Intrinsic Muscles of the Forelimb Flashcards
What muscles are on the lateral scapular and shoulder
ISDTL Infraspinatus Supraspinatus Deltoideus Teres minor Lateral scapula and shoulder
What muscles are on the medial scapula and shoulder
MSTC Mum stop tickling char Medial scapula and shoulder Subscapularis Teres major Coracobrachialis
What muscles are on the caudal arm
CATTA
Tensor fasciae antebrachii
Triceps brachii
Anconeus
What muscles are on the cranial arm
Cranial BB
Biceps brachii
Brachialis
What muscle are on the cranial and lateral forearm
Ellie calls lads ugly suck A Extensor carpi radialis Common digital extensor Lateral digital extensor Ulnaris lateralis Supinator Abductor digiti I longus
What muscles are on the caudal and medial forearm
CMPPFFDS Pronator teres Pronator quadratus Flexor carpi radialis Flexor carpi ulnaris Deep digital flexor Superficial digital flexor
Deltoideus
OIAI
About
O= spine and acromion process I = Deltoid Tuberosity A = Flex shoulder I = Axillary nerve
what are the heads of the triceps called
Long head
Lateral Head
Medial Head
Accessory Head
Tricep long head DOG
OIAI
Consists of four heads instead of the
usual three muscle with a common tendon of insertion to olecranon tuber. This muscle covers the bulk of humerus.
1. Long head: Two bellies
O: The caudal border of scapula
I: Olecranon tuber
A: To extend the elbow and flex the shoulder.
I = Radial Nerve
Triceps LAteral head
1’ Lateral head: Two bellies: transect to expose underlying accessory head and medial
O: deltoid tuberosity/ The tricepital line of humerus
I: Olecranon tuber
A: To extend the elbow
Innervation – Radial Nerve
Acessory head and medial head
Accessory: O = Neck of humerus Medial: O = crest of the lesser tubercle near tres major tuberosity
Accessory I = Olecranon tuber Medial = olecranon
A = Extend elbow
I = Radial nerve
Supraspinatus OIAI
O = supraspinous fossa
IN = greater tubercle of humerus, by a thick tendon
A: extension of the shoulder and the tendon acts as a lateral collateral ligament to stabilise the shoulder joint.
I= suprascapular nerve
Infraspinatus
O = infraspinous fossa I = small, circumscribed area in the lateral side of the greater tubercle of the humerus Action – can flex or extend the shoulder joint depending on limb position. Tendon acts as lateral collateral ligament to stabilise shoulder joint. Innervation – suprascapular nerve
Teres Minor
Origin: caudal angle and adjacent caudal border of scapula
Inserts: Teres major tuberosity of humerus
Action – flex shoulder, rotate shoulder medially, prevent lateral rotation when weight bearing
Innervation – axillary nerve
Deltoideus
Origin and insertion – has 2 parts: spinous part that arises from the scapular spine, and an acromial part arising from the acromion. Both parts unite to insert on the deltoid tuberosity of the humerus. Action – flexor of the shoulder Innervation – axillary nerve
Subscapularis
O: subscapular fossa. - described as being multipennate
(pennate = feather shaped, where the fibres approach the tendon from different directions).
I: short strong tendon on lesser tubercle of the humerus.
Action – adduct, extend and medially stabilize shoulder joint
Innervation – subscapular nerve
Teres Minor
O: infraglenoid tubercle and distal third of the caudal border of the scapula
I: Teres major tuberosity of humerus
Action – flex shoulder, rotate laterally adn prevent medial rotation when bearing weight
Innervation – axillary nerve
Biceps Brachii
Origin and Insertion – originates by way of a long tendon on the supraglenoid tuberosity, it then crosses the shoulder joint, runs craniomedially down the brachium and inserts, by way of 2 tendons onto the radius and ulna. Action – flexor of the elbow, extensor of the shoulder. Innervation – musculocutaneus nerve
Brachialis
Origin and insertion – originates on the proximal caudal humerus and inserts on the proximal ulna Action – flexor of the elbow Innervation – musculocutaneus nerve
Coracobrachialis
Origin: coracoid process of the scapula
Insertion: crest of lesser tubercle of the humerus, proximal to teres major tuberosity
Action – adduct, extend and stabilize shoulder joint
Innervation - musculocutaneus nerve
Anconeus
Ancon = elbow
Origin: lateral supracondylar crest and lateral and medial epicondyles of the humerus
Inserts: olecranon
Action – elbow extensor and capsular muscle of the elbow
Innervation – radial nerve
Tensor Fascia Antebrachii
Origin: arises from the fascia latissimus dorsi
Inserts: olecranon.
