Chapter 11 (The Muscular System)

Question 1

Muscle Attachment Sites: Origin & Insertion

Answer 1

1 - Skeletal muscles cause movements by exerting force on tendons, which pulls on bones or other structures.
2 - Articulating bones usually do not move equally in response to contraction.

Question 2

Origin

Answer 2

The attachment of a tendon to the stationary bone

Question 3

Insertion

Answer 3

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

Question 4

Action/s

Answer 4

The main movements that occur during contraction (e.g., flexion or extension).

Question 5

Lever

Answer 5

A rigid structure that can move around a fixed point called a fulcrum

Question 6

A lever is acted on at two different points by two different forces:

Answer 6

The effort and the load or resistance

Question 7

The effort

Answer 7

Is the force due to muscular contraction

Causes movement

Question 8

The load or resistance

Answer 8

Is the weight that is moved

Resistance opposes movement

Question 9

Motion occurs when …

Answer 9

Motion occurs when the effort applied to the bone at the insertion exceeds the load

Question 10

Types of Levers

Answer 10

There are 3 types of levers that differ on the positions of the fulcrum, effort, and load.

Question 11

First-class levers

Answer 11

Are not common

The fulcrum is between the effort and the load.

Question 12

Second-class levers

Answer 12

Are not common

The load is between the fulcrum and the effort.

Question 13

Third-class levers

Answer 13

Common

The effort is between the fulcrum and the load.