Changes

Forelimb - Anatomy & Physiology (view source)

Revision as of 17:12, 10 January 2011

128 bytes added , 17:12, 10 January 2011

→‎Intrinsic Musculature

Line 170: Line 170:

Medial:

−

~~:Innervated by:~~ '''Supscapularis''': Subscapular n. from the brachial plexus

+

'''Supscapularis''':

+

:Innervated by: Subscapular n. from the brachial plexus

:Origin: Deep surface of the scapula

:Insertion: medial tubercle of the humerus

Line 193: Line 194:

There are no defined extensors of the shoulder. Those involved (brachiocephalic m., biceps brachii, supraspinatus, and ascending pectorals) have other, more primary roles.

+

====Muscles of the Elbow====

−

''Extensors'': Radial n. from the brachial plexus

+

''Extensors'':

−

*'''Triceps brachii''': Three heads, four in the dog

+

:Innervated by: Radial n. from the brachial plexus

−

**Long head: caudal margin of the scapula

+

−

**Lateral, medial, and accessory heads: shaft of the humerus

+

:'''Triceps brachii''': Three heads, four in the dog

−

**Insertion: olecranon, proteced by tricipital bursa against the bone and subcutaneous bursa against the skin

+

::Long head: caudal margin of the scapula

−

*'''Tensor fasciae antebrachii'''

+

::Lateral, medial, and accessory heads: shaft of the humerus

−

**Overlies triceps extending from scapula to ~~olecranon~~

+

::Insertion: olecranon, proteced by tricipital bursa against the bone and subcutaneous bursa against the skin

−

*'''Anconeus'''

+

−

**Origin: distal humerus

+

:'''Tensor fasciae antebrachii'''

−

**Insertion: lateral olecranon

+

::Overlies triceps extending from scapula to olecranon

−

''Flexors'': Musculocutaneous n. from the brachial plexus

+

:'''Anconeus'''

−

*'''Biceps brachii'''

+

::Origin: distal humerus

−

**Origin: supraglenoid tubercle of the scapula

+

::Insertion: lateral olecranon

−

**Insertion: medial tuberosity of proximal radius and adjacent ulna

+

−

**Runs through the intertubercular groove of the humerus

+

−

*'''Brachialis'''

+

''Flexors'':

−

**Origin: proximocaudal humerus

+

:Innervated by: Musculocutaneous n. from the brachial plexus

−

**Insertion: spirals to insert next to biceps

+

:'''Biceps brachii'''

+

::Origin: supraglenoid tubercle of the scapula

+

::Insertion: medial tuberosity of proximal radius and adjacent ulna

+

::Runs through the intertubercular groove of the humerus

+

:'''Brachialis'''

+

::Origin: proximocaudal humerus

+

::Insertion: spirals to insert next to biceps

====Muscles of Supination and Pronation ====

−

''Supinators'': Radial n. from the brachial plexus

+

''Supinators'':

−

*'''Brachioradialis'''

+

:Innervated by: Radial n. from the brachial plexus

−

**Origin: lateral epicondyle of the humerus

−

**Insertion: distal medial forearm within superficial fascia

−

**Prominent in the cat but nearly absent in the dog

−

*'''Supinator'''

−

**Deep to extensor muscles, passing from lateral humeral epicondyles to upper medial radius

−

''Pronators'': Median n. from the brachial plexus

+

:'''Brachioradialis'''

−

*'''Pronator teres''': only functional in cat and dog

+

::Origin: lateral epicondyle of the humerus

−

**Origin: medial epicondyle of the humerus

+

::Insertion: distal medial forearm within superficial fascia

−

**Insertion: supinator

+

::Prominent in the cat but nearly absent in the dog

−

*'''Pronator quadratus''': only found in carnivores

+

−

**Origin: shaft of the ulna

+

:'''Supinator'''

−

**Insertion: shaft of the radius

+

::Deep to extensor muscles, passing from lateral humeral epicondyles to upper medial radius

