Study questions Flashcards
Name the muscles of the superficial compartment of the anterior forearm
Pronator Teres
Flexor Carpi Radialis
Palmaris Longus
Flexor Carpi Ulnaris
What is the common origin for all of the superficial muscles of the forearm
CFT/ medial epicondyle of the humerus
Pronator Teres
- P: CFT
- D: mid-shaft of radius
- N: median n. (C6-7)
- A: pronates arm
Flexor Carpi Radialis
- P: CFT
- D: base of 2nd and 3rd digits
- N: median n. (C6-7)
- A: flexes and aBducts (RD) hand
Palmaris Longus
- P: CFT
- D: palmer aponeurosis
- N: median n. (C7-8)
- A: flexes hand at wrist
Flexor Carpi Ulnaris
- P: CFT
- D: base of 5th digit, pisiform and hamate
- N: ulnar n. (C7-T1)
- A: flexes and aDducts (UD) hand
Flexor Digitorum Superficialis
- P: CFT
- D: middle phalanx of digits 2-5
- N: Median (C8-T1)
- A: flexes wrist, and MC/PIP flexion of digits 2-5
What muscle is in the intermediate layer of the anterior compartment of the forearm
Flexor Digitorum Superficialis
What muscles are located in the deep compartment of the forearm
Flwexor Digitorum profundus
Pronator Quadratus
Flexor Pollicis Longus
Flexor Digitorum Superficialis
- P: CFT
- D: middle phalanx of digits 2-5
- N: median n. (C8-T1)
- A: flexes wrist, and MC/PIP flexion of digits 2-
Pronator Quadratus
- P: distal ¼ of ulna
- D: distal ¼ of radius
- N: AIN (C8-T1)
- A: pronates arm
Flexor Pollicis Longus
- P: mid radius
- D: distal phalanx of thumb (IP)
- N: AIN (C8-T1)
- A: flexes thumb at IP
What muscles insert on the carpal bones?
Flexor Carpi Ulnaris Abductor Pollicis Longus Flexor Carpi Radialis Extensor Carpi radialis Longus Extensor Carpi Radialis brevis Extensor Carpi Ulnaris
**Consider Influence of the retnaculum
Pathway of the Median Nerve
Lateral and medial cords
No Innervation in arm
Exits medial to biceps tendon & brachial artery in cubital fossa
Passes between heads of pronator teres
Gives off AIN branch just distal to cubital fossa
Continues on anterior side of interosseous membrane to innervate deep
flexors -> (FDP, FPL, pronator quadratus)
Travels b/w superficialis & profundus to carpal tunnel & passes through carpal tunnel
Supplies lateral 2 lumbricals
Sensation via the common palmar digital branches & proper palmar digital braches (running w/ arteries)
Median Recurrent
To FPB (superficial head, opponens pollicis, abductor pollicis brevis
Pathway of Radial nerve
Come of posterior cord
With Profunda Brachi artery in radial groove
Innervates posterior compartment (triceps)
Emerges distally b/w brachioradialis & brachialis
Passes into cubital fossa laterally
Innervating brachioradialis & ECRL & divides into deep & superficial branch
Superficial branch
Continues under brachioradialis to radial side of wrist – supplies sensation to dorsal 3 ½ digits
Deep branch
Innervates ECRB & pierces supinator
After exiting supinator, name changes to PIN
PIN
Supplies posterior compartment of forearm & travels w/ posterior interosseous artery
Ulnar Nerve Pathway
comes off medial cord No innervation in arm Passes medially & then posterior to medial epicondyle Travels under FCU Innervates FCU & medial ½ of FDP
Dorsal branch of ulnar nerve prior to wrist to supply dorsal skin of 5th & ½ 4th digit
Superficial branch & Deep branch after passing through Guyon’s canal
Superficial branch to skin
Deep branch to intrinsics, hypothenar eminence, medial 2 lumbricals, adductor pollicis, deep head FPB
digit
Musculocutaneous nerve path
- Comes off lateral cord
- pierces corcobrachialis
- passes anterior to brachialis and beep to biceps brachii
- emerges laterally to biceps tendon as lateral cutaneous nerve
- provides sensory innervation to the later aspect of forearm
Axillary nerve path
- comes off posterior cord
- exits axilla through quadrangular space
Cutaneous Nerve Distrinutions
refer to areas innervated by specific peripheral nerves, which may contain fibers from multiple nerve roots (supply a smaller, more specific area)
Dermatones
