$$MA = \frac{\text{Effort Arm}}{\text{Load Arm}}$$

Question 1

Which muscle fascicle arrangement is best suited for producing the greatest range of motion, and why?

Accepted Answer

Parallel, because the fibers run parallel to the long axis and can shorten more than other arrangements.

Question 2

A muscle that crosses on the lateral side of a joint typically produces which movement?

Accepted Answer

Abduction

Question 3

Which type of lever system in the body is exemplified by standing on your toes, and what is the order of its components?

Accepted Answer

Second-class lever; load between fulcrum and effort

Question 4

Which muscle arrangement is most powerful, and what is the reason for this?

Accepted Answer

Multipennate, because it contains the highest number of muscle fibers in a given area.

Question 5

A patient is diagnosed with multiple sclerosis, a demyelinating disease. Which cells are most likely targeted by this disease?

Accepted Answer

Oligodendrocytes in the central nervous system

Question 6

Which equation best represents the mechanical advantage of a lever system in the human body?

Accepted Answer

$$MA = \frac{	ext{Effort Arm}}{	ext{Load Arm}}$$

Question 7

Which muscle name indicates that the muscle has three origins?

Accepted Answer

Triceps

Question 8

A muscle named 'extensor carpi radialis longus' tells you all of the following EXCEPT:

Accepted Answer

It is the shortest muscle in the group

Question 9

Which glial cell type is responsible for phagocytizing microorganisms and neuronal debris in the CNS?

Accepted Answer

Microglia

Question 10

Which of the following best describes the function of dendrites in a neuron?

Accepted Answer

Receptive region that receives input and conveys signals toward the cell body

Question 11

Which muscle fascicle arrangement is found in the orbicularis oris, and what is its primary function?

Accepted Answer

Circular; closes openings such as the mouth

Question 12

Which nervous system division is responsible for voluntary control of skeletal muscles?

Accepted Answer

Somatic nervous system

Question 13

A muscle with fibers running at right angles to the imaginary axis is likely to be named:

Accepted Answer

Transversus

Question 14

Which of the following is TRUE regarding myelination in the peripheral nervous system?

Accepted Answer

Schwann cells form myelin sheaths by wrapping around axons

Question 15

Which muscle fascicle arrangement allows for the greatest force production, and why?

Accepted Answer

Pennate, because more fibers are packed into a given muscle length

Question 16

Which of the following is a correct description of a third-class lever in the human body?

Accepted Answer

The effort is applied between the fulcrum and the load

Question 17

Which equation correctly describes the relationship between force, distance, and work in muscle contraction?

Accepted Answer

$$W = F 	imes d$$

Question 18

Which glial cell type lines the central cavities of the brain and spinal cord and helps circulate cerebrospinal fluid?

Accepted Answer

Ependymal cells

Question 19

Which structural class of neuron is most common in the human body?

Accepted Answer

Multipolar

Question 20

A patient presents with rapid loss of muscle power but retains a wide range of motion at a joint. Which type of lever system is most likely involved?

Accepted Answer

Mechanical disadvantage (speed lever)

Skeletal Muscle Structure, Function, and Lever Systems

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