Which form of epithelial tissue may be found in the upper respiratory system (URS)?

Correct Answer: A

Rationale: Step 1: The upper respiratory system requires protection and mucus secretion. Step 2: Pseudostratified epithelium provides protection and has cilia for moving mucus. Step 3: Ciliated columnar cells help sweep mucus and debris out of the respiratory tract. Step 4: Therefore, pseudostratified ciliated columnar epithelium is the correct choice. Summary: B: Moist cuboidal epithelium lacks cilia and isn't specialized for mucus clearance. C: Simple squamous epithelium is too thin and fragile for protection. D: Stratified squamous epithelium is more suited for areas with high mechanical stress.

Correct Answer: D

Rationale: The correct answer is D: oxygen-hemoglobin saturation curve. This is because the oxygen-hemoglobin saturation curve graphically depicts the relationship between the saturation of hemoglobin with oxygen and the partial pressure of oxygen. This curve helps visualize factors affecting oxygen release, such as pH, temperature, and carbon dioxide levels. A: Spirograph is a tool used for drawing geometric shapes and has no relevance to hemoglobin oxygen release. B: Pulmonary volume chart is used to measure lung volumes and capacities, not specifically related to hemoglobin oxygen release. C: Respiratory cycle chart may show breathing patterns but does not directly visualize factors affecting oxygen release from hemoglobin. In summary, the oxygen-hemoglobin saturation curve is the most appropriate tool for visualizing factors influencing oxygen release from hemoglobin, making it the correct choice over the other options.

Correct Answer: D

Rationale: The correct answer is D: Alveoli are expanded. Prior to birth, the alveoli in the lungs are collapsed, and they begin to expand and develop after birth when the baby starts breathing air. A: Pulmonary arterial resistance is high due to blood flow bypassing the lungs. B: Pulmonary vessels are collapsed to prevent blood flow in the fetal lungs. C: The rib cage is compressed in the womb due to the limited space, but it expands after birth to allow for lung expansion.

Correct Answer: B

Rationale: The correct answer is B: Edema. In heart failure patients, fluid buildup in the lungs is known as pulmonary edema. This occurs due to the heart's inability to pump effectively, leading to fluid leaking into the lungs' air sacs. Ascites (A) is fluid buildup in the abdomen, not the lungs. Pleurisy (C) is inflammation of the lining around the lungs, not fluid buildup. Effusion (D) refers to fluid accumulation in body cavities like the chest or abdomen, but it is not specific to the lungs like pulmonary edema.

Correct Answer: C

Rationale: The cochlea has 3 fluid-filled chambers: the scala vestibuli, scala media, and scala tympani. These chambers are essential for hearing as they contain different fluids (perilymph and endolymph) that help transmit sound vibrations. Choice A (1 chamber) is incorrect as the cochlea has multiple distinct chambers. Choice B (2 chambers) is incorrect as it does not accurately reflect the anatomical structure of the cochlea. Choice D (4 chambers) is incorrect as the cochlea typically consists of 3 chambers, not 4. Therefore, the correct answer is C (3 chambers) based on the accurate anatomical structure of the cochlea.