EXAM II - muscles of hand, arm

• circular: sphincter like, as seen in mouth
• convergent: origin is wider than point of insertion, max force production
• parallel: long muscles causing large movements, not very strong but good endurance
• unipennate: fibres arranged to insert in a diagonal direction onto the tendon, which allows great strength
• bipennate: two rows of muscle fibres in opposite diagonal directions with a central tendon (feather), greater power but less motion
• multipennate: multiple rows of diagonal fibres, w/a central tendon that branches into 2+ tendons
• fusiform: muscles are more spindle shaped, with the muscle belly being wider than the origin and insertion.

• Tendon: tough band of fibrous connective tissue that connects muscle to bone
• Origin: the point at which muscle attaches to a bone. The structure that it is attached to is not moved by contraction
• Insertion: the point at which a muscle attaches to the skin, a bone, or another muscle. The structure its attached to is moved by muscle contraction.

• Antagonist: a muscle that acts in opposition to the specific movement generated by the agonist, is responsible for returning limb initial position.
• Synergists: are muscles that act on movable joints
• Synergists and antagonistic muscle groups are formed during early development, prior to individual muscles
• Muscle tissue is derived from mesoderm

• Flex –extend
• Abduct– adduct
• Rotate
• Pronate – supinate
• Circumduct

Radial: supplies the upper limb, originates from the posterior cord of the brachial plexus with roots from C5, C6, C7, C8 & T1

Posterior interosseuos: nerve in the forearm. It is the continuation of the deep branch of the radial nerve, after this has crossed the supinator muscle.

runs near the ulna bone, the largest unprotected nerve in the human, directly connected to the little finger, and the adjacent half of the ring finger

It is in the upper limb, enter the forearm with the brachial artery, originates from the brachial plexus with roots from C5, C6, C7, C8, & T1, the only nerve that passes through the carpal tunnel, where it may be compressed to cause carpal tunnel syndrome.

arises from the lateral cord of the brachial plexus, opposite the lower border of the Pectoralis minor, its fibers being derived from C5, C6 and C7.

comes off the of the brachial plexus at the level of the axilla (armpit) and carries nerve fibers from C5 and C6

(also called circumflex nerve)

• Origin: lateral epincondyle of humerus
• Insertion: dorsal surfaces of phalanges 2-5
• Nerve: radial (post. interosseous n.)
• Action: extends wrist and joints of digits 2-5

• Extensor Digiti Minimi:
• Origin: lat. epicondyle of humerus
• Insertion: proximal phalanx 5 (little finger)
• Nerve: radial/post. inteross n.
• Action: extends wrist and all joints of little finger

• Extensor Indicis
• Origin: lat epicon, inteross mem
• Insertion: 2nd phalanx (index finger)
• Nerve: radial/post. inteross. n.
• Action: extend wrist and index finger

• Extensor Carpi Radialis Longus:
• O: lat epidondyle of humerus
• I: base of2nd metacarpal
• N: radial
• A: extends wrist; aids in radial felxion of wrist

• Extensor Carpi Radialis Brevis
• O: same
• I: 3rd metacarpal
• N: same
• A: same

• Extensor Carpi Ulnaris:
• O: olecranon process (post surface of ulnar shaft)
• I: 5th metacarpal
• N: same
• A: extends and fixes wrist when fist is clenched (gripping), aids in ulnar flexion of wrist

• Flexor Digitorum Profundus:
• O: anterior of ulna, inteross. membrane
• I: distal phalanges 2-5
• N: Median
• A: flexes wrist and joints of fingers 2-5

• Flexor Digitorum Superficialis:
• O: medial epicondyle of humerus, coronoid process
• I: middle phalanges 2-5
• N: Median
• A: flexes wrists and finger joints

• Flexor Pollucis Longus:
• O: radius, ulna, inteross. mem.
• I: distal phalanx 1
• N: median
• A: flexes phalanges of thumb

• Flexor Carpi Radialis:
• O: medial epicondyle
• I: base of metacarpals 2-3
• N: median
• A: flex, abduct (flexes wrist anteriorly)

• Flexor Carpi Ulnaris
• O: medial epidondlye
• I: pisiform, hamate, 5th metacarpal
• N: ulnar
• A: flex, adduct (flexes wrist anteriorly)

• Palmaris Longus:
• O: medial epicondle of humerus
• I: palmar aponeurosis
• N: median
• A: anchors skin of palmar region, resists shearing forces such as climbing, weakly developed or absent

• Biceps Brachialis (Brachii)
• O: long head: glenoid cavity, short head: coracoid process
• I: radial tuberosity
• N: musculocutaneous nerve
• A: flex

• Brachialis:
• O: anterior humerus
• I: coronoid process, tuberosity of ulna
• N: musculocutaneous nerve
• A: flex (prime mover of elbox felxion)

• Brachioradialis:
• O: distal humerus
• I: radius near styloid process
• N: radial
• A: flexes elbow

• Triceps Brachii:
• O: glenoid cavity, lateral humerus, medial humerus
• I: olecranon process
• N: radial
• A: extends elbow

• Pronator Teres:
• O: medial epicondyle, coronoid process
• I: lateral radius
• N: median nerve
• A: rotation (pronation)

• Pronator Quadratus:
• O: distal ulna
• I: distal radius
• N: median n.
• A: rotation (pronation)

• Supinator:
• O: lateral epicondyle of humerus
• I: lateral radius
• N: radial (post. inteross n.)
• A: supinates forearm