Nursing Elites

1. What term describes the bending of waves around obstacles or through openings?

• A. Reflection
• B. Refraction
• C. Diffraction
• D. Absorption

Correct answer: C

Rationale: The correct answer is C, Diffraction. Diffraction is the phenomenon that explains the bending of waves around obstacles or through openings. When waves encounter obstacles or pass through openings, they spread out and bend around them. Reflection (Choice A) involves waves bouncing back when they encounter a surface without bending, refraction (Choice B) is the bending of waves when passing from one medium to another due to a change in speed, and absorption (Choice D) is the process of a wave being taken in by a material rather than bending or bouncing.

2. Which organ system is most responsible for maintaining control of body temperature?

• A. The skeletal system.
• B. The circulatory system.
• C. The immune system.
• D. The muscular system.

Correct answer: B

Rationale: The circulatory system is the correct answer as it plays a crucial role in maintaining control of body temperature through a process called thermoregulation. Blood vessels near the skin surface dilate to dissipate heat when the body is too warm and constrict to reduce heat loss when it's too cold. Additionally, the circulatory system helps distribute heat produced from metabolic processes throughout the body to keep a stable internal temperature. The skeletal system provides structural support, the immune system defends against pathogens, and the muscular system is responsible for movement, but they are not primarily involved in regulating body temperature.

3. What are the two layers of the spinal cord?

• A. White matter and grey matter
• B. Epithelial and connective tissue
• C. Adipose and muscular tissue
• D. Dermis and hypodermis

Correct answer: A

Rationale: The correct answer is A: White matter and grey matter. The spinal cord is composed of an exterior layer of white matter, which surrounds an interior core of grey matter. White matter consists mainly of myelinated axons, while grey matter contains cell bodies, dendrites, and unmyelinated axons. White matter is responsible for transmitting nerve signals up and down the spinal cord, while grey matter processes sensory information and initiates motor commands. The other choices (B, C, D) are incorrect as they do not represent the anatomical layers of the spinal cord. Epithelial and connective tissue, adipose and muscular tissue, dermis, and hypodermis are not the layers of the spinal cord but are found in other parts of the body such as skin and organs.

4. What type of bond holds water molecules together?

• A. Covalent bond
• B. Hydrogen bond
• C. Ionic bond
• D. Peptide bond

Correct answer: B

Rationale: The correct answer is B: Hydrogen bond. Hydrogen bonds are responsible for holding water molecules together. In a water molecule, the oxygen atom is slightly negative, and the hydrogen atoms are slightly positive, creating a partial positive and negative charge. This polarity allows hydrogen bonds to form between adjacent water molecules. Covalent bonds involve the sharing of electrons, ionic bonds involve transfer of electrons between ions, and peptide bonds are specific to linking amino acids in proteins, which are not relevant to water molecule interactions.

5. What is the name of the white blood cells that attack foreign invaders?

• A. Phagocytes
• B. Lymphocytes
• C. Platelets
• D. Red blood cells

Correct answer: A

Rationale: Phagocytes are a type of white blood cell that plays a crucial role in the immune system by engulfing and digesting foreign invaders such as bacteria, viruses, and other harmful substances. They are part of the body's innate immune response and are essential for protecting the body against infections. Lymphocytes, on the other hand, are another type of white blood cell involved in the adaptive immune response, producing antibodies, and coordinating immune responses. Platelets are cell fragments involved in blood clotting, while red blood cells are responsible for carrying oxygen to tissues. Therefore, the correct answer is Phagocytes (Choice A) because they are specifically tasked with attacking and destroying foreign invaders in the body, distinguishing them from the other choices which have different functions within the immune system.

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