Anatomy & Muscle Quiz Questions

Fascicles are the bundles of fibers in a muscle. These fascicles are made up of individual muscle fibers that are grouped together to form a larger unit. The arrangement of fascicles within a muscle allows for efficient force production and control of movement.

The covering of a muscle fiber is called the sarcolemma. The sarcolemma is a specialized cell membrane that surrounds each muscle fiber, providing protection and allowing for the exchange of nutrients and waste products. It plays a crucial role in muscle contraction by transmitting electrical impulses throughout the muscle fiber via the t-tubules, which are invaginations of the sarcolemma. The myosin and troponin mentioned in the options are both proteins involved in muscle contraction, but they are not the covering of the muscle fiber.

The gluteus maximus is the muscle that allows hip extension. It is the largest muscle in the buttocks and is responsible for extending the hip joint, which means it helps to move the thigh backward. This muscle plays a crucial role in activities such as walking, running, and climbing stairs. The sartorius muscle is involved in hip flexion and rotation, the pectoralis major is a muscle of the chest that is involved in movements of the shoulder, and the platysma is a thin muscle in the neck region that helps with facial expressions.

The correct answer is "all of the above." This is because all three muscles listed (biceps femoris, semitendinosus, and semimembranosus) are responsible for knee flexion. Knee flexion refers to the bending of the knee joint, and these muscles work together to perform this movement.

Hugh Huxley is the scientist who developed the Sliding Filament Theory. This theory explains the mechanism of muscle contraction by proposing that muscle fibers shorten or lengthen by the sliding of overlapping actin and myosin filaments. Huxley's research and experiments provided evidence for this theory and contributed significantly to our understanding of muscle physiology.

The masseter muscle is responsible for closing the jaw during chewing. It is a strong muscle located at the side of the face, connecting the lower jawbone to the cheekbone. When this muscle contracts, it helps to elevate the mandible, allowing the jaw to close and enabling the process of chewing food.

The correct answer is 6. In a sarcomere, which is the basic functional unit of a muscle, there are six thin actin filaments that surround one thick myosin filament. This arrangement allows for the interaction between actin and myosin during muscle contraction.

The functional unit of skeletal muscle is the sarcomere. The sarcomere is the basic unit of muscle contraction and is composed of actin and myosin filaments. It is responsible for the sliding filament mechanism, where the actin and myosin filaments slide past each other, resulting in muscle contraction. The sarcomere is bounded by Z discs and is the smallest contractile unit within a muscle fiber.

The four quad muscles are named rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis. These muscles are located in the front of the thigh and work together to extend the leg at the knee joint. The rectus femoris is the only quad muscle that also flexes the hip joint. The vastus lateralis, vastus intermedius, and vastus medialis primarily function to extend the knee joint. Collectively, these muscles play a crucial role in activities such as walking, running, and jumping.

The four abdominal muscles are the transverse abdominis, rectus abdominis, internal oblique, and external oblique. These muscles play a crucial role in core stability and support. The transverse abdominis acts as a deep stabilizer, while the rectus abdominis is responsible for flexing the spine. The internal and external oblique muscles help with rotation and lateral flexion of the trunk. Together, these muscles contribute to maintaining posture, protecting the organs, and assisting in movements such as bending, twisting, and lifting.