4.7. Tendons in the Hand (Extensor Expansion)

Question 1

Where are the Muscles for the Tendons in the Hand located?

Answer 1

In the Forearm

Question 2

What are the 2 Broad Categories of Tendons in the Hand?

Answer 2

1. Flexor Tendons in the Fingers

2. Extensor Tendons in the Fingers

Question 3

Which Tendons allow for Flexion in the Fingers?

Answer 3

1. Flexor Digitorum Profundus

2. Flexor Digitorum Superficialis

Question 4

How do the Flexor Digitorum Profundus and Superficialis enter into the Hand?

Answer 4

Via the Carpal Tunnel

Question 5

What protects the Flexor Digitorum Profundus and Superficialis in the Hand?

Answer 5

Common Flexor Sheath

Question 6

What happens to the Common Flexor Sheaths as you travel Distally?

Answer 6

It Fans out into the Digital Synovial Sheaths

Question 7

Where are the Digital Synovial Sheaths located?

Answer 7

In each Finger

Question 8

What is the function of the Digital Synovial Sheaths?

Answer 8

To Permit the Free Movement of the Tendons over Each Other during Flexion

Question 9

1. What happens to the Flexor Digitorum Superficialis Tendon, as it enters the Base of the Proximal Phalanx of Each Finger?
2. What does this allow for?

Answer 9

1. It Splits and Inserts into the Intermediate Phalanx

2. The Flexor Digitorum Profundus Tendon to pass through and Insert onto the Distal Phalanx

Question 10

What happens to the Tendons of the Extensor Digitorum as they reach the Metacarpals?

Answer 10

They Flatten

Question 11

What do the Tendons of the Extensor Digitorum become as they Flatten?

Answer 11

They become Extensor Expansions (or Hoods)

Question 12

What happens to the Extensor Expansions (or Hoods)?

Answer 12

They Wrap around the Metacarpal and Proximal Phalanx

Question 13

What do the Extensor Expansions (or Hoods) Join onto as they Wrap around the Metacarpal and Proximal Phalanx?

Answer 13

The Palmar Plate

Question 14

What happens to the Extensor Expansions (or Hoods) as they travel Distally?

Answer 14

They Spread Out Further

Question 15

What does the Further Distal Expansion of the Extensor Expansions (or Hoods) form?

Answer 15

1. 1 x Median Band

2. 2 x xLateral Bands

Question 16

What does the Median Band, formed by the Extensor Expansions (or Hoods), attach to?

Answer 16

Intermediate (Middle) Phalanx

Question 17

What do the Lateral Bands, formed by the Extensor Expansions (or Hoods), attach to?

Answer 17

Distal Phalanx

Question 18

What effect does contraction of the Extensor Digitorum Muscle have on its Tendon?

Answer 18

It Tightens the Tendon, Extending the Intermediate and Distal Phalanges