ATI RN
Muscular System Exam Questions Questions
Question 1 of 5
Which part of the skeleton consists of the skull, vertebral column, and rib cage?
Correct Answer: B
Rationale: The axial skeleton includes the skull, vertebral column, and rib cage, forming the body's central axis for support/protection. Appendicular is limbs/girdles. Pectoral and pelvic girdles are appendicular parts. Axial's midline role, per skeletal division, makes 'b' correct.
Question 2 of 5
What is the function of the paranasal sinuses?
Correct Answer: D
Rationale: Paranasal sinuses (frontal, maxillary, etc.) warm/humidify air , produce mucus to trap debris, and lighten the skull (not a, reducing weight). All functions apply, enhancing respiration and skull structure, making 'd' correct.
Question 3 of 5
Metabolism can be defined as the
Correct Answer: D
Rationale: Metabolism is the sum of all chemical reactions in an organism, including catabolism (breaking down) and anabolism (building up), powering life processes like growth. Adjustment to changes is homeostasis, not metabolism. Cell specialization is differentiation, new cell formation is regeneration distinct processes. Metabolism's comprehensive chemical scope, per physiology, makes 'd' correct.
Question 4 of 5
To make a banana split, you halve a banana into two long, thin, right and left sides along the
Correct Answer: C
Rationale: The midsagittal plane divides the banana (or body) into equal right and left halves lengthwise, matching the split's vertical, midline cut. Coronal splits front-back, longitudinal is vague (often sagittal), transverse cuts horizontally. Midsagittal's symmetry, per planes, makes 'c' correct.
Question 5 of 5
The A band in a muscle appears and contains
Correct Answer: A
Rationale: The A band, a sarcomere's dark-staining region under a microscope, spans the length of thick myosin filaments, overlapping with thin actin filaments in its outer zones. This overlap causes its anisotropic property, scattering light and appearing dark, unlike the isotropic (I) band's lighter, actin-only composition. Thick filaments anchor at the M line, while thin filaments extend from Z lines, partially interdigitating within the A band during rest. This dual presence distinguishes it from the H zone (thick only) and I band (thin only). The dark appearance stems from dense protein packing, observable in electron micrographs, and remains constant in length during contraction, unlike shrinking I bands. Thin filaments alone wouldn't account for the A band's width or darkness, nor would thick filaments without actin overlap explain its full structure. Muscle physiology texts confirm this composition, critical for cross-bridge formation in contraction, making the A band's dual-filament nature a cornerstone of sarcomere function.