anatomy muscular system pt.2

synergist only

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

pectoralis major

A muscle located on the ventral (anterior) side of the body is the ________.

false

A muscle twitch results when the muscle is stimulated so rapidly that no evidence of relaxation is seen.

buccinator

A nursing infant develops a powerful sucking muscle that adults also use for whistling or blowing a trumpet called the ________.

the muscle twitch is a brief and "jerky" movement, while the tetanic contraction is prolonged and continuous

A skeletal muscle twitch differs from a tetanic contraction in that ________.

fused, or complete, tetanus

A smooth, sustained contraction is called ________.

true

Abduction and adduction are antagonistic actions.

true

Aerobic, or endurance, exercise involves jogging or biking.

muscular dystrophy

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

isotonic 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.

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.

The term, rectus, means straight. The fibers in this muscle run straight along a plane. The reference to the femur bone is relayed in femoris. Together, these terms tell us the muscle fibers of rectus femoris travel "straight along the femur bone."

Explain what meaning is inferred in the muscle name rectus femoris.

1. Circular—orbicularis oris, orbicularis oculi 2. Convergent—pectoralis major 3. Parallel—sartorius 4. Unipennate—extensor digitorum longus 5. Multipennate—deltoid 6. Fusiform—biceps brachii 7. Bipennate—rectus femoris

Fascicle arrangements produce skeletal muscles with different structures and functional properties, and determine their individual range of motion and power. List the seven different fascicle arrangements of human skeletal muscles and give a specific example of each:

false

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

true

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

antagonists

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

iliopsoas

Paralysis of which of the following would make an individual unable to flex the hip ________.

false

Plantar flexion at the ankle joint is accomplished by the tibialis anterior muscle.

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

extensor digitorum longus

Sandra is playing the piano for her recital. Which muscle is NOT involved in the movement of her hands and/or fingers ________.

false

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

circular

The arrangement of fascicles in orbicularis oris is ________.

insufficient intracellular quantities of ATP due to excessive consumption

The condition of skeletal muscle fatigue can be best explained by ________.

true

The deepest muscle of the abdominal wall is the transversus abdominis.

false

The deltoid is a prime mover of arm adduction.

true

The deltoid muscle is a common site for intramuscular injections.

false

The hamstring group inserts into the distal tibia.

extension ; flexion

The hamstring group is the prime mover of thigh ________ and knee ________.

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 ________.

orbicularis oculi

The muscle that closes each eye is the ________.

origin

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

deltoid

The prime mover of arm abduction is the ________ muscle.

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

atrophy

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

knee extension

What is the main function of the quadriceps group?

scapular spine and clavicle

What is the origin of the deltoid muscle?

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.

hamstring group

Which muscle group includes the biceps femoris, semimembranosus, and semitendinosus?

rectus abdominis

Which muscle helps compress the abdominal contents during defecation or childbirth?

tibialis anterior

Which muscle is an antagonist to gastrocnemius?

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?

both masseter and temporalis

Which of the following muscles closes the jaw?

temporalis

Which of these muscles is a synergist to masseter?

method of attachment of the muscle to bone

Which one of the following is NOT a criterion generally used in naming muscles?

deltoid

Which one of the following muscles is involved in abduction of the arm at the shoulder joint?

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 ________.