hbs 1.2.2- makeup of a muscle terms

endomysium

• a small bundle or cluster, especially of nerve or muscle fibers.

• fibrous connective tissue that attaches muscle to bone.

• the delicate connective tissue surrounding the individual muscular fibers within the smallest bundles.

• the connective-tissue sheath that surrounds a muscle and forms sheaths for the bundles of muscle fibers.

Answer explanation

The term 'endomysium' refers to a specific type of connective tissue. In this context, it is the delicate tissue that surrounds the individual muscle fibers within the smallest bundles. This tissue is not a bundle or cluster itself, nor does it attach muscle to bone or form sheaths for the bundles of muscle fibers. Thus, the correct answer to the question is that endomysium is the delicate connective tissue surrounding the individual muscular fibers within the smallest bundles.

epimysium

• the external connective-tissue sheath of a muscle.

• a threadlike structure, extending longitudinally through a muscle fiber (cell) consisting mainly of thick filaments (myosin) and thin filaments (actin, troponin, and tropomyosin).

• fibrous connective tissue that attaches muscle to bone.

• the delicate connective tissue surrounding the individual muscular fibers within the smallest bundles.

Answer explanation

The question asks about 'epimysium'. This term refers to the external connective-tissue sheath of a muscle. The other options provided discuss different aspects of muscle anatomy and physiology, but none of them correctly define 'epimysium' as the selected answer does.

perimysium

• the connective-tissue sheath that surrounds a muscle and forms sheaths for the bundles of muscle fibers

• fibrous connective tissue that attaches muscle to bone.

• a small bundle or cluster, especially of nerve or muscle fibers.

• a threadlike structure, extending longitudinally through a muscle fiber (cell) consisting mainly of thick filaments (myosin) and thin filaments (actin, troponin, and tropomyosin)

Answer explanation

The question asks about 'perimysium'. Perimysium is the connective-tissue sheath that surrounds a muscle and forms sheaths for the bundles of muscle fibers. The other options discuss different aspects of muscle and connective tissue but do not specifically describe perimysium.

fascicle

• the connective-tissue sheath that surrounds a muscle and forms sheaths for the bundles of muscle fibers.

• a small bundle or cluster, especially of nerve or muscle fibers.

• the external connective-tissue sheath of a muscle.

• the delicate connective tissue surrounding the individual muscular fibers within the smallest bundles.

Answer explanation

The term 'fascicle' is used to describe a small bundle or cluster of structures, especially nerve or muscle fibers. It is not specifically tied to the connective-tissue sheath that surrounds a muscle, or the external or delicate tissue surrounding the individual muscular fibers. The best definition among the options is thus, 'a small bundle or cluster, especially of nerve or muscle fibers.'

tendon

• the external connective-tissue sheath of a muscle.

• a small bundle or cluster, especially of nerve or muscle fibers.

• the connective-tissue sheath that surrounds a muscle and forms sheaths for the bundles of muscle fibers.

• fibrous connective tissue that attaches muscle to bone.

Answer explanation

The question asks about the definition of 'tendon'. The correct answer is 'fibrous connective tissue that attaches muscle to bone'. This is because by definition, a tendon is a flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to a bone. It's not a sheath or a bundle of fibers.

muscle cell/fibre

• a threadlike structure, extending longitudinally through a muscle fiber (cell) consisting mainly of thick filaments (myosin) and thin filaments (actin, troponin, and tropomyosin).

• the connective-tissue sheath that surrounds a muscle and forms sheaths for the bundles of muscle fibers.

• specialized type of cell found in muscle tissues; responsible for the contraction and relaxation of muscles, allowing for various movements and functions within the body.

• the delicate connective tissue surrounding the individual muscular fibers within the smallest bundles.

Answer explanation

The question is asking about the definition of a muscle cell or fibre. The correct answer is a specialized type of cell found in muscle tissues. These cells are responsible for the contraction and relaxation of muscles, which allows for various movements and functions within the body. The other options refer to components or attributes of muscle tissue, not the muscle cell itself.

Tags

NGSS.HS-LS1-4

myofibril

• a threadlike structure, extending longitudinally through a muscle fiber (cell) consisting mainly of thick filaments (myosin) and thin filaments (actin, troponin, and tropomyosin).

• a small bundle or cluster, especially of nerve or muscle fibers.

• specialized type of cell found in muscle tissues; responsible for the contraction and relaxation of muscles, allowing for various movements and functions within the body.

• the external connective-tissue sheath of a muscle.

Answer explanation

The question is about the definition of a myofibril. The correct answer describes it as a threadlike structure, extending longitudinally through a muscle fiber. It mainly consists of thick filaments (myosin) and thin filaments (actin, troponin, and tropomyosin). Other options including a small bundle or cluster, a specialized cell type, and an external sheath of a muscle are incorrect.