Muscle and Muscle Cell Anatomy

What does the prefix 'my' generally indicate in anatomical terms?

It denotes muscle-related structures.

What does the term 'sark' mean?

It means flesh, referring to muscle tissue.

What connects muscles to bones?

Tendons, which are dense regular connective tissues.

How do tendons and ligaments differ?

Tendons attach muscles to bones, while ligaments connect one bone to another.

What are fascicles in skeletal muscles?

They are individual chambers that contain bundles of muscle cells.

What surrounds each muscle cell in a fascicle?

Endomysium, a layer of connective tissue.

What envelops a fascicle?

Perimysium.

What is the outer protective layer of an entire muscle called?

Epimysium, made of dense irregular connective tissue.

What are skeletal muscle cells often referred to as?

Muscle fibers.

How long can some skeletal muscle fibers be?

Over a foot in length.

What are myofibrils?

They are smaller bundles within each muscle cell essential for muscle contraction.

What types of protein filaments are found in myofibrils?

Myosin (thick filament) and actin (thin filament).

What is the plasma membrane of muscle cells called?

Sarcolemma.

What is the cytoplasm of muscle cells referred to as?

Sarcoplasm.

What unique cellular feature do muscle cells exhibit?

They are multinucleate, having multiple nuclei within a single cell.

What is the smooth endoplasmic reticulum in muscle cells known as?

Sarcoplasmic reticulum.

What role does the sarcoplasmic reticulum play in muscle function?

It stores calcium ions necessary for muscle contraction.

What are terminal cisternae?

Enlarged portions of the sarcoplasmic reticulum on either side of the transverse tubules.

What do transverse tubules do?

They are inward folds of the sarcolemma that connect the terminal cisternae.

What structure is formed by the terminal cisternae and transverse tubules?

Triad.

Why is the triad important in muscle cells?

It effectively transmits electrical signals into the muscle cell to trigger contraction.

What pattern is observed in myofibrils regarding thin and thick filaments?

A repeating pattern of thin (actin) and thick (myosin) filaments.

What additional roles do actin and myosin play in the body?

They contribute to cellular shape and movement, impacting cytoskeleton dynamics and processes like cell division.

What is crucial for understanding muscular function?

The anatomy of muscles and muscle cells.

What tissue is considered the primary component of muscles?

Muscle tissue.

What is the primary function of skeletal muscles?

To generate force for body movements.

What type of connective tissue forms the tendons?

Dense regular connective tissue.

What connective tissue layer surrounds an entire muscle?

Epimysium.

How are fascicles organized within a skeletal muscle?

They are organized into individual chambers, each containing muscle cell bundles.

What structural characteristic differentiates muscle fibers from typical cells?

They are longer than typical cells.

What process is facilitated by the sarcoplasmic reticulum in muscle cells?

Muscle contraction.

What is generated along the myofibrils during muscle contraction?

Force.

What do actin and myosin facilitate beyond muscle function?

They facilitate movement and shape in nearly every cell.

Why is understanding the structure of muscle cells important?

It helps in understanding how muscles contract and function.

What term describes the dense connective tissue surrounding fascicles?

Perimysium.

In muscle cells, what are the primary functions of the sarcolemma?

It acts as the plasma membrane to protect and mediate cellular processes.

What major role do myofibrils play in muscle cells?

They are crucial for muscle contraction.

How do calcium ions influence muscle contraction?

They are necessary for triggering the contraction process.

What is a key feature of skeletal muscle that reflects its function?

Multinucleation allows for greater regulation of muscle activity.

How do muscle fibers relate to the overall structure of skeletal muscles?

They constitute the primary units of the muscle, arranged into fascicles.

What structure is critical for effective electrical signal transmission in muscle cells?

The triad formed by terminal cisternae and transverse tubules.

Why is the myofibril structure important for muscle contraction?

It allows for the efficient sliding of actin and myosin filaments.

What type of connective tissue is endomysium?

It is a layer of connective tissue that surrounds individual muscle cells.

How do ligaments function in contrast to tendons?

Ligaments connect bones to other bones, whereas tendons attach muscles to bones.

What allows skeletal muscles to withstand physical forces?

The protective structure provided by the epimysium.

What historical classification is associated with muscle cells due to their length?

They were originally classified as muscle fibers rather than individual cells.

What happens during muscle contraction at the myofibril level?

Myofibrils generate force through the interaction of actin and myosin filaments.

What is the significance of the repeating pattern of filaments in myofibrils?

It facilitates the mechanism of muscle contraction and force generation.

What enables the sarcoplasmic reticulum to play its role in muscle contraction?

The presence of terminal cisternae that store calcium.

Why is understanding muscle anatomy relevant to broader physiological studies?

It relates to how muscle function integrates with overall bodily functions.

What process does the term 'muscular function' commonly refer to?

The contraction and movement generated by muscle cells.

How do muscle cells exhibit unique characteristics compared to other cell types?

They are multinucleate and are designed for contraction.

What contributes to the specialized function of the sarcoplasmic reticulum in contraction?

Its ability to release calcium ions quickly.