Nursing Elites

1. Which muscle has involuntary cells that are branched and striated and connected by intercalated discs with gap junctions?

• A. Smooth muscle
• B. Cardiac muscle
• C. Skeletal muscle
• D. Epithelial muscle

Correct answer: B

Rationale: The correct answer is B: Cardiac muscle. Cardiac muscle cells fit the description provided in the question; they are involuntary, striated, and branched, with intercalated discs containing gap junctions that allow for synchronized contractions of the heart. Smooth muscle (choice A) lacks striations and is found in the walls of internal organs. Skeletal muscle (choice C) is voluntary and attaches to bones for movement. 'Epithelial muscle' (choice D) is not a valid muscle type, making it an incorrect choice.

2. Which part of the brain generates the rhythmic electrical activity responsible for brain waves?

• A. Cerebrum
• B. Thalamus
• C. Hypothalamus
• D. Reticular formation

Correct answer: D

Rationale: The reticular formation is a network of neurons located in the brainstem that plays a crucial role in regulating arousal and consciousness. It generates the rhythmic electrical activity responsible for brain waves, which are measured using electroencephalography (EEG). The cerebrum, thalamus, and hypothalamus do not primarily generate brain waves; they have other specialized functions within the brain. The cerebrum is responsible for higher brain functions such as thinking and voluntary movements. The thalamus acts as a relay station for sensory information. The hypothalamus is involved in various functions such as regulating body temperature, hunger, and hormonal activities.

3. Which organelle is responsible for the final stages of protein modification and packaging for secretion in animal cells?

• A. Rough endoplasmic reticulum (RER)
• B. Smooth endoplasmic reticulum (SER)
• C. Ribosomes
• D. Golgi apparatus

Correct answer: D

Rationale: The Golgi apparatus is responsible for the final stages of protein modification and packaging for secretion in animal cells. After proteins are synthesized in the rough endoplasmic reticulum (RER), they are transported to the Golgi apparatus for further processing, sorting, and packaging before being sent to their final destination within or outside the cell. The smooth endoplasmic reticulum (SER) is mainly involved in lipid metabolism and detoxification processes, not protein modification. Ribosomes are the cellular organelles responsible for protein synthesis, not the final stages of protein modification and packaging for secretion, which is the role of the Golgi apparatus.

4. Which hormone, produced by the pancreas, is released in response to low blood sugar levels and stimulates the release of glucose into the bloodstream?

• A. Insulin
• B. Glucagon
• C. Cortisol
• D. Thyroxine

Correct answer: B

Rationale: Glucagon is the hormone produced by the pancreas that is released in response to low blood sugar levels. It acts to stimulate the release of glucose into the bloodstream by promoting the breakdown of glycogen in the liver. Insulin, conversely, is released in response to high blood sugar levels and promotes the uptake of glucose by cells. Cortisol is a steroid hormone produced by the adrenal glands that regulates metabolism and the immune response. Thyroxine is a hormone produced by the thyroid gland that regulates metabolism but is not involved in responding to low blood sugar levels.

5. Which types of molecules can move through a cell membrane by passive transport?

• A. Complex sugars
• B. Non-lipid soluble molecules
• C. Oxygen
• D. Molecules moving from areas of low concentration to areas of high concentration

Correct answer: C

Rationale: The correct answer is C: Oxygen. Small, non-polar molecules like oxygen can easily pass through the cell membrane by passive transport as they move down their concentration gradient without the need for energy input. Complex sugars (choice A) are typically too large to pass through the membrane by passive transport. Non-lipid soluble molecules (choice B) may require active transport mechanisms. Choice D describes active transport, where molecules move against their concentration gradient, requiring energy input.

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