+

''Pronators'':

+

:Innervated by: Median n. from the brachial plexus

+

:'''Pronator teres''': only functional in cat and dog

+

::Origin: medial epicondyle of the humerus

+

::Insertion: supinator

+

:'''Pronator quadratus''': only found in carnivores

+

::Origin: shaft of the ulna

+

::Insertion: shaft of the radius

====Muscles of the Carpal and Digital Joints====

−

''Extensors'': Radial n. from the brachial plexus

+

''Extensors'':

−

*Craniolateral position on the forearm

+

:Innervated by: Radial n. from the brachial plexus

−

*Almost all originate from the lateral epicondyle of the humerus

+

:Craniolateral position on the forearm

−

*'''Extensor carpi radialis''': most medial, inserts on 2nd/3rd metacarpal bone

+

:Almost all originate from the lateral epicondyle of the humerus

−

*'''Ulnaris lateralis''': most lateral, inserts on accessory carpal bone

+

−

*'''Extensor carpi obliquus''': aka '''abductor pollicis longus'''

+

:'''Extensor carpi radialis''': most medial, inserts on 2nd/3rd metacarpal bone

−

**Origin: cranial radius

+

−

**Insertion: most medial metacarpal bone

+

:'''Ulnaris lateralis''': most lateral, inserts on accessory carpal bone

−

*Last two may also serve in medial deviation of the paw

+

−

*'''Common Digital Extensor'''

+

:'''Extensor carpi obliquus''': aka '''abductor pollicis longus'''

−

**Insertion: extensor process of the distal phalanx of each digit

+

::Origin: cranial radius

−

**Sends a medial branch to dew claw and medial digits in all but horse and cat

+

::Insertion: most medial metacarpal bone

−

*'''Lateral Digital Extensor'''

+

−

**Insertion: dorsal proximal phalanx

+

:Last two may also serve in medial deviation of the paw

+

:'''Common Digital Extensor'''

+

::Insertion: extensor process of the distal phalanx of each digit

+

::Sends a medial branch to dew claw and medial digits in all but horse and cat

+

:'''Lateral Digital Extensor'''

+

::Insertion: dorsal proximal phalanx

+

''Flexors'':

+

:Innervated by: Median or Ulnar n. of the brachial plexus

+

:Caudal position on the forearm

+

:Originate from the caudal medial epicondyle of the humerus

+

:'''Flexor carpi radialis''': most medial, inserts on upper 2nd/3rd metacarpal bone

+

:'''Flexor carpi ulnaris''': most lateral, inserts on the accessory carpal bone

+

:'''Superficial Digital Flexor'''

+

::Branches according to the number of digis and inserts in proximal interphalangeal joint

+

:'''Deep Digital Flexor'''

+

::Passes through carpal canal before branching and continues to palmar distal phalanges

+

−

~~''Flexors'': Median or Ulnar n. of the brachial plexus~~

−

*Caudal position on the forearm

−

*Originate from the caudal medial epicondyle of the humerus

−

*'''Flexor carpi radialis''': most medial, inserts on upper 2nd/3rd metacarpal bone

−

*'''Flexor carpi ulnaris''': most lateral, inserts on the accessory carpal bone

−

*'''Superficial Digital Flexor'''

−

**Branches according to the number of digis and inserts in proximal interphalangeal joint

−

*'''Deep Digital Flexor'''

−

**Passes through carpal canal before branching and continues to palmar distal phalanges

''Interosseus muscles''

−

*Support metacarpophalnageal joints

+

:Support metacarpophalnageal joints

−

*Arise from palmar proximal metacarpal bones and insert on sesamoid bones within the joints, continued by ligaments to phalanges

+

:Arise from palmar proximal metacarpal bones and insert on sesamoid bones within the joints, continued by ligaments to phalanges

==Vasculature of the Forelimb==

Bara

Author, Donkey, Bureaucrats, Administrators

53,803

edits