Thenar Muscles + Palmaris Brevis

Question 1

Palmaris Brevis

Answer 1

O: Medial Border of the Palmar Aponeurosis

I: Skin over the Ulnar Border of the Hand

A: Stabilizes the Palmar Skin during Gripping

N: Ulnar Nerve (C8-T1)

Question 2

Abductor Pollicis Brevis

Answer 2

O: Flexor Retinaculum, Trapezium, Scaphoid

I: Radial Side and Base of the Proximal Phalanx of the Thumb

A: Abducts Thumb

N: Median Nerve (C8-T1)

Question 3

Flexor Pollicis Brevis

Answer 3

O: Lateral Head: Flexor Retinaculum, Trapezium

Medial (Deep) Head: Capitate, Trapezoid

I: Base of the Proximal Phalanx of the Thumb

A: Flexion of 1st Metacarpal, Aids in the Opposition and Adduction of the Thumb

N: Lateral Head:
Median Nerve (C8-T1)

Medial Head:
Ulnar Nerve (C8-T1)

Question 4

Opponens Pollicis

Answer 4

O: Flexor Retinaculum,
Trapezium

I: 1st Metacarpal

A: Opposition of the Thumb

N: Median Nerve (C8-T1)

Question 5

Adductor Pollicis

Answer 5

O: Oblique Head:
Base of Metacarpals 2-4, Trapezoid, Trapezium, Capitate

Transverse Head:
3rd Metacarpal

I: Ulnar Side and Base of the Proximal Phalanx of the Thumb

A: Adduction and Flexion of the Thumb

N: Ulnar Nerve (C8-T1)