Ch11 the muscular system

Question 1

What are the two main types of muscle attachments?

Answer 1

Origin (stationary bone) and Insertion (movable bone).

Question 2

How do skeletal muscles produce movement?

Answer 2

Skeletal muscles produce movement by contracting, pulling on tendons, and moving bones at joints.

Question 3

Name the five types of fascicle arrangements.

Answer 3

Parallel, Fusiform, Circular, Triangular, Pennate (Unipennate, Bipennate, Multipennate).

Question 4

What is the relationship between fascicle arrangement and muscle performance?

Answer 4

Fascicle arrangement correlates with the muscle’s power and range of motion.

Question 5

What are the benefits of stretching muscles?

Answer 5

Improved performance, reduced injury risk, reduced soreness, better posture, increased synovial fluid, and neuromuscular coordination.

Question 5

Define the roles of prime mover, antagonist, synergist, and fixator in muscle groups.

Answer 5

Prime mover causes the action, antagonist opposes it, synergist steadies movement, fixator stabilizes origin.

Question 6

List six criteria used to name muscles.

Answer 6

Location, size, number of origins, shape, direction of fibers, origin and insertion, action.

Question 7

What is an example of a muscle named for its shape?

Answer 7

Deltoid (triangular shape).

Question 8

What type of movement does an abductor muscle perform?

Answer 8

Moves a bone away from the midline.

Question 9

Name a muscle with a ‘short’ designation.

Answer 9

Adductor brevis.

Question 10

What is the function of tendons in muscle movement?

Answer 10

Tendons attach muscles to bones and transmit force to create movement.

Question 11

Describe the pennate fascicle arrangement.

Answer 11

Short fascicles attach obliquely to a central tendon running the length of the muscle; types include unipennate, bipennate, and multipennate.

Question 12

What is the difference between fusiform and parallel fascicle arrangements?

Answer 12

Fusiform muscles taper at the ends, while parallel muscles run along the muscle’s length without tapering.

Question 13

Which fascicle arrangement forms sphincter muscles?

Answer 13

Circular fascicle arrangement.

Question 14

What are the key features of triangular fascicle arrangement?

Answer 14

Fascicles spread out from a broad area and converge on a single tendon, forming a triangular shape.

Question 15

What determines the power a muscle can generate?

Answer 15

The number of fibers per cross-sectional area.

Question 16

What determines the range of motion of a muscle?

Answer 16

The length of the muscle fibers.

Question 17

Name the injection sites for intramuscular injections (IM).

Answer 17

Deltoid, Gluteus medius, Vastus lateralis.

Question 18

What muscle group action helps prevent unwanted movements during prime mover activity?

Answer 18

Synergists.

Question 19

What type of muscle stabilizes the origin of a prime mover?

Answer 19

Fixator.

Question 20

How does the term ‘rectus’ relate to muscle naming?

Answer 20

It means ‘parallel to the midline’ (e.g., Rectus abdominis).

Question 21

How are muscles named based on their origin and insertion?

Answer 21

By their attachment points (e.g., Sternocleidomastoid originates on the sternum and clavicle, inserts on the mastoid process).

Question 22

Give an example of a muscle named for its action.

Answer 22

Flexor carpi radialis (flexes the wrist).

Question 23

What is the role of an antagonist muscle?

Answer 23

It opposes the action of the prime mover and stretches during the movement.

Question 24

Why is the deltoid muscle commonly used for IM injections?

Answer 24

It has good blood supply for prompt absorption and a sufficient muscle mass for injection.

Question 25

What are the muscles involved in facial expression, and how do they work?

Answer 25

• Orbicularis oris: Closes and shapes lips (kissing).
  
  • Buccinator: Compresses cheeks (whistling, blowing).
  • Platysma: Draws lower lip down (pouting).
  • Orbicularis oculi: Closes eyes.

Question 26

What are the actions of the muscles that move the eyeballs?

Answer 26

• Superior rectus: Elevates and adducts.
  
  • Inferior rectus: Depresses and adducts.
  • Lateral rectus: Abducts.
  • Medial rectus: Adducts.
  • Superior oblique: Depresses, abducts, rotates medially.
  • Inferior oblique: Elevates, abducts, rotates laterally.

Question 27

What muscles assist in mastication?

Answer 27

• Masseter: Elevates mandible.
  
  • Temporalis: Elevates and retracts mandible.
  • Medial pterygoid: Elevates, protracts, and moves mandible side to side.
  • Lateral pterygoid: Protracts and depresses mandible.

Question 28

What is the role of the sternocleidomastoid (SCM) muscle?

Answer 28

it flexes the cervical vertebral column and extends the head. Acting singly, it laterally flexes and rotates the head.

Question 29

What muscles assist in breathing?

Answer 29

• Diaphragm: Flattens for inhalation.
  
  • External intercostals: Elevate ribs for inhalation.
  • Internal intercostals: Depress ribs for forced exhalation.