Final answer:
Anatomic structures that show a fibrillar pattern on ultrasound are muscles, which includes skeletal, smooth, and cardiac muscle cells, characterized by their striations or fibrous appearance on ultrasound imaging. The correct option is D.
Step-by-step explanation:
The anatomic structures that display a fibrillar pattern on ultrasound are muscles. Muscles, including skeletal, smooth, and cardiac muscle cells, are characterized by their striations or fibrous appearance, which is typically captured on imaging modalities like ultrasound.
Specifically, skeletal muscle cells show prominent striation with nuclei on their periphery, smooth muscle cells have a single nucleus and no visible striations, and cardiac muscle cells are striated with a single nucleus. These characteristics allow muscles to be distinguished from other tissue types on an ultrasound due to their unique fibrillar pattern.
While the other options listed (a) blood vessels, (b) liver parenchyma, and (c) kidney cortex do not exhibit a fibrillar pattern on ultrasound, muscles do, making them the correct answer to the question asked by the student.