Thoracic muscles (improved)

Latissimus dorsi m.

Attachments: Thoracolumbar fascia, teres major tuberosity

Actions of latissimus dorsi m.

Draws forelimb caudally, flexes shoulder joint

Innervation of latissimus dorsi m.

Thoracodorsal n

Blood supply of latissimus dorsi m.

Thoracodorsal a, lateral thoracic a (carnivores)

Action of brachiocephalicus m.

Draw forelimb cranially, extend shoulder joint, draw head laterally

Innervation of brachiocephalicus m, trapezius m, omotransversarius m

Accessory n

Parts of cleidocephalicus m. for dogs

Mastoid and cervical parts

Parts of cleidocephalicus m. for cows

Mastoid and occipital parts

Parts of cleidocephalicus m. for horses

Mastoid part

Blood supply of brachiocephalicus m.

Superficial cervical artery (carnivores)

External thoracic a (large animals)

Parts of trapezius m

Cervical and thoracic parts

Actions of trapezius m

Elevate and abduct forelimb

Blood supply of trapezius m

Subscapular a

Parts of rhomboideus m

Capitis (not in equids or ruminants), cervicis, thoracis parts

Actions of rhomboideus m

Elevate forelimb, draw scapula against trunk (“secondary shrug muscle”)

Opposite fibers

How can you tell the brachiocephalicus m apart from the omotransversarius m?

Equids

In which species does the omotransversarius m fuse with the brachiocephalicus m?

Actions of omotransversarius m

Advance forelimb, flex neck laterally

Blood supply of omotransversarius m

Superficial cervical a (carnivores)

External thoracic a (large animals)

Parts of serratus ventralis m

Cervicis, thoracis

Serratus ventralis m

Which muscle is represented by a fan under the armpit?

Actions of serratus ventralis

Depresses scapula, suspends trunk

Parts of superficial pectoral m

Transverse, descending

Actions of superficial pectoral m

Adduct forelimb, support trunk

Innervation of serratus ventralis m

Long thoracic n

Innervation of superficial pectoral m

Cranial pectoral n

Actions of deep pectoral m

Supports trunk, adducts forelimb, flexes shoulder joint when not weight-bearing but extends it when weight-bearing

Innervation of deep pectoral m

Caudal pectoral n

Blood supply of deep pectoral m

Lateral thoracic a (carnivores), external thoracic a (large animals)

Blood supply of superficial pectoral m

External thoracic a

Subclavius m

What muscle is well-developed in horses, rudimentary in ruminants, and absent in small animals?

Parts of deltoideus m

Acromial, scapular

Acromial part

Which part of the deltoideus m. is missing in equines and pigs? (Hint: Has something to do with a certain part of the scapula that they don’t have either)

Actions of deltoideus m

Flexes shoulder joint

Innervation of deltoideus m, teres minor, teres major

Axillary n

Blood supply of deltoideus m

Caudal circumflex humeral a

Actions of supraspinatus m, infraspinatus m, subscapularis m

Stabilize shoulder joint, extend shoulder joint

Innervation of supraspinatus m, infraspinatus m

Suprascapular a

Innervation of subscapularis m

Subscapular and axillary nn

Blood supply of supraspinatus m

Suprascapular a

Blood supply of infraspinatus m

Suprascapular a, subscapular a, caudal circumflex humeral a

Blood supply of subscapularis m

Subscapular a, suprascapular a

Actions of teres minor m

Flex shoulder joint; rotate shoulder joint

Blood supply of teres minor m

Caudal circumflex humeral a

Actions of teres major m

Flex shoulder joint, minor shoulder stabilizer, medially rotate shoulder

Blood supply of teres major m

Subscapular a, caudal circumflex humeral a, cranial circumflex humeral a (in large animals), thoracodorsal a

Actions of coracobrachialis m

Extends shoulder joint; adducts shoulder joint

Innervation of coracobrachialis m, biceps brachii m, brachialis m

Musculocutaneous n

Blood supply of coracobrachialis m

Caudal circumflex humeral a, cranial circumflex humeral a, bicipital a (in large animals)

Tensor fasciae antebrachii m

What is attached to the fascia of the latissimus dorsi m and the olecranon?

Actions of tensor fasciae antebrachii m

Extend elbow joint

Innervation of tensor fasciae antebrachii m, triceps brachii m, anconeus m, extensor carpi radialis, common digital extensor, lateral digital extensor, ulnaris lateralis, abductor pollicis longus, extensor obliquus, supinator

Radial n

To Tell Alvin Even Common Logic Uses All Energy Supply

Mnemonic for muscles innervated by radial n

Blood supply of tensor fasciae antebrachii m

Deep brachial a, collateral ulnar a

Actions of triceps brachii m

Extend elbow joint

Action of long head of triceps brachii m

Flex shoulder joint

Blood supply of triceps brachii m

Caudal circumflex humeral a, deep brachial a, collateral ulnar a

Anconeus m

Which muscle is located transverse to the elbow?

