When the inspiratory muscles are relaxed, the lungs are said to be at?

Correct Answer: D

Rationale: When inspiratory muscles (diaphragm, external intercostals) relax post-normal expiration, lungs reach functional residual capacity (FRC, ~2.5-3 L), the resting volume where lung and chest wall recoils balance, with no airflow (alveolar pressure = 760 mmHg). Vital capacity (VC, ~4-5 L) is maximal exhalable volume, requiring active inspiration false. Residual volume (RV, ~1-1.5 L) is post-maximal expiration false. Minimal volume' isn't standard, possibly RV or collapse (not natural) false. FRC is the passive rest state, key for gas exchange baseline, distinct from volumes tied to effort, making it the correct point of muscle relaxation.

Correct Answer: A

Rationale: The pterygopalatine fossa is a key junction. The maxillary artery enters via the pterygomaxillary fissure (A) from the infratemporal fossa, branching to supply the nose, palate, and pharynx. The maxillary nerve (V2) enters from the middle cranial fossa (C) through the foramen rotundum, exiting variably (e.g., infraorbital canal, D, for the face). At the pterygomaxillary fissure (A), the artery enters while the nerve is already within, heading elsewhere, fulfilling different directions.' B (infratemporal fossa) is the artery's origin, not passage point; C and D are partial paths, not the junction. A is the precise anatomical site of divergence.

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: A

Rationale: Paramesonephric (Müllerian) ducts, in females, develop into the uterus and upper vagina (A), forming under estrogen influence as the mesonephric ducts regress. Ovaries (B) arise from gonadal ridges (mesoderm), not paramesonephric ducts, which are separate from gamete-forming tissues. Testes (C) and prostate (D) develop in males from mesonephric (Wolffian) ducts under testosterone, while paramesonephric ducts degenerate. A is correct paramesonephric ducts' role in female reproductive tract formation contrasts with the others' distinct embryological pathways.

Correct Answer: A

Rationale: Salivary gland ducts are lined with simple cuboidal epithelium (A), suited for secretion and transport, transitioning to stratified near openings. Simple squamous (B) is for diffusion (e.g., alveoli), not ducts. Stratified squamous (C) protects (e.g., esophagus), not typical here. Transitional (D) is urinary, not salivary. A is correct cuboidal cells' secretory role fits salivary ducts.