Muscular System of Humans
Muscular System of Humans: Overview
This Topic covers sub-topics such as Skeletal Muscle, Sarcomere, Cori Cycle, Muscle Contraction, Mechanism of Muscle Contraction, Troponin, Myoglobin, Myofibril, Myosin, Oxygen Debt, Actin, Muscle Fatigue, Muscle Fibre and, Contractile Proteins
Important Questions on Muscular System of Humans
Arrange the following order of events taking place during muscle contraction in correct order.
a. Nerve impulse
b. Cross-bridge formation
c. Release of calcium ions
d. Impulse reaches sarcoplasmic reticulum
e. Actin - Myosin complex
f. Muscle contraction
Explain muscular energy with an example.
Anatomical unit of muscle is –
The protein which maintains the muscular storage of oxygen is
Troponin is made up of how many subunits?
Which of the following masks the binding active site for myosin on the actin filament?
Globular head of myosin contains binding site for
Which of the following statements about the molecular arrangement of actin in myofibrils is incorrect?
1. Each actin (thin) filament is made up of two 'F' (filamentous) actins helically wound to each other.
2. Each 'F' actin is a polymer of monomeric 'G' (globular) actins.
3. Two filaments of another protein, tropomyosin also run close to the 'F' actins throughout its length.
4. A complex protein called troponin is distributed at regular intervals on the tropomyosin.
Which portion of sarcomere does not contain thin filament?
The functional unit contraction in myofibril is the portion present between two successive
The centre of I band is characterized by which of the following line?
Thick filament in the middle of A-band are held together by
Which of the following statements about striated muscles are false?
1. Thick filaments in the 'A' band are also held together in the middle of this band by a thin fibrous membrane called 'M' line.
2. In the centre of each 'I' band is an elastic fibre called 'Z' line which bisects it.
3. The thin filaments are firmly attached to the 'Z' line.
4. This central part of thick filament not overlapped by thin filaments is called the 'H' zone.
Match the columns.
| Column I | Column II | ||
| (A) | Inflammation of joints. | (1) | H-zone |
| (B) | Protein of thick filament. | (2) | Myosin |
| (C) | Protein of thin filament. | (3) | Actin |
| (D) | The central part of thick filament is not overlapped by thin filament. |
(4) | Arthritis |
Select the correct statement from the following.
Identify A, B, C and D in the given figure.
At full muscle contraction, the lines attached to the thin filaments are almost touching
ATP ase enzyme needed for muscle contraction is in
The functional unit of muscle is called:
What is the location of troponin in the process of muscle contraction?
