ap6

synergist only

A muscle group that works with and assists the action of a prime mover is a(n) ________.

true

Abduction and adduction are antagonistic actions. t/f

true

Aerobic, or endurance, exercise involves jogging or biking. t/f

true

All types of muscle have endomysium covering individual muscle cells. t/f

muscular dystrophy

An inherited disease that causes muscles to degenerate and atrophy is known as ________.

false

Bundles of muscle fibers are known as aponeuroses. t/f

true

Cardiac and skeletal muscle both possess striations. t/f

isometric contractions

Contractions in which muscles shorten and produce movement are known as ________.

Dorsiflexion and plantar flexion are special actions occurring at the ankle joint. Dorsiflexion is accomplished by lifting your foot so that its superior surface moves toward the shin while plantar flexion is accomplished by depressing the foot (pointing the toes or "planting" the toes toward the ground).

Describe where and how dorsiflexion and plantar flexion occur.

an individual muscle cell

Endomysium covers ________.

1. Isometric contractions are contractions in which the muscles do not shorten. An example of an isometric contraction is pushing against a wall with bent elbows. The muscles cannot shorten since the wall doesn't move 2. Isotonic contractions occur when muscles shorten and movement occurs due to the sliding of the myofilaments. Flexion and extension of the arm are just two examples of isotonic contractions.

Explain how isometric and isotonic contractions differ, using examples of each.

false

Isometric contractions produce movement when filaments slide past one another and the muscle shortens. t/f

true

Muscle development in babies occurs in a cephalic/caudal direction. t/f

cardiac muscle tissue

Muscle tissue composed of branching cells and intercalated discs

cardiac muscle tissue

Muscle tissue found only in the heart

smooth muscle tissue

Muscle tissue that activates arrector pili muscles to stand hairs on end

smooth muscle tissue

Muscle tissue that forms valves to regulate the passage of substances through internal body openings

skeletal muscle tissue

Muscle tissue that is multinucleate

skeletal muscle tissue

Muscle tissue that maintains posture, body position, and stabilizes joints

antagonists

Muscles that perform opposite actions to one another are termed ________.

smooth muscle tissue

Performs very slow, sometimes rhythmic, contractions

adduction

Primary action of the adductor muscles

abduction

Primary action of the deltoid

extension

Primary action of the erector spinae

flexion

Primary action of the rectus abdominis

involuntary

Smooth muscle cells are ________.

cardiac muscle

Striated involuntary muscle tissue found in the heart is ________.

cardiac

Striated involuntary muscle tissue is classified as ________ muscle.

false

Supination and pronation refer to up and down movements of the foot at the ankle. t/f

false

The deltoid is a prime mover of arm adduction. t/f

tendons; aponeuroses

The epimysium covering on the outside of the muscle can blend into cordlike ________ or sheetlike ________.

origin

The least movable point of muscle attachment to a bone is termed its ________.

rotation

The movement of a bone around its longitudinal axis

abduction

The movement of a limb away from the body midline

adduction

The movement of a limb toward the body midline

adduction

The movement opposite to abduction is ________.

sarcolemma

The plasma membrane of a skeletal muscle cell is called the ________.

origin

The point of muscle attachment to an immovable or less movable bone is known as the ________.

supination

Type of movement that allows you to carry a soup bowl

flexion

Type of movement that decreases the angle of the joint

plantar flexion

Type of movement that points the toes

inversion

Type of movement that turns the sole of the foot medially

skeletal muscle tissue

Voluntary muscle tissue

atrophy

What condition results if muscles are not used, such as when immobilized in a cast for healing a broken bone? t/f

Abduction and adduction are antagonistic actions performed during jumping jacks. Abduction is moving a limb away from the midline of the body. When you jump and move your arms and legs away, you are performing abduction. Adduction is the movement of a limb toward the body midline. When you return your arms and legs and add them back to your body, you are performing adduction.

What types of movements are demonstrated by your arms and legs when you perform jumping jacks in physical education class? Describe these movements.

hematopoiesis

Which of the following is NOT a function of the muscular system?

pushing against an immovable wall

Which of the following is an example of an isometric contraction?

biceps brachii and triceps brachii

Which of the following muscles are antagonists?

skeletal

Which type of muscle tissue contracts most quickly upon stimulation?

abduction

While doing "jumping jacks" during an exercise class, your arms and legs move laterally away from the midline of your body. This motion is called ________.

Although cells in both skeletal muscle tissue and cardiac muscle tissue are striated, look for intercalated discs and branched cells in the cardiac muscle cells to distinguish between these two tissues. Furthermore, skeletal muscle cells are multinucleate while cardiac muscle cells are uninucleate. Cells in smooth muscle tissue lack striations, making it easy to distinguish from skeletal and cardiac muscle tissues. Like the cells in cardiac muscle tissue, smooth muscle cells are uninucleate. However, smooth muscle tissue cells do not branch nor do they possess intercalated discs.

You have lost the labels to your muscle tissue slides in laboratory. Explain the characteristics that allow you to distinguish among skeletal muscle, smooth muscle, and cardiac muscle tissue.