Intrinsic Muscles of the forelimb Flashcards
Deltoideus m.
All parts, Action, Innervation
2 Parts:
Spinous- covers the infraspinatus m.
Acromial- arises from the acromion process and has fusiform shape
ACTION: to flex the shoulder
INNERVATION: Axillary nerve
Infraspinatus m.
Insertion, Action, Innervation
Lies in the infraspinous fossa and is fusiform in shape.
INSERTION: A small, circumscribed area on the lateral side of the greater tubercle of the humerus.
ACTION: To extend or flex the joint, depending on the degree or position of the joint. To abduct the shoulder and rotate humerus laterally. Also to prevent medial toation when weight bearing and lateral stability of shoulder joint.
INNERVATION: Suprascauplar nerve
Teres minor m.
Action, Innervation
Small, wedge-shaped muscle, covered superficially by the deltoideus
ACTION: To flex the shoulder, rotate the shoulder laterally, and prevent medial rotation when weight bearing.
INNERVATION: Axillary nerve
Supraspinatus m.
Insertion, Action, Innervation
INSERTION: The greater tubercle of the humerus, by a thick tendon.
ACTION: To extend and stabilize the shoulder joint.
INNERVATION: Suprascapular nerve
Subscapularis m.
Insertion, Action, Innervation
INSERTION: The lesser tubercle of the humerus
ACTION: To adduct, extend, and medically stabilize the shoulder joint. Also to rotate the shoulder joint medially and prevent lateral rotation when bearing weight. Very important in stabilizing the shoulder joint in addition to the infraspinatus and teres minor caudally, as well as supraspinatus cranially.
INNERVATION: Subscapular nerve
Teres Major m.
Action, Innervation
ACTION: To flex the shoulder joint, rotate the shoulder medially, and prevent lateral rotation when weight bearing.
INNERVATION: Axillary nerve
Coracobrachialis m.
Action, Innervation
ACTION: To adduct, extend, and stabilize the shoulder joint.
INNERVATION: Musculocutaneous nerve
Tensor Fasciae Antebrachii m.
Action, Innervation
ACTION: To extend the elbow joint
INNERVATION: Radial nerve
Triceps Brachii m.
All parts, Origin, Insertion, Action, Innervation
4 heads in the dog, common tendon to the olecranon tuber. Only the long head arises from the scapula, the other three from the proximal end of the humerus.
Long head: ORIGIN: Caudal border of scapula INSERTION: the Olecranon tuber ACTION: To flex the shoulder joint and extentend the elbow joint. INNERVATION: Radial nerve
Lateral Head: ORIGIN: Tricipital line of the humerus INSERTION: The Olecranon tuber ACTION: To extend the elbow joint INNERVATION: Radial nerve
Accessory Head: ORIGIN: The neck of the humerus INSERTION: The olecranon tuber ACTION: to extend the elbow joint INNERVATION: Radial Nerve
Medial Head: ORIGIN: The crest of the lesser tubercle near the teres major tuberosity INSERTION: the olecranon ACTION: To extend the elbow joint INNERVATION: radial nerve
Anconeus m.
Action, Innervation
Small muscle, located almost completely in the olecranon fossa.
ACTION: To extend the elbow joint
INNERVATION: Radial nerve
Biceps Brachii m.
ORIGIN, INSERTION, ACTION, INNERVATION
Has only one head, long fusiform muscle that lies on the medial and cranial surfaces of the humerus.
ORIGIN: The supraglenoid tubercle of the scapula
INSERTION: The ulnar and radial tuberosities
ACTION: to flex the elbow and extend the shoulder joint
INNERVATION: Musculocutaneous nerve
Intertubercular Bursa
Also known as the Bicipital Bursa, extension of the shoulder joint that lies within the intertubercular groove, acts as a synovial sheath for the bicipital tendon.
Brachialis m.
Origin, Inerstion, Action, Innervation
ORIGIN: The proximal third of the lateral surface of the humerus. (The muscle runs through the brachialis groove of the humerus).
INSERTION: The ulnar and radial tuberosities
ACTION: To flex the elbow joint
INNERVATION: Musculocutaneous nerve
Extensor Capri Radialis m.
Origin, Insertion, Action, Innervation
ORIGIN: The lateral supracondylar crest
INSERTION: The small tuberosities on the dorsal surfaces of the bases of metacarpals II and III
ACTION: To extend the carpal joints
INNERVATION: Radial nerve
Common Digital Extensor m.
Origin, Insertion, Action, Innervation
ORIGIN: The lateral epicondyle of the humerus
INSERTION: The extensor process of the distal phalanges of II,III,IV, and V
ACTION: To extend the joints of the four principal digits and carpus (functional digits)
INNERVATION: Radial nerve
Lateral Digital Extensor m.
Origin, Insertion, Action, Innervation
Lies between the common digital extensor and ulnar is lateralis
ORIGIN: The lateral epicondyle of the humerus
INSERTION: The proximal ends of all the phalanges of digits III,IV, and V
ACTION: To extend the carpus and digits III,IV and V.
INNERVATION: Radial nerve
Ulnaris Lateralis m.
Action, Innervation
ACTION: To abduct the manus and flex the carpal joints and support carpus when bearing weight.
INNERVATION: Radial nerve
Supinator m.
Action, Innervation
ACTION: To rotate the forearm laterally so that the palmar side of the paw faces medially (supination); to flex the elbow joint.
INNERVATION: Radial nerve
Abductor Digiti I Longs m.
Action, Innervation
ACTION: To abduct digit I and extend carpal joints
INNERVATION: Radial nerve
Pronator Teres m.
Action, Innervation
ACTION: To rotate the forearm medially so that the palmar side faces the ground, also to flex the elbow.
INNERVATION: Median nerve
Flexor Carpi Radialis m.
Origin, Insertion, Action, Innervation
ORIGIN: The medial epicondyle of the humerus and medial border of the radius
INSERTION: the palmar side of the base of metacarpals II and III
ACTION: to flex the carpal joints
INNERVATION: Median nerve
Superficial Digital Flexor m.
Origin, Insertion, Action, Innervation
Know relationship with DDF m.
ORIGIN: The medial epicondyle of the humerus
INSERTION: The base of the middle phalanx of digits II-V
ACTION: To flex the carpal, metacarpophalangeal, and interphalangeal joints of II-V
INNERVATION: Median nerve
Flexor Carpi Ulnaris m. (Know all parts)
Origin, Insertion, Action, Innervation
2 parts: Ulnar head and numeral head
ORIGIN: Ulnar head: the caudal border and medial surface of the olecranon;
Humeral head: the medial epicondyle of the humerus
INSERTION: The accessory carpal bone
ACTION: To flex the carpus
INNERVATION: Ulnar nerve
Deep Digital Flexor m.
Origin, Insertion, Action, Innervation
Humeral head is the largest, ulnar head is smaller and arises from the caudal border of the ulna, radial head is smallest and comes from the medial border of the radius.
ORIGIN: Humeral head: the medial epicondyle of the humerus
Ulnar head: small and arises from the caudal border of the ulna
Radial head: middle 1/3 medial border of the radius
INSERTION: The flexor tubercle on the palmar surface of the distal phalanx of each digit (I-V)
ACTION: To flex the carpal and metacarpophalangeal and proximal and distal interphalangeal joint
INNERVATION: Median and ulnar nerves
Carpal Canal
Formed by the accessory carpal bone laterally, the palmar carpal ligament and the carpal bones dorsally, and flexor retinaculum on the palmar surface.
Pronator Quadratus m.
Fills the space between the radius and the ulna.
ACTION: To pronator the paw.
INNERVATION: Median nerve