Represent which spinal nerve roots innervate a specific region of the skin
Name the muscles in the superficial layer in the posterior compartment of the arm
Brachioradialis Extensor Carpi radialis longus Extensor carpi radialis brevis Extensor digitorum Extensor digiti minimi Extensor carpi Ulnaris
Extensor carpi ulnaris
a. Origin: Lateral Epicondyle of the humerus
b. Insertion: Base of the 5th metacarpal
c. Action: Extend and Adduct the wrist (ulnar deviation)
d. Innervation: Posterior Interosseus Nerve C7 – C8
Extensor digiti minimi
a. Origin: Lateral epicondyle of the humerus
b. Insertion: Distal Phalanx of digit 5
c. Action: extends digit 5
d. Innervation: Posterior Interosseous Nerve C7-C8
Extensor Digitorum
a. Origin: Lateral Epicondyle of the humerus
b. Insertion: dorsal side of distal phalanx 2-5
c. Action: extension of digits 2-5 at MCP, PIP and DIP and wrist extension
d. Innervation: Posterior Interosseous Nerve C7-C8
Extensor Carpi Radialis Brevis
a. Origin: Lateral epicondyle of the humerus
b. Insertion: Dorsal side of the 3rd metacarpal bone
c. Action: extends the wrist
Innervation: Deep Radial . C7, C8
Extensor Carpi Radialis
a. Origin: inferior 1/3rd of the lateral supracondylar ridge of the humerus
b. Insertion: Dorsal side of the 2nd metacarpal bone
c. Action: Extend and Abduct the wrist (radial deviation of the wrist)
d. Innervation: Radial n. C6, C7, C8
Brachioradialis
a. Origin: proximal 2/3rds of lateral supracondylar ridge of the humerus
b. Insertion: base of styloid process of the radius
c. Action: flexion and abduction of the forearm
d. Innervation: radial n. C5-6
Name the muscles of the deep layer of the posterior compartment of the forearm
Supinator Adbuctor pollicis longus Extensor Pollicis Longus Extensor Pollicis Brevis Extensor Indicis
Supinator
a. Origin: Lateral Epicondyle of humerus, radial collateral/annular ligaments, ulnar crest
b. Insertion: Lateral, posterior and anterior surfaces of the proximal radius
c. Action: Supinates the forearm
d. Innervation: Deep Radial Nerve C6-C7
Abductor Pollicis Longus
a. Origin: posterior proximal half of the ulna, radius and interosseous membrane
b. Insertion: base of the first metacarpal
c. Action: Abduct the thumb and the hand
d. Innervation: Posterior Interosseous Nerve C7-C8
Extensor Pollicis Longus
a. Origin: Posterior middle third of the ulna and interosseous membrane
b. Insertion: Dorsal Base of the distal phalanx of the thumb
c. Action: Extends the thumb
d. Innervation: Posterior Interosseous Nerve C7- C8
Extensor Pollicis Brevis
a. Origin: Posterior distal third of the radius and interosseous membrane
b. Insertion: Dorsal base of the proximal phalanx of the thumb
c. Action: extends the thumb at the MC joint
d. Innervation: Posterior Interosseous Nerve C7-C8
Extensor Indicis
a. Origin: Posterior distal third of ulna and interosseous membrane
b. Insertion: distal phalanx of the 2nd digit
c. Action: extend the index finger
d. Innervation: Posterior Interosseous Nerve C7-C8
Describe the superficial fascia of the arm
fascial sheet that lies directly beneath the skin (subcutaneous)
i. Contains the nerves, veins, and arteries, which could be injured by trauma
ii. Axillary a/n, radial n., median n., ulnar n., musculocutaneous n., etc.
Describe the deep(investing) fascia of the arm
i. Divides groups of muscles into fascial compartments
1. Anterior (flexors) Compartment
2. Posterior (extensors) Compartment
What are the boundaries of the carpal tunnel?
i. Deep border: carpal bones
ii. Superficial border: flexor retinaculum
What are the contents of the carpal tunnel?
Tendons of FDS (3/4 on top &2/5 under)
Tendons of FDP
Tendon of pollicis longus
median nerve
What is CTS? What are some symtpoms?
is a compression or entrapment of the median nerve
Causes pain, numbness, tingling and/or burning in the hand (usually in the 1st, 2nd, 3rd, and radial side of the 4th digit) Sometimes extends up the forearm, arm, and/or shoulder
