Muscle Tissue Study Guide

Rachel is helping her sister install a heavy light fixture. While her sister connects the wires, Rachel must hold the light fixture in place. The wiring is taking longer than expected and Rachel's arms are beginning to tire even though she isn't moving. What type of muscle contraction is occurring in her arms?

Isometric

Which of the following is true concerning isotonic eccentric contraction?

The muscle lengthens but tension remains constant.

Which of the following is true concerning isotonic concentric contraction?

The muscle shortens but tension remains constant.

Which of the following marks the boundaries of a sarcomere?

Z discs

Shortening a muscle while it maintains constant tension is called __________.

an isotonic contraction

Loss of muscle mass from lack of activity is called __________.

atrophy

A muscle twitch produces external tension and moves an object by shortening the muscles during the _____ phase.

contraction

Resistance exercise will most likely cause muscle to __________.

hypertrophy

The thick filaments of the sarcomere are made up mostly of the protein __________.

myosin

A skeletal muscle generates the greatest tension when it is __________.

partially stretched before being stimulated

Skeletal muscle is described as __________.

striated and voluntary

In skeletal muscle, the term that describes the alternating light and dark bands is ___________.

striations

The minimum stimulus needed to cause muscle contraction is called the __________.

threshold

The protein that acts as a calcium receptor in skeletal muscle is __________.

troponin

Skeletal muscle is called ___________, because it is usually subject to conscious control.

voluntary

How many somatic motor neurons stimulate one muscle fiber?

1

How many steps are involved during a muscle contraction?

4

Which of the following contains overlapping thick and thin filaments?

A band

Where in the human body would this tissue be found?

Biceps brachii

Harriet is a body builder, and regularly lifts weights to maintain muscle size. Which of the following statements correctly describes processes related to hypertrophy in skeletal muscles? Check all that apply.

Decrease in tone and size of muscle Increase in number of myofibrils per muscle fiber

Which type of muscle tissue is found in the walls of hollow organs?

Smooth muscle

Which muscle(s) can contract without the need for nervous stimulation?

Smooth and cardiac muscle

Which of the following is predominately made up of myosin?

The thick filament

Based on the size, shape, and ratio of muscle fibers to motor neurons (motor units), rank the following muscles in order of strongest to weakest, starting with #1 being the strongest. Rank the options below.

Gastrocnemius, Orbicularis oculi, Lateral rectus, Brachialis, Quadriceps femoris.

Which of the following is/are a characteristic of skeletal muscle? Check all that apply.

Overlapping thin and thick filaments Striations Excitability Involuntary

Smooth and cardiac muscles are under involuntary control.

True