Lecture 3 - Upper Extremity Flashcards
What important muscles are innervated by the musculocutaneous nerve?
- Biceps brachii
- Brachialis
- coracobrachialis
What action does the biceps brachii perform?
- forearm supination
- Elbow flexion
- Shoulder flexion
- Shoulder adduction
What is the main action of the briachialis muscle?
elbox flexion
What is the main action of the coracobrachialis muscle?
- shoulder flexion
2. shoulder adduction
What important nerve innervates the triceps brachii?
radial nerve
What is the main action reformed by the triceps brachii?
Elbow extension
What 5 muscles are included in the anterior compartment of the forearm in the superficial layer?
- pronator teres
- flexor carpi radialis
- plamaris longus
- flexor carpi ulnaris
- Flexor digitorum superficialis
the anterior forearm muscles are responsible for what actions?
flexors/pronators
What forearm muscle group compartment arises from the medial epicondyle?
anterior forearm muscles
the posterior forearm muscles are responsible for what actions?
extensors/supinators
What forearm muscle group compartment arises from the lateral epicondyle?
posterior forearm muscles
“extrinsic muscles” of the hand refers to?
all forearm muscles
What forearm muscle compartment is responsible for thumb flexion?
anterior forearm
What forearm muscle compartment is responsible for thumb extension and thumb abduction?
posterior forearm
What muscles make up the superficial layer of the the anterior compartment of the forearm?
1. pronator teres 2 flexor carpi radialis 3. plamaris longus 4. flexor carpi ulnaris 5. flexor digitorum superficialis
What is the origin and insertion of the pronator teres?
origin: medial epicondyle of humerus and coronoid process of ulna
insertion: middle of lateral surface of radius
What muscle creates the carpal tunnel?
flexor retinaculum
What are the 5 muscles in the deep layer of the posterior compartment of the forearm?
- supinator
- Abductor Pollicis Longus
- Extensor Pollicis Longus
- Extensor Pollicis Brevis
- Extensor Indicis
What are the 5 muscles in the superficial layer of the posterior compartment of the forearm?
- extensor carpi radialis longus
- extensor carpi radialis brevis
- extensor digitorum
- extensor digiti minimi
- extensor carpi ulnaris
thenar
the fleshy prominence on the radial side of the palm and is comprised of 3 muscles that act on the thumb. Innervated by the median nerve
- opponens pollicis
- abductor pollicis brevis
- flexor pollicis brevis
palmar aponeurosis
connects skin to underlying structures of the hand
hypothenar
the fleshy prominence on the ball of the little finger com pried of 3 muscles and is innervated by the ulnar nerve.
- abductor digiti minimi
- flexor digiti minimi
- opponens digiti minimi
central compartment
The muscles between the thenar eminences. Muscles more prominent on the palmer surface. 3 muscle groups
- inter-ossei
- lumbricals
- adductor pollicis
What arteries supply the arm?
- axillary
2. brachial artery
What nerves innervate the arm?
- musculocutaneous
- radial
- axillary
What arteries supply the forearm and hand?
- ulnar
2. radial
What nerves innervate the forearm and hand?
- median
- ulnar
3 radial
What are the three muscles in the deep layer of the anterior compartment?
- Flexor digitorum profundus
- flexus pollicis longus
- pronator quadratus
What is the origin and insertion of the supinator muscle? Where is this muscle located? is it in the deep or superficial layer? What is its action?
O: lateral epicondyle of the humerus
I: lateral, posterior and anterior surfaces of proximal third of radius
This muscle is located in the posterior compartment of the forearm and it is in the deep layer. Its action is to supinate the forearm
What is the action of the adductor pollicis?
adducts thumb toward middle digit
What group does the adductor pollicis belong?
central compartment of the hand
What is the main action of the brachioradialis muscle? What nerve innervates this muscle?
Powers elbow flexion and semi-pronation; radial nerve. *Not considered a member of either the flexor or extensor group
How many metacarpals are there?
5
What number digit is assigned to the thumb? the pinky?
thumb - 1st digit
pinky - 5th digit
What two bones articulate with the radius?
carpal bones scaphoid and lunate
What bone does the 1st metacarpal articulate with?
trapezium
Which bone does the 2nd metacarpal articulate with ?
trapezoid
What bone does the 3rd metacarpal articulate with?
capitate
What bone does the 4th metacarpal articulate with?
hamate
What bone does the 5th metacarpal articulate with?
hamate
How many carpal bones are there?
8
What are the purpose if the carpal bones?
They allow for mobility of the hand and opposition which is unique to the human species
Name the proximal row of carpal bones from lateral to medial
Scaphoid –> lunate –> Triquetral –> pisiform
Name the distal row of carpal bones from lateral to medial
trapezium –> trapezoid –> capitate –> hamate
What is special about the 1st phalange?
The thumb (1st digit) has only 2 bones: the proximal and distal phalanx. It does not have a middle bone. The rest of the 4 digits have 3: proximal, middle and distal
What type of joint is the elbow?
synovial; hinge
What is the carrying angle?
Since the trochlear is larger medially, the ulna migrates laterally. This creates a 15 degree carrying angle of the forearm which is greater in females than in males to accommodate for the wider pelvic girdle.
What kind of joint is the proximal radioulnar joint? What kind of movement does it allow?
pivot joint; pronation and supination
What bones make up the wrist joint?
the distal end of the radius and the proximal row of carpal bones
is the ulna part of the wrist joint?
no because it is separated from the carpals by a fibre-cartilagenous disc and does not contribute to the wrist joint
What kind of joint is the wrist joint?
condyloid, synovial joint because of the shape of the radius and the two carpal bones that the radius directly articulates with: scaphoid and lunate
What bones make up the metacarpal-phalangeal joints (MCPs)? What actions do they allow?
metacarpals and phalanges. The heads make up the knuckles.
- flexion/extension
- abduction/adduction
What type of joint is between the trapezium and the base of the first metacarpal?
saddle-type, synovial joint. This joint allows for opposition.
Movements:
- flex/ext
- abd/add
- opposition
What are the joints between the phalanges called? What kind of joints are they?
interphalangeal joints
- proximal interphalangeal joints (PIP)
- Distal interphalangeal joints (DIP) (digits 2-5)
Interphalangeal joints are hinge joints
PRONATOR TERES
O: medial epicondyle of humerus
I: middle of lateral surface of radius
A: pronates forearm and flexes elbow
anterior compartment of forearm; superficial layer
SUPINATOR
O: Lateral epicondyle of humerus
I: lateral, posterior, and anterior surfaces of proximal third of radius
A: supinates forearm
posterior compartment; deep layer
PRONATOR QUADRATUS
O: Distal 4th of anterior surface of ulna
I: Distal fourth of anterior surface of radius
A: Pronates forearm
anterior compartment; deep layer
EXTENSOR DIGITI MINIMI
O: lateral epicondyle of humerus
I: Extensor expansion of 5th digit
A: Extends the 5th digit at the metacarpophalangeal and interphalangeal joints
innervated by: radial nerve
posterior compartment; superficial layer
