Question

Latissimus dorsi muscle is a
(a) Chest muscle
(b) Shoulder muscle
(c) Leg muscle
(d) Arm muscle

Answer 1

Hint: Latissimus dorsi muscle is a skeletal muscle that is considered as one of the largest muscles in the upper body part. It plays a major role in strenuous exercises like push-ups.

Complete answer:
The latissimus dorsi muscle is one of the largest muscles of the back. This shoulder muscle originates from the seventh thoracic vertebra and extends up to the joining point of the humerus. It is not used extensively in normal daily activities but its function is amplified in strenuous exercises like climbing, swimming, and pull-ups, etc. Injury in this muscle in the form of rips and tears can be a cause of chronic pain in the back due to the strategic position of this muscle.

Additional Information: -Muscles is a specialized tissue of mesodermal origin and accounts for about 40-50% of the total body weight of an adult human.
-Based on the appearance of muscle cells, they are broadly classified into three groups- Striated or skeletal muscle, Un-striated or smooth muscle, cardiac, or heart muscle.
-Skeletal muscles are attached to the skeletal elements and are responsible for the movement of the trunk, appendages, respiratory organs, mouthparts, and so on.
- Smooth muscles lack striations, unlike the skeletal muscle. They are long and spindle-shaped with taperings at both the ends. They are organized into sheets of muscles surrounding the walls of alimentary canals, blood vessels, respiratory passages, urinary and genital ducts.
-Cardiac muscles are solely found in the walls of the heart. They resemble striated muscles in appearance but on the functionality, they resemble smooth muscles. Two or more cardiac fibers are connected through intercalated discs or zig-zag junctions.
So, the correct answer is ‘Shoulder muscle.’

Note: -Skeletal muscles are voluntary muscles as their movement is under the control of a person’s will.
-Smooth muscles are under the control of the autonomic nervous system, hence, are involuntary and unconscious.
-Cardiac muscles are fast-acting muscles due to the presence of intercalated discs between the fibers. They are continuously contracting and relaxing under the autonomic control of the body.