i want 25 multiple choice questions with their model answer below each question about Objectves • Muscles of the anterior compartment of the forearm:
• Superficial: 4 • Intermediate: 1 • Deep: 3Forearm
• Bones: radius, ulna
• Joints:
radioulnar joints (proximal, middle
&distal)
• Muscles:
- anterior compartment: superficial (flexor
carpi ulnaris, palmaris longus, flexor carpi radialis,
and pronator teres), intermediate (flexor
digitorum superficialis) and deep (flexor digitorum
profundus, flexor pollicis longus and pronator
quadratus).
- posterior compartment.'Rule of 3s'
• 3 wrist flexors (flexor carpi radialis, flexor carpi
ulnaris, palmaris longus)
• 3 finger flexors (flexor digitorum superficialis,
flexor digitorum profundus, flexor pollicis longus)
• 3 wrist extensors (extensor carpi radialis longus,
extensor carpi radialis brevis, extensor carpi
ulnaris)
• 3 finger extensors (extensor digitorum, extensor
indicis, extensor digiti minimi)
• 3 thumb extensors (abductor pollicis longus,
extensor pollicis brevis, extensor pollicis longus)• The muscles in the anterior compartment of
the forearm are organised into three layers:
• Superficial: pronator teres, flexor carpi
radialis, palmaris longus and flexor carpi
ulnaris
• Intermediate: flexor digitorum superficialis.
• Deep: flexor digitorum profundus, flexor
pollicis longus and pronator quadratus.
• This muscle group is associated with
pronation of the forearm, flexion of the wrist
and flexion of the fingers.• Nerve supply: They are mostly
innervated by the median nerve (except
for the flexor carpi ulnaris and medial half
of flexor digitorum profundus, which are
innervated by the ulnar nerve).
• Arterial supply: they receive from the
ulnar artery and radial arterySuperficial group
• The superficial muscles in the anterior
compartment are: from lat. To med.
1. pronator teres
2. flexor carpi radialis
3. palmaris longus
4. flexor carpi ulnaris
• Origin: common flexor origin (front of the
medial epicondyle of the humerus).Pronator Teres
• Origin: It has two heads, one from
the medial epicondyle of the
humerus, and the other from the
coronoid process of the ulna.
• insertion: It attaches laterally to the
mid-shaft of the radius.
• Actions: Pronation of the forearm.
• Nerve supply: Median nerve.Pronator
teresFlexor Carpi Radialis
• Origin: Originates from the
medial epicondyle (CFO).
• Insertion: attaches to the base
of metacarpals II and III.
• Actions: Flexion and abduction
at the wrist.
• Nerve supply: Median nerve.Flexor
carpi
radialisPalmaris Longus
• This muscle is absent in about 15% of the population.
• Origin: Originates from the medial epicondyle (CFO).
• Insertion: to the flexor retinaculum of the wrist & palmar aponeurosis.
• Actions: Flexion at the wrist. • Nerve supply: Median nerve.• Palmaris
longusFlexor Carpi Ulnaris
• Origin: two origins: humeral head originates
from the medial epicondyle of the humerus with
the other superficial flexors.
ulnar head originates from the olecranon of
the ulna.
• insertion: The muscle tendon passes into the
wrist and attaches to the pisiform bone, hook of
hamate, and base of the 5th metacarpal bone.
• Actions: Flexion and adduction at the wrist.
• Nerve supply: Ulnar nerve.• Flexor
carpi
ulnarisIntermediate Compartment
• The flexor digitorum superficialis is the only
muscle of the intermediate compartment.
• It can sometimes be classed as a superficial muscle,
but in most individuals, it lies between the deep
and superficial muscle layers.
• The muscle is a good anatomical landmark in
the forearm: the median nerve and ulnar artery
pass between its two heads, and then travel
posteriorly.• Origin: It has two heads:• Actions: Flexes the wrist, the
metacarpophalangeal joints and
proximal interphalangeal joints of
the medial 4 fingers.
• Nerve supply: Median nerve.Deep group
Flexor digitorum profundus.
Flexor pollicis longus.
Pronator quadratus.Flexor digitorum profundus muscle
• Origin: from the proximal half of the anterior border of the ulna and the interosseous membrane.
• Its four tendons run through the carpal tunnel and between the split end tendons of the flexor digitorum superficialis at the level of the middle phalanges.
• insertion: at the palmar surface of the base of the distal phalanges of the second to fifth fingers (medial 4 fingers).• Nerve supply: the anterior
interosseus nerve, a branch of
the median nerve (second and
third finger, root values C8-T1)
and ulnar nerve (fourth and
fifth finger, root values C8-T1).• Actions: flexion of the wrist,
carbometacarbal,
metacarpophalangeal
and
proximal
&distal
interphalangeal joints of the
medial 4 fingers.Flexor pollicis longus muscle
• Origin: anterior surface of the radius and the
interosseous membrane of the forearm. Its
tendon runs also through the carpal tunnel.
• insertion: at the palmar surface of the distal
phalanx of the thumb.
• Nerve supply: the anterior interosseus nerve, a
branch of the median nerve.
• Actions:flexion of the wrist, carbometacarbal,
metacarbophalangeal and proximal &distal
interphalangeal joints of the thumb.Pronator quadratus muscle
• Origin: from the anterior surface of the lower
end of the ulna and extends horizontally.
• insertion: to the anterior surface of the the
lower end of the radius giving the muscle a
square-shaped appearance. It is the deepest
muscle in the anterior forearm.
• Nerve supply: the anterior interosseus nerve,
a branch of the median nerve (C7-C8).
• Actions: pronation of the forearm.Pronator
quadratusFlexor digitorum
profundus
Origins: proximal half of anterior
surface of ulna, interosseous
membrane
Insertions: palmar surfaces of distal
phalanges of digits 2-5
N.S: digits 2-3: Anterior
interosseous nerve (from median
nerve C8, T1);
Digits 4-5: Ulnar nerve (C8, T1)
Action: metacarpophalangeal and
interphalangeal joints 2-5: Finger
flexionOrigins: anterior surface of the radius and interosseous
membrane
Flexor pollicis longus
Insertions: base (palmar side) of the distal phalanx
of the thumb
N.S: anterior interosseous nerve (from median nerve
C7, Action: interphalangeal
metacarpophalangeal of
joint (Thumb)flexion.
Origins: distal end of anterior surface of the ulna
Pronator quadratus
Insertions: distal end of anterior surface of the radius
N.S: anterior interosseous nerve (from median nerve
C7, Action: pronation of the forearm C8) C8) and finger 1