BIO NMDCAT

Correct: Skeletal muscles are attached to bones and produce voluntary body movements. A: Cardiac muscle pumps blood. B & D: Smooth (visceral) muscles control internal organs. Concept: Voluntary muscle action.

Correct: Branched fibers connected by intercalated discs are unique to cardiac muscle. A: Skeletal fibers are long and unbranched. B: Smooth muscle is spindle-shaped. D: Not muscle tissue. Concept: Histology of cardiac muscle.

Correct: Smooth muscle in blood vessel walls controls vasoconstriction and vasodilation. A: Skeletal muscle moves bones. C: Cardiac muscle forms the heart. D: Tendons connect muscles to bones. Concept: Function of smooth muscle.

Correct: Skeletal muscle is striated due to the organized arrangement of actin and myosin filaments. A: Smooth muscle also has a single central nucleus. B: Skeletal muscle is voluntary. D: Spindle-shaped cells are characteristic of smooth muscle. Concept: Structural comparison of muscle types.

Correct: Smooth muscle in the walls of the digestive tract performs involuntary peristalsis. A: Skeletal muscle controls voluntary movement. B: Cardiac muscle is restricted to the heart. D: Tendons connect muscles to bones. Concept: Functional significance of smooth muscle.

Correct: Intercalated discs electrically and mechanically connect cardiac muscle cells, allowing synchronized contractions. A: Cardiac muscle is involuntary. C: Cardiac muscle is not attached to bones. D: Cardiac muscle contains numerous mitochondria. Concept: Adaptations of cardiac muscle.

Correct: Smooth muscle cells are fusiform (spindle-shaped), uninucleate, and lack striations. A & D: Describe skeletal muscle. B: Describes cardiac muscle. Concept: Morphology of muscle tissues.

Correct: Branched fibers and intercalated discs are unique features of cardiac muscle. A: Smooth muscle is non-striated and spindle-shaped. B: Skeletal muscle is unbranched and multinucleated. D: Dense connective tissue lacks muscle fibers. Concept: Histological identification of muscle types.

Correct: Both possess striations, but skeletal muscle is voluntary while cardiac muscle is involuntary. A: Cardiac muscle is usually uninucleate. C: Skeletal muscle is striated. D: Skeletal muscle is attached mainly to bones. Concept: Comparison of skeletal and cardiac muscles.

Correct: Cardiac and smooth muscles function without conscious control. A: Only skeletal muscle is voluntary. C & D: These statements are incorrect. Concept: Voluntary vs. involuntary muscle control.

Correct: Skeletal muscles attach to bones and produce voluntary body movements while maintaining posture. A: Smooth muscle controls internal organs. B: Cardiac muscle pumps blood. D: Visceral muscle refers to smooth muscle. Concept: Functional role of skeletal muscle.

Correct: Skeletal muscle fibers are multinucleated with peripheral nuclei and visible striations. A: Cardiac muscle has one or two central nuclei. B: Smooth muscle lacks striations. D: Epithelial tissue is not muscle. Concept: Microscopic characteristics of skeletal muscle.

Correct: Intercalated discs synchronize contraction, while abundant mitochondria provide continuous ATP for rhythmic activity. A: Cardiac muscle is rich in mitochondria. C: It is involuntary. D: Spindle-shaped cells are characteristic of smooth muscle. Concept: Functional adaptations of cardiac muscle.

Correct: Children's bones contain more cartilage and collagen, making them more flexible. A & C: These increase rigidity. D: Osteoblast activity is actually higher during growth. Concept: Age-related differences in bone composition.

Correct: Chondrocytes, lacunae, an avascular nature, and a flexible matrix are characteristic features of cartilage. A & B: Bone contains osteocytes and blood vessels. D: Tendons consist mainly of dense connective tissue with fibroblasts. Concept: Identification and characteristics of cartilage.

Correct: Articular cartilage cushions joints and reduces friction during movement. A: Synovial membrane produces synovial fluid. C: Bone stores calcium. D: Tendons connect muscles to bones. Concept: Function of articular cartilage.

Correct: Compact bone consists of osteons with concentric lamellae around Haversian canals. A, B & D: Cartilage lacks osteons and Haversian canals. Concept: Histology of compact bone.

Correct: Loss of articular cartilage increases friction, causing pain and restricted movement. A: Bone marrow production is unrelated. C: Calcium storage is unaffected. D: Bone flexibility does not increase. Concept: Function of articular cartilage.

Correct: Osteoclasts resorb bone; excessive activity weakens bones. A: Bone density decreases. C: Osteoclasts do not form cartilage. D: Muscle strength is unrelated. Concept: Bone remodeling.