Action – extend elbow
Innervation – radial nerve
Extensor Carpi Radialis
Origin and Insertion: Originates from the lateral supracondylar crest of humerus. Inserts on the proximo-dorsal surface of metacarpal II & III. Action – Extensor of the carpus, flexor of the elbow Innervation – radial nerve
Common Digital Extensor
Origin and Insertion – originates from the
lateral epicondyle of the humerus, and
inserts on the distal phalanges of digits II to V.
Action – extends carpus and digits II to V
Innervation – radial nerve
Lateral Digital Extensor
Origin and Insertion – originates from the
proximal radius and ulna and inserts on the
distal phalnges of digits III, Iv and V.
Action – Extension of digits II, IV and V
Innervation – radial nerve
Ulnaris Lateralis
Origin and Insertion – originates from the
lateral epicondyle of the humerus and
inserts on the proximal end of metacarpal
V.
Action – Extension or flexion of the carpus,
depending on the position of the limb.
Innervation – radial nerve
Supinator
Origin and insertion – this muscle lies laterally on the cranial surface of the elbow. It arises from the lateral collateral ligament and the lateral epicondyle of the humerus. It inserts on the cranial surface of the radius. Action – rotation of the paw so that the palmer surface faces medially Innervation – radial nerve
Abductor Pollicis Longus
pollex = thumb Origin and Insertion – Originates from craniolateral surface of Ulna Inserts on the medial aspect of the proximal end of metacarpal I/II. It has a small sesamoid near the point of insertion. Action – Extends carpus and abduct the first digit Innervation – radial nerve
Pronator Teres
Origin and Insertion – this muscle lies medially on the cranial surface of the elbow. It originates from the medial epicondyle of the humerus and inserts on the cranial radius. Action – rotation of the paw so that the palmer surface is in contact with the ground Innervation – median nerve
Flexor Carpi Radialis
Origin and insertion – originates from the medial epicondyle, inserts on the palmer aspect of metacarpals II and III. Action – flexor of the carpus Innervation – median nerve
Superficial Digital FLexor
Origin and Insertion – originates from the
medial epicondyle of the humerus, inserts
on the palmer proximal edge of the middle
phalanx of all digits.
Action – flexor of the digits
Innervation - median nerve
Flexor Carpi Ulnaris
Origin and insertion – this muscle has two heads –
a weaker ulnar head that originates from the
proximal ulna, and a strong humeral head that
arises from the medial epicondyle of the humerus.
Both insert onto the accessory carpal cone.
Action – flexor of the carpus
Innervation – ulnar nerve
Deep Digital Flexor
Origin and insertion –
This muscle has 3 heads. The humeral head
is the strongest and itself consists of 3 bellies.
It arises from the medial epicondyle of the
humerus. The radial head is the weakest
division and arises from the medial border of
the radius. The third head is the ulnar head.
It arises from the caudal border of the ulna.
All three heads unite to form the strong
tendon which then splits and inserts on the
distal phalanges of all digits.
Action – flexor of the digits
Innervation – median nerve
Pronator Quadratus
Origin and Insertion – this muscle fills the
space between the radius and ulna. It arises
on the ulna and inserts on the radius.
Action – to rotate the paw inwards
Innervation – median nerve
Interosseousei/ Interossei
4 in total lying on the palmer aspect of metacarpal bones II, III, IV and IV.
Distally, each muscle divides into 2 short tendons that attach to the proximal end of P1.
Each tendon has a sesamoid embedded in it.
Action : flexion of metacarpophalangeal joints
Innervation : Ulnar nerve
