Nursing Elites

1. Where do nearly all of the gaseous exchanges between air and blood take place in the lungs?

• A. Pleura
• B. Trachea
• C. Bronchioles
• D. Alveoli

Correct answer: D

Rationale: Nearly all gaseous exchanges between air and blood take place in the alveoli of the lungs. The walls of the alveoli are thin and surrounded by an extensive network of tiny blood vessels called capillaries. Oxygen from the air diffuses through the alveoli walls and into the bloodstream, while carbon dioxide, a waste product, diffuses from the blood into the alveoli to be exhaled out of the body. This process is essential for respiration and providing oxygen to the body's cells. Choices A, B, and C are incorrect. Pleura is the membrane surrounding the lungs, trachea is the windpipe that carries air to the lungs, and bronchioles are the smaller air passages in the lungs. However, the primary site for gaseous exchange is the alveoli due to their structure and function.

2. A tissue examined under the microscope exhibits the following characteristics: cells found on the internal surface of the stomach, no extracellular matrix, cells tall and thin, and no blood vessels in the tissue. What type of tissue is this?

• A. Epithelial
• B. Connective
• C. Muscle
• D. Cartilage

Correct answer: A

Rationale: The correct answer is 'Epithelial.' Epithelial tissue is characterized by cells that cover internal and external surfaces, such as the lining of the stomach. It lacks an extracellular matrix, has tall and thin cells, and does not contain blood vessels. The other choices are incorrect because connective tissue typically has an extracellular matrix, muscle tissue is composed of contractile cells, and cartilage is a type of connective tissue with a specific extracellular matrix and cell arrangement.

3. What is the main function of the endocrine system?

• A. To fight infections
• B. To regulate body functions through hormones
• C. To produce red blood cells
• D. To transport oxygen

Correct answer: B

Rationale: The main function of the endocrine system is to regulate various body functions by releasing hormones, which act as chemical messengers. These hormones help maintain homeostasis, regulate metabolism, growth, development, and other essential functions in the body. Option A is incorrect as fighting infections is primarily the role of the immune system, not the endocrine system. Option C is incorrect as the production of red blood cells mainly occurs in the bone marrow. Option D is incorrect as the transportation of oxygen is primarily carried out by the respiratory and circulatory systems. Therefore, option B is the correct answer as it accurately describes the primary role of the endocrine system.

4. Which hormone is released by the pancreas to lower blood glucose levels?

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

Correct answer: A

Rationale: Insulin is the hormone released by the pancreas to lower blood glucose levels. Insulin facilitates the uptake of glucose into cells, helping to decrease blood glucose levels and store excess glucose for energy or future use. Glucagon, on the other hand, raises blood glucose levels by promoting the breakdown of glycogen into glucose. Cortisol and somatostatin do not directly regulate blood glucose levels in the same manner as insulin and glucagon.

5. What part of the eye is responsible for focusing light on the retina?

• A. Cornea
• B. Lens
• C. Retina
• D. Pupil

Correct answer: B

Rationale: The lens of the eye is responsible for focusing light on the retina. When light enters the eye, it first passes through the cornea, which helps in bending the light, and then the lens further refracts and focuses the light onto the retina at the back of the eye. The retina contains photoreceptor cells that convert light into neural signals, which are then sent to the brain for visual processing. The cornea is the transparent outermost layer of the eye that helps in focusing light, but the main responsibility lies with the lens. The retina is the layer at the back of the eye that receives the focused light and initiates the process of vision. The pupil is the opening in the center of the iris that controls the amount of light entering the eye and is not directly involved in focusing light on the retina.

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