?

• A. Pyloric sphincter
• B. Cardiac sphincter
• C. Ileocecal valve
• D. Sphincter of Oddi

Correct answer: B

Rationale: The correct answer is the Cardiac sphincter (lower esophageal sphincter). It is situated at the junction of the esophagus and the stomach, controlling the passage of food into the stomach. The cardiac sphincter opens and closes to regulate the flow of food and prevent reflux. The pyloric sphincter, on the other hand, is located between the stomach and the small intestine, not the esophagus and stomach. The ileocecal valve is positioned between the small and large intestines, while the Sphincter of Oddi is found in the duodenum, not between the esophagus and stomach.

4. Which of the following structures is located in the pelvic cavity?

• A. The kidneys
• B. The colon
• C. The bladder
• D. The rectum

Correct answer: C

Rationale: The correct answer is the bladder. The bladder is situated in the pelvic cavity, specifically in the lower part of the abdomen. The kidneys are positioned higher up in the abdominal cavity, not in the pelvic region. The colon and rectum are part of the large intestine and are primarily located in the abdominal cavity, not the pelvic cavity. Therefore, the bladder is the only structure listed that is anatomically situated in the pelvic cavity.

5. Which hormone, produced by the thyroid gland, regulates calcium levels in the blood by enhancing calcium absorption in the intestines and reducing calcium loss in the kidneys?

• A. Calcitonin
• B. Parathyroid hormone (PTH)
• C. Thyroxine
• D. Insulin

Correct answer: A

Rationale: Calcitonin is the hormone produced by the thyroid gland that regulates calcium levels in the blood. It enhances calcium absorption in the intestines and reduces calcium loss in the kidneys. Parathyroid hormone (PTH) operates oppositely to calcitonin by increasing calcium levels in the blood. Thyroxine is a thyroid gland hormone that primarily regulates metabolism, not calcium levels. Insulin, produced by the pancreas, is responsible for controlling blood sugar levels, not calcium levels. Therefore, the correct answer is Calcitonin as it specifically targets calcium regulation in the body.

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