ATI RN
Questions About Muscular System with Answers Questions
Question 1 of 5
What is the role of calcium ions in muscle contraction? To
Correct Answer: A
Rationale: Calcium ions bind troponin, altering its shape to displace tropomyosin, exposing actin's binding sites for myosin. They don't detach cross-bridges (ATP does), propagate action potentials (acetylcholine initiates), or join ADP in respiration. This regulatory role distinguishes calcium as contraction's trigger, essential for sarcomere shortening, contrasting with energy or nerve functions.
Question 2 of 5
The muscle known as the transversus abdominus is named according to
Correct Answer: D
Rationale: Transversus abdominus indicates location (abdomen) and fibre direction (transverse, horizontal) compressing the abdomen. Size, origins, or action (e.g., flexion) aren't named. This location-direction naming distinguishes it, key to understanding abdominal wall structure and function.
Question 3 of 5
Where is the temporalis muscle located?
Correct Answer: C
Rationale: The temporalis muscle is on the side of the head, originating from the temporal bone's fossa and inserting on the mandible's coronoid process, aiding jaw closure. The forehead hosts frontalis, part of occipitofrontalis. The neck has muscles like sternocleidomastoid, not temporalis. The chin relates to mentalis, not temporalis. Its lateral cranial position, visible when clenching teeth, confirms 'c' as the correct location in head anatomy.
Question 4 of 5
The rhomboid major and minor muscles are deep to the
Correct Answer: C
Rationale: Rhomboid major and minor, between the scapulae, retract and stabilize the shoulder blades, lying deep to the trapezius, a superficial back muscle covering them. Rectus abdominis is anterior, unrelated. Scalenes are neck muscles, not over rhomboids. Ligamentum nuchae , a neck ligament, isn't superficial to rhomboids. Trapezius's broad, upper-back coverage over rhomboids, per anatomical layering, makes 'c' correct.
Question 5 of 5
In the region just deep to the eyebrows, are present which allow nerves and arteries to pass.
Correct Answer: C
Rationale: The supraorbital foramina (or notches), located just deep to the eyebrows on the frontal bone's supraorbital margin, allow the supraorbital nerve and artery to pass, supplying sensation and blood to the forehead. The nasal bridge is the bony junction of nasal bones, not a passage site. The frontal sinus , an air cavity above the eyes, doesn't transmit nerves or arteries. The maxillary sinus , below the eyes in the maxilla, is unrelated to this region. The supraorbital foramina's specific location and function in neurovascular passage make 'c' the correct answer.