10-1. The Muscular System

Question 1

Skeletal muscles produce motion by ___, which in turn ____.

Answer 1

exerting force on tendons; pull on bones

Question 2

Most muscles ____.

Answer 2

cross a joint (attached to articulating bones that form the joint)

Question 3

As muscle contracts, one ___ is drawn to ____, and the ___ of the joint decreases.

Answer 3

bone; the other bone; angle of the joint decreases

Question 4

origin

Answer 4

attachment of a muscle to the more stationary bone of an articulation

Question 5

Where is the origin of biceps brachii?

Answer 5

scapula (corocoid process and glenoid cavity)

Question 6

insertion

Answer 6

attachment of a muscle to the bone it moves

Question 7

Where is the insertion of biceps brachii?

Answer 7

radius (radial tuberosity)

Question 8

When a muscle contracts, the ___ moves to the ___.

Answer 8

insertion; origin

Question 9

belly

Answer 9

fleshy part between the tendons of the origin and insertion

Question 10

Muscle fibers are arranged in parallel within a bundle called a ____.

Answer 10

fascicle

Question 11

What are the four types of fascicle arrangements?

Answer 11

parallel
convergent
pennate
circular

Question 12

parallel

Answer 12

fascicles run parallel to the long axis of the muscle, terminating at either end in a flat tendon

Question 13

What is an example of a parallel arrangement?

Answer 13

sartorius

Question 14

convergent

Answer 14

a broad origin converges to a narrow insertion, giving the muscle a triangular or fan shape

Question 15

What is an example of a convergent arrangement?

Answer 15

pectoralis major

Question 16

pennate

Answer 16

The fascicles are short, and they attach to a central tendon that runs the length of the muscle, like the plumes of a feather

Question 17

What is an example of a pennate arrangement?

Answer 17

rectus femoris

Question 18

circular

Answer 18

fascicles are arranged in concentric rings around an opening in the body, which closes as they contract

Question 19

What is an example of a circular arrangement?

Answer 19

orbicularis oris

Question 20

prime mover

Answer 20

muscle that causes the desired action by contracting

Question 21

What is the prime mover for elbow flexion?

Answer 21

biceps brachii

Question 22

antagonist

Answer 22

muscle whose action opposes that of the prime mover; it relaxes when the prime mover contracts

Question 23

What is the antagonist for elbow extension?

Answer 23

biceps brachii

Question 24

synergist

Answer 24

a muscle that assists a prime mover, helping to steady the movement

Question 25

fixator

Answer 25

a muscle that stablizes the origin of the prime mover so it can move more efficiently

Question 26

What happens if a prime mover and antagonist both contract at the same time and with equal force?

Answer 26

isometric contraction

Question 27

How many skeletal muscles are there in the human body

Answer 27

nearly 700

Question 28

What are some characteristics that muscles may be named after?

Answer 28

1. location (indicating the bone or body region they are near)
2. shape (named for a distinctive shape)
3. size
4. direction (of fibers)
5. number of origins
6. location of origin and insertion
7. action of the muscle

Question 29

What are some examples of muscles named for their location?

Answer 29

frontalis, tibialis anterior, rectus abdominus

Question 30

What are some muscles named for their shape?

Answer 30

deltoid, trapezius

Question 31

maximus

Answer 31

largest

Question 32

minimus

Answer 32

smallest

Question 33

longus

Answer 33

long

Question 34

brevis

Answer 34

short

Question 35

What are some muscles named for their size?

Answer 35

gluteus maximus, palmaris longus

Question 36

rectus

Answer 36

fibers run parallel to midline

Question 37

transverse

Answer 37

fibers run perpendicular to midline

Question 38

oblique

Answer 38

fibers run diagnol to midline

Question 39

What are some muscles named for the number of origins?

Answer 39

biceps (2), triceps (3), quadriceps (4)

Question 40

flexor

Answer 40

bends a joint

Question 41

extensor

Answer 41

straighten a joint

Question 42

adductor

Answer 42

moves a bone closer to midline

Question 43

levator

Answer 43

produces an upward movement (eg. levator labii)

Question 44

tensor

Answer 44

makes a body part rigid

Question 45

What can you tell from the name flexor carpi radialis

Answer 45

action - bends wrist; location - next to radius