Actions of anconeus m

Extend elbow joint

Blood supply of anconeus m

Collateral ulnar a

Actions of biceps brachii m

Flex elbow joint, extend shoulder joint

Blood supply of biceps brachii m

Cranial circumflex humeral a, bicipital a

Lacertus fibrosus

Fibrous structure that links the central tendon of the biceps brachii muscle to the extensor carpi radialis tendon, which inserts on the cannon bone

Plays a key role in the passive stay apparatus of equids

Transverse humeral retinaculum

Fibrous band that holds the bicipital tendon in the intertubercular groove

Not present in equids

Bicipital tenosynovitis

Inflammation of the tendon of origin of the biceps brachii m. and its associated tendon sheath

Presents as lameness

Presents in dogs

Actions of brachialis m

Flex elbow joint

Blood supply of brachialis m

Caudal circumflex humeral a (carnivores), deep brachial a (equids), bicipital a (ruminants)

Actions of extensor carpi radialis m

Extend carpal joints (or carpus)

Blood supply of extensor carpi radialis m, common digital extensor m, lateral digital extensor m

Transverse cubital a, cranial interosseous a

Common digital extensor m

In which muscle do ruminants have two distinct heads, while most species only have one?

Actions of common digital extensor m, lateral digital extensor m

Extend carpal joints, extend digital joints

Actions of ulnaris lateralis m

May help maintain the extension of an already extended carpus; may further flex an already flexed carpus

Blood supply of ulnaris lateralis m

Caudal interosseous a, ulnar a (carnivores)

Abductor digiti I longus m

What is also known as the abductor pollicis longus m?

Actions of abductor pollicis longus m

Abduct digit I (if present), extend digit I (if present), extend the carpal joints

Blood supply of abductor pollicis longus m

Caudal interosseous a

Extensor carpi obliquus m

What extensor muscle is only present in large animals?

Actions of extensor carpi obliquus m

Extend carpal joints

Extensor retinaculum

Fibrous band that holds the tendons of the extensor muscles in place over the dorsal surface of the carpus

Actions of flexor carpi radialis m, flexor carpi ulnaris m

Flex carpal joint

Innervation of flexor carpi radialis m, superficial digital flexor m, pronator teres m, pronator quadratus m

Median n

Blood supply of flexor carpi radialis m, superficial digital flexor m

Caudal interosseous a, deep antebrachial a

Innervation of flexor carpi ulnaris m

Ulnar n

Blood supply of flexor carpi ulnaris n

Ulnar a (carnivores), caudal interosseous a, deep antebrachial a

Actions of superficial digital flexor m

Flex the carpal, metacarpophalangeal, and proximal interphalangeal joints

Actions of deep digital flexor m

Flex carpal joints, flex digital joints

Innervation of deep digital flexor m

Median and ulnar nn

Blood supply of deep digital flexor m

Ulnar a (carnivores), caudal interosseous a, deep antebrachial a

Flexor retinaculum

Fibrous band that holds the digital flexor tendons in the carpal canal

Has a superficial and deep part

The deep portion forms the caudal border of the carpal canal

Flexor manica

Sleeve formed by the superficial digital flexor tendon; surrounds the deep digital flexor tendon at the level of the metacarpophalangeal joint

Allows the passage of the deep digital flexor tendon to insert in the distal phalanx (or phalanges)

One per weight-bearing digit; 1 for equids, 2 for ruminants, and 4 for carnivores

Palmar annular ligament

Holds the flexor manica on the palmar surface of the metacarpophalangeal joint

Proximal and distal digital annular ligaments

Holds the flexor tendons on the palmar surface of the proximal and middle phalanx respectively

In equids, these ligaments resemble an “X”

No

Do large animals have supinators or pronators?

Actions of supinator m

Supinate forearm, flex elbow joint

Actions of pronator teres m

Pronate forearm, flex elbow joint

Actions of pronator quadratus m

Pronate forearm

Pronator quadratus m

What muscle fills the space between the radius and ulna?

Interosseous m

Associated with weight-bearing metacarpal bone(s)

Often referred to as the suspensory or interosseous ligament(s) in large animals

Check ligaments

Help stabilize the flexor tendons in equids and prevent the excessive lengthening of the tendons

Component of the equid passive stay apparatus

Proximal and distal

What are the components of the check ligament?