3.4.1. Thenar Muscle Compartment

Question 1

What are the 2 Groups, which the Muscles that act on the Hand, can be Divided into?

Answer 1

1. Extrinsic Muscles

2. Intrinsic Muscles

Question 2

Where are the Extrinsic Muscles of the Hand located?

Answer 2

1. Anterior Compartment of the Forearm

2. Posterior Compartment of the Forearm

Question 3

What are the functions of the Extrinsic Muscles of the Hand?

Answer 3

1. Control Crude Movements

2. Produce a Forceful Grip

Question 4

Where are the Intrinsic Muscles of the Hand located?

Answer 4

Within the Hand itself

Question 5

What is the function of the Intrinsic Muscles of the Hand?

Answer 5

Fine Motor Control of the Hand

Question 6

What are the 5 Muscle Compartments, of the Intrinsic Muscles of the Hand?

Answer 6

1. Thenar Muscle Compartment
2. Hypothenar Muscle Compartment
3. Adductor Compartment
4. Lumbricals and Long Flexor Tendons (Central) Compartment
5. Interossei Compartment

Question 7

How many Thenar Muscles are there?

Answer 7

3

Question 8

Where are the Thenar Muscles Located?

Answer 8

The Base of the Thumb

Question 9

What is the name of the Bulge which the Thenar Muscle Bellies produce?

Answer 9

Thenar Eminence

Question 10

What are the Thenar Muscles responsible for?

Answer 10

Fine Movements of the Thumb

Question 11

What innervates the Thenar Muscles?

Answer 11

Recurrent Branch of the Median Nerve

Question 12

What are the 3 Thenar Muscles?

Answer 12

1. Opponens Pollicis
2. Abductor Pollicis Brevis (APB)
3. Flexor Pollicis Brevis (FPB)

Question 13

Which of the Thenar Muscles is the Largest?

Answer 13

Opponens Pollicis

Question 14

Where is the Opponens Pollicis located, in relation to the other 2 Thenar Muscles?

Answer 14

Deep to the other 2 (Underneath)

Question 15

Where does the Opponens Pollicis Originate from?

Answer 15

1. Tubercle of the Trapezium

2. Associated Flexor Retinaculum

Question 16

Where does the Opponens Pollicis attach distally?

Answer 16

Lateral Margin of the Metacarpal of the Thumb (i.e. the First Metacarpal)

Question 17

1. What is the function of the Opponens Pollicis?

2. How does it do this?

Answer 17

1. It Opposes the Thumb

2. By Medially Rotating and Flexing the Metacarpal on the Trapezium

Question 18

What is the innervation of the Opponens Pollicis?

Answer 18

Recurrent Branch of the Medial Nerve

Question 19

Where is the Abductor Pollicis Brevis (APB) located, in relation to the other 2 Thenar Muscles?

Answer 19

1. Anteriorly to the Opponens Pollicis

2. Proximal to the Flexor Pollicis Brevis (FPB)

Question 20

Where does the Abductor Pollicis Brevis (APB) Originate from?

Answer 20

1. Tubercle of the Scaphoid
2. Tubercle of the Trapezium
3. Associated Flexor Retinaculum

Question 21

Where does the Abductor Pollicis Brevis (APB) attach distally?

Answer 21

Lateral Side of the Proximal Phalanx of the Thumb

Question 22

What is the function of the Abductor Pollicis Brevis (APB)?

Answer 22

Abducts the Thumb

Question 23

What is the innervation of the Abductor Pollicis Brevis (APB)?

Answer 23

Recurrent Branch of the Median Nerve

Question 24

Where is the Flexor Pollicis Brevis (FPB) located, in relation to the other 2 Thenar Muscles?

Answer 24

Distal to them both

Question 25

Where does the Flexor Pollicis Brevis (FPB) Originate from?

Answer 25

1. Tubercle of the Trapezium | 2. Associated Flexor Retinaculum

Question 26

Where does the Flexor Pollicis Brevis (FPB) attach distally?

Answer 26

Base of the Proximal Phalanx of the Thumb

Question 27

What is the function of the Flexor Pollicis Brevis (FPB)?

Answer 27

Flexion of the Metacarpophalangeal (MCP) Joint of the Thumb

Question 28

What is the innervation of the Flexor Pollicis Brevis (FPB)?

Answer 28

Recurrent Branch of the Median Nerve