Question 1

What is the MAJOR function of the finger flexor pulley system?

Accepted Answer

The finger flexor pulley system is responsible for allowing tendons to conform to the curve of the digits. As the fingers are flexed, the tendons pull on the bones and without the pulley system, the tendons would not be able to properly conform to the curve of the fingers, resulting in reduced grip strength and possibly injury. The function of providing nutrition and lubrication to the tendons is important, but not the major function of the finger flexor pulley system. Additionally, the system does not allow tendons to extend digits.

Question 2

Which of the following bones forms a saddle joint with the base of the first metacarpal?

Accepted Answer

The bone that forms a saddle joint with the base of the first metacarpal is the trapezium.

Question 3

Which of the following directions is MOST CORRECT to palpate the capitate bone?

Accepted Answer

The capitate bone is located at the base of the third metacarpal bone. Therefore, the correct direction to palpate it is proximal to the base of the third metacarpal bone.

Question 4

How many degrees of freedom is present at the thumb carpometacarpal joint?

Accepted Answer

The thumb carpometacarpal joint, also known as the trapeziometacarpal joint, is a saddle joint that allows for two degrees of freedom: flexion-extension and abduction-adduction.

Question 5

Which of the following structures pass through the carpal tunnel?

Accepted Answer

The carpal tunnel is a narrow passageway in the wrist that is formed by the carpal bones on the bottom and the transverse carpal ligament on the top. It contains several structures, including the finger flexor tendons and the median nerve. Therefore, choice C is the best answer as it correctly identifies the finger flexor tendons and median nerve as the structures that pass through the carpal tunnel.

Question 6

What is the function of the wrist flexor and extensor retinaculum?

Accepted Answer

The wrist flexor and extensor retinaculum functions to prevent bowstringing of finger flexor and extensor tendons.

Question 7

What is the influence of the medial tilt of the radial styloid process on movement of the wrist?

Accepted Answer

The medial tilt of the radial styloid process influences the wrist's range of motion by allowing greater movement through ulnar deviation compared to radial deviation. This anatomical feature restricts the amount of radial deviation due to the bony structure, while permitting a larger range of motion towards ulnar deviation.

Question 8

Which of the following carpals are located in the floor of the anatomical snuff box?

Accepted Answer

The scaphoid and trapezium are the two carpals located in the floor of the anatomical snuff box. The snuff box is a triangular depression on the lateral aspect of the dorsum of the hand.

Question 9

Which of the following structures comprise the radiocarpal joint?

Accepted Answer

The radiocarpal joint is formed by the articulation of the distal radius and the articular disk with the proximal row of carpal bones, which includes the scaphoid and lunate. Therefore, choice B is the best answer as it includes both the scaphoid and lunate as part of the radiocarpal joint.

Question 10

A person has 85° of passive right wrist flexion, 45° of extension, and 21° of ulnar and radial deviation.Which directions of motion are limited for this person compared with the average norms?

Accepted Answer

The answer of A person has 85° of passive right...

Question 11

Which of the following statements is MOST CORRECT about the longitudinal arch of the hand?

Accepted Answer

The longitudinal arch of the hand is supported by the second and third metacarpals, which act as central pillars, while the thumb and fourth and fifth digits move around them.

Question 12

Which of the following muscle groups have a common proximal attachment on the lateral humeral epicondyle and supracondylar ridge?

Accepted Answer

The answer of Which of the following muscle groups have...

Question 13

Which of the following statements BEST describes hand mobility that allows greater closure of the hand?

Accepted Answer

The statement that "available joint range of motion increases from radial to ulnar aspects of the hand" best describes hand mobility that allows greater closure of the hand. This is because the radial aspect of the hand has less available joint range of motion, while the ulnar aspect has more available joint range of motion, which allows for a greater closure of the hand. Choice A and D are incorrect because they do not describe the increasing joint range of motion from radial to ulnar, and choice C is incorrect because it suggests that there is no change in joint range of motion across the hand, which is not true.

Question 14

Which of the following statements BEST describes thumb abduction?

Accepted Answer

Thumb abduction refers to the movement of the thumb away from the palm in a plane that is perpendicular (at a right angle) to the palm. This allows the thumb to move in the direction away from the other fingers.

Question 15

What wrist motion occurs as the wrist moves toward the palmar surface of the hand in a sagittal plane around a frontal axis?

Accepted Answer

As the wrist moves towards the palmar surface, the angle between the palm and forearm decreases, which is defined as flexion. The other options (B) ulnar deviation, (C) extension, and (D) radial deviation, involve movement towards the ulnar side, away from the sagittal plane; movement of the wrist towards the dorsal surface of the hand, in the opposite direction of the sagittal plane; and movement of the wrist towards the radial side, away from the sagittal plane, respectively.

Question 16

What wrist motion occurs as the wrist moves toward the thumb side in the frontal plane around a sagittal axis?

Accepted Answer

Radial deviation (also known as radial flexion) is the movement of the hand and wrist towards the thumb side, occurring in the frontal plane around a sagittal axis. This motion is opposite to ulnar deviation, which is the movement of the hand and wrist towards the little finger side. Flexion and extension refer to movements in the sagittal plane, so they are not the correct choices for this question.

Question 17

What motion is produced when extensor carpi ulnaris and flexor carpi ulnaris are activated together?

Accepted Answer

Extensor carpi ulnaris and flexor carpi ulnaris are muscles that are responsible for ulnar deviation or movement of the wrist towards the ulnar side. When these muscles are activated together, they produce ulnar deviation.

Question 18

Which of the following muscles stabilize the wrist during a powerful grip by the hand?

Accepted Answer

The extensor carpi radialis longus, extensor carpi radialis brevis, and extensor carpi ulnaris muscles stabilize the wrist during a powerful grip. They counteract the flexion force of the flexor muscles in the forearm, preventing the wrist from flexing and thus maintaining a stable position for effective grip strength.

Question 19

Which of the carpometacarpal joints is the most stable functioning as the central pillar of the hand?

Accepted Answer

The third carpometacarpal joint is the most stable and functions as the central pillar of the hand, providing a stable axis for hand movements.

Question 20

A person with a C6 spinal cord injury uses a tenodesis action at the wrist and hand to pick up objects.Which of the following statements BEST describes hand muscle function to grasp the object during this action?

Accepted Answer

Concentric contraction of wrist extensors with passive stretching of finger flexors allows individuals with a C6 spinal cord injury to utilize tenodesis action for grasping objects. This action relies on the natural biomechanics where extending the wrist passively flexes the fingers due to the tension created in the finger flexors.

Quiz 10: Structure and Function of the Wrist and Hand Complex