Nursing Elites

1. Which of the following is the cardiac muscle layer that forms the bulk of the heart?

• A. Endocardium
• B. Epicardium
• C. Fibrous skeleton
• D. Myocardium

Correct answer: D

Rationale: The correct answer is D, Myocardium. The myocardium is the cardiac muscle layer that comprises the majority of the heart's muscle mass. It is responsible for the heart's contractions, allowing it to pump blood throughout the body. The endocardium is the innermost layer of the heart lining the chambers, while the epicardium is the outermost layer covering the heart. The fibrous skeleton provides structural support and serves as an attachment point for cardiac muscle fibers. Therefore, choices A, B, and C are incorrect as they do not represent the primary muscle layer of the heart.

2. During inhalation, which muscle contracts to increase the volume of the thoracic cavity, allowing air to flow into the lungs?

• A. Diaphragm
• B. Intercostal muscles
• C. Abdominal muscles
• D. Pectoral muscles

Correct answer: A

Rationale: The diaphragm is the primary muscle responsible for inhalation. When it contracts, it moves downward, increasing the volume of the thoracic cavity and creating a pressure gradient that allows air to flow into the lungs. While the intercostal muscles also play a role in expanding the chest cavity during inhalation, the diaphragm is the main muscle involved in this process. Abdominal muscles and pectoral muscles are not directly involved in the process of inhalation.

3. The adaptive immune system has two main branches: humoral and cell-mediated immunity. Which type of immune cell is primarily responsible for antibody production?

• A. Helper T cells
• B. Cytotoxic T cells
• C. B cells
• D. Natural killer cells

Correct answer: C

Rationale: B cells are primarily responsible for antibody production in the adaptive immune system. When activated, B cells differentiate into plasma cells, which are specialized to produce antibodies. Helper T cells play a crucial role in activating B cells, but they do not directly produce antibodies. Cytotoxic T cells are involved in cell-mediated immunity by killing infected cells, while natural killer cells are part of the innate immune system and target virus-infected and cancerous cells. Therefore, the correct answer is C (B cells) as they are directly involved in the production of antibodies, essential for humoral immunity.

4. What is the scientific name for the building blocks of proteins?

• A. Residues
• B. Monomers
• C. Macromolecules
• D. Peptides

Correct answer: B

Rationale: Rationale: - Proteins are made up of long chains of amino acids. - Amino acids are the building blocks of proteins and are considered monomers. - Monomers are the individual units that can be linked together to form larger molecules called polymers. - In the context of proteins, amino acids are the monomers that are linked together through peptide bonds to form polypeptide chains, which then fold into functional proteins. - Residues refer to the specific amino acids within a protein after certain modifications or cleavages have occurred, so it is not the correct term for the building blocks of proteins. - Macromolecules are large molecules made up of smaller subunits, such as proteins, nucleic acids, and carbohydrates, but they are not the specific building blocks of proteins. - Peptides are short chains of amino acids linked by peptide bonds, but they are not the fundamental building blocks of proteins.

5. What is the milky-white fluid transported by the lymphatic vessels called?

• A. Plasma
• B. Blood
• C. Chyle
• D. Mucus

Correct answer: C

Rationale: The milky-white fluid transported by the lymphatic vessels is called chyle. Chyle is formed in the small intestine during the digestion of fatty foods and contains a mixture of lymph and emulsified fats. Plasma is the liquid component of blood, not lymphatic fluid. Blood refers to the fluid that circulates in the cardiovascular system, not lymphatic fluid. Mucus is a slimy substance secreted by mucous membranes, not the fluid transported by lymphatic vessels.

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