Term 1 Exam: Muscular System Chapter 11

Question 1

What three traits are found in all muscles?

Answer 1

1. origin
2. insertion
3. primary action

Question 2

What are the two muscle attachment sites?

Answer 2

1. Origin (doesn’t move)

2. Insertion (moves towards origin during contraction)

Question 3

How do skeletal muscles cause movement?

Answer 3

• muscle exerts force on tendons

- tendons pull on bones or other structures

Question 4

What is the origin site?

Answer 4

Attachment of tendon to the stationary bone

Question 5

What is the insertion site?

Answer 5

attachment of the muscle’s other tendon to the movable bone

Question 6

What is the belly of a muscle?

Answer 6

the fleshy portion of muscle between tendons

Question 7

What is the primary action of the muscle?

Answer 7

-the main movement(s) that occur during contraction (eg flexion or extension)

Question 8

What is Reverse Muscle Action (RMA)?

Answer 8

when action of the muscle is reversed and the positions of origin and insertion are switched

Question 9

What is a lever system?

Answer 9

Lever is a rigid structure that can move around a fixed point called a fulcrum

Question 10

What two forces act on a lever?

Answer 10

1. the effort - causes movement due to contraction

2. the load or resistance that oppose movement

Question 11

motion occurs when the _____ applied exceeds the ______or_____

Answer 11

effort, load or resistance

Question 12

There are three types of levers, name them.

Include the position of the fulcrum, effort and load for each type

Answer 12

1. First class lever - not common
   - fulcrum is between the effort and the load
2. Second-Class lever (less common)
   - load is between the fulcrum and efford
3. Third class lever (most common)
   - Effort is between the fulcrum and the load

Question 13

What are five patterns that fascicles form with respect to tendons?

Answer 13

1. parallel
2. fusiform
3. circular
4. triangular
5. pennate (unipennate, bipennate, multipennate)

Question 14

What does the power of a muscle depend on?

Answer 14

total cross-sectioned area NOT length

Question 15

Most skeletal muscles are arranged in ______ pairs at the ______
include example

Answer 15

opposing (antagonistic)
joints
eg flexors and extensors

Question 16

What is the agonist?

Answer 16

The prime mover
-Muscle that is responsible for action when it contracts
eg the biceps brachii is an agonist that causes flexion of the elbow joint

Question 17

What is the antagonist?

Answer 17

the muscle that opposes the action of the agonist

eg the triceps brachii is the antagonist to biceps brachii

Question 18

What is the synergist? (3)

Answer 18

1. Muscle that assist the agonist or prime mover
2. Prevents unwanted movement of other joints
3. Contraction stabilizes intermediate joints

Question 19

Provide an example of a synergist

Answer 19

muscles that flexes the fingers (prime movers) cross the intercarpal and radiocarpal joints (intermediate joints). Synergistic contraction of the wrist extensor muscles allows the hand to form a fist without flexing the wrist

Question 20

What are fixators?

Answer 20

Muscles that stabilizes the origin of the agonist so that the agonist is more efficient

eg when muscles of the arm contracts, the scapula must be held steady

Question 21

What are 8 criteria for naming muscles?

Answer 21

1. orientation of muscle fibres
2. Muscle attachment to site
3. Specific body region
4. Muscle shape
5. Muscle size
6. Muscle heads/tendons of origin
7. Muscle function or movement
8. Muscle position at body surface

Question 22

Provide an example for each of the following muscle naming criteria:

1. Shape
2. Location
3. Attachment
4. Size
5. Orientation
6. Relative position
7. Function

Answer 22

1. Shape = rhomboids, triceps, biceps
2. Location = intercostals (between ribs)
3. Attachment= temporalis, nasalis
4. Size = maximus (largest), brevis (short)
5. Orientation = Rectus (straight), oblique
6. Relative Postition = Lateral, internal, medial, sub-
7. Function = adductor, levator (lifter), flexor, pronator