Locomotion and Movement MCQs

Select the correct combination of statements about sarcoplasmic calcium action in muscles:

I. Increase in sarcoplasmic calcium levels leads to calcium binding with a subunit of troponin on actin filaments.
II. Binding of calcium with troponin removes the masking of active sites for myosin.
III. Sarcoplasmic reticulum of muscle fibers acts as a reservoir storing calcium ions.
IV. Active pumping of calcium back into the sarcoplasmic cisternae allows muscle relaxation to occur.

Analyze these statements about muscle contraction and structural changes according to the sliding filament theory:

I. Contraction is initiated by the sliding of thin filaments over the thick filaments.
II. The myosin head binds to exposed active sites on actin utilizing energy from ATP hydrolysis to form a cross-bridge.
III. During shortening (contraction), the I bands get reduced, whereas the A bands retain their length.
IV. The Z lines attached to actin filaments are pulled outwards, extending the sarcomere.

Consider these statements about the cross-bridge cycle and chemical events:

I. The myosin head, utilizing ATP hydrolysis, binds to actin to form a cross-bridge.
II. Pulling of the actin filaments causes them to slide towards the center of the A band.
III. Myosin releases ADP and inorganic phosphate (Pi) to return to its relaxed state.
IV. A new ATP molecule binds to the myosin head, which stabilizes and strengthens the established cross-bridge.

Read the following statements comparing Red and White muscle fibers:

I. Red muscle fibers contain high concentrations of the oxygen-storing pigment myoglobin.
II. Red muscle fibers contain plenty of mitochondria that can utilize oxygen for aerobic ATP production.
III. White muscle fibers contain a high quantity of myoglobin, giving them a distinct whitish appearance.
IV. White muscle fibers contain few mitochondria and depend primarily on anaerobic processes for energy.

Which of the following statements about bone and cartilage matrices are correct?

I. Bone and cartilage are specialized connective tissues.
II. Bone has a very hard matrix due to the presence of calcium salts in it.
III. Cartilage has a slightly pliable matrix due to chondroitin salts.
IV. The adult human skeletal system is composed of 300 bones and numerous cartilages.

Consider the statements regarding the human axial skeleton division:

I. The axial skeleton comprises 80 bones distributed along the main longitudinal axis of the body.
II. The skull, vertebral column, sternum, and ribs constitute the axial skeleton.
III. Limb bones and their respective girdles form the axial skeleton.
IV. Sternum is a flat bone situated on the ventral midline of the thorax.

Identify the correct statements regarding the bones of the human skull:

I. The skull is composed of cranial and facial bones, totaling 22 bones.
II. Cranial bones are 8 in number and form the hard protective cranium for the brain.
III. The facial region consists of 14 skeletal elements forming the front part of the skull.
IV. A single U-shaped hyoid bone is located at the roof of the mouth and acts as an ear ossicle.

Read the statements regarding middle ear bones and skull articulation:

I. Each middle ear contains three tiny bones: malleus, incus, and stapes, collectively called ear ossicles.
II. The ear ossicles are part of the facial bone division.
III. The skull region articulates with the vertebral column via two occipital condyles.
IV. Because of its articulation, the human skull is classified as dicondylic.

Which of the following statements about the human vertebral column are true?

I. The vertebral column is dorsally placed and formed by 26 serially arranged units called vertebrae.
II. Each vertebra contains a central hollow portion (neural canal) through which the spinal cord passes.
III. The first cervical vertebra is the axis, which articulates with the occipital condyles.
IV. The vertebral column is differentiated into cervical (7), thoracic (12), lumbar (5), sacral (1-fused), and coccygeal (1-fused) regions in adults.

Select the correct statements regarding the anatomy of human ribs:

I. There are 12 pairs of ribs in human beings.
II. Each rib is a thin flat bone connected dorsally to the vertebral column and ventrally to the sternum.
III. Ribs have two articulation surfaces on their dorsal ends and are therefore called bicephalic.
IV. Every pair of ribs is connected directly to the sternum using dense fibrous cartilage.