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, no blood vessels in the tissue. What type of tissue is this?

Correct Answer: A

Rationale: The correct answer is 'Epithelial.' Epithelial tissue is characterized by cells lining surfaces and cavities, such as the stomach. It does not contain blood vessels, and the cells are tall and thin. The absence of an extracellular matrix is typical of epithelial tissue, making it the most suitable choice in this scenario. Connective tissue, like cartilage and nervous tissue, have different characteristics that do not align with the description provided in the question.

Correct Answer: A

Rationale: Endocytosis is a cellular process where the cell engulfs and internalizes solid particles by forming vesicles. It is a mechanism used for nutrient uptake, cell signaling, and maintaining cellular homeostasis. Options B, C, and D describe processes that are opposite to endocytosis. Choice B is incorrect because it describes pinocytosis, which is the process of engulfing liquid material. Choice C is incorrect as it describes exocytosis, the process of expelling material from the cell. Choice D is incorrect as it describes the process of releasing liquid material from the cell. Therefore, the correct answer is A.

Correct Answer: C

Rationale: The lateral side of the right knee is the side that is farthest from the left knee when looking at the knee joint from the front. The term 'lateral' refers to the side of the body that is farther away from the midline or center of the body. In this case, the lateral side of the right knee is on the outer side of the knee joint, away from the other knee. Choice A is incorrect as the kneecap is located at the front of the knee. Choice B is incorrect as it describes the medial side, not the lateral side. Choice D is incorrect as it refers to the underside, which is not related to the lateral aspect of the knee.

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.

Correct Answer: C

Rationale: The intercostal muscles located between the ribs play a crucial role in respiration by aiding in the enlargement and reduction of the space in the thorax. During inspiration, these muscles contract, lifting the rib cage, which increases the volume of the thoracic cavity and allows the lungs to expand and fill with air. This process directly relates to the expansion of the thorax rather than protecting bronchioles and alveoli (Choice A), signaling intra-alveolar pressure changes (Choice B), or maintaining the separation between pleurae (Choice D). Therefore, the correct answer is C.