The partial pressure of oxygen in the interstitial space of peripheral tissues is approximately

Correct Answer: A

Rationale: The correct answer is A: 40 mm Hg. In peripheral tissues, oxygen is delivered by the blood through capillaries. The partial pressure of oxygen in the interstitial space of peripheral tissues is lower than in the blood, around 40 mm Hg. This allows for the diffusion of oxygen from capillaries to cells. Choice B (45 mm Hg) and C (50 mm Hg) are slightly higher pressures and would not promote efficient oxygen diffusion. Choice D (70 mm Hg) is closer to arterial blood oxygen levels and would not allow sufficient oxygen release to tissues. Thus, the correct answer is A as it reflects the physiological conditions necessary for effective oxygen delivery to cells.

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.

Correct Answer: C

Rationale: The correct answer is C: Diaphragmatic breathing. During rest, normal breathing involves the diaphragm contracting and moving downward to draw air into the lungs. This type of breathing is known as diaphragmatic breathing. Choice A (Breathing) is too broad and does not specify the involvement of the diaphragm. Choice B (Diaphragmatic) does not fully describe the process of breathing during rest. Choice D (Non) is incorrect as it does not provide any information related to the breathing process during rest state. Therefore, C is the most accurate choice as it specifically identifies the type of breathing that occurs during rest.